During 2014, Pembrokeshire’s breeding
peregrine population was monitored for the 34th successive year. This
season’s results will also contribute to a national census of the species – the
last such similar survey having been conducted in 2002.
Provisional results indicate that the number
of occupied territories (38) was similar to that recorded in 2013 (39). However,
overall breeding success seems to have been quite poor. A minimum of 26 young
fledged from 26 nest-sites (compared with 40+ young fledging from 26 sites in
2013). Back in 2002, 46 territories were occupied, and that year 35 pairs
reared a minimum of 47 young.
Compared with the last national census
year, the peregrine population does seem to have declined in the County. Closer
scrutiny of the records suggests that this is largely due to a sharp decline
in the number of inland sites being occupied, where the population had been
expanding to during the last 20 years. Coastal sites are faring better, but even
here evidence of breeding was lower in 2014.
Weather conditions and food availability are significant
factors that influence breeding success. It seems possible that last winter’s severe
storms may have impacted the population in some way – perhaps causing the
deaths of some birds, or weakening others prior to the breeding
season? Abandonment of inland sites is interesting. Has food availability declined
near these areas? If so could this be due to competition with other predatory species? Or maybe this is an indication of the current
general health of the environment, where populations of some bird
species (which peregrines might be dependent on in spring) are also
declining? It will be interesting to see what the national picture reveals this year.
There are usually a number of younger peregrines
in the population, birds that are probably not yet mature enough to breed
successfully. This year the proportion of younger birds observed paired
with older birds (based on plumage differences) occupying territories does seem
to have been quite high.
Following the winter storms, spring was relatively mild and settled and summer weather
was also generally quite warm and benign. In May though it was occasionally quite
unsettled with some stormy, wet periods. It is likely that some breeding pairs
may have failed at this time.
Obtaining evidence of peregrine territory occupancy
and proof of breeding takes quite a lot of time and effort. Considerable thanks are due
to a number of volunteers who, between them all, dedicated many hours to checking
more than 100 locations, making repeated visits to
confirm if breeding had occurred. Thanks also to several birders who contacted
me directly about their own particular observations, or added records to BirdTrack – all
these records were valuable.
It is hoped that a more detailed account will
be published in the Reports section of the Pembs Bird Group Blog Site in due
course.