This is the 22nd year of our study at Leighton Moss RSPB. It was an interesting year with good productivity and survival.
Breeding Population and Survival
This year we have either re-trapped or re-sighted a total of 15 adult females and 11 adult males. Past experience is that we always miss a few and this would suggest a breeding population of ca 18 pairs. Survival this year has been most interesting. Of 31 adults known to be alive in 2012, 15 were present in the breeding season of 2013. This gives a crude survival rate of 49%. The lower numbers of grit tray sightings obtained this year has probably reduced the numbers of adult re-sightings. However 49% survival rate is about average for adults in years with reasonable winter weather. However of 17 juveniles ringed in the 2012 breeding season no less than 12 survived to the 2013 breeding season, a survival rate of 77% and the best survival rate yet recorded for juveniles and only the third year in the 22 years of the study that juvenile survival has been better than adult survival. Overall this gives a survival rate of 60%, one of the highest yet recorded.
Productivity was much better this year with 48 ringed although one un-ringed bird was seen in late October. After a cold start, which surprisingly did not delay breeding the weather was good with a low water level so no flooding out of natural nests. Of 21 nestlings ringed 16 were caught as juveniles so survival at this stage was good.
Grit Tray Sightings
A total of 191 sightings of colour ringed birds were obtained between August 24th and December 17th on the grit trays. A total of 54 different birds were recorded, 24 adults and 29 juveniles. Total sightings were 114 down on 2012 probably due to the mild autumn with large numbers of insects present and a low water level, allowing access to the substrate.