Swifts, swallows and martins may only be with us for a few months each year, but they make a huge impression in that time. However, numbers of all these birds have plummeted in recent decades. Installing nest boxes is a great way to provide these birds with the opportunity to breed and help combat population declines.
Swifts, swallows and martins may only be with us for a few months each year, but they make a huge impression in that time. For many people the return of swallows marks the start of summer and swifts’ distinctive cries are a common accompaniment to balmy evenings.
However, numbers of all these birds have plummeted in recent decades. Between 1995 and 2015 there was a 51% decrease in the UK breeding population of swifts. There are various factors behind this, but the main one is a loss of suitable nesting sites, particularly for swifts which are secondary cavity-nesting birds, meaning they use existing holes rather than creating their own. Modern properties are far less likely to offer useful sites to cavity-nesting birds and renovations can remove potential nest sites from older buildings.
Swifts, in particular, are creatures of habit, returning to the same nest season after season, making them especially vulnerable to habitat and nest site loss. However, this can be mitigated by providing artificial nest boxes which can be installed either as part of the building fabric or retrospectively as external addition. Successful nest boxes are extremely useful and rewarding as once swifts have found them and nested there once, it is highly likely they will return year after year.
Nest boxes should be installed high under the eaves, preferably at least 4m from the ground. Easy flight access to the boxes is more important than a specific orientation. Because swifts are colony birds, playing swifts calls from the end of May can help attract birds. In their first season or two, swifts prospect for nests before returning the following year to breed so don’t worry if your boxes aren’t occupied initially. If you want to ensure your boxes are used primarily by swifts, it is worth keeping an eye on the boxes to make sure they are not being commandeered by other species, they are particularly popular with sparrows who start nesting before swifts arrive for the summer. This can be prevented, if you wish, by blocking the entrance hole until early May.
The Save our Swifts, Swallows, House Martins and Sand Martins group on Facebook has started an SOS campaign, setting of a target of 505 new nest boxes installed for the start of the 2021 season. Please join the group if you’re installing a new box and would like to register it as part of the tally.
More information is available at Swift Conservation or from the RSPB.
By Bethan Nowell
