Farm Ireland

Wednesday 24 January 2018

'Poisons pose serious threat to our wildlife'

The indiscriminate laying of poisons is killing the birds and small animals that act as a natural check on vermin

Local populations of Long-eared Owls have been threatened by increased rodenticide use
Local populations of Long-eared Owls have been threatened by increased rodenticide use
Éanna Ní Lamhna
The stoat, which is protected in Ireland, has been a victim of secondary poisoning in recent years

Siobhán English

Let the wildlife themselves take care of the vermin, instead of the poisoned vermin killing our wildlife.

That's the advice from wildlife expert Éanna Ní Lamhna. She says that the ongoing use of poisons is destroying the natural eco-system in Ireland which, if left alone, could itself go a long way in controlling the vermin that causes millions of euro worth of damage each year.

"We cannot tell people what to do and of course they must take action to control mice and rats. But they must also realise that while these poisons are killing the vermin, with improper use they are also inadvertently killing birds such as kestrels and owls and mammals such as stoats and pine martins, which are these vermin's natural predators," she says.

"Not many people would know that one pair of Barn Owls alone can kill up to 500 rats in a year. But the numbers of these owls in Ireland are still dropping primarily due to secondary poisoning from mice and rats."

It is believed that there are just 150 nest sites for Barn Owls remaining in Ireland.

From the time a mouse or rat first eats poison, several days pass before it dies.

Meanwhile, it returns to the bait repeatedly, ultimately ingesting many times the lethal dose. The rodent grows lethargic, unable to dart to cover, and becomes an easy target for its natural predators. While these predators then enjoy the easy catch, they die a slow, painful death from secondary poisoning.

As communications officer for the Campaign for Responsible Rodenticide Use (CRRU), Éanna is hoping that a series of courses aimed at pest control technicians will, in turn, help educate people further on the proper use of certain rodenticides that have decimated some of the rare bird of prey population in Ireland in recent years.

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"Currently we have 103 qualified Wildlife Aware Pest Management Technicians accredited with the Irish Agricultural Supply Industry Standards (IASIS).But it would be great to see more coming on board by attending the courses that take place regularly throughout the year," she says.

"It is so important that people are aware of the affect they are having on Irish wildlife by not following protocol when using these poisons."

New rules due to come into force in Britain from June 1 2016 will require people to hold a certificate of competence in rodent pest control if they wish to buy professional-standard rodenticides.

However, farmers who are members of a farm assurance scheme will be deemed 'qualified' to use rat poison, without undergoing any further training.

Last year CRRU's chairman Mark Lynch warned that Ireland could also be faced with similar regulations if Irish wildlife isn't safeguarded.

As one of Ireland's most recognised names in wildlife conservation, Eanna believes that it's not just a small number of farmers who have caused the accidental poisoning of these rare birds, but also owners of large industrial properties that lay poison on a much bigger scale.

"In the end it is all down to education and I would hope that people would also make themselves familiar with the CRRU seven-point Code of Practice which is a valuable tool (see panel)."

GLAS, the new Agri-Environment Scheme, also specifies that participants should comply with the CRRU Code in their daily farming activities, particularly those eligible for grants.

Since its inception in 2013 CRRU has worked tirelessly with the authorities to raise awareness on the hazards of rodenticides. One of its main concerns is the length of time these rodenticides are left down on the ground.

"We are advising people not to leave poisons down for any longer than 35 days. There is no benefit in leaving it down any longer than that, as it really should have taken effect by then," Eanna said.

The use of poison has been greatly restricted under EU law in recent years and some substances have been illegal in Ireland since 2010. This includes Alphachloralose which, up to 2010, was registered to kill crows.

Second-generation baits approved for use in Ireland contain Difenacoum, Bromadiolone, Brodifacoum or Flocoumafen.

While these rodenticides are legal to use, direct poisoning or use of poison meat baits is strictly prohibited.

The use of poison to control foxes and crows is a breach of the cross compliance measures for the Basic Payment.

In recent years the European population of White-tailed eagles has been evaluated as rare, with currently less than 10,000 pairs breeding in the region.

Experts believe that the species suffered this decline due to kills and use of pesticides.

