DOI: 10.5061/dryad.np5hqbzwn
title: Intensive hunting fundamentally changes human-wildlife relationships

description: Wildlife alter their behaviors in a trade-off between consuming food and
 fear of becoming food themselves. The risk allocation hypothesis posits
 that variation in the scale, intensity, and longevity of predation threats
 can influence the magnitude of antipredator behavioral responses. Hunting
 by humans represents a threat to wildlife thought to be perceived as
 similar to those of a top predator, although hunting intensity and
 duration vary widely around the world. Here we evaluate the effects of
 hunting pressure on wildlife by comparing how two communities of mammals
 under different management schemes differ in their relative abundance and
 response to humans. Using camera traps to survey wildlife across
 disturbance levels (yards, farms, forests) in similar landscapes in
 southern Germany and the southeastern USA, we tested the prediction of the
 risk allocation hypothesis: that the higher intensity and longevity of
 hunting in Germany (year-round vs 3 months, 4x higher harvest/km2) would
 reduce relative abundance of hunted species and result in a more
 significant fear-based response to humans (i.e., more spatial and temporal
 avoidance). We further evaluated how changes in animal abundance and
 behavior would result in potential changes to ecological impacts (i.e.,
 herbivory and predation). We found that hunted species were relatively
 less abundant in Germany and less associated with humans on the landscape
 (i.e., yards and urban areas), but did not avoid humans temporally in
 hunted areas while hunted species in the USA showed the opposite pattern.
 These results are consistent with the risk allocation hypothesis where we
 would expect more spatial avoidance in response to threats of longer
 duration (i.e., year-round hunting in Germany vs. 3-month duration in USA)
 and less spatial avoidance but more temporal avoidance for threats of
 shorter duration. The expected ecological impacts of mammals in all three
 habitats were quite different between countries, most strikingly due to
 the decreases in the relative abundance of hunted species in Germany,
 particularly deer, with no proportional increase in unhunted species,
 resulting in American yards facing the potential for 25x more herbivory
 than German yards. Our results suggest that the duration and intensity of
 managed hunting can have strong and predictable effects on animal
 abundance and behavior, with corresponding changes in the ecological
 impacts of wildlife. This shows that hunting can be an effective tool for
 reducing wildlife conflict due to overabundance but may require more
 intensive harvest than is seen in much of North America.
description: <strong>Study sites</strong>: In Germany, we sampled
 sites around the city of Konstanz (pop 84,911), BW. Our study covered an
 approximate area of 60,000km<sup>2</sup> surrounding the city
 (Fig. 1) where the landscape was 25.9% forested, 16.8% urban, and 30.7%
 agricultural land cover with an average population density of 259
 people/km<sup>2</sup>. In the United States, we focused on a
 similar sized area (50,000km<sup>2</sup>) from Raleigh, NC
 (pop 464,485) to the east (Fig. 1), which was 41.4% forested, 9.1% urban
 and 29% agricultural landcover with an average population density of 103
 people/km<sup>2</sup>. The climates of the two sites were
 similar (BW=coastal, NC= humid subtropical; Kottek <em>et
 al</em>. 2006) with similar mean annual precipitation (1195mm BW,
 1218mm NC; Fick & Hijmans 2017) but with higher mean annual
 temperatures in NC (7.5C BW, 15.6C NC; Fick & Hijmans 2017). Both
 areas had similar levels of gross primary productivity (13083 kg C/square
 meter BW, 13418 NC in 2015; Hobi <em>et al</em>. 2017) with
 rolling hills (BW mean elevation = 136m, NC = 146m) of mixed deciduous and
 coniferous forests fragmented by similar levels of agriculture and urban
 development. Thus, our two study landscapes were broadly similar with the
 biggest differences being: 1) the amount of forest cover was higher in NC
 (41% vs 26%), 2) human population density was higher in BW (259 vs.
 102/km<sup>2</sup>), 3) average temperature was higher in NC
 (15.6 vs 7.5C) and 4) the German landscape featured small, densely settled
 villages while the American landscape had one larger city with more
 dispersed housing across rural areas. As much as possible, our statistical
 analysis controlled for these differences to strengthen inference related
 to the different hunting systems. Our study focused on
 the big game species which are both largest and most heavily managed
 (i.e., bag and season limits) and/or heavily hunted in each region,
 hereafter referred to as “hunted” species (Table 1). In BW these are roe
 deer and wild boar (<em>Sus scrofa</em>; hereafter “boar”),
 both having long hunting seasons with no bag limits (Table 1). In NC there
 are white-tailed deer, American black bear (<em>Ursus
 americanus</em>; hereafter “bear”), and wild turkey
 (<em>Meleagris gallopavo</em>; hereafter “turkey”), all of
 which have short hunting seasons (1-3 months) and strict bag limits (Table
 1). Though different in size (roe deer are smaller), roe deer and
 white-tailed deer are ecologically similar with similar diets (Vangilder
 <em>et al</em>. 1982; Tixier & Duncan 1996), habitat
 preferences (Williamson & Hirth 1985; Tufto <em>et
 al</em>. 1996) and ability to live close to humans (Etter
 <em>et al</em>. 2002; Wevers <em>et al</em>.
 2020). However, deer competitors are absent from NC but present in BW
 (European fallow deer (<em>Dama dama</em>) and sika deer
 (<em>Cervus nippon</em>)), though far less common and unlikely
 to broadly compete with roe deer (Burbaiteė & Csányi 2009).
 Additionally, large carnivores capable of preying upon deer, especially
 fawns, are absent from BW but present in NC (coyote (<em>Canis
 latrans</em>), bobcat (<em>Lynx rufus</em>), and bear;
 Boone 2019). <strong>Field data
 collection</strong>: We used a consistent camera trapping protocol
 between sites (BW and NC) to facilitate comparisons. For each site,
 trained citizen science volunteers (see Parsons <em>et
 al</em>. 2018 for details) or staff deployed unbaited camera traps
 across each study region (Fig. 1). Sample size was 233 camera deployment
 sites in BW and 242 in NC, with camera placement stratified between hunted
 and unhunted areas as well as residential yards, forest fragments and
 agricultural fields (&gt; 0.02km<sup>2</sup>; Appendix 1).
 Information on whether a site allowed hunting came directly from the
 property owner. In Germany, all hunted areas were forests with no samples
 from hunted yards or open areas, while in NC some forests, fields, and
 rural yards were hunted (Appendix 1). We used Reconyx (RC55, PC800, and
 PC900, Reconyx, Inc. Holmen, WI, USA) and Bushnell (Trophy Cam HD,
 Bushnell Outdoor Products, Overland Park, KS, USA) camera traps attached
 to trees at approximately 40cm above the ground. Trigger sensitivity was
 set to high for all cameras and we verified that both camera brands had
 similar trigger speeds (&lt;0.5s). Cameras were left undisturbed for
 3-4 weeks and then moved to a new location (at least 200m apart), with
 sampling taking place over several overlapping seasons and years
 (2018-2020 Germany, 2013-2019 NC). Cameras recorded multiple photographs
 per trigger, re-triggering immediately if the animal was still in view. We
 grouped consecutive photos into one sequence if they were &lt;60
 seconds apart (Parsons <em>et al</em>. 2016), and used these
 sequences as independent records, counting detections by sequence, not
 individual photos. Initial species identifications were made by volunteers
 or staff using customized software (eMammal.org) and all were subsequently
 reviewed for accuracy before being archived at the Smithsonian Digital
 Repository. Detection rates for each species at each camera site were
 calculated as the count/days camera ran, considering groups as a single
 detection.