The trend of people feeding wild animals such as deer has been linked to the artificial selection of "harassment behaviour" in some species, putting the safety of both humans and wildlife at risk, a new study has found.
Researchers from University College Dublin said feeding wild animals could lead to some species consistently harassing people, following their study based on the fallow deer population in the Phoenix Park.
As the largest walled park in any European capital, Phoenix Park is host to roughly 10 million visitors every year who are able to feed the deer population which live there.
Researchers who monitored the deer found fawns from mothers who consistently begged the public for food were significantly heavier than those whose mothers rarely approached visitors.
The 134 fawns measured were from the same herds, across the same grazing areas, and all came from mothers who had equal opportunity to interact with people, meaning begging behaviour is the defining difference that could be causing the detected disparity in birthweight.
The research, which has been published in the, says this begging behaviour can be associated with animals who have bolder personality types.
Lead author and UCD researcher Laura Griffin said the rise in this begging trait could see some animals become more aggressive when trying to obtain food, putting the safety of both themselves and people at risk.
“There is a high risk of this herd becoming highly habituated over time due to the artificial selection that we have highlighted here,” she explained.
“In other words, in 10 years, if actions are not taken, you could end up with deer that consistently harass people, as the boldest individuals have been selected for, which clearly holds enormous risks for the people and animals involved.
“It also stands to reason that if this is occurring in this population, then it is very likely also the case across other populations and species as well,” Ms Clancy added.
The study found the Phoenix Park deer fall into three categories: consistent beggars, occasional beggars, and rare beggars, with 24% of the population consistently approaching people for food.
Those deer received all kinds of prohibited treats from visitors, including bread, crisps, carrots, apples, and biscuits, causing them to have a drastically different diet.
Park visitors are not supposed to feed the deer at all, yet the pandemic saw a rise in the number of people taking trips to the park and interacting with the deer.
In other parts of the world, there are examples of animals refusing to leave markets and other busy areas until they get food, such as Rhesus monkeys in India.
Closer to home, Sammy the seal in Wicklow town was often seen crossing the road from the harbour to the chip shop in search of a bit of fish.