Establishing baseline values of parameters potentially indicative of chronic stress in red deer (Cervus elaphus) from different habitats in western Germany

Abstract

The use of habitats by wild animals is commonly assumed to be decreasing due to human activities, such as tourism or the installation and use of wind-energy plants. These anthropogenic interferences may subject animals to chronic stress. To be able to objectively characterise the effects on animal populations or on individual animals, the collection of data that might be suitable to monitor such chronic stress is required. In this study of hunted red deer, we report data that are related to adrenal activity and are not affected by the acute stress induced by hunting. Adrenal glands and samples from ileal digesta were collected from 75 hunted deer from seven different habitats in the German Rhineland. The adrenal glands were evaluated histomorphometrically; in the digesta, the concentration of cortisol metabolites, i.e. of 11,17-dioxoandrostanes (11,17-DOA), was measured. Digesta were also examined for parasites. Animals were grouped according to age, sex, habitat, and hunting method. Animals were infected with gastrointestinal helminths and lungworms; examination for liver flukes was negative. Significant differences were not established among the different groups for any of the recorded parameters. For sex, a tendency (P=0.11) towards higher DOA levels was observed in female deer when compared to male deer. The variability of the parameters together with the lack of identifiable influences of hunting indicates that chronic stress might indeed have been a relevant factor. However, none of the parameters analysed can presently be validly used to evaluate habitat quality for red deer since physiological stressors cannot be differentiated.

Disease risks and overabundance of game species

“…Hence, there is a need to define reference values for each of these signs of overabundance (e.g. Eve and Kellogg 1977;Fierro et al 2002;Sauerwein et al 2004;Vicente et al 2005Vicente et al , 2006. A useful alternative in regions or species with little references in the literature is to monitor the changes of the defined signs in time.…”

Habitat selection by ungulates in relation to predation risk by wolves and humans in the Białowieża Forest, Poland

“…Ripple and Beschta, 2003;Wolff and Van Horn, 2003;Frair et al, 2005;Herná ndez and Laundré , 2005;Mao et al, 2005;Winnie et al, 2006). European studies, on the other hand, dealt mostly with human influence as study areas usually lack large carnivores (Jeppesen, 1987;Dö ring, 1990;Herbold, 1990;Petrak, 1996;Hewison et al, 2001;Ciuti et al, 2004;Sauerwein et al, 2004).…”

“…Hunting causes changes in the reproductive strategy of deer (Proaktor et al, 2007) and human presence can lead to chronic stress in deer (Sauerwein et al, 2004), which do not differentiate between hunters and other people. Human predation can therefore affect the density of ungulates, not only by direct removal of individuals and avoidance behaviour but also through reduced fitness.…”

Characterising a unique recreational hunting method: hound hunting of sambar deer (Cervus unicolor) in Victoria, Australia

“…In this context, sambar deer have evolved with a suite of large mammalian predators, such as, for example, tigers (Panthera tigris) in southern Asia (Hayward et al 2012) and are likely to be harrassed or attacked occasionally by dingoes/wild dogs in contemporary southeastern Australia (Forsyth et al 2019). Although the stress experienced prior to death is likely to be significant for sambar deer hunted with hounds, the impact of hunting on chronic stress of surviving deer is unknown (Sauerwein et al 2004). Bradshaw and Bateson (2000) questioned what proportion of red deer that are hunted but escape die from severe physiological injuries (i.e.…”

“…2019). Although the stress experienced prior to death is likely to be significant for sambar deer hunted with hounds, the impact of hunting on chronic stress of surviving deer is unknown (Sauerwein et al . 2004).…”