Constancy of seabird species assemblages: an exploratory look
In: Biological Oceanography. Crane, Russak: New York. ISSN 0196-5581, meer
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| Trefwoord |
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| Author keywords |
Seabirds, community structure, weight ratios, species assemblages, habitat structure |
| Abstract |
The temporal and spatial persistence of seabird species assemblages is described from investigations using strip-censuses conducted on 10 cruises that traversed the South Pacific Ocean from tropical to antarctic regions as well as east to west. Several groups of pelagic seabird species persisted over time and between widely spaced localities. Another group, that of the Peruvian upwelling region, was restricted spatially. Sea-surface temperature was the primary factor explaining variability in species group composition; secondary factors differed among regions, but included salinity, distance to land, water depth, and the presence of pack ice. The temperature-salinity relationship may not directly influence species occurrence, but rather may indicate a relationship to relative productivity of different water masses. Within species groups, ecological structure may be a function of prey size and type as mediated by predator body size and feeding behavior, respectively. These results from exploratory analyses of an existing data set indicate that more formal study of seabird species groups and their relationship to environmental variables should prove fruitful. |
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