AfS Nest forms
We have shown that Swifts move into nest boxes with nest forms much more quickly than nest boxes without nest forms. There is also some evidence that Swifts are more likely to attempt breeding in their first year of occupancy. This is important because with an average life span of 7 years, Swifts only have 4 or 5 breeding seasons, so an increase of 1 is significant.
However, we have had reports that with a nest form, in some experiences, the Swifts do not bring in as much nest material so, in the case of a flat-bottomed nest form, the eggs roll around, are less likely to get properly incubated and are more likely to get knocked out.
On inspection of nest boxes after the breeding season, it is not uncommon to find abandoned eggs on the floor of the box.
So is there a way of keeping the advantages of nest forms without incurring potential disadvantages?
Made like a swift would
Swift expert and engineer Dick Newell has spent time measuring a number of natural nest forms.
This has resulted in a shape that attempts to emulate a natural nest (appendix below). The concave part is 75mm diameter and 18 mm deep. A swift’s egg is about 16mm diameter. Eggs should gravitate towards the centre. It has a vertical inside rim which should help keep the eggs in. The 'steps' hopefully help any displaced chick to clamber back in. The maximum outside dimension is 110 mm so it would need to be trimmed to fit inside the narrowest boxes (100mm).
The 2 versions available are for the corner or against the side of a nest box.
A cross section is shown below, dimensions are 11cm across, ridges 1cm and nest hollow 7.5cm across. Height is 2.5cms in total, with a 2mm base at the bottom and a vertical incline of 1cm.
£4.50 each plus VAT and shipping
