Nest Box News No 2 Tawny Owls

Photos Chris Hoyle
The four pairs of Tawny Owls in our nest boxes this year appear to be struggling somewhat. Looking back through our records, average clutch size in previous years has been just short of 3 eggs. This year all four pairs have just two eggs each. Average brood size in previous years worked out at 2.4 per nest. This year only one pair has 2 young the others started with 2 but now have only one.
The reason for this poor productivity is probably the low numbers of small mammals this year. This scarcity has been commented on by a number of observers and may well be affecting other predators. Small mamal numbers tend to be cyclic with this year being at the low point of the cycle.

The photos show a Tawny Owl which has been hunting in daylight in a garden near Kirkby Lonsdale successfully taking small birds. Further evidence that their normal prey is scarce.

John Wilson

Nest Box News

Nuthatch photo by David Mower

Following last years abysmal weather during the nesting season which resulted in below average productivity in many of our nest boxes we rather expected a decline in the numbers of pairs . To date I have had reports from three schemes we run within the Arnside/Silverdale area and the results tabulated below show that although there has been a decline in the use by Great Tit and Blue Tit it is only a comparatively small decline.

Great Tit 51 in 2008 to 47 in 2009
Blue Tit 23 in 2008 to 21 in 2009
Nuthatch 2 in both years
Marsh Tit Nil in 2008 1 in 2009

To date despite the recent period of cold easterly winds the number of chicks surviving has been good. However today's forcast of periods of heavy rain, which makes the finding of sufficent caterpillars difficult may further test the birds.

First results from our other schemes in the Lune valley suggests a similar decline in tit population except Marsh Tit which this year we have 5 pairs nesting compared with a nil return last year. Pied Flycatchers arrived early but numbers appear to be down somewhat but full details will not be available for a few days yet.

John Wilson