Open AccessDiel Foraging Behavior of American White Pelicans Pelecanus erythrorhynchos on Experimental Aquaculture Ponds
Author(s) -
Werner Scott J.
Publication year - 2004
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.2004.tb00117.x
Subject(s) - foraging , catfish , biology , ictalurus , zoology , fishery , morning , diel vertical migration , nocturnal , aquaculture , fish <actinopterygii> , ecology , botany
Abstract Videography and night vision equipment were used to observe the diurnal and nocturnal activities of American white pelicans Pelecanus erythrorhynchos ( N =6) foraging on three experimental (0.04 ha) channel catfish ( Ictalurus punctatus ) aquaculture ponds in March 2001. Captive pelicans spent most time foraging per hour from 1700 through 2300 h (CST). No foraging was observed from 0700 through 0800 h. Fish captures per hour were greatest from 1700 through 1900 h. On average, captive pelicans ( N = 5) consumed 1.0 ± 0.2 kg of catfish per bird per day during the 10‐d foraging trial. This consumption corresponds with an average intake of over 60,000 kJ of energy per bird during the trial. Relative to morning hours, the average number of bill dips per min was greater during afternoon foraging bouts. Fish captures per bill dip, however, did not differ among trial hours. Thus, pelicans were observed to increase foraging effort subsequent to 1500 h and thereby consumed 224 to 532 catfish (average = 313 ± 74 fish; N = 4) during the 10‐d foraging trial in ponds stocked with approximately 74,000 catfish/ha.