trapping

Gunnison's Prairie Dog Restoration Experiment (GPDREx): Small Mammal Mark-Recapture Population Assessment within Grasslands at the Sevilleta National Widlife Refuge, New Mexico (2013-2014)

Abstract: 

Prairie dogs (Cynomys spp.) are burrowing rodents considered to be ecosystem engineers and keystone species of the central grasslands of North America. Yet, prairie dog populations have declined by an estimated 98% throughout their historic range. This dramatic decline has resulted in the widespread loss of their important ecological role throughout this grassland system. The 92,060 ha Sevilleta NWR in central New Mexico includes more than 54,000 ha of native grassland. Gunnison’s prairie dogs (C. gunnisoni) were reported to occupy ~15,000 ha of what is now the SNWR during the 1960’s, prior to their systematic eradication. In 2010, we collaborated with local agencies and conservation organizations to restore the functional role of prairie dogs to the grassland system. Gunnison’s prairie dogs were reintroduced to a site that was occupied by prairie dogs 40 years ago.  This work is part of a larger, long-term study where we are studying the ecological effects of prairie dogs as they re-colonize the grassland ecosystem. With this project, we would like to further investigate the impact that Gunnison’s prairie dogs have on the landscape.  Gunnison’s prairie dog monitoring data has been collected from the beginning of the reintroduction project, but little information has been collected on how grassland species respond to the sudden presence of prairie dogs on the refuge.

This project will help determine if the prairie dog reintroduction has had positive impacts on the grassland ecosystem.  Prairie dogs benefit grasslands in many ways, but their role as ecosystem engineers directly impacts other species by creating new habitat that would not be present without prairie dogs.  We have documented physical landscape changes, but we have not specifically documented benefits to other grassland species.  This work will help determine if the reintroduced prairie dog populations on Sevilleta NWR are now acting as a keystone species in a grassland ecosystem by monitoring small mammal populations to see if species richness, diversity, and density are different on prairie dog colonized areas versus non-colonized areas.

Data set ID: 

239

Core Areas: 

Additional Project roles: 

275

Keywords: 

Methods: 

Trapping Location and Design:

Trapping will be done on the 16ha Prairie Dog Relocation Study Plots.  There are 4 of them- A, B, C, and D.  Each plot will have 169 traps placed in a grid covering 9 hectares. Using the vegetation quad map, there will be a trap placed at 1 meter to the north at each of the following vegetation plots 11-17, 20-26, 29-35, 38-44, 47-53, 56-62, 65-71.  This accounts for 49 of the traps.  There will also be a trap placed in between each veg plot, with rows running North/South, which accounts for 42 more of the traps.  Then making a complete row in between the North/South vegetation quad rows, will account for the remaining 78 traps. To locate the veg plots, each are marked with a rebar and short white PVC.  There is a numbered tag on each PVC corresponding to the map.

Flag each trap with a numbered pin flag to designate trap numbers.   This is important in ensuring that all traps are checked and closed each day.

Trapping Periods:

Trapping period will be one plot a week for 4 nights.

Trapping Procedure:

The traps are set each evening for four nights.  This entails setting and baiting the traps at a given locality on Monday afternoon, then checking the traps at dawn on Tuesday (night 1), Wednesday (night 2), Thursday (night 3), and Friday (night 4). Each trap is baited with a handful of steamed, crimped oats tossed into the trap after it is placed on the ground; a few oats are left outside the trap entrance to entice passers-by.  The ground needs to be smoothed out with a foot to make sure that the trap is level and not unbalanced.  

Each morning, traps are checked as follows:  the worker walks up and down the transects and closes open traps as you go along.  Traps are not reopened until the late afternoon/early evening, at which time additional bait is also put in.  When a closed trap is encountered, it is first checked to see if an animal is present by carefully and just slightly opening the door of the trap and looking inside.  Be aware that kangaroo rats can jump out while doing this, so use caution. Sometimes, although a trap may appear empty, a tiny rodent may be hiding under the treadle (especially in the large traps).  To check for this, one must reach into the trap and lightly push down the treadle.  If the treadle will not go down, there is likely a mouse underneath.  If no animal is in the trap, the trap is left closed until the afternoon. If a trap has an animal, the worker processes the animal at the stake and takes the relevant data.  While checking for animals on Friday morning (night four), traps are picked up, emptied of seed, and returned to storage boxes, ready for placement at another locality the following week.  Importantly, traps MUST BE counted as they are placed into storage boxes in order to insure that no traps (or animals) are left on the plot.  If rain falls on the baited traps, they may require cleaning and drying back at the field station before storage or use the following week.

Animal Processing:

Removing rodents from trap

For each capture, the trap number is recorded first.  Next, a given animal is shaken from the trap into a plastic gallon ziploc bag.  This is accomplished by wrapping the opening of the ziploc bag over the door end of the trap. Make sure that they bag is tight so the rodent can’t squeeze out between the bag and the trap.  Open the front door through the bag and lock open.  Roll the trap upside down and swing it in an arc downward.  As soon at the rodent enters the bag, close the bag off with your hand so the rodent cannot reenter the trap.  With kangaroo rats, you often do not need to shake the trap to get the animals out.  Instead, put the Ziploc bag on trap as normal and open trap door, but hold the trap angled upward instead of down and the rodent should come out on its own.  Hold tight on the bag though because sometimes they come out rather quickly.

If a trap is triggered, but appears empty, don’t assume there is no animal in trap.  Small species such as pocket mice can hide under the treadle.  Make sure and lightly press down on the treadle to make sure it goes all of the way down.  If not then there is most likely a rodent under treadle.  You can also open up the back door to look under treadle, but use caution as to not let rodent escape.

If another animal (lizard, bird, rabbit, prairie dog) is caught in the trap, they can simply be released.  However, make sure and mark on data sheet that the trap was closed due to bird/lizard/rabbit.  If you do find a trap that was triggered by wind or large animal and is in fact empty, make sure and mark on the datasheet that that trap number was triggered but empty.

Handling and Processing rodents

In the bag, the processor positions the rodent with its head in the corner of the bag.  Hold its head down with one hand from the outside of the bag, pressing gently on the back of the skull.  Then reach in the bag with the other hand and grasp the animal with the thumb and forefingers by the loose skin around the back of the neck and shoulders, and then remove it for inspection. 

First off check to see if the rodent is tagged or marked.  If it is then you will mark that individual as a recapture on data sheet.  After recording the ear tag number or other marking and the species of animal, it can be released.  If it is not marked, then it will need to be marked and processed.

Dipodomys spp, Onychomys spp, Neotoma spp, Peromyscus spp, and any other large species you may catch will be uniquely marked with one ear tag.  Ear tags should be placed at the very base of the ear on its interior edge (or the front of the ear).  Putting it on the external side or back of the ear allows the rodent to rip the ear tag off more easily, by scratching at it with its hind legs. 

Other species such as, Perognathus spp, Spermophilus spp, and other small rodents that have too small of ears to place an ear tag, will be marked with sequential individual numbers on their chest, using permanent markers.  A different color must be used for each night (blue for 1st night, black for 2nd night, and red for 3rd night).  Small rodents do not need to be marked the 4th night,  but large rodents do need to be ear tagged.  Start with number 1 and increase as necessary for catches.

Next, each animal is identified to species, sexed, and aged.  Specific measurements are taken only for those genera which required them for species identification:

            Peromyscus: Total length, tail, foot, ear;

            Onychomys:  Total length, tail, foot.

            Perognathus, and Reithrodontomys: Total length, tail.

All measurements are taken to the nearest millimeter using a plastic ruler.  The species is recorded by a 4-letter code that represents the first 2 letters of the genus and the first 2 letters of the species.

Sex and reproductive status is then determined by examination of the genitalia (lactating/vaginal/pregnant/scrotal).  Look for enlarged scrotum, enlarged nipples, or an enlarged vaginal opening.  If none of these are apparent, then the rodent is non-reproductive. Females will still have visible nipples when non-reproductive.

ADULT MALES reproductive status:

-Scrotal (ST): the scrotum can be fully enlarged or partially enlarged.

