We are pleased to report sighting a few swifts in Brigg town centre at the weekend - over Bigby Street. They have been very late arriving this year and numbers appear to be down. Any idea why?
Several: 1. General late arrival due to poor weather. 2.Colony size related to suitable number of nesting sites. 3.Thousands of swifts spotted in other local areas ie Spurn Observatory..but few in Brigg, which, at one time attracted many.... WHY? Loss of nesting sites .....house eaves and gaps on older houses have now been filled. Anti-pigeon netting etc maybe also affecting access to suitable nesting sites. A swift is around 4 years old before it builds a nest (usually inside a crevice)...younger birds just use holes as shelter...so there is a time delay in building, or re-establishing a colony.......
Several:
ReplyDelete1. General late arrival due to poor weather.
2.Colony size related to suitable number of nesting sites.
3.Thousands of swifts spotted in other local areas ie Spurn Observatory..but few in Brigg, which, at one time attracted many....
WHY?
Loss of nesting sites .....house eaves and gaps on older houses have now been filled. Anti-pigeon netting etc maybe also affecting access to suitable nesting sites. A swift is around 4 years old before it builds a nest (usually inside a crevice)...younger birds just use holes as shelter...so there is a time delay in building, or re-establishing a colony.......