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Students help with the 'petrel project'

3 May 2012

Students studying Carpentry and Joinery at Inverness College have generously contributed their time and skills to assist with a study of the Leach’s storm-petrels on St Kilda. The first year Modern Apprenticeship students constructed nest boxes for the second phase of a long term project investigating the breeding biology of this species.  Help from the College was greatly appreciated as the boxes were ably and quickly constructed then donated to the NTS. According to Paul Moody, programme development manager (Faculty of Technology), the task was "mutually beneficial because it provided the students with valuable experience of a ‘real’ world conservation project".

Modern Apprenticeship students at Inverness College - thanks for the help!Photo - students: Christopher Currie, Stephen Faryma, Robaidh Halliday, Lewis Leckie, Sean Leslie, Christopher MacCallum, Dale MacFadyen, John MacInnes, Michael Mackenzie, Max Malicki, Alexander McFarlane   and tutors: Alex Fraser, Kenneth Taylor, Paul Moody

Students building Leachs storm petrel nest boxesPhoto: Students working on the nest boxes

The St Kilda archipelago is an important breeding area for this small nocturnal seabird as 94% of the British and Irish population are found on the islands. Unfortunately, surveys in 2000 and 2006 indicate that one of the largest sub-colonies on Dun has experienced a 52% in just six years. While some research implicates great skuas (bonxies) in the decline, there is very little known about the breeding biology of this species and whether factors associated with nesting may impact population size.

Close up a petrel

Studying Leach’s storm-petrels on the nest is extremely difficult as birds breed in crevices under boulders, at the base of stone structures such as cleits and in burrows dug into grassy slopes. The entrances to Leach’s storm-petrel burrows are often indistinct, tend to show little sign of use and the nest chamber is rarely visible from the burrow entrance. Because of this, artificial nest boxes are the only method that allows easy repeatable access to the nests of breeding birds. 

In 2005, the Joint Nature Conservation Committee installed 25 wooden nest boxes in cleits that are known to contain an active colony of birds.  It was hoped that it would be possible to track the timing of laying and incubation, obtain a measure of breeding success and monitor the attendance patterns of parent birds and the growth rates of chicks. Original nest box in cleitphoto: wooden nest boxes inside a cleit, access to the box is via the drain pipe tunnel  (entrance, bottom right of picture)

Over the next four years several of the boxes were investigated but most activity occurred late in the season by pre-breeding pairs ‘playing house’.  The nest boxes within the cleits are clearly capable of attracting birds so we have decided to trial a new design in the same area. This should hopefully allow us to determine whether the nest box design or the location itself is responsible for the lack of breeding success.

New smaller wooden nest chambers with a perspex lid were made to fit inside the existing nest box.  This design has several potential benefits: the nesting chamber is less spacious and possibly more attractive as a breeding site, the transparent lid will reduce disturbance when the boxes are inspected because the lid does not need to be removed, camera equipment could be placed in the empty space surrounding the nest chamber if more detailed monitoring is required, and the large box may prevent sheep from accessing the cleit so the box should be more secure.
New design nest box, lid closedNew design nest box, lid openPhoto: the smaller nesting chamber secured inside the large nest box. 

The boxes were made as a flat pack kit that were quickly constructed on island and installed in the first two weeks of April.  I will inspect the boxes on a weekly basis and record all signs of use - fingers crossed the new design is a success!

(Seabird and Marine Ranger)

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