- Non-reproductive (N)

ADULT FEMALES reproductive status:

-Vaginal (V): in estrus; vagina is obviously swollen and looks large and puckered, vaginal plug can be present or absent

-Pregnant (P):  heavier weight, can palpate babies

-Lactating (L): nipples (at least one) reddish and/or enlarged

-Non-reproductive (N)

Before releasing the individual, it is then weighed to the nearest gram, using a Pesola scale clipped to the base of the animal’s tail.   Larger animals can easily get off of scale so it is easier to put them back in the bag and weigh them inside the bag.  Make sure and weigh bag after rodent is released and subtract from first weight to get actual weight of rodent.

Animals which perished during captivity on plots are noted in the comments on field data sheets as 'D.I.T' (Dead In Trap).

Data sources: 

sev239_REUrodenttrapping_20140605.txt

Additional information: 

This data is collected each summer, starting in 2013, by an student in the Sevilleta LTER Research Experience for Undergraduates Summer Program.  Ear tagging started taking place in the summer of 2014.

Data Collector History

Ty Werdel 2013

Betsy Black & Andrew Velselka 2014

Gunnison's Prairie Dog Restoration Experiment (GPDREx): Population Dynamics within Grasslands at the Sevilleta National Widlife Refuge, New Mexico

Abstract: 

Prairie dogs (Cynomys spp.) are burrowing rodents considered to be ecosystem engineers and keystone species of the central grasslands of North America. Yet, prairie dog populations have declined by an estimated 98% throughout their historic range. This dramatic decline has resulted in the widespread loss of their important ecological role throughout this grassland system. The 92,060 ha Sevilleta NWR in central New Mexico includes more than 54,000 ha of native grassland. Gunnison’s prairie dogs (C. gunnisoni) were reported to occupy ~15,000 ha of what is now the SNWR during the 1960’s, prior to their systematic eradication. In 2010, we collaborated with local agencies and conservation organizations to restore the functional role of prairie dogs to the grassland system. Gunnison’s prairie dogs were reintroduced to a site that was occupied by prairie dogs 40 years ago.  This work is part of a larger, long-term study where we are studying the ecological effects of prairie dogs as they re-colonize the grassland ecosystem.

Data set ID: 

236

Additional Project roles: 

401

Core Areas: 

Keywords: 

Methods: 

Experimental Design

Four replicate paired 16 ha plots were established in spring 2010. Each pair consists of a treatment plot with prairie dogs (reintroduced), which are plots B and D and a control plot with no prairie dogs (plots A and C). The closest distance between adjacent plots, either within a block or between blocks, is 200 m (Figure 1). The treatment and control within each pair were randomly assigned. Each plot is a 400x400 m on 9x9 grid array with systematically located sample locations for 81 vegetation quadrats. There are also 4 more plots, E and H are control plots and F and G are treatment plots. F and G have been equipped with artificial burrows and are release sites. However, E and H were not set up to do vegetation quads.

Trapping Period

Prairie dogs will be sampled using capture-recapture methods in the summer (3rd week of June) each year and spring (last week of March) and fall when possible.

Pre-baiting Procedure

Set 150 traps within each 300m x 300m trapping area. Place traps in pairs near active burrows at least 4 days prior to trapping. At this time trap doors should be wired open (make certain all traps are properly wired open) with bait trailing from the outside into the back of (or through) the trap. Traps should be baited with sweet feed. Make sure that all traps are functioning properly by testing the trap door sensitivity and adjusting with pliers if needed. Pre-bait traps every morning for 3 days total. All pairs of traps should be numbered with one pin flag for each pair (1-75). All trap pairs should also be GPSed by their number and have maps made for ease of locating traps during trapping.

Trapping Procedures

On the morning of the first trapping day, well before sunrise, the wire should be removed from the traps and the traps then set and baited to capture animals. This can also be done the day before trapping begins. Prairie dogs should be trapped for 3 consecutive mornings.Each morning of trapping, make sure that the traps are all opened well before sunrise, so animals are not disturbed by human activity. This is very important. Traps should only be left opened during the early morning period, until about 10:00 or 11:00 am, depending on the weather conditions and time of year. Prairie dog activity declines by 10:00-11:00, so even if the weather conditions are fine for continued trapping, trap success after this time will decline. Traps should be collected by around 9:00 am, depending on the weather conditions and time of year, and all trapped animals should be brought to a common processing station. The team walks the plot to make sure and check every trap for dogs. As dogs are found trapped, a piece of masking tape is attached to the front of the trap, labeled with the trap number so that that animal can be released where it was trapped. Animals at the processing site should be kept at all times in the shade and carrots should be given to provide moisture during the heat and stress. Once animals have been processed they should be released into their burrow, at the location of their capture. All traps should then be closed for the day. To make sure all are closed, one person should close all the traps from one of the plots and mark the number on the GPS sheet to note the trap has been closed. This can also be done as a team effort, but traps need to be checked twice to make sure they are all closed.

Data sources: 

sev236_pdog_captures_20150630.txt

Gunnison's Prairie Dog Relocation Project: Population Dynamics within Grasslands at the Sevilleta National Widlife Refuge, New Mexico (2005-2014)

Abstract: 

The Sevilleta Gunnison’s Prairie Dog (Cynomys gunnisoni) Restoration project examines keystone consumer (herbivore) effects on grassland in concert with ecological restoration of a “species of greatest conservation need in New Mexico” (NMG&F Comprehensive Wildlife Conservation Strategy, 2007). SevLTER partners directly with Sevilleta National Wildlife Refuge, New Mexico Game and Fish, USFS Rocky Mountain Research Station and non-profit Prairie Dog Pals on this ambitious effort to re-establish Gunnison’s prairie dogs to blue grama dominated (Bouteloua gracilis) Great Plains grassland at the foothills of the Los Pinos Mountains on Sevilleta. While engaged in wildlife management aimed at translocation of approximately 3000 individual prairie dogs, ultimately establishing 5-6 colonies over a 500 ha area, SevLTER is focusing resources on monitoring population dynamics of reintroduced prairie dogs and their effects on vegetation production and diversity, soil disturbance and grasshopper community composition. In this experiment, prairie dogs act as the treatment on a grassland site where the species was extirpated 40 years ago. The long term nature of the project lies in the course of re-establishing prairie dogs combined with the ultimate research goal of describing the functional role of Gunnison’s prairie dogs in an arid grassland ecosystem: first we are challenged to develop and document an economical and efficient management strategy which maximizes reintroduction success and colony survival; second we are tasked with monitoring prairie dog dynamics and their effects on the grassland throughout re-establishment and into a future state, when presumably management intervention will have subsided and we characterize the ecosystem as ‘restored’ – both in the face of highly variable abiotic inputs such as precipitation and temperature and biotic impacts such as predation.

Data set ID: 

257

Core Areas: 

Keywords: 

Data sources: 

sev257_pdog_trapping_20140116

Methods: 

Sampling Period

Prairie dogs will be sampled using mark-re-sight methods in the spring (last week of March) and summer (3rd week of June) each year.  The justification for this sampling period is to understand overwinter survival and offspring recruitment.

Mark Re-sight Methodology

Prebaiting and Observation Towers

Prior to any trapping, traps in the field are checked to make sure all wooden covers are in place, if not, traps should be repaired as needed.  Set 100 traps within each 100m x 100m trapping area.  Place traps near active burrows 4 days prior to trapping.  At this time trap doors are wired open (make certain all traps are properly wired open) with bait trailing from the outside into the back of (or through) the trap. Traps are baited with sweet feed. Make sure that all traps are functioning properly by testing the trap door sensitivity and adjusting with pliers if needed. Pre-bait traps every morning for 3 sequential days total. All traps should be GPSed and have an adjacent numbered flag and tape with a corresponding number located on the trap. 

