Portal de Periódicos da CAPES

Social Facilitation of Foraging Behavior by the Hermit Crab, Coenobita compressus, in Costa Rica

1982; Wiley; Volume: 14; Issue: 2 Linguagem: Inglês

10.2307/2387742

1744-7429

Allen Kurta,

Crustacean biology and ecology

The terrestrial hermit crab Coenobita compressus appears to detect and approach aggregations of conspecifics. Since this hermit crab tends to form clusters surrounding a food item, individual approaching aggregation will often discover a desirable piece of food. This study provides quantitative field evidence for the use of social facilitation in by C. compressus. Coenobita IS A WIDE-RANGING, LARGELY TROPICAL GENUS of terrestrial hermit crabs. Shell selection (Kuris and Brody 1976, Abrams 1978, Vuillemin 1970), aggressive movements (Hazlett 1966), orientational mechanisms (Vannini 1975a), digging patterns (Vannini 1975b), and migratory tendencies (Vannini 1975a, 1976a) have been carefully examined for various members of the genus. A number of natural history reports also provide brief descriptions of feeding behavior or list preferred foods (see review in Vannini 1976b). Little experimental work, however, has been performed on the behavior of Coenobita. The subject of this report is Coenobita compressus, a conspicuous resident of Pacific beaches from Lower California to Chile (Bright 1966, Ball 1972). While often considered nocturnal (Bright 1966, Ball 1972, Haig et 4a. 1970), this decapod crustacean is also very active during the early-morning hours. fn Costa Rica, C. compressus may be found in densities as low as 3.1 crabs per m2 on sunlit, uncluttered beaches or in aggregations of up to 400 active animals per m2 near a shaded food source (pers. obs.). This habit of aggregating around a food item suggested that C. conipressus might employ social facilitation (Zajo,nc 1965) as a strategy. Social facilitation involves an ordinary pattern of behavior that is initiated or increased in pace or frequency by the presence or actions of others (Wilson 1975). Finding food by observing the actions of conspecifics (see reviews in Erwin 1978, Krebs 1974) is a form of social facilitation that has also been called local enhancement (Hinde 1973) and imitative foraging (Wilson 1975). This method of food detection has been suggested for animals as varied as lizards (Greenberg 1976) and vultures (Rand 1954). Such reports, however, are usually observational and do not attempt to quantify the presumed attractiveness of conspecifics. The present study will attempt to demonstrate the use of social facilitation in by the hermit crab C. compressus.