Feb 26, 2009

raptor report

This is a wee summary of last years raptor report. It is taken from the abridged report that is sent out to all members of the RSPB’s local group. So what we have here is the bare bones of that report that I have paired away to fit the format of the blog.

All this quality information is freely available on a regular basis to members of the local members group and is yet another excellent reason to join up with the Royal society. Give them a ring on 01856 850176 or drop by the office on North end road opposite the cop shop and you will be most welcome…..you ken it makes sense!!

Orkney is in the enviable position of having fairly good numbers of raptors occurring to hunt across all of the habitats available. There are no shooting estates on the islands and consequently there is less pressure in the form of illegal persecution. Local farmers have taken advantage of the Hen harrier scheme that pays them to let rough grazing grow rank and their grazing efforts be steered towards creating a suitable habitat for Voles. The Orkney Vole is a major part of the diet for Hen Harriers here in Orkney. Most of the other raptors also benefit from this bounty and these fields will be well patrolled by quartering Short Eared Owls and Kestrels. Peregrines And Merlin’s along with Sparrow Hawks that will also hunt this ground looking for wee birds like Linnet and Twite that are naturally attracted to such ground to feed.
A wet start to the breeding season followed by a very dry spell may not have helped things along and the lack of cliff breeding birds may also have been a factor for some of the Peregrine failures this year, but I am only speculating here…


A single bird showed interest in an east mainland site in the spring but there was no breeding attempt. There was no sign of breeding at the other two sites where nesting has taken place in recent years.


Across Orkney as a whole there were 62 occupied sites at which 51 were found. 39 of these failed, three pre-laying,15 during incubation and 5 at the chick stage while the stage was unknown of the other 16. The remaining 23 nests successfully reared 64 chicks to at or near fledging. Of the 64 chicks(at or near fledging) whose sex was known, 31 were males and 33 were females.


2008 was a good year for Orkneys breeding Sparrowhawks. 12 sites were known to be occupied, 3 of which had not been recorded before. Nests were found at 10 of these sites and eight of them successfully reared young. The two unsuccessful nests both failed during incubation.
The occupancy rate was far higher than usual this year. Generally we have about 3 or 4 sites that are successful in any one year.


For the first time in many years there was no proved breeding on Hoy. Birds were seen at known breeding sites but no nests were found and no evidence of any young being reared. On the mainland site first used in 05 a bird was heard calling and acting as though on territory on may16th but no signs were found thereafter.


As usual data for this species was far from complete. There were seven defiantly occupied sites, all in the west mainland and nests were found at 5 of these. Of these one was a moor land ground nest, one was in a working quarry. One was on an old building, one was on a small in land crag and one was in an old Hoodies nest in a tree. One failed during incubation and the outcome of another was unknown. The other three reared 12 chicks in broods of 3, 4,and 5.
Birds were seen in at least 7 other areas during the breeding season but no evidence of breeding was obtained.


All known breeding sites were checked and 18 were found to be occupied. Nests were found at 16 of these sites but a poor season resulted in only 7 rearing young. 19 chicks were reared to or near fledging. There were two re-lays one successful and one failed. Of the 19 chicks reared 13 were females and 6 were males. The west mainland had 7 sites two of which were successful producing 5 chicks. The east mainland had one successful site producing one chick. Rousay had 2 sites with no successes. Hoy had 8 sites, 4 of which were successful producing 7 chicks.


It was a poor year for birds breeding on the isles. At both sites on Westray nothing was found. On Eday birds were present early in the season at one of the two sites but did not nest. On Stronsay three old kills were found at one of the two sites but there was no sign of nesting. On Rousay a pair reared four chicks at the site that has been regularly used in recent years. On Shapinsay though there was no sign of occupation at the known site. All the west mainland sites were checked and only two sites were occupied. Of these one fledged two chicks whilst the other failed. In the East Mainland all sites were checked but only one was occupied and it reared at least one chick. The usual site on South Ronaldsay was found to have a brood of three chicks a week old but fledging success is unknown. Hoy is the most difficult to cover because of the remoteness of some of the sites and the height of some of the nesting cliffs. One site fledged at lest one chick while another is believed to have failed. Territorial birds were seen at least three possibly four sites but the outcome of any nesting attempts was unknown.


There were 33 apparently occupied sites located. In the west mainland birds were seen in 22 likely breeding localities but nests of young were only found at four of these. In the East Mainland there were birds in six likely sites but no nests or chicks were located. Birds were present in at least two areas of Burray/South Ronaldsay but no nests or chicks were found. On Flotta, an island with out voles, a fledged chick was seen. A hunting bird was seen on South Walls, another vole free zone. Finally on Rousay birds were seen in two areas, including one where a food pass was observed.


Chris Booth once again covered all the known Mainland sites. At least 50 pairs attempted to nest of which 33 were successful rearing 97 young. 29 of the pairs used sea cliff sites and 21 used inland sites that comprised quarries ,trees, buildings, a steep bank side and an inland crag.


Thanks go to the following folks for all there hard work. With out them this report would not be possible

Eric Meek, Chris Booth, Martin Bruengger, Mike Cockram, Lorna Dow, Kieth Fairclough, Ailne Gerber, Paul Higson, Paul Hollinrake, Andy Knight, Alan Leitch, Brian Ribbands, Lee Shields, Jim Williams, Andrew Upton, Stuart Williams.

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