Trapping

On the morning of the fourth day, well before sunrise, the wires are removed from the traps and the traps then set and baited to capture animals. The traps are all opened well before sunrise, so animals are not disturbed by human activity.  This is very important.  Prairie dogs are trapped for 3 consecutive mornings.  Traps are only left opened during the early morning period, until about 10:00 or 11:00 am, depending on the weather conditions and time of year.  Prairie dog activity declines by 10:00-11:00, so even if the weather conditions are fine for continued trapping, trap success after this time will decline dramatically.  Traps are collected by around 9:00 am, depending on the weather conditions and time of year, and all trapped animals are brought to a common processing station. At the processing station the trap location, ear tag number, sex, weight, and age of the animal are recorded. It is indicated if the animal is new or a re-capture during this trapping period.  If no ear tags are present, new ear tags are clipped to both ears, and the numbers recorded. If one ear tag is missing, another is added to the ear with no tag, and the number recorded. All animals are marked with Nyanzol black dye.  For our purposes, it is not necessary to mark each animal with numbers.  The goal is to make sure each animal has a clear black mark on its back. Animals at the processing site are kept at all times in the shade and carrots should be given to provide moisture during the heat and stress.  Once animals have been processed they are released into their burrow, at the location of their capture. All traps are closed for the day.  To make sure all are closed, one person  closes all the traps from one of the plots and mark the number on the GPS sheet to note the trap has been closed.

Additional information: 

Additional Study Area Information

Study Area Name: Prairie Dog Town

Study Area Location: The study area is about 655 ha (~2.5 sq mi) in size and approximately1 km due west from the foothills of the Los Pinos Mountains. The study is also just north of the Blue Grama Core Site.

Elevation: 1670 m

Soils: sandy loam and sandy clay loam

Site history: historically large prairie dog colonies inhabited the study area

Gunnison’s Prairie Dog Use of Resource Pulses in a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico: Re-sight Scan Data

Abstract: 

Seasonal environments experience cyclical or unpredictable pulses in plant growth that provide important resources for animal populations, and may affect the diversity and persistence of animal communities that utilize these resources. The timing of breeding cycles and other biological activities must be compatible with the availability of critical resources for animal species to exploit these resource pulses; failure to match animal needs with available energy can cause population declines. Adult Gunnison’s prairie dogs emerge from hibernation and breed in early spring, when plant growth is linked to cool-season precipitation and is primarily represented by the more nutritious and digestible plants that utilize the C3 photosynthetic pathway. In contrast, summer rainfall stimulates growth of less nutritious plants using the C4 photosynthetic pathway. Prairie dogs should therefore produce young during times of increased productivity from C3 plants, while pre-hibernation accumulation of body fat should rely more heavily upon C4 plants.  If seasonal availability of high-quality food sources is important to Gunnison’s prairie dog population growth, projected changes in climate that alter the intensity or timing of these resource pulses could result in loss or decline of prairie dog populations.  This project will test the hypothesis that population characteristics of Gunnison's prairie dog, an imperiled grassland herbivore, are associated with climate-based influences on pulses of plant growth.

Data set ID: 

242

Core Areas: 

Additional Project roles: 

40
41

Keywords: 

Methods: 

Gunnison’s prairie dogs will be monitored at 6 colonies, with 3 colonies each occurring with the range of prairie and montane populations. Colonies for study within the prairie populations occur at Sevilleta National Wildlife Refuge (n = 3 prairie populations) and at Vermejo Park Ranch (n = 3 montane populations).  Live-trapping of prairie dogs will be conducted during 3 periods of the active seasons—following emergence (April), after juveniles have risen to the surface (mid-to-late June), and pre-immergence (beginning in August).  Trapping will occur for 3-day periods, following pre-baiting with open traps.  At capture, sex and body mass of each individual will be recorded.  Blood and subcutaneous body fat samples will be collected nondestructively for analysis of isotopic composition.  Prairie dogs will be marked with dye, and released on site immediately following processing.  After trapping periods at each site have concluded, population counts will be conducted during 2-3 re-sighting (or recapture) periods for each prairie dog colony.  Resighting observation periods will be ~3 hours in length, and consist of 2-6 systematic scans of the entire colony, beginning and ending from marked points outside of the colony boundary.  During each observation period, prairie dogs will be counted, recorded as marked or unmarked, and location on the colony noted.  

Vegetation cover and composition measurements will be collected (or obtained at Sevilleta, where such data is already being collected) during pre- and post-monsoon periods of the active season.  Total cover will be measured by plant species (or to genus if species is indeterminable). Total cover will be measured at 12 grid points per colony using Daubenmire frames (0.5 m x 0.5 m), and at 12 grid locations 200-800 m outside of each colony boundary.  Adjacent to each Daubenmire frame, a 20 cm x 30 cm sample of vegetation will be clipped and dried for determination of volumetric moisture content of vegetation.  

Primary productivity variables (cover, moisture content) will be tested for correlations to individual and population-level condition indicators in prairie dogs.  Carbon isotope ratios (δ13C) from prairie dog blood and fat samples will be analyzed on a continuous flow isotope ratio mass spectrometer.  The relative contribution of C3 and C4 plants to the diet of each individual will be determined based upon δ13C ratios for C3 and C4 plants in the study area and a 2-endpiont mixing model, and will be calculated for each individual animal, population and season.  Population estimates will be calculated using mark-resight estimates, and compared to maximum above-ground counts.  The influence of resource pulses on prairie dog population parameters will be tested by comparing the vegetation cover, moisture content, and ratio of total C3:C4 plant cover to the ratio of C3:C4 plants in prairie dog diets, population estimates, and juvenile:adult ratios as an index to population recruitment.   

Instrumentation: 

*Instrument Name: Continuous flow isotope ratio mass spectrometer

*Manufacturer: Thermo-Finnigan IRMS  Delta Plus 

*Instrument Name: Elemental Analyzer

*Manufacturer: Costech

*Model Number: ECS4010

Additional information: 

Other Field Crew Members: Talbot, William; Duran, Ricardo; Gilbert, Eliza; Donovan, Michael; Nichols, Erv; Sevilleta LTER prairie dog field crew led by Koontz, Terri; Sevilleta NWR prairie dog field crew led by Erz, Jon.

Tissue samples are analyzed for stable carbon isotope ratios in stable isotope laboratory operated by Dr. Zachary Sharp and Dr. Nicu-Viorel Atudorei of the Department of Earth and Planetary Sciences, University of New Mexico.

Gunnison's Prairie Dog Use of Resource Pulses in a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico: Capture Data

Abstract: 

Seasonal environments experience cyclical or unpredictable pulses in plant growth that provide important resources for animal populations, and may affect the diversity and persistence of animal communities that utilize these resources. The timing of breeding cycles and other biological activities must be compatible with the availability of critical resources for animal species to exploit these resource pulses; failure to match animal needs with available energy can cause population declines. Adult Gunnison’s prairie dogs emerge from hibernation and breed in early spring, when plant growth is linked to cool-season precipitation and is primarily represented by the more nutritious and digestible plants that utilize the C3 photosynthetic pathway. In contrast, summer rainfall stimulates growth of less nutritious plants using the C4 photosynthetic pathway. Prairie dogs should therefore produce young during times of increased productivity from C3 plants, while pre-hibernation accumulation of body fat should rely more heavily upon C4 plants. If seasonal availability of high-quality food sources is important to Gunnison’s prairie dog population growth, projected changes in climate that alter the intensity or timing of these resource pulses could result in loss or decline of prairie dog populations. This project will test the hypothesis that population characteristics of Gunnison's prairie dog, an imperiled grassland herbivore, are associated with climate-based influences on pulses of plant growth.

