Status and Distribution of Franklin\u27s and Richardson\u27s Ground Squirrels in Eastern South Dakota

Over the last century the Northern Great Plains has been altered substantially, largely due to native grasslands being converted into cropland. Over 99% of tall grass prairie and an estimated 70 to 90% of native mixed grass prairie have been lost. In addition, expiring conservation reserve program contracts and decreased government incentives to keep grassland on the landscape has increased pressure on landowners to convert remaining grassland habitat into row crops. Obligate grassland mammal species such as the Richardson’s ground squirrel (Urocitellus richardsonii) and Franklin’s ground squirrel (Poliocitellus franklinii) have suffered declines in abundance and distribution throughout their range due to loss of grassland. However, little is known about the Richardson’s and Franklin’s ground squirrel in South Dakota. During 2013 and 2014, I surveyed eastern South Dakota for sites occupied by these 2 species of ground squirrels. I surveyed a total linear distance of 1,522 km for Richardson’s ground squirrels. Sixty-eight Richardson’s ground squirrel locations were detected along survey routes. Transect lengths varied from 16 to 48 km with an average of 0.05 Richardson’s ground squirrel occupancy locations per kilometer. An additional 35 Richardson’s ground squirrel occupancy locations were detected off of survey routes. Habitat types occupied by Richardson’s ground squirrels were 92% pasture land, 4% hay land, 2% mowed farmyard, and 2% ditch. I trapped 81 sites for Franklin’s ground squirrels of which only 6 locations were occupied. Seventeen FGS locations were visually detected. Primary habitats trapped were 72% tame grasses, 21% reseeded native grassland, 6% remnant native grassland, and 1% forbs. Primary habitat types of capture locations were tame grasses (n=5) and reseeded native grasses (n=1). Lack of long-term monitoring of these species has made it difficult to quantify their status in terms of colonization, extinction, survival, and growth rates. Future research on both species in South Dakota is pertinent due to these unknown population parameters

Survey of Turtles Nesting on the Missouri River on the South Dakota–Nebraska Border

We conducted surveys for nesting false map turtles (Graptemys pseudogeographica), spiny softshell turtles (Apalone spinifera), and smooth softshell turtles (A. mutica) along the lower Missouri River on the South Dakota–Nebraska border in 2006 and 2007. We found 62 active nests (45 softshell species and 17 false map turtles) and 190 predated nests over two field seasons. Of the combined intact and predated nests, there were 2.7 false map turtle nests per sandbar and 4.2 softshell species nests per sandbar on the three man-made sandbars. On natural sandbars, there were 1.4 false map turtle nests per sandbar and 16.3 softshell species nests per sandbar. The nest characteristics that we measured were similar to those in populations of these turtles in other areas of the United States. We found no difference in the straight-line distance from nest to water between softshell species and false map turtles (t55 = 0.601, p = 0.552). Also, we found no difference in distance from nests to water between the species (t55 = 0.601, p = 0.552). In general, the distance to water traveled by nesting turtles was farther than that in previously studied populations, with softshell species averaging 61.3 m from water and false map turtles averaging 54.2 m from water. For all species, the slope of the shore nearest the nests on man-made sandbars was less (2.8°) than that on natural sand bars (11.0°) (t55= 3.699, p = 0.003). We found no difference in nearest distance to water from the nest between man-made and natural sandbars. The predation rate of monitored nests was 36% (all on natural sandbars). Softshell species nested exclusively in bare sandy areas while false map turtles tolerated sparse vegetation around the nest site. The constructed sandbars seemed to provide quality nesting habitat and were being used by turtles for nesting. The 2012 flood removed or reduced several man-made sandbars, increased the size of others, and created new sandbars. These new sandbars should be monitored to assess turtle nesting success. If the new sandbars provide suitable habitat, it may not be necessary to simulate a natural flooding regime or build new sandbars for a few years. If more constructed sandbars are needed, they should include large areas of open sand to provide easy access to nesting females, minimal vegetation for predator habitat, and a sufficient number of high areas to prevent turtle nests from being flooded

Habitat selection and nest survival in two Great Plains shorebirds

As breeding populations of many grassland bird species decline, assessments of breeding habitat selection and reproductive success can provide useful insight into breeding ecology to support conservation delivery. Here, we demonstrate the use of nest location and survival data collated from 20 data contributors across the Prairie Pothole Region of the United States and Canada over a half century to examine habitat selection and nest survival of Western Willets (Tringa semipalmata inornata) and Marbled Godwits (Limosa fedoa), hereafter "willets" and "godwits." Both willets and godwits selected territories with less variation in vegetation height and topography relative to available locations. Willets selected nest sites that were flatter, closer to wetlands, and had shorter vegetation than Marbled Godwits, while godwits selected territories with greater wetland cover and shorter vegetation. Despite differences in fine-scale habitat selection, willets and godwits experienced similar daily nest survival rates and ecological drivers of nest survival. Nest success for the entire nest exposure period was estimated to be 0.521 (95% credible interval: 0.39-0.65) for willets and 0.562 (95% credible interval: 0.42-0.70) for godwits. Nest survival for both species increased with nest age and distance from the nest to the nearest wetland edge, while nest survival of godwits declined with conspecific breeding density. These relationships, as well as a weaker positive effect of microtine rodent abundance on nest survival, resembled drivers of upland nesting waterfowl reproductive success in the same region, which we attribute to their shared nest predators. Nest survival analyses of our collaborative dataset required substantial consideration of biases emerging from different data collection methods, ultimately reaffirming the importance of nest aging techniques in proper nest fate assignment. Analysis of compiled datasets using emerging analysis methods will continue to grow our understanding of the ecology of data sparse species