Landscape characteristics and predation risk influence spatial variation in auditory courtship of an upland game bird

Abstract

Context Numerous wildlife species use a polygynous mating system, where males use auditory courtship behaviors to secure breeding opportunities. The acoustic adaptation hypothesis, risk reward, and landscape of fear theories suggest spatial variation in male auditory courtship will be influenced by areas in landscapes where sound transmission is increased, and predation risk is reduced. However, it is often unclear what landscape features drive spatial variation in courtship behaviors. Objectives We quantified the influence of predation risk, land cover type, and resource selection on spatial trends in the auditory courtship behavior (gobbling activity) of Eastern wild turkeys (Meleagris gallopavo silvestris). Methods We used 53,025 gobbles coupled with GPS locations from 111 turkeys and 36 coyotes (Canis latrans), and distance metrics associated with hunter activity and land cover type, to investigate influences of predation risk, resource selection, and land cover type on spatial variation in gobbling activity in Georgia, USA. Results Distance to public access during hunting was the most influential predictor of gobbling activity, wherein the expected number of daily gobbles increased by 40% for every 500 m farther from public access. Daily gobbles decreased by 22% for every 500 m farther away from private property during hunting. We failed to find significant effects of land cover type and coyote use but found limited evidence that areas with increased predicted probability of turkey use was associated with increased gobbling. Conclusions Predation risk associated with increased anthropogenic disturbance had the greatest influence on gobbling activity. Our findings suggest that altering hunter access by closing roads to vehicle use, reducing hunter activity, or creating refuge areas on the landscape could positively influence gobbling activity.

Sex‐specific resource use by wild turkeys in response to hunting activity

“…Male wild turkeys tended to avoid primary roads after the onset of hunting as these roads provided access points for hunters on our study site. Our data parallel contemporary works noting that male wild turkeys move away from areas associated with public access and increase the frequency of using courtship vocalizations farther from public access during and after hunting (Wightman et al 2023a, b).…”

“…Our results contribute to the growing body of literature demonstrating that game species perceive hunters as predators and shift resource selection to avoid predation risk (Ordiz et al 2012, Gross et al 2015, McGrath et al 2018, Wightman et al 2023a). We specifically investigated how male resource selection changed prior to and within the hunting season in response to hunter distribution.…”

“…Gross et al (2015) reported that 75% of all turkey hunter locations were within 150 m of a trail, and 40% of hunter locations were within 25 m of the nearest trail on our study site (Gerrits et al 2020). Although hunters may exert anti-predator responses in their prey, their strong selection for trails suggests these responses may be spatially limited to clearly defined and easily traversed access routes (Brøseth and Pedersen 2001, Lebel et al 2012, Wightman et al 2023a).…”

“…Spring harvest is the primary form of mortality for male wild turkeys (Vangilder 1992, Chamberlain et al 2012, Wightman et al 2023c. Recent work also indicates hunting negatively influences gobbling activity (Chamberlain et al 2018;Wightman et al 2019Wightman et al , 2023b and could affect reproduction (Chamberlain et al 2018, Wakefield et al 2020. Likewise, spring wild turkey hunting seasons often occur concurrent with female egg laying and nesting periods, so hunting-induced shifts in female habitat selection could indirectly affect fitness (Isabelle et al 2018).…”

“…Unlike animals that can avoid hunters by shifting to more nocturnal movements (Gaynor et al 2018), wild turkeys are diurnal and must access resources and engage in reproductive activities while hunters are present on the landscape. Several studies have evaluated wild turkey responses to hunting activity (Gross et al 2015, Wakefield et al 2020), but detailing how hunting pressure is distributed across the landscape and how hunter resource selection affects wild turkey behavior would provide a useful case study of anti-predator responses (Gerrits et al 2020, Wightman et al 2023a.…”