The Kestrel in Ayrshire - annual report 2009

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Annual Report 2009

The 2009 season was one of the least productive for many years for kestrels due to a combination of low vole numbers and a very cold and wet spell of weather in the last week of April and the first week of May. Indicative of the poor vole year was the total lack of voles seen cached at nest sites and the almost total lack of barn owls breeding in the study areas compared to previous years.

The most telling statistic was territory occupation, at less than 50% it was one of the lowest on record and it is hoped that this figure is merely a reflection of a very poor vole year rather than a symptom of the decline which is taking place over much of the country. On the positive side the pairs which did breed produced 3.4 young per successful pair and it was very noticeable that these pairs were in core territories where kestrels have traditionally bred each year.

The 2009 breeding statistics are as follows :-

	2009	2008	2007	2006	2005	2004	2003	2002

Number of territories checked	39	41	34	35	35	33	30	34
% occupation	49	73	59	72	51	84	66	44
Number of clutches known	10	18	12	16	14	24	13	9
Average clutch size	4.6	5.3	5.25	4.75	4.5	5.5	5.46	4.4
% of eggs which hatched	91	83	95	84	74	92	83	82
Number of results known	19	26	17	25	14	26	20	12
Average young per breeding pair	2.8	3.81	4	3.2	3.2	4.2	3.1	2.75
Average young per successful pair	3.4	4.3	5.15	3.8	4.1	4.8	3.9	4.1
Number of breeding attempts failed	4	3	3	4	3	3	4	4
% failed	21	11	17	16	21	11	20	33
% brood survival	90	96	93	98	89	90	91	82
Number of young ringed	23	46	44	46	40	67	40	30

Number of field days: 30

The first egg was laid on 17 April and only one pair at the Dam, which has been occupied since the 1960s, completed a full clutch of 6 eggs. As usual the percentage of eggs which hatched and brood survival was high. Those pairs which did start breeding produced young but their output was quite low. Two pairs failed at the prelaying stage, one brood was predated at a nest box and plucked inside, and the outcome of a fourth failure was unexplained.

Only 23 young were ringed, the second lowest since work began in 1973. One recovery was recorded, a bird ringed as a nestling in June 2008 was found freshly dead in a building in Penrith on 14 April 2009 – a duration of 305 days, 11 miles from the natal site.