Data set ID: 

241

Core Areas: 

Additional Project roles: 

37
38
39

Keywords: 

Methods: 

Gunnison’s prairie dogs will be monitored at 6 colonies, with 3 colonies each occurring with the range of prairie and montane populations. Colonies for study within the prairie populations occur at Sevilleta National Wildlife Refuge (n = 3 prairie populations) and at Vermejo Park Ranch (n = 3 montane populations). Live-trapping of prairie dogs will be conducted during 3 periods of the active seasons—following emergence (April), after juveniles have risen to the surface (mid-to-late June), and pre-immergence (beginning in August). Trapping will occur for 3-day periods, following pre-baiting with open traps. At capture, sex and body mass of each individual will be recorded. Blood and subcutaneous body fat samples will be collected nondestructively for analysis of isotopic composition. Prairie dogs will be marked with dye, and released on site immediately following processing. After trapping periods at each site have concluded, population counts will be conducted during 2-3 re-sighting (or recapture) periods for each prairie dog colony. Resighting observation periods will be ~3 hours in length, and consist of 2-6 systematic scans of the entire colony, beginning and ending from marked points outside of the colony boundary. During each observation period, prairie dogs will be counted, recorded as marked or unmarked, and location on the colony noted. Vegetation cover and composition measurements will be collected (or obtained at Sevilleta, where such data is already being collected) during pre- and post-monsoon periods of the active season. Total cover will be measured by plant species (or to genus if species is indeterminable). Total cover will be measured at 12 grid points per colony using Daubenmire frames (0.5 m x 0.5 m), and at 12 grid locations 200-800 m outside of each colony boundary. Adjacent to each Daubenmire frame, a 20 cm x 30 cm sample of vegetation will be clipped and dried for determination of volumetric moisture content of vegetation. Primary productivity variables (cover, moisture content) will be tested for correlations to individual and population-level condition indicators in prairie dogs. Carbon isotope ratios (δ13C) from prairie dog blood and fat samples will be analyzed on a continuous flow isotope ratio mass spectrometer. The relative contribution of C3 and C4 plants to the diet of each individual will be determined based upon δ13C ratios for C3 and C4 plants in the study area and a 2-endpiont mixing model, and will be calculated for each individual animal, population and season. Population estimates will be calculated using mark-resight estimates, and compared to maximum above-ground counts. The influence of resource pulses on prairie dog population parameters will be tested by comparing the vegetation cover, moisture content, and ratio of total C3:C4 plant cover to the ratio of C3:C4 plants in prairie dog diets, population estimates, and juvenile:adult ratios as an index to population recruitment.

Instrumentation: 

Instrument Name: Continuous flow isotope ratio mass spectrometer Manufacturer: Thermo-Finnigan IRMS Delta Plus Model Number: Instrument Name: Elemental Analyzer Manufacturer: Costech Model Number: ECS4010

Additional information: 

Field Crew: Hayes, Chuck; Talbot, William; Duran, Ricardo; Gilbert, Eliza; Donovan, Michael; Nichols, Erv; Sevilleta LTER prairie dog field crew led by Koontz, Terri; Sevilleta NWR prairie dog field crew led by Erz, Jon.

Burn Exclosure Rodent Population Study at the Sevilleta National Wildlife Refuge, New Mexico (1991-1993)

Abstract: 

Small mammal densities were estimated from small mammal recapture data in burned and unburned grassland.

Data set ID: 

15

Additional Project roles: 

53

Core Areas: 

Keywords: 

Methods: 

Web trapping design:

Experimental units were established in a 4 x 4 grid as part of a burn and antelope exclosure experiment. Small mammals were trapped in fireblocks 1, 2, 3, and 4. Each fireblock contains four webs, for a total of 16 webs. Small mammal densities are estimated from recapture data.

Within each location four webs were established. Each web contains twelve 100m transects radiating from a central point in a spoke like fashion. Four "Sherman" traps were placed around this central point. Twelve traps are placed along each of the radiating lines, the first four are placed at 5m intervals, and the remaining eight placed at 10m intervals. Rebar were used to mark the location of trap placement. Each rebar was tagged with a number from 1 to 145, with trap number 1 at the north facing spoke and radiating out to trap number 12, with each spoke following with successive numbers increasing in a clockwise fashion. Trap number 145 includes the four traps placed in the center of the web. Traps were placed adjacent to rebar unless a shaded area could be found within a meter or so along an arc of equal radius from the center. The webs are separated by distances from approx. 100m to 600m. Within each fireblock, each web is marked with a number from 1-4.

Trapping times:

Each summer was divided into two periods: period 1 and period 2.
Mammals were trapped as follows:

1991: period 1: NA
         period 2: September 4 - October 4
1992: period 1: April 15 - May 8
         period 2: August 4 - September 17
1993: period 1: April 6 - 29
         period 2: September ??

Each location was trapped in the same order for each period.
The order is as follows:

1. Fireblock 1
2. Fireblock 2
3. Fireblock 3
4. Fireblock 4

Each trapping session consisted of placing and baiting traps on Monday, then checking the traps at dawn on both Tuesday (night 1), Wednesday (night 2), and Thursday (night 3). The traps were collected on Thursday after being checked for animals. A small handful of rolled oats was placed into each trap, with small amounts placed outside trap door. Animals were removed form closed traps with the aid of plastic bags. They were then identified to species. Weight was determined to the nearest gram using a pesola scale. Body, tail, foot, and ear measurements were taken for Peromyscus. Body and tail measurements were taken for Onychomys, Perognathus, and Reithrodomtomys. All measurments were taken to the nearest millimeter using a plastic ruler. Reproductive status was determined by examination of the genitalia. The animal was also sexed, aged, and marked. Marking was done to each animal on the first nights capture for each individual animal.

Data sources: 

sev015_burnxrodentpop_10191995.txt

Maintenance: 

File created by Susan McKelvey 3/29/93. File supplemented by Rosemary Vigil 24 June 1993. Checked Oct 20, 1995; James Brunt

Quality Assurance: 

Data Entry

1. Data were entered at Biology Annex using data entry program "mammal-entry"
2. Data were checked for errors by comparing original data sheets with the
data entered into the computer.
3. After all errors were corrected, a dbf file was created using a Sun machine.
(/research/local/mammal/bin/SASmam2dbf filename > filename.dbf) This
modifies the comments, leaving out comments noted as "na".
4. A rdb file was then created using "arc2rdb filename.dbf > filename.rdb".
5. The rdb file was then checked for errors using "check < filename.rdb".
6. After errors were corrected, the rdb file was sorted using "sort
filename | uniq -c | page" to check that every entry was unique.
7. Duplications were investigated and corrected.
8. Dbf and rdb files were then copied to /research/archive/dbwork/vertebrate/
mammal/burnplot
9. From sevilleta, at burnplot>, the rdb file was run through a program called
webDist to create an input file as such: " webDist filename.rdb location
period > conventional input name. (naming conventions: site-season-year.in)
10.Input file was copied into /research/archive/dbwork/vertebrate/mammal/
burnplot
11.From a PC, the input file was run through a distance program in order to
get densities. (from dos: L:, cd distance, dist i=L:\burnplot/filename.in
o=L:\burnplot\filename.out)
12.Densities were cbtained from the output file and put into /mammal/data/
density-data/mammal_densities.data.burn which is a table containing the
following: year season location web n density stderr cv lcl ucl.
13.At this point, nothing further has been done.

Reptile Populations at the Sevilleta National Wildlife Refuge, New Mexico (1989-1990)

Abstract: 

Reptile populations were sampled in spring and summer in various habitats: grassland, creosote shrubland, pinyon-juniper woodland, cottonwood forest, subalpine forest, and subalpine meadow. On 18 sites mark-release methods were used; on 12 sites, all animals were kept for museum specimens. Museum specimen preparations included skulls, whole skeletons, and alcohol preservations; all specimens had tissue samples (liver, heart) taken for ultra-cold preservations for genetic analyses; some were karyotyped. All museum specimens were checked for internal parasites.

Data set ID: 

9

Core Areas: 

Additional Project roles: 

52

Keywords: 

Methods: 

Livetrapping of lizards and snakes on the Sevilleta was done by using pitfall traps connected with drift fences.  A pitfall trap consisted of two large ( 10) cans connected end to end resulting in a trap approximately 44 cm deep and 15 cm in diameter.  The traps were inserted into the ground so the tops are flush.  Two pitfalls were placed into the ground approximately 6 meters apart and connected with a 12 cm tall aluminum flashing fence.  The fence guided the reptiles into the pitfall traps.

There were 24 pitfall traps per web (12 sets) totaling 120 per site. Seventy-two of these were for mark and recapture studies, while the remaining 48 werefor the collection of museum specimens.

