Red Kites in Yorkshire – Growth despite poisoning

Red kite numbers are growing in Yorkshire.

Courtesy of Yorkshire Red Kites - www.yorkshireredkites.net

December 2010. It is now eleven years since the process of reintroducing Red Kites into Yorkshire began. They are being seen on an increasingly regular and widespread basis - a sure sign that the programme has been successful. The presence of the birds in our countryside has met with widespread acclaim, bringing a great deal of pleasure to a lot of people. Some have said that their presence adds another dimension to their outdoor enjoyment, whilst others have remarked that seeing a Red Kite on their way to work lifts their spirits for the day! An added bonus has been the awakening of many people to nature conservation issues of which they were previously unaware. Detailed information about the birds and the Project can be found on the Red Kite in Yorkshire website, where there is also a facility for reporting sightings.

11 Red kite reintroduction projects in the UK & Ireland
Red Kites became extinct in England and Scotland around 150 to 200 years ago. The Yorkshire Red Kite Project is one of eleven seeking to see them re-established in suitable habitat in England, Scotland, Northern Ireland and the Irish Republic and linking up with the Welsh population, which has made an incredible recovery after narrowly avoiding extinction.

The Yorkshire Project, the fifth in this sequence, began in 1999. Sixty-nine young birds, all sourced from the very successful initial English release area in The Chilterns, were released in Yorkshire between 1999 and 2003. This figure was boosted by an untagged bird of unknown origin which arrived in late 1999, settling in with the released birds and making a significant contribution to the establishment of a Yorkshire breeding population. Up to and including the 2010 breeding season, around 700 young Red Kites have been raised in Yorkshire nests. The Yorkshire Project is the only one of the release projects, to date, to have had successful breeding in its first year.

Breeding in 2010
Monitoring of breeding pairs in 2010 got off to a difficult start. No fewer than 25 pairs (37%) which had bred in 2009 were not found at the nests which they had previously used. Eleven pairs were found to have built new nests not far away; four pairs had moved up to two miles; five territories had single birds on them and five other pairs were simply not found. It is suspected that the hard winter weather may have accounted for some of those missing. This being the case, perhaps some consolation can be drawn from the probability that it was the less robust birds which succumbed.

The spread of breeding birds continued, particularly into North Yorkshire. Seventeen new pairs were located overall, though it is likely that a number of pairs went unfound - the true breeding figures for 2010 no doubt being higher than those actually recorded. Golf courses attracted a further two breeding pairs, bringing the total using such locations to three. A particularly encouraging feature was the increased number of young raised per successful pair. Details of the pairs found are as follows:

Southern Yorkshire
The satellite breeding population in the southern section of the Yorkshire Wolds maintained its 2009 level of confirmed pairs, with a significant increase in the number of young raised. These figures are likely to be an under-estimate, as access issues significantly restricted monitoring in one key area. The East Yorkshire population was created by birds unexpectedly moving to the area from the initial Harewood releases. It has been subsequently boosted by the young that those birds have raised, as well as more arrivals from both Harewood and other release areas (Midlands and the North-East).

Sightings
Sightings of Red Kites reported by members of the public provide much useful information about the geographical spread and progress of the population. There are hundreds of potentially suitable areas of woodland in Yorkshire in which kites might settle to breed. It is not possible to check them all for occupation and we are very much dependent on receiving reports of the presence of kites from people living or working in their vicinity. Records of birds, whether singles or pairs, seem to be regularly frequenting a particular area are very welcome. It is by this means that we are able to discover new breeding pairs and monitor the progress of the expanding population. They can be reported to either the contacts named below or through the website www.yorkshireredkites.net

It has sometimes been found that people who know about the regular presence of kites in a particular locality do not report them to us because they expect that we'll already know about them - when maybe we don't. We'd rather be informed twice than not at all!

Yorkshire kite ID
Up to and including 2006, Red Kites in Yorkshire were fitted with wing tags. An orange tag on the left wing indicated that the bird had been tagged in Yorkshire. Kites are no longer being tagged here and, because of the shortage of available alternative colours, orange has now become the area indicator tag colour for Cumbria, where releases began in August 2010. Visiting kites from North Scotland and Wales, recognisable by their wing-tags, have been seen in East and West Yorkshire in 2010.

