Can't believe that the summer has flown by so fast, with so little time for ringing. Nothing too exciting to report but here's a round up for the Preseli area.
The woodland CES at Llandilo was fairly quiet during the July and August visits when many of the breeding adults and newly fledged young leave the woods and (presumably) head for the hedgerows to feed on fruits and seeds. Any remaining adults are moulting and tend to skulk around without getting caught. In 2017 the number of individuals caught during all 12 visits was 269; this compares to 194 (2016 ) and is almost identical to the the 2015 result of 270. The number of adults this season was down on the previous two years, probably reflecting the two previous fairly poor breeding seasons, especially in 2016. The number of juveniles caught this year was much higher than in either 2015 or 2016, suggesting that this season has been a significantly more productive season (see graph below).
Most of the species caught are common woodland species with the top three being Blackcap (126), Blue Tit (88) and Robin (70) though the red-listed Marsh Tit just about makes it into the top ten with 20 (totals are 2015 - 2017).
The numbers of adult wheatears returning to breed at the Preseli study plot dropped substantially this year to 43, compared to 61 in 2016. Overwinter adult survival was the lowest recorded at 40% compared to an average of 59% since 2013, and nest success has been negatively affected by bad weather in four seasons of the past six seasons. This year, three broods of up to six nestlings were found dead due to starvation/chilling, so a population bounce-back next year is not predicted, unless breeders are recruited from more productive areas.
The photo below was taken in 2012 following a particularly cold, wet and windy June day. The male was seen entering the nest cavity with food, only to re-emerge with his beak full, looking a bit confused, and when the nest was inspected, all the nestlings were dead and the nest soaking wet. Some of the nest cavities can also act as drainage holes during intense rain, perhaps forcing the brooding female to leave. This season, the three broods found in a similar state were all at the same stage, though well feathered young and nests at the egg stage had fared better.
|Unfeathered wheatear nestlings are very vulnerable during cold, wet weather|
Reading the colour combinations is always a bit of a challenge and you can be sure a bird is colour-ringed by the way it hides its legs from view just as you take the photo...