Human Interactions Leading to Changes in Deer’s Behavioural Patterns

The Office of Public Works (OPW) launched the ‘Protect Our Park – Don’t Feed the Deer’ campaign today, aimed at changing public behaviour to protect the wild deer in the Phoenix Park. This initiative comes in response to a recent report from University College Dublin (UCD), which highlights the detrimental impact of human feeding on the behaviour and well-being of the park’s iconic deer population.

The UCD report, conducted in collaboration with the OPW, reveals the impact on the deer of human feeding by tourists and members of the public. The result is a significant alteration in the natural behaviour patterns of the deer.

Feeding disrupts the deer’s natural foraging instincts, leading to dependency on human-provided food sources. This causes the deer to seek out human interaction, which can lead to aggressive encounters in their aim to find food. This dependence not only affects their health but also alters their social dynamics and habitat utilisation within the park.

Some of the key findings in the UCD report showed:

  • Deer have been fed foods such as chocolate, crisps, fizzy drinks, bread and carrots.
  • 25% of the park’s deer population now regularly approach people for food.
  • Mothers accepting food from visitors tend to give birth to heavier fawns, continuing the cycle of dependency. Fawns of begging mothers are more likely to become begging individuals.
  • Deer accepting artificial food items from visitors results in changes to their digestive system, with long-term effects on their ability to digest natural food.
  • Male deer – who have been shown to receive much lower quality food items from the public (e.g. crisps, chocolate, biscuits etc) than females (carrots and salads) – tend to have smaller antlers and be less successful during the mating season.
  • Male-female encounters are often disrupted by park visitors, which impacts the quality of males accessing females for reproduction. This leads to interference in sexual selection and female productivity.
  • Deer in the Phoenix Park have tested positive for Covid-19, indicating that at some point humans passed this disease to them.
  • Deer, when disturbed, form very tight groups and have increased stress levels.

The ‘Protect Our Park – Don’t Feed the Deer’ campaign wants visitors to the Park to understand how this behaviour impacts our wild deer.  As part of this initiative, the OPW will install educational signage throughout Phoenix Park, emphasising the importance of preserving the deer’s natural behaviours and the potential hazards associated with feeding.

Failure to change visitor habits and awareness about feeding the Park’s iconic deer could have long-term ramifications including; increasing the risk of transmitting disease, increasing the risk of human injuries as deer seek out food from humans, and increasing stress to the deer with more unwanted human interactions.

Many of us live in large urban settings today, with little or no access to large, live, wild mammals. It is understandable that in our enthusiasm to get close to these beautiful animals, we try to entice them to us with food. Sadly this conduct is posing significant threats to the animals and with time, to humans. It is not just about the different types of food which are fed to the deer, it is about the increasing interaction with humans that the research demonstrates poses significant risks.

The park’s fallow deer primarily subsist on a diet comprising 90% grass, supplemented occasionally by other vegetation.

Visitors should keep a distance of at least 50 metres from the deer and not engage in behaviour that poses risks to the deer or the visitor. This includes feeding and posing for selfies.

For further information on the ‘Protect Our Park – Don’t Feed the Deer’ campaign and ways to support conservation efforts in Phoenix Park, please visit Phoenix Park

Kieran O’Donnell TD, Minister of State for the Office of Public Works, added:

“By keeping our distance from the deer and refraining from feeding them, visitors can play a pivotal role in safeguarding the future of these magnificent creatures, who have called the Phoenix Park home for over 350 years. Feeding disrupts the delicate ecological balance and could ultimately jeopardise the deer population’s existence in the park. Dubliners take immense pride in the Phoenix Park and it is a wonderful place to visit for locals and tourists. I am asking all visitors to support this campaign and keep these iconic deer safe in their natural home.”


Paul McDonnell, Phoenix Park Superintendent, remarked:

“The Phoenix Park is renowned for its rich biodiversity, with the majestic deer serving as a treasured emblem of our natural heritage. While the allure of these wild creatures is undeniable, it’s imperative to recognise that they are precisely that – wild. Feeding them, far from being good for them, inflicts significant stress and harm. Human-deer interactions pose a substantial safety risk, not only to the animals but potentially to ourselves as well.

“The practice of feeding wild deer is perilous to their welfare and must cease immediately. We implore visitors, both locals and tourists alike, to refrain from feeding the deer and to observe their natural behaviours from a respectful distance of at least 50 metres.

“I would also like to extend my gratitude to University College Dublin for its invaluable research contributions.”


For more information or to arrange an interview opportunity with an OPW spokesperson, please contact

Photographs will be available after the launch, please contact or Gareth Chaney at


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