Habitat selection of Gould's wild turkeys in southeastern Arizona

In semi-arid environments, resources necessary for survival may be unevenly distributed across the landscape. Gould's wild turkeys (Meleagris gallopavo mexicana) are spatially restricted to mountainous semi-arid areas of southwestern United States and Mexico, and information on their distribution and habitat use is limited. We described how landcover type and topographical features influenced space use and habitat selection by Gould's wild turkeys in southeastern Arizona. We used GPS data from 51 Gould's wild turkeys to describe resource selection during 2016-2017 in southeastern Arizona, USA. We estimated home ranges and calculated resource selection functions using distance from landcover types, slope, aspect, and elevation at used locations and random locations within individual home ranges. Gould's wild turkeys selected areas closer to pine forest and water. Likewise, Gould's wild turkeys selected locations with moderate elevations of 1641 ± 235 m (range = 1223-2971 m), and on north and west facing slopes with a 10° ± 8.5 (range = 0.0-67.4°) incline. Our findings suggest that conserving portions of the landscape with appropriate topography and landcover types as described above will promote habitat availability for Gould's wild turkeys.

Effects of grazing strategy on facultative grassland bird nesting on native grassland pastures of the Mid-South USA

Understanding how livestock grazing strategies of native warm season grasses (NWSG) can impact facultative grassland bird nesting can provide insight for conservation efforts. We compared pre and post treatment effects of rotational grazing (ROT) and patch-burn grazing (PBG) for facultative grassland bird species nest success and nest-site selection on NWSG pastures at three Mid-South research sites. We established 14, 9.7 ha NWSG pastures and randomly assigned each to either ROT or PBG and monitored avian nest-site selection and nest success, 2014-2016. We collected nesting and vegetation data in 2014, before treatment implementation, as an experimental pre-treatment. We implemented treatments across all research sites in spring 2015. We used a step-wise model selection framework to estimate treatment effect for ROT or PBG on avian nest daily survival rate (DSR) and resource selection function (RSF) at the temporal scale and within-field variables. Daily survival rates were 0.93% (SE = 0.006) for field sparrow (Spizella pusilla), 0.96% (SE = 0.008) for red-winged blackbird (Agelaius phoeniceus), and 0.92% (SE = 0.01) for indigo bunting (Passerina cyanea). Model support for PBG treatment and vegetation height were indicated as negative and positive influences for field sparrow DSR, respectively. Red-winged blackbirds' DSR were negatively influenced by ROT while vegetation height positively affected DSR, and DSR for indigo bunting did not differ among treatments. Combined RSF models indicated nest-site selection for all species was positively related to vegetation height and only weakly associated with other within-field variables. We provide evidence that ROT and/or PBG effects vary by species for DSR for these three facultative grassland birds, and vegetation characteristics affected their nest-site selection in the Mid-South USA. A lack of disturbance in Mid-South grasslands can lead to higher successional stages (i.e., mix shrub-grassland), but some combination of ROT, PBG, and unburned/ungrazed areas can provide adequate nesting habitat on small pasture lands (∼1.8 -7.8 ha) for various facultative grassland birds and potentially offer the opportunity to simultaneously maintain livestock production and grassland bird nesting habitat.