Saturday, 2 April 2016

A headstart for redstarts?

Photo by John Richardson
The Common redstart (Phoenicurus phoenicurus) is a relative of our garden robin. The male has a striking red chest, black face and grey back. Its redstart name refers to its twitching red tail.

The redstart spends its winters in the warmth of Africa and returns to Britain to breed in the spring.

Across Europe the bird continues to do well, but in Britain its numbers have fallen, making it a bird of amber status conservation concern. It seems that the Common redstart imay be common no more.

40mm entrance
Here in Nottinghamshire, our mature oak woodland provides perfect habitat for redstarts: these areas are their strongholds in our county. Redstarts seek out fissures in decaying oaks for nest sites but can be persuaded to use nest boxes.

Triangular entrance
The reasons for the birds’ decline are complex, but one possible reason could be loss of nest sites. (Prof Ian Newton tells us that it is insufficient nest sites or food that are the main factors that limit bird populations). Our great tits nest earlier than redstarts and have similar  requirements for their homes. When the redstarts return from migration, all the best homes have already been taken!

It was put to me by our qualified bird ringing friends that it would be a fine idea for me to make nesting boxes for redstarts. And perhaps find whether they have a preference for one style of entrance over another.

So, armed with my BTO Nest Box Guide I set about making 24 nest boxes from 150mm wide gravel boards. Each was the same size, with a 40mm entrance.

Internal ledge
As the birds like a nest site that closely resembles a hole in a decaying tree I was advised to darken the cavity by sloshing creosote inside and outside the boxes; put a handful of spent potting compost into the bottom of each box to replicate the decay of an old tree; and put an internal ledge beneath the entrance to reduce light entering the boxes. For most of the boxes I placed the entrance in the top corner, so that this was the greatest distance from the potential nest.
'How many people does it take to fix a nest box to a tree?'
By the time I'd finished I'd recreated light conditions inside the box that only ancient candle-lit colliers will have experienced in an very deep seam
on a moonless night. I'm told that redstarts like their nest holes to be dark - they've got it!

We sited the boxes in areas where redstart males had been heard singing last year. 

The boxes were placed in groups of four, with a range of different entrances in each group.

The birds return in April and we hope to return to the area and check on progress during May.







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