The Breeding Ecology of a Declining Farmland Bird: The Turtle Dove Streptopelia turtur.

Abstract

The Turtle Dove is a migrant to Britain, being present only during its breeding season. In recent years the species has undergone a 69% decline in population size and a 25% contraction in breeding range in Britain. Since the early 1960s, very little work had been carried out on the species in this country.
This study uses a variety of data sources to investigate the breeding ecology of the species and compares the results with those collected in the 1960s.
Territories were established in areas with scrub, hedges and woodland with these habitats being used for nesting. The comparison of data showed that Turtle Doves today have a shorter breeding season and produce about half the number of clutches and young per pair than formerly. This would lead to a population decline of 17% per annum. No aspect of breeding ecology or success altered significantly for individual nesting attempts during 1940 to 2000. A shift in the timing of autumn migration supports the theory that Turtle Dove are undertaking fewer nesting attempts.
A change in the species foraging ecology resulted in a switch in the diet from predominately weed seeds in the 1960s to cultivated seeds today. Experimental supplementary feeding did not lead to a detectable change in territory density, territory size or breeding success.
In recent years the availability of suitable Turtle Dove nesting habitat, has been greatly reduced in the farmed environment, and that which remains is less suitable. The lack of suitable nesting habitat may preclude or limit the numbers of Turtle Doves breeding in certain areas of its British breeding range. Reduced food availability, both spatially and temporally, may make birds more likely to cease breeding earlier than during the 1960s and to reduce their number of nesting attempts.
This study suggests that the recovery of Turtle Doves in Britain is dependent upon the provision and sympathetic management of nesting and foraging habitats.