The double-crested cormorant, Phalacrocorax auritus, is considered the primary depredating bird species on commercially produced channel catfish, Ictalurus punctatus, in the southeastern USA. We simulated different levels of cormorant predation on losses at harvest and economic effects on channel catfish production in a multiple-batch cropping system. We observed significant (P< 0.05) declines ...

—Concomitant with increasing numbers of the Double-crested Cormorant ( Phalacrocorax auritus ), catfish producers in eastern Mississippi and western Alabama have reported damage caused by cormorant predation. VHF telemetry was used to document movements of 25 cormorants from all known night roosts in the aquaculture producing areas of eastern Mississippi and western Alabama, January-April 1998....

—An overview is provided of a symposium on the direction of research and management of Doublecrested Cormorants (Phalacrocorax auritus) heading into the 2000s. The current symposium built on previous efforts and described a number of focus areas of informational need, including cormorant impacts on natural resources, demographics of cormorants, assessment of control efforts, assessment of fish ...

To assess the inducibility of avian MT genes and potential tolerability of their proteins to element exposure, we investigated the expression profiles of MT isoforms by metal accumulation in wild cormorants (Phalacrocorax carbo) and mallards (Anas platyrhynchos). We also measured transcriptional activities of avian MT genes by elements and detoxification potencies of their in vitro-expressed MT...

A pied cormorant (Phalacrocroax varius) was found sleeping on rocks in a coastal region near Adelaide. Examination revealed entanglement by fishing line with superficial wounds to the left leg. The cormorant was also reported to have ingested a number of fishing hooks, however, the exact location of the hooks was not known. In addition, the bird was found to be underweight and shocked. X-ray ex...

For the first time the data on helminths in piscivorous birds (the great cormorant and the Mongolian gull) in Mongolia were obtained. Surveys yielded 11 species (Cestoda--2, Trematoda--6, Nematoda--3). The cormorant hosted 5 helminth species, the herring gull--6 species.

Oklahoma has about 324 ha of surface water in catfish (Ictalurus spp.) production. The state also supports a large number of migrating and wintering piscivorous birds, particularly double-crested cormorants (Phalacrocorax auritus). To address concerns of aquaculture facility operators regarding loss of fish to cormorants, we asked 11 operators to conduct regular counts of piscivorous birds at e...

Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often p...

Many aquatic birds use sounds extensively for in-air communication. Regardless of this, we know very little about their hearing abilities. The in-air audiogram of a male adult great cormorant (Phalacrocorax carbo) was determined using psychophysical methods (method of constants). Hearing thresholds were derived using pure tones of five different frequencies. The lowest threshold was at 2 kHz: 1...