The pitfalls were covered with aluminum flashing lids that sit approximately 2.5 cm off the ground.  The lids provided complete shade and protection from precipitation.  The trap floors were also punctured to permit drainage if necessary.

The pitfall traps were opened for three weeks at a time, and were checked every two or three days by a crew of two to five.  At the end of the three weeks they were closed by covering the openings with a square ceramic tile, 20 cm per side.  The edges of the tiles were then covered with dirt as an extra safeguard against penetration. All pitfalls were checked for the presence of animals by removing the aluminum lids and visually inspecting each trap's interior.  Lizards found in the traps on the collection webs were removed from the traps, placed in plastic bags with an adequate supply of air, and transported to the lab for processing.  Lizards found in pitfalls on mark-recapture webs were removed by hand, then identified to species level, checked for previous capture and individual identification marks, measured, weighed and sexed.  The lizards were toe-clipped with no more than two toes cut per foot, and the longest toes on the hind feet left intact.

All snakes were identified to species level, and non-venomous snakes were measured and weighed but not marked because so few are captured. Venomous snakes were removed from pitfalls by the head animal technician using a "snake stick" which enabled the user to handle snakes safely without injury to the snake.

All lizards and snakes are released at the exact location of capture.

Data sources: 

sev009_reptilepopn_09072011.txt

Additional information: 

This data set was obtained from the Mac computer of Howard Snell, Asst. Professor at UNM. All data from years 1989 and 1990, were entered by him or his assistants. As 1989 and 1990 data sets were in separate files, they have been merged together as one file in this data set. The format was changed to "rdb" format in order to allow the data set to be used on the Sevilleta system. File begin edit: May 28, Michelle L. Murillo: changing to rdb format.File end edit: May 28, Michelle L. Murillo.

Note: holder, measurer, recorder taken out, can be found on original data sheets.

Ground Arthropod Community Survey in Grassland, Shrubland, and Woodland at the Sevilleta National Wildlife Refuge, New Mexico (1992-2004)

Abstract: 

This data set contains records for the numbers of selected groups of ground-dwelling arthropod species and individuals collected from pitfall traps at 4 sites on the Sevilleta NWR, including creotostebush shrubland, both black and blue grama grasslands, and a pinyon/juniper woodland. Data collections begin in May of 1989, and are represented by subsequent sample collections every 2 months. One site (Goat Draw/Cerro Montosa) was discontinued in 2001, and a new site (Blue Grama) was initiated . Only three sites, creosotebush, black grama, and blue grama were continued between 2001-2004.

Core Areas: 

Data set ID: 

29

Additional Project roles: 

332
333
334
335

Keywords: 

Purpose: 

To monitor the species composition and relative abundance's of select ground dwelling arthropod taxa and trophic groups from principal long-term study sites/environments in relation to climate change and plant production. 

Data sources: 

sev029_arthropop_02162009

Methods: 

Experimental Design

Arthropods have been collected from four subjectively chosen sites on the Sevilleta National Wildlife Refuge (SNWR), representing the following habitat types:  pinyon-juniper (elev. 2195 m), black grama grassland, blue grama grassland, and creosotebush shrubland (elev. ~1400 m for all three). At each of the four sites there were 30 traps arranged in five replicate lines with six traps per line.  Each line was located outside a mammal trapping web, except at Goat Draw, where mammal trapping webs were installed three years after the arthropod traps.  In 1995 Robert Parmenter and Sandra Brantley decided to reduce the number of traps by half.  Comparative statistical tests run with data from 15 traps showed no difference in mean abundances of dominant species compared to tests with 30 traps. The interannual variability is high and it is hoped that the long-term aspect of the monitoring will produce clearer patterns than intensive sampling over a short period has done.  Traps 1, 3 and 5 were left and traps 2, 4 and 6 were removed.  The decision was also made to process samples from only the odd-numbered traps beginning with the 1993 samples. The experimental design was intended to provide data for long-term monitoring of ground arthropods in relation to climate and plant production. The traps within each trap line are subsamples, and data from those should be summed or averaged for a single value per line, per sample period. The lines are intended to serve as replicate samples for each habitat site, however, they were not randomly located. The lines were located to provide a systematic array with trap lines approximately 200 meters from each other on the landscape.

Field Methods

During a collection period the contents of each trap are strained out of the glycol so that it can be reused.  Glycol is replenished as needed to keep the cups about half full.  Arthropods are transferred from the strainers to glass vials containing site labels.  The contents of each trap are stored in a separate vial. Trap condition forms are filled out at the time of collection and kept with the samples. Any traps that are damaged or not functioning are re-set.

Sampling Design

Arthropods are collected in pitfall traps, made of a 15 oz. can (11 cm tall and 7.5 cm in diameter) dug into the ground so that the opening of the can is flush with the ground. A screen apron was fitted around the top of the can to prevent rodent digging. Plastic 10 oz. cups about half-full of propylene glycol (ethylene glycol prior to March 1994) are inserted in the can.  The glycol is a preservative; no live pitfall trapping of arthropods is done.  The traps are covered by raised ceramic lids, 15 cm x 15 cm in size.  The traps remain open all year, and samples are collected everly two months during the week of the 15th day of each months, for the months: February, April, Jun, August, October, and December.During a collection period the contents of each trap are strained out of the glycol so that it can be reused, using standard hand-held metal screen kitchen strainers approximately 3 inches diameter.  Glycol is replenished as needed to keep the cups about half full.  Arthropods are transferred from the strainers to glass vials containing site labels.  The contents of each trap are stored in a separate vial. Trap condition forms are filled out at the time of collection and kept with  the samples.

Laboratory Procedures

Specimens are stored in 70 % ethanol. Specimens are brought back to the UNM Museum of Southwestern Biology (MSB) wet lab for processing. Sample sorting, arthropod identification, and data tabulation are performed only by individuals trained as entomologists, or entomologically experienced graduate students trained in arthropod identification specifically for this project.  Individual arthropods are identified to morphospecies and counted.  Classifications generally follow Nomina Insecta Nearctica: a checklist of the insects of North America, Volumes 1-4, however, taxonomic levels above family follow Borror, DeLong and Triplehorn's An Introduction to Entomology, 5th edition.  Higher classification for Orthopteroids follow Arnett, 2000 (per DLC). And classification of Aranae follows Roth's Spider Genera of North America, 2nd and 3rd editions. The species code, number of individuals, site name and date of  collection are entered on a data sheet. After processing, all the samples from one site and date are pooled for long-term storage in sealed jars containing 70% ethanol, at the UNM Biology Field Station, located at the Sevilleta NWR.  Detailed procedures for sorting and identifying the arthropods are available from the Sevilleta data manager (data-use@sevilleta.unm.edu).  Reference collections are maintained at the Sevilleta Field Station and at the UNM Museum of Southwestern Biology Division of Arthropods. Voucher specimens are housed in the UNM MSB Division of Arthropods. 

Ground arthropod species in the following taxonomic groups are collected, counted and identified to morphospecies:-orthopterans, including grasshoppers, field crickets and camel crickets-blattarians, sand cockroaches-mantodeans, only ground mantids-phasmatodeans, walkingsticks-hemipterans, selected taxa only: lygaeids, alydids, one genus of mirid, thyreocorids, cydnids-coleopterans-microcoryphians, bristletails-chilopods-diplopods -isopods-arachnids, including spiders, scorpions, solpugids, uropygids, opiliones.

Specimens are pinned or placed in 70 % ETOH, labeled, and added to the LTER collection or to the UNM Division of Arthropods collection as needed.  If the specimens are not needed they are kept in alcohol storage and housed at the Sevilleta Field Station. See: /sevilleta/export/db/work/insect/specieslists/sevrefcoll for a list of specimens vouchered by the MSB. The focus of the pitfall collections is on the adult stage, but nymphs of orthopteroids and hemipterans and immature stages of arachnids are identified to genus or species if possible.  If not, these groups have species i.d. numbers for nymphal or immature stages. Larval beetles are not counted.  The aleocharine staphylinid species are grouped together under species number Co Sta 001 088.

