Small Mammal Responses to the Reintroduction of Gunnison’s Prairie Dog Betsy Black, Amherst College Andrew Veselka, Dickinson College Stephanie Baker Photo: Cassie Miller

King Prairie Dog ● Ecosystem engineer o Burrowing o Grazing/clipping ● Modify o Vegetation structure o Population structures

Small Mammals ● Burrowing provides habitat ● Vegetation alteration affects herbivorous rodents ● Arthropod alteration affects carnivorous rodents ●Prairie dog presence increases small mammal abundance and decrease small mammal diversity

Expected Responses to Prairie Dogs Positive associationNegative association

Expected Responses to Prairie Dogs Positive associationNegative association Grasshopper Mouse Onychomys sp

Expected Responses to Prairie Dogs Positive associationNegative association Grasshopper Mouse Onychomys sp Spotted Ground Squirrel Spermophilis spilosoma Peromyscus sp Silky Pocket Mouse Perognathus flavus Banner Tailed and Merriam’s Kangaroo Rat Dipodomys spectabiis and merriami

Expected Responses to Prairie Dogs Positive associationNegative association Grasshopper Mouse Onychomys sp Spotted Ground Squirrel Spermophilis spilosoma Peromyscus sp Silky Pocket Mouse Perognathus flavus Banner Tailed and Merriam’s Kangaroo Rat Dipodomys spectabiis and merriami Southern Plain’s Woodrat Neotoma micropus

Expected Responses to Prairie Dogs Positive associationNegative association Grasshopper Mouse Onychomys sp Spotted Ground Squirrel Spermophilis spilosoma Peromyscus sp Silky Pocket Mouse Perognathus flavus Banner Tailed and Merriam’s Kangaroo Rat Dipodomys spectabiis and merriami Southern Plain’s Woodrat Neotoma micropus Ord’s Kangaroo Rat Dipodomys ordii

Oh. And a bunny. And a bunny.

Oh. And a bunny. And a bunny. Sylvilagus audubonii SILL-vih-LAG-uhs AW-duh-BON-ee

Objectives ● Are there significant differences in abundance and diversity of small mammals populations between sites with and without prairie dogs? ● Can a correlation be seen between prairie dog burrow entrance density and number of individuals caught?

Sevilleta National Wildlife Refuge ● Gunnison’s prairie dogs extirpated before conversion to refuge ● Reintroduction began in 1997

Small Mammal Trapping ● Conducted in plots A through D on the East side of the refuge ● Gunnison’s prairie dogs reintroduced to plots B and D in 2010 ● Set 169 traps per plot

Small Mammal Sampling ● Examined for: o species o previous capture o mass o sex o reproductive status o age group ● Mark recapture method used Ear tagged kangaroo rat Marked ground squirrel

Results ● Total of 677 small mammals captured ● 240 captured on control plots and 437 captured on treatment plots SpeciesTreatmentControlTreatmentControl Dipodomys ordii Dipodomys merriami4070 Dipodomys spectabilis Neotoma micropus2324 Onychomys sp Peromyscus sp Perognathus flavus Spermophilus spilosoma 8672

2014 Treatment Plots vs. Control Plots

Treatment versus Control Values less than 0.05 (highlighted) indicate significant differences in population between treatment and control plots Species Dipodomys merriami Dipodomys ordii Dipodomys spectabilis Neotoma micropus Onychomys sp Perognathus flavus Peromyscus sp Spermophilis spilosoma Total small mammals

Control Treatment

Control Treatment

Dipodomys ordii ● Avoid active prairie dog colonies ● Frequently found in abandoned burrows SpeciesTreatmentControlTreatmentControl Dipodomys ordii p= p=0.0299

Independent sources of variation Precipitation variation between years ● Above average rainfall amplifies unique features of prairie dog towns ● Leads to more distinct small mammal communities

Objectives ● Are there significant differences in abundance and diversity of small mammals populations between sites with and without prairie dogs? ● Can a correlation be seen between prairie dog burrow entrance density and number of individuals caught?

Objectives ● Can a correlation be seen between prairie dog burrow entrance density and number of individuals caught?

Burrow Mapping ● Plotted prairie dog burrow entrances and trap grids using a GeoExplorer Trimble ● Overlayed resulting maps using ArcGIS ● Used the data to determine relationship between burrow location and trap success

Prairie Dog Burrow Buffers

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● Average burrows within 12.5m of traps Results

● No discernible trend *Species under red arrows were significantly more abundant on treatment than control plots

Conclusion ● Overall abundance of small mammals increased on treatment plots ● Dipodomys merriami, Dipodomys ordii, Onychomys sp., and Perognathus flavus significantly more abundant on treatment plots

Conclusion (contin.) ● No species were significantly less abundant on treatment than control plots ● No trends in burrow location relative to trap success

Future Focus ● Assess effect of o amount of prairie dog burrows o annual rainfall o insect biomass ● Compare microclimates of plot B and D

Future Focus ● Assess effect of o amount of prairie o annual rainfall o insect biomass ● Compare microclimates of plot B and D

Acknowledgements Stephanie Baker Amaris Swann Ty Werdel Ari AnadaJari Javier Faith CarneyShane Piaso Cassie MillerJenny Sparks Ariel ElliotNathan Tutchton Wendy FloresSze Wing Yu Ben SpecterRina Ouellette

“Teamwork makes the dream work” -Dizzy Wright