Status of Neotropic Cormorant in Arizona with Notes on Identification and Ageing

Articles | By Kurt Radamaker and Troy Corman | Accepted January 01, 2008

The  Neotropic Cormorant (Phalacrocorax brasilianus) is widespread throughout most of the western hemisphere, but in the United States is found primarily along the Gulf States of Texas and Louisiana, north locally to Kansas, and in south-central New Mexico. The species is sedentary throughout most of their breeding range, with widespread postbreeding dispersal. Neotropic Cormorant was first confirmed in Arizona in 1961 when two specimens were found shot at Arivaca Junction (Monson and Phillips 1964).  By 1980, Neotropic Cormorants were considered a rare but regular straggler to lakes, ponds, and drainages in the Santa Cruz River valley north to Tucson, occasionally east to southern Cochise County (Monson and Phillips 1981). They were also found once north to the Phoenix area and a few individuals had been noted along the lower Colorado River north to Lake Havasu (Rosenberg et al. 1991). Most of these early records pertained to only one or two individuals, but observations ranged through all seasons (Corman 2005). Since then Neotropic Cormorants have increased in southeastern Arizona and expanded north into central Arizona to northeastern Pinal County, southern Gila County, and across Maricopa County west to Painted Rock Reservoir northwest of Gila Bend. The increase in population occurred gradually through the 1970s and 1980s with a rapid increase in the late 1990s and 2000s.