Merriam's Turkey Nest Survival and Factors Affecting Nest Predation by Mammals

Abstract

Nest success is an important parameter affecting population fluctuations of wild turkeys (Meleagris gallopavo). Factors influencing mammalian predation on turkey nests are complicated and not well understood. Therefore, we assessed nest hazard risk by testing competing hypotheses of Merriam's turkey (M. g. merriami) nest survival in a ponderosa pine (Pinus ponderosa) ecosystem during 2001–2003. We collected nesting information on 83 female Merriam's turkeys; annual nest success averaged 50% for adult females (range = 45–59%) and 83% for yearling females (range = 75–100%). Proportional hazard modeling indicated that precipitation increased the hazard of nest mortality. However, estimated hazard of nest predation was lowered when incubating females had greater shrub cover and visual obstruction around nests. Coyotes (Canis latrans) were the primary predator on turkey nests. We hypothesize that precipitation is the best predictor of nest survival for first nests because coyotes use olfaction effectively to find nesting females during wet periods. Temporally, as the nesting season progressed, precipitation declined and vegetation cover increased and coyotes may have more difficulty detecting nests under these conditions later in the nesting period. The interaction of concealment cover with precipitation indicated that nest hazard risk from daily precipitation was reduced with greater shrub cover. Management activities that promote greater shrub cover may partially offset the negative effects of greater precipitation events.

Eastern wild turkey nest site selection in two frequently burned pine savannas

“…Fuller et al (2013) evaluated Eastern wild turkey nest survival in Connecticut as a function of nest site and patch-level habitat metrics and found the nest site scale (vegetation surrounding the nest site) was most important to nest site selection and survival. Lehman et al (2008) evaluated Merriam's turkey (Meleagris gallopavo merriami) nest site selection and survival in South Dakota as a function of multiple habitat components collected at multiple spatial scales. They provided evidence for a hierarchical nest site selection process because they found land cover patch size (ha) and visual obstruction at the nest site to be the two primary habitat components that influenced nest site selection and survival.…”

“…Research is needed to fill this gap in our understanding of wild turkey nest site selection in pine savannas and direct future management decisions. Additionally, few studies have evaluated the role of spatial scale on turkey nest site selection (Thogmartin 1999, Lehman et al 2008, Fuller et al 2013.…”

“…Selection of nest sites with greater understory vegetation may also reduce transmission of olfactory and visual cues to potential nest predators and impede predator foraging efficiency (Bowman andHarris 1980, Lehman et al 2008). For example, Lehman et al (2008) found that coyotes (Canis latrans) were the primary predator of turkey nests, and as nesting season progressed, nest survival increased, which they suggested may be a function of reduced precipitation making detection of nesting turkeys increasingly difficult via olfactory senses. Wild turkeys have also been shown to select nest sites in large patches with reduced edge density presumably to reduce the risk of nest predation (Thogmartin 1999).…”

“…For example, Thogmartin (1999) suggested that wild turkey nest site selection and success likely depends on patterns and processes at multiple spatial scales such as fine-scale vegetation structure within patches (nest site), broader scale land cover composition and configuration, and mesocarnivore densities. Lehman et al (2008) evaluated the effects of multiple spatial scales on turkey nest site selection and survival and found that successful turkey nests were located in larger land cover patches that contained greater visual obstruction surrounding the nest site. Conversely, Fuller et al (2013) evaluated the effects of nest site and patch-level metrics on turkey nest site selection and survival and found little support for a hierarchical process concluding that vegetation around the nest site was most important.…”

“…Additionally, Streich et al (2015) used distance metrics to evaluate nest site selection, which do not incorporate the juxtaposition and potential importance of multiple land cover types that may be biologically relevant to nest site selection. Frequently burned pine systems provide a unique opportunity to evaluate the effects of spatial scale on turkey nest site selection because this system is primarily characterized by open, park-like conditions with a predominantly herbaceous understory, which is not characteristic of habitat conditions in many previous studies (e.g., Lehman et al 2008, Fuller et al 2013. Therefore, our objective was to evaluate whether turkeys exhibited a hierarchical nest site selection in two pine-dominated systems managed by frequent fire (≤3 years).…”