Status of the Pelecanidae

Abstract

The recent history, current status and prospects in the immediate future of the seven species of the Pelecanidae are reviewed. As a consequence of pesticide poisoning, Pelecanus occidentalis suffered severe population declines in the 1950s and 1960s in portions of its range in the United States. However, since the ban on use of DDT in 1972 the species is again laying eggs of near normal thickness, reproductive success appears to be normal and populations are stable or increasing. Similarly, available data indicate that the world populations of P. rufescens, P. conspicillatus, and P. erythrorynchos remain stable, although local population fluctuations do occur. Data for P. onocrotalus show a stable population in Africa but a decline in Asia and Europe, both in numbers of birds and breeding colonies. More seriously, only very small populations of P. crispus and P. philippensis exist. Fewer than 1000 pairs of P. crispus next in 19 colonies in eastern Europe and Asia. Fewer than 1200 pairs of P. philippensis nest in four colonies in eastern/southern India and 23 colonies in Sri Lanka. The populations of both species have declined considerably in the past few decades. The causes for the declines are not documented but are thought to result from a combination of human disturbance in nesting colonies; destruction of nesting and roosting-loafing areas; declines in fish availability; and pesticide contamination. Only immediate action and concerted efforts at stabilizing the populations in the wild, in conjunction with the establishment of captive breeding populations, will preserve these two species from extinction.