Habitat Use and Life History as Predictors of Bird Responses to Habitat Change

• Published in: Conservation biology 2008-02, Vol.22 (1), p.151-162
• Main Authors: OKES, NICOLA C, HOCKEY, PHILIP A.R, CUMMING, GRAEME S
• Format: Article
• Language: English
• Subjects: Africa; Animal, plant and microbial ecology; Animals; Applied ecology; Aves; Biological and medical sciences; Biology; Birds; Birds - genetics; Birds - physiology; características de la historia de vida; conservación de aves acuáticas; Conservation; Conservation biology; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; contracción de rango de distribución; Demography; Ecological life histories; Ecosystem; Environmental conservation; expansión de rango de distribución; Fundamental and applied biological sciences. Psychology; Habitat conservation; Habitats; Life cycles; life-history traits; Marshes; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Phylogeny; Predictions; pérdida de humedales; range contraction; range expansion; Riverine habitats; Species; Theory; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; waterbird conservation; Waterfowl; Wetland ecology; wetland loss; Wetlands
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/j.1523-1739.2007.00862.x

In theory the consideration of life-history characteristics should provide a way of making predictive generalizations about the responses of different species to environmental modification. Nevertheless, few studies have tested the validity of this assumption or attempted to apply it across large numbers of related species. We explored both quantitative and qualitative contrasts between species of waterbirds that have either expanded or contracted their ranges in southern Africa over the past 40 years to test the hypothesis that expansionists and contractionists, respectively, should share life-history characteristics and/or ecological attributes. Similarities and differences in life history and ecology were explored through multivariate statistics. Overall, life-history traits provided an inadequate explanation of whether species would be range expansionists or contractionists. By contrast, ecological attributes of species that related to habitat use correlated well with range changes. In particular, waterbird species that inhabit pans seemed to be preadapted to using human-made dams and impoundments. The ability of many species to use artificial wetlands has aided their westward range expansions into arid regions of southern Africa. By contrast, species that rely on vegetated wetlands and that require reeds for nesting were predisposed to range contraction because their habitats have been severely affected by agricultural development and urbanization. In direct contrast to range expansions, most range contractions were west to east, the eastward contraction reflected the high level of wetland loss and degradation in the eastern lowlands of South Africa. Based on analysis of ecological attributes of regional contractionists, several additional species were identified as of potential conservation concern, although such concern may not as yet have been expressed.