PROBABLE TIMES TO EXTINCTION OF SOME RARE BREEDING BIRD SPECIES IN THE UNITED-KINGDOM

Using a stochastic exponential model of population growth based on the Wiener-drift process, the most likely times to, and probabilities of, regional extinction were estimated for 35 rare breeding bird species in the United Kingdom. A quarter of these species were predicted to have probabilities of extinction equal to 1, and a further third probabilities of greater than 0.1. The most likely time to attaining the threshold of a single individual was 50 years or less for both groups and often much shorter. Although there was also support for some acknowledged conservation success stories (e.g. osprey, avocet), overall these results suggest a poor prognosis for many species and a challenge to conservation agencies.