Nest site selection and nest survival of eastern wild turkeys in a pyric landscape

Abstract

Pine (Pinus spp.)‐dominated forests are commonly managed with prescribed fire in the southeastern United States to reduce fuel loads, maintain diverse plant communities, and increase habitat quality for wildlife. Prescribed fire alters understory vegetation, which is a key component of nesting habitat for ground‐nesting birds. We assessed the influences of vegetation, prescribed fire, and landscape features (e.g., roads, edge) on nest site selection and nest survival of eastern wild turkeys (Meleagris gallopavo silvestris) in a pine‐dominated ecosystem in west‐central Louisiana. We radio‐marked 55 female wild turkeys and evaluated vegetation and landscape characteristics associated with 69 nests during the 2014 and 2015 reproductive periods. We used conditional logistic regressions with matched‐pairs case‐control sampling and information‐theoretic approaches to determine if vegetation characteristics within 15 m of a nest site, distances to surrounding vegetation communities and edges, and prescribed fire history of patches where a nest was located influenced nest site selection. We calculated hazard ratios for covariates in our top‐performing models to determine if any of these characteristics affected nest site survival. Turkeys in our study had a longer reproductive season and higher nesting and renesting rates relative to other populations in the southeastern United States. At the local scale, turkeys nested in areas with higher percent ground cover vegetation. At the landscape scale, turkeys nested closer to roads and farther from edges of 2 plant communities. Turkeys selected to nest in forest stands burned 2 years prior. Nest survival was not affected by percent ground cover, distance to roads, or distance to edge but was negatively associated with time‐since‐fire; turkey nests in stands burned ≥3 years prior had lower survival than nests in stands burned the current year. We suggest that burning on a 3‐year fire return interval is compatible with management for wild turkeys in southeastern pine‐dominated forests. © 2017 The Wildlife Society.

Nest and brood site selection of eastern wild turkeys

“…We found that females selected nest sites with increased visual obstruction but daytime use sites with decreased visual obstruction. Conversely, visual obstruction was not an important predictor of nest site selection in a fire‐managed landscape in Louisiana, USA (Yeldell et al ).…”

“…We did this to create a more conservative estimate of space use because a new UD would be overly biased towards locations taken during the incubation period (Cohen et al ). To facilitate comparisons with recent studies, we mirrored the methodology of Yeldell et al (), and generated 5 paired random locations within each pre‐nesting range for each individual female across each nest attempt. To calculate landscape characteristics at ground roosts and daytime use sites, we constructed daily ranges using 100% minimum convex polygons around GPS locations for the day prior to roost sampling, and around GPS locations for the day of daytime use sampling.…”

“…We based 4 models on the prediction that selection was influenced by ground cover, visual obstruction, canopy closure, or basal area. Ground cover influences selection of nests (Badyaev , Fuller et al , Yeldell et al ), as does visual obstruction (Holbrook et al , Streich et al , Little et al ). Ideal habitat for broods should provide adequate concealment for poults while providing females unobstructed views to detect predators (Porter ).…”

“…Contemporary research has noted declining productivity of turkeys throughout the southeastern United States (Byrne et al ), and fire affects vegetation and landscape composition in ways that could affect nest and brood survival. Predation is the primary cause of nest (Byrne and Chamberlain , Kilburg et al , Little et al , Yeldell et al ) and brood loss (Speake et al , Palmer et al ), and predation risk likely operates across multiple spatial scales (Fleming and Porter , Gibson et al ). Because fire affects vegetation composition across landscapes, it could influence predation rates and nest survival (Yeldell et al ).…”

“…Predation is the primary cause of nest (Byrne and Chamberlain , Kilburg et al , Little et al , Yeldell et al ) and brood loss (Speake et al , Palmer et al ), and predation risk likely operates across multiple spatial scales (Fleming and Porter , Gibson et al ). Because fire affects vegetation composition across landscapes, it could influence predation rates and nest survival (Yeldell et al ). For example, recently burned areas tend to be avoided by common nest predators including raccoons ( Procyon lotor ; Jones et al ), which could increase nest survival in patches burned within the previous growing season.…”