Spatiotemporal variability of fire characteristics affect animal responses in pyric landscapes

Abstract

Background: Behavioral responses are the most immediate ways animals interact with their environment, and are primary mechanisms by which individuals mitigate mortality risk while ensuring reproductive success. In disturbancedriven landscapes, animals must adjust behaviors both spatially and temporally to maximize individual fitness. Prescribed fire is an important ecosystem driver in many coniferous forests, as fire cycles nutrients, creates spatially heterogeneous distributions in quantity and quality of forage and cover, and provides opportunities for fire-adapted taxa. Because fire immediately shifts resource distribution, and fire characteristics may drive behavioral responses to recent burns, we examined behavioral responses of 105 Global Positioning System (GPS)-tagged female eastern wild turkeys (Meleagris gallopavo silvestris Linnaeus, 1758) to fire application at three sites in southeastern United States. We used satellite-derived imagery to calculate burn severity and burn heterogeneity. We also calculated distance to adjacent unburned stands and time-since-fire at GPS locations of each turkey while inside burned stands. We used behavioral change point analyses to estimate behavioral state for turkeys using burned areas, and generalized linear mixed models to estimate how fire characteristics affected turkey behavior inside burned areas. Results: Turkeys focused their use in less severely burned areas, and were less likely to use the interior of burned areas. Turkeys were more likely to forage and rest in less severely burned areas, suggesting that managers should apply prescribed fire frequently enough to promote low-severity burns. We found that, as distance to neighboring unburned areas increased, turkeys were more likely to walk through the interiors of recently burned areas, as opposed to resting or foraging in them, suggesting that the interiors of some burn units are less suitable habitat in the year that prescribed fire is applied. Our findings suggest that prescribed fire applied to ensure that interior areas of burned stands are <250 m from adjacent unburned stands or to stands shaped to maximize edge-to-area ratios likely create more suitable conditions for foraging and resting. Conclusions: The application and spatial arrangement of prescribed fire, even in frequently burned areas, affect animal response and behaviors. Prescribed fire regimes should be created in recognition that sizes of burned stands and fire severity, along with determinants of fire severity (e.g., fuel loads, return intervals, timing), are important influences on animal behavior in frequent-fire-managed landscapes.

Wild Turkey Nest Success in Pine‐Dominated Forests of the Southeastern United States

“…The lack of support for landscape metrics may be due to the resolution of land cover data that masked important, local‐scale heterogeneity within land cover classes. For example, recent work in the southeastern United States has indicated that wild turkeys readily use mature pine forests wherein females select stands that have been recently burned (Kilburg et al 2014, Streich et al 2015, Yeldell et al 2017 a , Cohen et al 2019, Wood et al 2019), but site‐specific spatial and temporal information on fire histories were necessary to evaluate and draw such conclusions. Our inability to capture potential differences in reproductive success relative to landscape metrics highlights the limitations of using coarse‐grained remotely sensed data products in landscapes dominated by a single cover type.…”

“…forests are the dominant cover type in the Southeast, and on public lands, may be maintained via prescribed fire every 3–5 years (Carter and Foster 2004). Fire plays an important role in creating suitable nesting conditions for wild turkeys (Cohen et al 2019). Consequently, ground vegetation conditions on public lands in the Southeast may be considerably different from those in agro‐forested regions of the Northeast and Midwest, and landscape metrics identified in northern studies may not be useful for turkey management in southern forests.…”

Fine‐scale movements and behaviors of coyotes (Canis latrans) during their reproductive period

“…(2014) and Cohen et al. (2019) both recently used FPT values to infer the scale at which wild turkeys ( Meleagris gallopavo ) reacted to changes within their environment. We used similar methodology to infer the scale at which coyotes responded to their environment.…”

“…We used behavioral change‐point analysis (BCPA) to model coyote behavior (Gurarie et al., 2009) using methods outlined in Cohen et al. (2019). The BCPA is a likelihood‐based method that identifies changes in movement patterns using locational time‐series data.…”

Spatial Scale and Shape of Prescribed Fires Influence Use by Wild Turkeys

“…Nonetheless, previous researchers have already reported how timing of fire influences turkey behavior (Little et al 2016; Yeldell et al 2017 a , b , c ; Wood et al 2018). Likewise, our model did not account specifically for spatial variations in fire intensity across burn units, although Cohen et al (2019) detailed influences of fire severity within burn units on turkey movements, and we used those data in our analyses as detailed herein (ODD in Supporting Information). We also recognize our model used landscapes represented by burn units with different fire‐return intervals arranged systematically in a checkerboard fashion, rather than randomly distributing fires or otherwise distributing units with different fire‐return intervals across the landscape.…”