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Deer Culls

Dáil Éireann Debate, Thursday - 21 February 2019

Thursday, 21 February 2019

Questions (81)

Clare Daly

Question:

81. Deputy Clare Daly asked the Minister for Public Expenditure and Reform the alternatives to deer culling at the Phoenix Park, Dublin, that have been considered by his Department to control the population of deer and to avoid the slaughter of same. [8630/19]

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Written answers

In general terms, I wish firstly to advise the Deputy of the general context of the management of the Fallow deer herd in the Phoenix Park. The Office of Public Works has long experience managing the herd gained over many years. This is supported by scientific advice from the School of Biology & Environmental Science at University College Dublin and the Department of Agriculture, Food and Marine (Deer Management in Ireland a Framework for Action – 2015). OPW also liaises with the Royal Parks London, whose deer management practices are endorsed by The British Deer Society and the Deer Initiative of England. OPW is also a member of the Irish Deer Society and it might interest the Deputy to know that it received the John Nicholson Perpetual Trophy in 2016. This trophy is the Society’s highest honour, awarded for meritorious service in the welfare, conservation, management and protection of deer in Ireland.

Deer culling is of course an activity that OPW would prefer not to have to carry out. However, the cull, as undertaken, is considered to be the most appropriate and humane way to sustainably manage the population of deer in the Park. While there are a number of potential strategies for population control, as outlined below, there are specific reasons why each such strategy is unfeasible.

1. 1. Live Capture

A live capture was carried out in 1991 with over 100 persons involved from Ireland and the UK. However, with current health & safety requirements, skills shortage and the size of the current herd, it is not practicable or safe to undertake this exercise today. Professional advice from the School of Biology & Environmental Science at University College Dublin suggests that this practice has the following consequences:

(i) live capture takes hours to be completed. Stress levels (i.e. corticosteroids) can reach abnormal levels in the animals leading to immune-depression and abortion in females

(ii) live capture requires the gathering of many deer in limited spaces (e.g. temporary corrals) and this can lead to severe or sometimes lethal injuries (especially among fawns and younger deer injured by bucks)

(iii) these risks are accentuated during the transport of deer to a different location. Deer are wild animals and, unlike livestock, they become particularly stressed when transported on trucks.

1. 2. Tranquillising deer for administration of contraceptives and/or removal

Use of drugs to tranquillise deer is usually limited to a small number of individual deer selected for research purposes (e.g., body condition check, parasite screening, and deployment of radio tracking devices for individual monitoring). Darting of deer for capture to administer contraceptives would be an extremely dangerous procedure to undertake in a public park. Darts are often lost during such operations resulting in a dangerous hazard to the public and other wildlife. The quantities of tranquiliser required to sedate a deer could be fatal for humans which is obviously of particular concern in a park frequented by large volumes of visitors. In order to carry out a safe procedure, darting should be carried out from short distances (less than 25 meters), which means that only a small number of animals could be darted over several days of work in the field. The exercise would be costly, time-consuming and ineffective. Ultimately, this would be an extremely dangerous procedure for the deer (if carried out from long-distances with the intention of capturing more animals) and for the public.

1. 3. Transportation to other locations

The Phoenix Park deer are part of a wild herd and transportation would be very stressful for such wild animals. They would be also prone to injury during transport, as already highlighted above. Furthermore, it is illegal to release deer into the wild. Most importantly, the deer would suffer significant stress through live capture and transport before being released into a completely new environment, which could soon be over-populated with deer after just a few release events leading ultimately to the same over-population problem and requiring a deer management plan and population control plan for the new location.

1. 4. Contraception

There are no contraceptives licensed for use on wild deer in Ireland.

Although not licensed yet, there are different contraception strategies available for deer, but in most cases, they refer to heavily managed herds (not wild herds), ie. animals kept within enclosures like livestock. The most common strategy would be steroids, which are given to each female on a yearly basis (from Sept to Jan). These steroids can regulate the ovarian cycle so as to produce anoestrus female deer. The main challenge in administering these steroids is that each female must get the correct dose. The only way to do this is to get close enough to each female deer to make sure that it receives the correct dose. This is entirely impractical in a large, wild herd as this form of artificial feeding would disrupt normal herd behaviour and, based on a study by UCD, a success rate of only 10-15% is achievable. Most importantly, females who are not individually identifiable in a wild herd (e.g. without colour-coded ear-tags) could not be administered with steroids as, potentially, individual deer could receive multiple doses over time resulting in an overdose of the medication.

The alternative is to administer steroids via supplementary feeding (e.g. pills mixed with attractive food). This is considered to be high risk due to potential overdosing among females and the ingestion of the food by male deer which would have a detrimental effect on them. As far as injecting contraception, this would require the capture and immobilisation of each female for injection which is clearly not feasible. Most contraceptive strategies would require multiple captures per year of each female with clear negative consequences for the animals. It would also be virtually impossible to capture all the females of the deer population. Wild deer simply cannot be rounded up in any realistic way without causing severe stress and injury to both animals and operatives involved.

Perhaps most importantly, steroidal contraceptives are a significant risk in respect of pollution to both the environment and the food chain (e.g. crows and foxes eat deer that have perished from natural causes). Oral contraceptives, similar to those used by humans, cannot be given to wild animals because other animals would potentially pick on leftovers of deer feed and would be adversely affected. Droppings and urine from the deer would also contaminate the habitat. Hormonal contraceptives would interfere with antler growth and shedding. It would be impossible to feed such contraceptives to females only and to prevent male deer consuming them.

Sterilization of males has been deemed inefficient, as just one fertile male remaining in the herd is sufficient to sire a very large number of deer. When considering the use of contraceptives among the female deer population, there are other negative aspects to consider in respect of the welfare of the male deer. The adoption of female contraception strategies, assuming that these were possible, would have the effect that most of the females would not be in oestrus during the rutting season. This would have a significant effect on male stress and behaviour. The males would inevitably fight for the limited number of oestrus females available (as indicated above it would be impossible to give the proper contraception dose to all females, so some of them will be in oestrus during the rut). Male stress levels would be higher due to increased male competition for access to the fewer oestrus females. Many males would likely roam the Park in the continuous search of oestrus females, increasing the likelihood of being involved in traffic accidents and, as recorded in other study sites, they may attempt to leave the Park to look for females in the wider urban setting.

The wild deer herd is an integral part of the biodiversity of the Phoenix Park and has been such for over 350 years. Adopting measures that would significantly reduce numbers instead of maintaining them at sustainable levels would have a major impact on the biodiversity of the Park and result in significant change to other wildlife habitats.

I can assure the Deputy that OPW will continue to monitor options available to it in managing the wild herd and will continue to engage with the School of Biology & Environmental Science in University College Dublin, the Department of Agriculture, Food and the Marine, the National Parks and Wildlife Service and the Irish Deer Society in this regard.

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