Thursday 19 December 2013

A Summary of the Year


The BTO recently published the national Preliminary Results for its Nest Record Scheme and the details for three of our species are summarised in the table below:

Species
Laying Date Days
Clutch Size %
Brood Size %
Egg Stage Survival %
Chick Stage Survival %
Fledglings Survival %







Kestrel
19.6
-9.3
-16.0
-6.6
-8.7
-28.3
Barn Owl
6.7
-14.6
-3.0
-5.2
-2.1
-10.0
Tawny Owl
3.5
-2.6
-10.8
8.1
-7.0
-10.4

Table 1. Laying dates and breeding success in 2013 relative to the average for the previous five years (2008-12). Laying dates are given as the number of days earlier or later than the five-year average while productivity figures represent a percentage change relative to the five-year average.


Our own local experience is broadly in line with these national trends and the earliest egg laying date this year for Barn Owls in Mid-Cheshire was 24 April. This compares to dates of 3 March in 2012, 8 April in 2011, 2 April in 2010 and 11 March in 2009. The cold snap in March meant that many birds were unable to attain the body condition required for them to be able to breed successfully and this, along with poor prey availability, resulted in many birds electing not to breed at all  this year.



This manifested itself in the dearth of breeding Owls and Kestrels that we were able to find and many long-standing sites were simply devoid of birds which resulted in one of the least productive breeding seasons for many years.


Adults Ringed
Retraps & Recoveries
Young Ringed
Number of Broods
Average Brood  Size






Tawny Owl
1
0
4
2
2
Little Owl
1
0
4
2
2
Barn Owl
21
26
29
9
3.2
Kestrel
1
2
14
5
2.8

Table 2. 2013 Birds in Mid Cheshire.  Both Kestrels that were recovered were birds that were sadly found dead during the Spring cold spell and seven of the eight Barn Owls were also discovered dead; again these birds were found during the Spring. Two of these owls were first year  birds that had travelled a relatively long distances (38 and 44 km) in an attempt to establish territories of their own.

Of the birds that were retrapped eight were found in the same nest boxes as previous years which betrays the sedentary habits of the Barn Owl and only six were discovered more than 10 km from where they had originated. Among these birds was our furthest ever traveller, a female that had moved over 100 km from Anglesey.

In the hope that things pick up during 2014 we have erected 34 new Barn Owl boxes and replaced a further 6 during the year. Additionally, a further 7 Tawny Owl boxes, 10 Kestrel boxes, 2 Long-eared Owl baskets  and 16 Little Owl boxes have also been put up. 




The last Barn Owl ringed in 2013.