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La dispersión y el uso de corredores por aves en parches boscosos de un paisaje agrícola
Author(s) -
Haas Carola A.
Publication year - 1995
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1046/j.1523-1739.1995.09040845.x
Subject(s) - biological dispersal , shrike , windbreak , ecology , geography , woodland , landscape connectivity , habitat , riparian zone , wildlife corridor , seed dispersal , biology , population , demography , sociology
Dispersal behavior has important effects on the persistence and recolonization of populations, but is one of the least understood traits of most organisms. Knowledge of patterns of fledgling, natal, and breeding dispersal of birds in a patchy environment will assist in decisions regarding reserve design and protection or construction of corridors. I present data on movement patterns of three migratory bird species, American Robin ( Turdus migratorius ), Brown Thrasher ( Toxostoma rufum ), and Loggerhead Shrike ( Lanius ludovicianus ). These birds are relatively common breeders in south‐central North Dakota (U.S.) in riparian woodlands and in shelterbelts (woodlots planted as windbreaks in the open agricultural environment). Field assistants and I individually marked and monitored the movements of more than 500 adults breeding in a network of shelterbelts across an 8 × 11 km study area. Most movement occurred at relatively short distances within a shelterbelt. Movements by adults between shelterbelt sites, although rare, occurred significantly more frequently between sites connected by a wooded corridor than between unconnected sites. For robins, there were on average 2.5 dispersal events between each pair of connected sites, but only 0.17 dispersal events between each pair of unconnected sites (Mann‐Whitney test, significant at p < 0.009). Because unconnected and connected sites were similar in average area (1.7 to 1.9 ha), distance to next wooded habitat, and tree‐species composition, this result provides a test of the hypothesis that organisms disperse preferentially along connecting corridors.