Nesting habitat selection by booted eagles Hieraaetus pennatus and implications for management.
Abstract
The booted eagle (Hieraaetus pennatus) is a poorly known and scarce raptor that breeds in Spain. In Doñana National Park (SW Spain) its population has increased from only 6 breeding pairs in the early 1980s to about 150 today. In order to guide habitat management for this raptor in the park, nesting habitat selection was related to breeding success. Birds withstood some human disturbance when nesting, choosing sites closer to pastures besides marshes, footpaths and crops than would occur in a random distribution. Birds also selected areas near to marsh and stands of cork oak (Quercus suber). Trees used for nesting were wider and taller than would occur at random. They were usually in small groups, or were large isolated trees, typically eucalyptus (Eucalyptus spp.). The most productive nests were close to marshland and stone pine trees (Pinus pinea). On the basis of these findings, habitat management to improve the breeding success of booted eagles in Doñana should include: (i) retaining small groups of trees or large isolated trees, especially eucalyptus and cork oaks close to marshland, isolated buildings and crops; (ii) creating clearings in stone pine plantations; (iii) burying potentially dangerous power lines to reduce collision risks; (iv) clearing some areas of scrubland to increase the rabbit population; and (v) controlling forest activities, especially in the breeding season. The increase in booted eagle populations in western Europe during recent decades may be a consequence of the species' capacity to adapt to environmental change. Deforestation policies designed to favour agricultural use implemented during the second half of the 20th century have not had a detrimental effect on this raptor. The study demonstrates how scarce and important organisms can be favoured by sensitive management in forestry and agricultural habitats.
Key words
- deforestation
- disturbed forests
- environmental impact
- forest ecology
- forest fragmentation
- forest management
- forest plantations
- forestry practices
- forests
- habitat selection
- habitats
- marshes
- natural enemies
- nesting
- pastures
- pines
- predators
- predatory birds
- reproductive performance
- scrub
- stand characteristics
- trees
- wetlands
- wild animals
- wild birds
- wildlife conservation
- wildlife management
- woody plants