Jason B. Hardin

Artificial Nests Identify Possible Nest Predators of Eastern Wild Turkeys

Abstract Poor nest survival is a critical limiting factor in the recruitment of wild birds. Nest predation is often cited as one of the main causes of nest failure, especially for ground-nesting species. We monitored artificial Meleagris gallopavo silvestris (Eastern Wild Turkey) nests, using time-lapse and motion-sensitive trail cameras to determine which predators were likely to be responsible for preying on Wild Turkey nests in the Pineywoods of East Texas. Sixty-one percent of all artificial nests were preyed upon. Corvus brachyrhynchos (American Crow) preyed on 48% of artificial nests and Procyon lotor (Raccoon) preyed on 35%. There was a seasonal increase in the number of artificial nests preyed upon from spring to summer. Mammalian mesopredators, Raccoon and Didelphis virginiana (Opossum), were primarily responsible for this increase, suggesting an increase in search effort by mesopredators that coincided with increased dietary diversity in a period of reduced prey resources. Predators other than mesopredators—American Crows, Picoides sp. (woodpeckers), Dasypus novemcinctus (Nine-banded Armadillo), and snakes—were responsible for 53% of all predation on the artificial Wild Turkey nests, with American Crows being the most important of these. After nest deployment, American Crows located and preyed on artificial nests more quickly than other nest predators. We suggest video monitoring of natural Eastern Wild Turkey nests to confirm the identity of nest predators.

Encounter Rates From Road-Based Surveys of Rio Grande Wild Turkeys in Texas

Abstract Traditional index-based techniques have indicated declines in Rio Grande wild turkey (Meleagris gallopavo intermedia; hereafter, wild turkey) populations across much of Texas, USA. However, population indices can be unreliable. Research has indicated that road-based surveys may be an efficacious technique for monitoring wild turkey populations on an ecoregion level. Therefore, our goal was to evaluate applicability of road-based distance sampling in the Cross Timbers, Edwards Plateau, Rolling Plains, and South Texas ecoregions of Texas. We conducted road-based surveys in each ecoregion during December 2007–March 2008 to estimate wild turkey flock encounter rates and to determine survey effort (i.e., km of roads) required to obtain adequate sample sizes for distance sampling in each ecoregion. With simulations using inflatable turkey decoys, we also evaluated effects of distance to a flock, flock size, and vegetative cover on turkey flock detectability. Encounter rates of wild turkey flocks from road-based surveys varied from 0.1 (95% CI  =  0.0–0.6) to 2.2 (95% CI  =  0.8–6.0) flocks/100 km surveyed. Encounter rates from surveys restricted to riparian communities (i.e., areas ≤1 km from a river or stream) varied from 0.2 (95% CI  =  0.1–0.6) to 2.9 (95% CI  =  1.5–6.7) flocks/100 km surveyed. Flock detection probabilities from field simulations ranged from 22.5% (95% CI  =  16.3–29.8%) to 25.0% (95% CI  =  13.6–39.6%). Flock detection probabilities were lower than expected in all 4 ecoregions, which resulted in low encounter rates. Estimated survey effort required to obtain adequate sample sizes for distance sampling ranged from 2,765 km (95% CI  =  2,597–2,956 km) in the Edwards Plateau to 37,153 km (95% CI  =  12,861–107,329 km) in South Texas. When we restricted road-based surveys to riparian communities, estimated survey effort ranged from 2,222 km (95% CI  =  2,092–2,370 km) in the Edwards Plateau to 22,222 km (95% CI  =  19,782–25,349 km) in South Texas.

Prey Selection by Three Mesopredators that are Thought to Prey on Eastern Wild Turkeys (Meleagris gallopavo sylvestris) in the Pineywoods of East Texas

Abstract Predation, especially during the nesting and poult-rearing seasons, may inhibit Meleagris gallopavo (Wild Turkey) recruitment in east Texas. Numerous authors cite Lynx rufus (Bobcat), Canis latrans (Coyote), and Procyon lotor (Raccoon) as predators of Wild Turkey. Consequently, we investigated prey selection of these 3 common mesopredators using scat analysis. We also investigated prey-population dynamics using capture—mark—recapture techniques for small mammals (Rodentia), and spotlight surveys and track plate counts for Sylvilagus floridanus (Eastern Cottontail). We found no evidence that mesopredators preyed upon Wild Turkeys. Small mammals and lagomorphs were the primary components of mesopredator diets. Small-mammal numbers varied seasonally; however, Cottontail relative abundance did not. Mesopredator diets were most diverse in summer. In summer, Bobcats increased their use of small mammals, whereas Coyotes and Raccoons diversified their diets to include seasonal fruits. Decline in small-mammal populations and increase in mesopredator dietary diversity coincided with Wild Turkey nesting and poultrearing seasons, which potentially could result in an increased threat to Wild Turkeys during the nesting and poult-rearing season.