Maintenance: 

January 2009Combined all data from 1992-2004. QA/QC'd data from 2001-2004 in excel using a filter and checking data line by line. All data were then imported into Navicat using the import wizard.

Data from 1989-1991 were removed and stored elsewhere. Contact data manager for data. --A.Swann

Additional information: 


Additional Information on the Data Collection Period

Field collections are made every even-numberedmonth as close to the 15th as possible. 

This study/data set is a subset of the original larger scale Sevilleta LTER data set #: SEV0029; "Arthropod Populations". The number of arthropod taxa included in this data set ("Sevilleta Ground Arthropods") has been reduced to those taxa that are appropriately sampled by pitfall traps, and those taxa or taxonmic ranks that can be easily identified and tabulated by expert technical staff. The number of study sites also was reduced from seven to four for this data set. Associated data sets include climate data from representative Sevilleta LTER meterological stations, and plant production data from Sevilleta LTER above ground net primary production plots, located on or near the arthropod pitfall trap sites.

Small Mammal Mark-Recapture Population Dynamics at Core Research Sites at the Sevilleta National Wildlife Refuge, New Mexico (1989 - present)

Abstract: 

This file contains mark/recapture trapping data collected from 1989-2012 on permanently established web trapping arrays at 8 sites on the Sevilleta NWR. At each site 3 trapping webs are sampled for 3 consecutive nights in spring and fall. Not all sites have been trapped for the entire period. Each trapping web consists of 145 rebar stakes numbered from 1-145. There are 148 traps deployed on each web: 12 along each of 12 spokes radiating out from a central point (stake #145) plus 4 traps at the center point. The trapping sites are representative of Chihuahuan Desert Grassland, Chihuahuan Desert Shrubland, Pinyon-Juniper Woodland, Juniper Savanna, Plains-Mesa Sand Scrub and Blue Grama Grassland.

Data set ID: 

8

Core Areas: 

Additional Project roles: 

517
518

Keywords: 

Methods: 

Sampling Design
Permanent capture-mark-release trapping webs were used to estimate density (number of animals per unit area) of each rodent species at each site. The method makes use of concepts from distance sampling, i.e., point counts or line-intercept techniques. The method makes no attempts to model capture-history data, therefore it was not necessary to follow individuals through time (between sessions). Distance sampling methods allow for sighting or detection (capture) probabilities to decrease with increasing distance from the point or line. The modeling of detection probability as a function of distance forms the basis for estimation. Trapping webs were designed to provide a gradient of capture probabilities, decreasing with distance from the web center. Density estimation from the trapping web was based on three assumptions:1. All animals located at the center of the web were caught with probability 1.0; 2. Individuals did not move preferentially toward or away from the web center; 3. Distances from the web center to each trap station were measured accurately. Each web consisted of 12 trap lines radiating around a center station, each line with 12 permanently-marked trap stations. In order to increase the odds of capturing any animals inhabiting the center of a web, the center station had four traps, each pointing in a cardinal direction, and the first four stations of each trap line were spaced only 5 m apart, providing a trap saturation effect. The remaining eight stations in a trap line were spaced at 10 m intervals. The web thus established a series of concentric rings of traps. Traps in the ring nearest the web center are close together, while the distances separating traps that form a particular ring increase with increasing distance of the ring from the web center. The idea is that the web configuration produces a gradient in trap density and, therefore, in the probability of capture. Three randomly distributed trapping webs were constructed at each site. The perimeters of webs were placed at least 100 m apart in order to minimize homerange overlap for individuals captured in the outer portion of neighboring webs.

Measurement Techniques

Each site containing three webs was sampled for three consecutive nights during spring (in mid May or early June) and summer (in mid July or early August for years 1989 to 1993, then mid September to early October for years 1994 through 2000). In that rodent populations were not sampled monthly over the study period, there is no certainly that either spring or summer trapping times actually captured annual population highs or lows. Based on reproductive data in the literature, an assumption was made that sampling times chosen represent periods of the year when rodents have undergone, and would register, significant seasonal change in density. During each trapping session, one Sherman live trap (model XLF15 or SFAL, H. B. Sherman Traps, Tallahassee, FL) was placed, baited with rolled oats, and set at each permanent, numbered station (four in the center) on each web, for a total 444 traps over three webs. Traps were checked at dawn each day, closed during the day, and reset just before dusk. Habitat, trap station number, species, sex, age (adult or juvenile), mass, body measurements (total length, tail length, hind foot length, ear length), and reproductive condition (males: scrotal or non-scrotal; females: lactating, vaginal or pregnant) were recorded for each initial capture of an individual. Each animal was marked on the belly with a permanent ink felt pen in order to distinguish it from other individuals during the same trapping session. The trap station number for an initial capture related to a particular trapping ring on a web and, therefore, to a particular distance from the center of the web. The area sampled by a ring of traps was computed based on circular zones whose limits are defined by points halfway between adjacent traps along trap lines; an additional 25 m radius was added to the outer ring of traps in order to account for homerange size of individuals caught on the outer ring.

Analytical Procedures
Area trapped and number of individuals caught for each ring of traps was the basis for estimating the probability density function of the area sampled. The program DISTANCE produced the estimators used to calculate density. Where sample size for a particular species and web was less than an arbitrarily chosen n=10, the number of individuals captured during that session was simply divided into the area of the web plus the additional 25 m radius (4.9087 ha). This dataset includes only the raw capture data.

Data sources: 

sev008_rodentpopns_20161027

Instrumentation: 

 

Sherman live traps: model XLF15 or SFAL, H. B. Sherman Traps, Tallahassee, FL

Maintenance: 

Trap sets require care and cleaning as well as proper storage. Otherwise, webs are made up of durable rebar and aluminum tags which only need repair if disturbed. Tools used in the field - scales and rulers, pouches, trap bags and ziplock supply must be maintained on hand at SevFS for trapping events.

Additional information: 

Additional Information on the personnel associated with the Data Collection / Data Processing

Sevilleta Field Crew Employee History

Chandra Tucker April 2014-present, Megan McClung, April 2013-present, Stephanie Baker, October 2010-Present, John Mulhouse, August 2009-June 2013, Amaris Swann, August 25, 2008-January 2013, Maya Kapoor, August 9, 2003-January 21, 2005 and April 2010-March 2011, Terri Koontz, February 2000-August 2003 and August 2006-August 2010, Yang Xia, January 31, 2005-April 2009, Karen Wetherill, February 7, 2000-August 2009, Michell Thomey, September 3, 2005-August 2008, Jay McLeod, January 2006-August 2006, Charity Hall, January 31, 2005-January 3, 2006, Tessa Edelen, August 15, 2004-August 15, 2005, Seth Munson, September 9, 2002-June 2004, Caleb Hickman, September 9, 2002-November 15, 2004, Heather Simpson, August 2000-August 2002, Chris Roberts, September 2001-August 2002, Mike Friggens, 1999-September 2001, Shana Penington, February 2000-August 2000.

*In fall 2013, the Grassland Core site was not able to be trapped due to government shutdown. 

Rodent Parasite Data for the Sevilleta National Wildlife Refuge, New Mexico (1990-1998)

Abstract: 

The 100,000 ha Sevilleta National Wildlife Refuge (SNWR) in central New Mexico lies in a transition zone that straddles several major biomes of the Southwest, including Great Basin Shrub-Steppe, Mogollon Pinon-Juniper Woodland, Great Plains Grassland and Chihuahuan Desert. During 9 years, (1990-1998), collaborating with the University of New Mexico's Long Term Ecological Research (LTER) program, 3,235 rodents (28 species in 4 families) were collected and identified from permanent collecting sites on the 3 major habitat types (grassland, desert/creosote, woodland) on the SNWR. Hosts were necropsied for endoparasites (protozoa [coccidia], helminths) and some ectoparasites. We identified and analyzed all the parasites found in these hosts. By 1998, we had in place the means to easily identify and moniter the parasites from all mammalian hosts caught on the LTER Phase II grant.