Casualties & poisoning
Known incidents involving 17 birds in Yorkshire and 1 in Cumbria in 2010 were as follows:

Cumbria:

- September. A dead kite was recovered by Yorkshire Red Kites. It was close to the border with Yorkshire and was one of 30 which had been released in Cumbria in the first stage of a new project based in the Lake District. It had been shot just three weeks after being released. Cumbria Police are pursuing enquiries.

Primary and Secondary poisoning.  When it is suspected that a kite has been poisoned, samples are sent to the FERA laboratory at Sand Hutton, near York. Testing identifies what poison substances are present and at what level. Expert interpretation of these findings  determines the cause of death. This usually falls into one of two categories.

Rat poisons

The widespread intensive use of anti-coagulant rodenticides probably represents the greatest single threat to kites and other scavenging species in the UK. First-generation substances such as warfarin and coumatetralyl would probably be effective in controlling fresh outbreaks in new areas. However, it appears that their availability is limited and rat populations in some areas are known to have developed a resistance to them. Newer, stronger poisons, based on difenacoum, brodifacoum and bromadiolone, are in widespread use. They have a longer residual effect than the first-generation types and have been known to cause spontaneous haemorrhaging in kites which have fed on carcases of rats killed by them.

Six Yorkshire Red Kites are known to have suffered rodenticide-related deaths. Additionally, findings based on routine testing for rodenticide of birds which had died from other causes, show that these substances are widely finding their way into the food chain.  All six of the poisoned North Yorkshire kites recorded above tested positive for difenacoum and bromadiolone. Additionally, two of them also had traces of brodifacoum. This is of particular concern, as products based on this substance are licensed for use only in indoor situations. Its presence in these kites suggests either that rats feeding on the poison indoors were able to escape outside or that it was being illegally used in outdoor situations. It is imperative that manufacturers' instructions are followed. Rats poisoned by rodenticides should be regularly collected up and safely disposed of to prevent them entering the food chains of kites and other scavenging species.

Rehabilitation Pen

The rehabilitation pen, constructed in 2009 through funding provided by Yorkshire Water and Yorkshire Wildlife, was put to good use in 2010. Three birds have been housed in it, following injury. It is an extremely useful facility that has removed the problem of what to do with a bird which has received treatment, but requires observation and assessment to determine if and when it is suitable for release again.

European significance of UK Red Kite population

In recent years there have been dramatic reductions in the Red Kite population in some parts of France, Germany and Spain. The causes include modernisation of farming methods, rodenticides, uncontrolled use of pesticides and illegal persecution. This unfortunate turn of events shows the increasing importance of the growing UK population.

Funding

The continued support of Yorkshire Wildliife Trust has facilitated the monitoring of Red Kites in Yorkshire during 2010. We are grateful that, in funding these activities, they have enabled us to continue to determine the breeding and geographical progress of the growing population.

Acknowledgements

The co-operation and assistance received from the many landowners and their representatives, gamekeepers, farmers, veterinary practices and members of the public who have assisted us during 2010 is very much appreciated.

Our thanks to Doug Simpson MBE

Report crime

If you suspect that a bird has been poisoned or shot, or that its nest has been illegally interfered with, please contact the Police (North Yorkshire - 0845 60 60 247, West Yorkshire - 0845 60 60 606, Humberside - 0845 60 60 222, South Yorkshire - 0114 220 2020).  You should ask for the information to be reported immediately to a Wildlife Crime Officer. Further advice can be obtained from the RSPB Investigations team on 01767 693399 (office hours) or 07841 804 672.

Suspected poisoning incidents (eg multiple deaths; obvious bait and victim(s) etc.) should be reported to the Wildlife Incident Investigation Scheme (WIIS) on 0800 321600 in addition to the Police. Sick or injured birds may be reported to the RSPCA on 0300 1234999.