However, projects to re-introduce the birds again, such as those which started in Ireland in 2007, marked an important phase in wildlife conservation.

However, since then project manager Dr Allan Mee and his team have faced an uphill struggle to ensure their survival, with a total of 31 reported deaths from the 100 released in Killarney National Park, Co Kerry in the past eight years.

A young female was found dead in Connemara last April, marking the 13th White-tailed eagle death due to poisoning.

The deaths of other birds of prey such as the Red Kite, Barn Owl, Long-eared Owl, Buzzard and Golden Eagle have also been recorded. In most of those cases the poison used was Alphachloralose.

Commenting on the alarming number of incidents, Catherine Keena, a Teagasc Countryside Management Specialist, said: "Recent studies, in Ireland, have shown that Barn Owls and Red Kites have evidence of rodenticides in their bodies, likely acquired through consumption of prey.

"The contamination of such species has been confirmed through post-mortem examination of carcases collected as part of ongoing statutory monitoring and is a matter of serious concern."

Bird of Prey poisoning and kills are monitored under the Recording and Addressing Persecution and Threats to Our Raptors (RAPTOR) protocol, which is managed by the National Parks and Wildlife Service (NPWS), the Regional Veterinary Labs of the Department of Agriculture, and the laboratory of the Department of Public Expenditure and Reform.

Last year saw the highest number of raptor persecution cases and the NPWS is currently pursuing a number of investigations.

How to use rodenticides safely and responsibly


A thorough survey of the infested site is essential when using any rodenticide.

Make environmental changes that will reduce the attraction of the site to rodents after the treatment. Usually this will involve rodent proofing and removing rubbish and weeds that provide harbourages and cover.

However, the site should not be cleared before treatment since this will disturb the rodent population and make bait acceptance more difficult to achieve.

Remove spilled grain, and cover food sources.

Rodenticide baits should only be used for as long as is necessary to achieve satisfactory control.

In most cases, any anti- coagulant bait should have achieved control within 35 days. Should activity continue beyond this time, the likely cause should be determined and documented.

If bait continues to be consumed without effect, a more potent anticoagulant should be considered.

If bait take is poor, relative to the apparent size of the infestation, look at re-siting the bait points and possibly changing to another bait base.

Record the quantity and location of bait used and where it is placed

Draw up a site plan or location list identifying areas of particular concern.

Maintain a record of all bait points and the amount of bait laid. Activity should be noted at each bait point, including any missing or disturbed baits.

By recording the sites of all bait points, responsible users of rodenticides are able to return to these sites at the end of the treatment and remove uneaten bait. baiting points

Users should follow the label instructions about the size and frequency of bait points and the advice on the frequency and number of visits to the site.

By using enough bait points the rodent control treatment will be conducted most efficiently and in the shortest possible time. This will reduce the exposure of non-target animals to a minimum.

Collection and disposal of rodent bodies

The bodies of dead rodents may carry residues of rodenticides and, if eaten by predators or scavengers, may be a source of wildlife exposure to rodenticides.

Carry out regular searches for rodent bodies, both during and after the treatment period. Bodies may be found for several days after rats have eaten the bait and rats may die up to 100 metres or more away from the baited site.

Dispose of rodent bodies by using the methods recommended on rodenticide labels. Never leave bait exposed to non- target animals and birds

Ensure that bait is sufficiently protected to avoid accidentally poisoning other mammals and birds. Natural materials should be used where possible.

Bait stations should be appropriate to the site. They should provide access to the bait by rodents, while reducing the risks of non- target access and interference by unauthorised person.

Stations should protect the bait from contamination by dust or rain.

Their design, construction and placement should be such that interference is minimised.

Inspect bait regularly

Where the risk assessment or treatment records show that multiple visits are required, these should be made as frequently as is considered necessary. Daily inspection may be required in some circumstances.

At each visit, baits should be replenished according to the product label and a thorough search made to ensure that bodies and any spilled bait are removed and disposed of safely. Maintain records of this process.

Never leave bait down at the end of the treatment

Bait left out at the end of a treatment is a potential threat to wildlife.

Update records to note that the infestation is controlled and that all practical steps have been taken to ensure that the site is free of rodenticide bait.

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