Conservation of migratory species

An understanding of the behavior of species at risk can also assist managers to devise conservation strategies. Sutherland (1998) describes an intriguing case where the knowledge of migratory and dispersal behavior has proved critical. A scheme was devised to alter the migration route of the lesser white-fronted geese (Anser erythropus) from southeastern Europe, where they tend to get shot, to spend their winters in the Netherlands. A population of captive barnacle geese (Branta leucopsis) breeds in Stockholm Zoo but overwinters in the Netherlands. Some were taken to Lapland where they nested and were given lesser white-fronted goose eggs to rear. The young geese then flew with their adopted parents to the Netherlands for the winter, but next spring the lesser white-fronted geese returned to Lapland and bred with conspecifics there, subsequently returning again to the Netherlands. Another example involves the reintroduction of captive-reared Phascogale tapoatafa, a carnivorous marsupial. Soderquist (1994) found that if males and females were released together, the males dispersed and females could not using behavioral ecology... ... to conserve endangered species . . .

Core Habitat

Summer habitat

Scale 1:800,00

Year-round habitat

Fall-winter-spring habitat

0 10 20 km

Nature reserves

find a mate. Much more successful was a 'ladies first' release scheme; this allowed the females to establish a home range before males came and joined them.

Where migrating species are concerned, the design of nature reserves must take account of their seasonal movements. The Qinling Province in China is home to approximately 220 giant pandas (Ailuropoda melanoleuca), representing about 20% of the wild population of one of the world's most imperiled mammals. Of particular significance is the fact that pandas in this region are elevational migrants, needing both low and high elevation habitat to survive, but current nature reserves do not cater for this. Pandas are extreme dietary specialists, primarily consuming a few species of bamboo. In Qinling Province, from June to September pandas eat Fargesia spathacea, which grows from 1900 to 3000 m. But as colder weather sets in, they travel to lower elevations and from October to May they feed primarily on Bashania fargesii, which grows from 1000 to 2100 m. Loucks et al. (2003) used a combination of satellite imagery, fieldwork and GIS analysis to identify a landscape to meet the long-term needs of the species. The process for selecting potential habitat first excluded areas lacking giant pandas, forest block areas that were smaller than 30 km2 (the minimum area needed to support a pair of giant pandas over the short term) and forest with roads, settlements or plantation forests. Figure 7.15 maps summer habitat (1900-3000 m; F. spathacea present), fall/winter/

Figure 7.15 Core panda habitats (A-D), each of which caters for the year-round needs of the elevational migration of giant pandas in China's Qinling Province. Superimposed are current nature reserves (cross-hatched) and their names. (After Loucks et al., 2003.)

spring habitat (1400-2100 m; B. fargesii present) and a small amount of year-round habitat (1900-2100 m, both bamboo species present) and identifies four areas of core panda habitat (A-D) that provide for the migrational needs of the pandas. Superimposed on Figure 7.15 are the current nature reserves; disturbingly, they cover only 45% of the core habitat. Loucks et al. (2003) recommend that the four core habitat areas they have identified should be incorporated into a reserve network. Moreover, they note the importance of promoting linkage between the zones, because extinction in any one area (and in all combined) is more likely if the populations are isolated from each other (see Section 6.9, which deals with metapopulation behavior). Thus, they also identify two important linkage zones for protection, between areas A and B where steep topography means few roads exist, and between B and D across high elevation forests.

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