| Popis: |
Human encroachment into wildlife habitats is increasingly having an impact on shaping wildlife populations. The increased contact rates between humans and wildlife, also boosted by the rise of social media, has led to an increase in wildlife-human conflicts, including a rise in numbers of people intentionally feeding wild animals within human-dominated landscapes. These feeding practices, whenever they do not occur in a random fashion but rather target specific individuals, put wildlife populations at risk of artificial selection, although very little is known about the effects of these interactions on wildlife. Here, for the first time, we examine the implications that these interactions may have on the body condition in a charismatic population of fallow deer living on the edge of a metropolis, which experiences 10 million tourists a year. We combined unique behavioural observations of males interacting with and accepting food from humans with antler size data - a proxy for body condition - collected using non-invasive photogrammetry. We tested the hypothesis that males receiving supplementary food from humans are likely to gain an advantage over males avoiding human interactions when it comes to growing larger sexual secondary traits. We found that these feeding interactions are far more complex than predicted a priori. In areas of the park mainly used by female deer there is reduced male-male competition and it is mostly accessed by resident visitors who tend to provide food of higher quality (e.g. carrots, apples). The males interacting with and accepting food from humans in these areas were shown to gain an advantage in terms of enhanced antler size when compared to males living in the same areas and avoiding these interactions. The opposite trend was found in the male dominated area with significant male-male competition for food of lower quality (e.g. chocolate, crisps) provided mostly by international visitors. For the first time, this study shows the complex dynamics associated with artificial feeding and its potential effects on male antler size, a secondary sexual ornament for deer, which is linked to mating success. This study highlights the risk of artificial selection processes (only a subset of males receiving a benefit) and gathers empirical evidence which suggests avoiding any intentional feeding of wildlife as it can lead to effects never predicted before. |
