Birds already on the look out for next year's home; CONSERVATION.

MERSEYSIDE nature lovers who put up nestboxes for birds ahead of next spring's breeding season may find the avian real estate is used for some unusual "house shares" between different species, says the RSPB.

The wildlife charity is urging people to clean out existing boxes and put up new ones now, before birds start house-hunting for spring and to provide spaces for winter roosting when the weather turns too cold.

But, according to calls to the RSPB in recent years, some nestboxes end up with surprising sublets.

Barn owl nestboxes in particular seem to attract other tenants, with reports of the owls sharing with species including jackdaws, kestrels and stock doves.

Other cohabiting species include blue tits and great tits, both of which have also been seen sharing with pied flycatchers.

Experts believe there could be a number of reasons for birds sharing nests, including multiple cavities in some nest boxes, birds unwittingly laying their eggs in the active nests of other species or even a lack of nesting sites in some areas.

The RSPB said many larger birds which nest in holes in trees or old buildings may have increasing difficulty finding suitable nesting sites as old structures are knocked down or converted.

The charity is urging people who discover two species sharing a box in their garden to put up another nestbox nearby, as both types of birds might want to return to the same place next year.

Richard James, RSPB wildlife adviser, says: "When two species both have young in the nest box, it will get crowded. They'd both appreciate another box."

CAPTION(S):

House sparrow perched at a nest hole Wren chicks call out for food from their coconut shell nest