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.
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.
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 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 mSoils: sandy loam and sandy clay loamSite history: historically large prairie dog colonies inhabited the study area