This is not just another parasite survey; the data we collected was unique for several reasons: 1) This was the first complete inventory of a natural assemblage of parasites from all mammalian (rodent) hosts in 3 different communities, each from a distinctly defined geographic locality (habitat type) over the period of a decade, and beyond; 2) This study was part of a multidisciplinary approach to address conceptual issues of climate change on ecosystem structure and function at multiple scales (individuals, communities, etc) and correlative data from these related studies will strengthen and contribute to the robustness of this data set; 3) As the only parasite study on any of the LTER projects nationwide, it provided an ideal model, and perhaps incentive for parallel longterm studies of parasite communities to be examined in a variety of other habitat types, and from a variety of different perspectives, and other LTER sites in the network.

Upon completing the work, we were able to use these long-term data to try to understand the dynamics of natural host-parasite assemblages. Hypotheses were then erected to test/address at least these questions: How do the different parasite communities colonize, mature, climax and senesce over time (or do they?), Do they vary in response to abiotic (climate change) and/or biotic (dispersal, colonization) factors? What temporal and spatial scales, and among what kinds of organisms, do coevolutionary processes influence the community organization of these parasites? Studies of the dynamics of multiple, coexisting species are confined primarily to microtine rodents and have hinted that multiannual cycles tend to be synchronous (Brown and Heske 1990). Are similar patterns seen for the parasites of our desert rodents? Answers to these questions relating to community structure, as well as to questions concerning parasite biodiversity on the SNWR, can be answered paritially or completely by the information we gathered on the parasite species infecting rodents collected on the SNWR. Initial emphasis of our work was on identifying all the parasites collected, by processing 8 consecutive years of parasite data, and on training the undergraduate and graduate students involved in the art of taxonomy and nomenclature of parasitic protozoans and helminths,  to supply some of these answers.

Data set ID: 

13

Core Areas: 

Keywords: 

Data sources: 

sev013_rodentparasite_20130818.txt

Methods: 

Web Trapping Design

Small mammal densities were estimated by utilizing the following web design: Within each location 5 webs are established. Each web contains 12 100 m transects radiating from a central point in spoke-like fashion. Pieces of rebar, placed vertically in the ground, are used to mark the location and maintain permanency of trap placement, and each rebar is numbered (1-145). Four Sherman traps (model XLF15 and SFAL, H.B. Sherman Traps, Tallahassee, FL) are placed around the center stake of the web (numbered 145) and 12 traps are placed along each of the 12 spokes of the web, the first 4 at 5 m intervals and the remaining 8 placed at 10 m intervals. Trap number 1 is on the spoke facing due north and radiating out from the  center to trap number 12; the remaining 11 spokes follow with successive numbers increasing in a clockwise fashion. Traps are placed adjacent to rebar or in the nearest shaded area found within a 1 m radius from that rebar. The webs in any habitat type are seperated from each other by distances ranging from 100-600 m.

Web Description

At each habitat location, 2 webs are designated as "removal" webs. The other 3 webs are "mark-and-recapture" webs. Each web is numbered from 1 to 5. The following is a list of each web number at each site:

Sepultura Canyon removal:
web 2
web 5

Sepultrua Canyon mark-and-recapture:
web 1
web 3
web 4

Five Points Grassland removal:
web 1: 1060 43' 30.9533" W, 340 20' 6.6669" N
web 4: 1060 43' 13.2383" W, 340 20' 10.3392" N

Five Points Grassland mark-and-recapture:
web 2: 1060 43' 19.5235" W, 340 20' 18.0169" N
web 3: 1060 43' 5.6546" W, 340 20' 17.6016" N
web 5: 1060 43' 20.5284" W, 340 20' 3.3414" N

Five Points Larrea removal:
web 2: 1060 43' 56.5134" W, 340 19' 52.0534" N
web 4: 1060 44' 21.5012" W, 340 20' 3.0532" N

Five Points Larrea mark-and-recapture:
web 1: 1060 43' 44.5722" W, 340 19' 50.1725" N
web 3: 1060 44' 11.5427" W, 340 19' 59.6857" N
web 5: 1060 44' 31.7639" W, 340 20' 4.0357" N

Rio Salado Grassland removal:
web 2: 1060 55' 54.3702" W, 340 17' 39.4343" N
web 3: 1060 56' 9.5089" W, 340 17' 28.8966" N

Rio Salado Grassland mark-and-recapture:
web 1: 1060 55' 44.2188" W, 340 17' 41.6938" N
web 4: 1060 55' 58.7518" W, 340 17' 29.7131" N
web 5: 1060 55' 47.9346" W, 340 17' 30.0713" N

Rio Salado Larrea removal:
web 1: 1060 55' 25.7955" W, 340 17' 42.1532" N
web 3: 1060 54' 15.3606" W, 340 17' 18.5052" N

Rio Salado Larrea mark-and-recapture:
web 2: 1060 55' 16.9269" W, 340 17' 39.8632" N
web 4: 1060 54' 16.0466" W, 340 17' 9.6752" N
web 5: 1060 54' 18.5054" W, 340 17' 1.6667" N

Two-twenty-two removal:
web 2: 1070 02' 7.2931" W, 340 25' 13.8862" N
web 3: 1070 01' 45.1839" W, 340 25' 5.4165" N

Two-twenty-two mark-and-recapture:
web 1: 1070 01' 36.5102" W, 340 25' 12.5298" N
web 4: 1070 01' 36.5047" W, 340 25' 0.8576" N
web 5: 1070 01' 57.2927" W, 340 25' 6.1467" N

Trapping Times

The season of 1990 was divided into 2 trapping periods: 1 (early summer) and 2 (late summer).

period 1: 22 May - 28 June
period 2: 10 July - 15 August

Locations were trapped in the same order for each period, as follows:
1. Sepultura Canyon (septulur)
2. Five Points Grassland (5pgrass)
3. Five Points Larrea (5plarrea)
4. Rio Salado Larrea (rslarrea)
5. Rio Salado Grassland (rsgrass)
6. Two-twenty-two (two22) currently: Ladron Foothills

Collection Procedures:

Mark-and-recapture webs

A small handful of rolled oats is placed into each trap, with an additional small amount of oats placed outside the trap door when it is set in the evening. Animals caught the next morning are removed from traps by forcefully dumping them into plastic bags; this allows one to orient the animal and get a good grip on it for identification and measurement. Each animal is then identified to species and weighed to the nearest gram using a pesola scale. Body, tail, foot, and ear measurments are taken to the nearest millimeter using a plastic ruler. Reproductive status is determined by examining the genitalia. Each animal is sexed, aged (juvenile/adult) and marked. Marking is done with a Sharpie permanent marker on each animal on the first night's capture for that individual. The animals are then placed back into their traps and released at the exact site of capture after which the traps are rebaited.

Removal webs

Removal traps are checked and rebaited as the mark-and-recapture traps. All closed traps are checked to insure they contained small mammals (other animals such as birds and reptiles are released); each trap is marked with the web and trap number and then removed from the web and replaced with an empty a trap. The animals are then brought back to the laboratory to be processed.

Below is the species list of all the small mammals caught on the 6 trapping sites. Each species is given a four letter field code, usually consisting of the first 2 leters of the genus and the first 2 leters of the specific names. Measurements made in the field and laboratory for each species also are listed:

1. BL: body length

2. TL: tail length

3. HF: hind foot length

4. EL: ear length


The species and their measurements are as follows:

anim: Ammospermophilus interpres measurements: none
amle: Ammospermophilus leucurus measurements: none
chin: Chaetodipus intermedius measurements: none
clga: Clethrionomys gapperi measurements: ?
dior: Dipodomys ordi measurements: none
dime: Dipodomys merriami measurements: none
disp: Dipodomys spectabilis measurements: none
euqu: Eutamias quadrivittatus measurements: none
eudo: Eutamias dorsalis measurements: none
euci: Eutamias cinereicollis measurements: none
eusp: Eutamias species measurements: none
mime: Microtus mexicanus measurements: ?
neal: Neotoma albigula measurements: none
neme: Neotoma mexicana measurements: none
nemi: Neotoma micropus measurements: none
nest: Neotoma stephensi measurements: none
nesp: Neotoma species measurements: none
onar: Onychomys arenicola measurements: BL, TL
onle: Onychomys leucogaster measurements: BL, TL
onsp: Onychomys species measurements: BL, TL
pgfv: Perognathus flavus measurements: BL, TL
pgfl: Perognathus flavescens measurements: BL, TL
pgsp: Perognathus species measurements: BL, TL
pmbo: Peromyscus boylii measurements: BL, TL, HF, EL
pmdi: Peromyscus difficilis measurements: BL, TL, HF, EL
pmer: Peromyscus eremicus measurements: BL, TL, HF, EL
pmle: Peromyscus leucopus measurements: BL, TL, HF, EL
pmma: Peromyscus maniculatus measurements: BL, TL, HF, EL
pmtr: Peromyscus truei measurements: BL, TL, HF, EL
pmsp: Peromyscus species measurements: BL, TL, HF, EL
remg: Reithrodontomys megalotis measurements: BL, TL
remo: Reithrodontomys montanus measurements: BL, TL
resp: Reithrodontomys species measurements: BL, TL
spsp: Spermophilus spilosoma measurements: none
spva: Spermophilus variagatus measurements: none
syau: Sylvilagus auduboni measurements: none

Laboratory Procedures:

When animals are brought back to the field station, each is given an NK (New Mexico Karyotype) number and then killed by accepted and approved procedures. The animal is immediatedly removed from the jar and brushed for ectoparasites using a toothbrush. Any ectoparasites found are placed into a small vial (Wheaton, 4 ml) with 70 0.000000E+00tOH and a label with its NK number. The host is then given to the mammalogists for identification, measurement, collection of tissues for electrophoresis, etc. (see mammal procedures). Once the carcass is returned, an incision is made in the abdomen beginning just above the genital area and ending just below the thoracic cavity. The entire gastrointestinal tract is removed by cutting the esophagusjust anterior to the stomach and the colon just anterior to the anus. The GI tract is then placed into a Petri dish with a small amount of water (to keep it moist); it is then untangled and the mesentary is removed. Fecal pellets are then removed from the colon and placed into a Wheaton vial (20 ml) containing 2138ebcotassium dichromate (K2Cr2O7) and the host's NK number. The stomach is then removed by cutting the pyloric sphincter. The stomach is then cut open by making a lateral incision along the length of the stomach after which the contents are emptied into a sieve (40mesh) and rinsed with tap water. The remaining material is placed back into a clean Petri dish and surveyed for parasites using a dissecting scope. The small intestine (duodenum, ileum, jejunum) is dissected in a clean Petri dish making a longitudinal incision along the length of the intestine. The contents of the intestine are then examined (scraping the intestine with a #0 insect pin) for parasites using a dissecting scope. The cecum is dissected by making an incision along the length of the cecum after which the contents are emptied into a sieve (60 mesh) and rinsed with tap water. The remaining material is then placed into a clean Petri dish and examined using a dissecting scope. Nematodes are fixed in GAA (Glacial Acetic Acid) until they are relaxed (3-4 min) and then stored in 100uffered formalin. Cestodes and Acanthocephalans are relaxed in dH2O (30-45 min) and then fixed and stored in 100uffered formalin. Fecal pellets are examined by sugar floatation. If viscera were not necropsied in the field they were frozen for later examination.

Below is the species list of all the parasites found in the small mammals caught on the 2 removal trapping webs from all 6 sites. Each species is given a four letter code, usually consisting of the first 2 letters of the genus and the first 2 letters of the specific name. The coccidia are different however, the first letter designates the genus with the last 3 letter comming from the specific name and is periodically being updated. A updated list can be found on the web site (http://sevilleta/data/species/parasite/)

The species are as follows:

acan: acanthocephala sp
adsp: Adelina species
caut: Catenotaenia utahensis
cuau: Cuterebra austeni
cune: Cuterebra neomexicana
cusp: Cuterebra species
cest: cestode sp
ealb: Eimeria albigulae
eari: Eimeria arizonensis
ebal: Eimeria balphai
ecal: Eimeria callospermophili
echa: Eimeria chaetodipi
echi: Eimeria chihuahuaensis
echo: Eimeria chobotari
edip: Eimeria dipodomysis
edor: Eimeria dorsalis
eere: Eimeria eremici
ehis: Eimeria hispidensis
elad: Eimeria ladronensis
elan: Eimeria langebarteli
elat: Eimeria lateralis
eleu: Eimeria leucopi
elio: Eimeria liomysis
emer: Eimeria merriami
emoh: Eimeria mohavensis
eneo: Eimeria neotomae
eony: Eimeria onychomysis
epeg: Eimeria perognathi
eper: Eimeria peromysci
eree: Eimeria reedi
esch: Eimeria scholtysecki
espp: Eimeria species
etam: Eimeria tamiasciurus
euta: Eimeria utahensis
flea: Siphonaptera sp
hede: Heteromyoxyuris deserti
hyci: Hymenolepis citelli
issp: Isospora species
iper: Isospora peromysci
lice: Mallophaga or Anoplura
madi: Mastophorus dipodomis
madp: Mathovetaenia dipodomi
mite: Acari
mocl: Moniliformis clarki
na: not available
nega: negative na
nema: Nematode sp
oode: Oochoristica deserti
posi: positive na
phma: Physaloptera massino
ptdi: Pterygodermatites dipodomis
rare: Raillietina retactalis
scdi: Schizorchodes dipodomi
syeu: Syphacia eutamii
tick: Acari
trdi: Trichuris dipodomis
trel: Trichuris elatoris
trem: trematode sp
unsp: unsporulated na

Maintenance: 

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson.  Helminth ID's entered and Eimeria Id's checked SKH and MR 7-98. Kristin Vanderbilt (October 25, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Checked by S. K. Heckscher 12 Feb. 1998. Helminth IDs entered and Eimerian ids checked 7-98 SKH and MR. Ectoparasites (fleas and lice) IDs by Dick Fagerlund entered by SKH 9-98 (3 entries). Kristin Vanderbilt (October 25, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth id's entered and Eimeria id's checked SKH and MR 7-98. 4 Feb. 1997: Changed host on 26105 from pgfl to pgfv, and added nk#'s and error checked 26102. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file. doc

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth ids entered and Eimeria ids checked 7-98 SKH and MR. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth ids entered and Eimeria ids checked 7/98 SKH and MR. Ectoparasites (fleas and lice) IDed by Dick Fagerlund entered by SKH 9/98. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth ids entered and Eimeria Ids checked 3 August 1998, SKH and MR. Ectoparasites (fleas and lice) IDed by Dick Fagerlund and entered by SKH 9-98. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth ids entered and Eimeria ids checked August 3, 1998, SKH and MR. Ectoparasites (fleas and lice) IDed by Dick Fagerlund, entered by SKH 9-98. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

File created by W.D. Wilson/D.W. Duszynski, 24 May 1993. Data entered by W.D. Wilson. Helminth ids entered and Eimeria ids checked 4 August, 1998 SKH and MR. Ectoparasites (fleas and lice) IDed by Dick Fagerlund, entered by SKH 9-98. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field. Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns. Archived file.

Set up by S.K. Heckscher July 1998. Season 1 entered July 98 SKH. Season 2 entered December 98 KHD. Both seasons checked, December KHD and MR. Checked with Mammal.dbf 1/99. Peromyscus IDs could still change esp. nk 10082. The 10000 numbers are actually 100000 numbers. Since the database is only set up for a five digit nk number, we didn't want to mess it up so we left off one '0', this only happens this year. Kristin Vanderbilt (October 29, 2001) Inserted _'s between words in comments field.  Used get_maxcol_width.csh to calculate number of dashes for header section of file. Used align_IAF_columns.csh to left align all columns.  Archived file.

The specimen with nk# 10082 is identified as pmle in this file, but is identified as pmbo in the mammal population dataset.  The specimen exists in the Museum of Southwest Biology, and its identification can be checked. 

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