Frequency and Distribution of Polygyny in Great Lakes Herring Gulls in 1978

Endocrine disrupters – potential modulators of the immune system and allergic response

“…In animals EDs may be a serious cause of disturbances in fertility (23,24) and decreased hatching success (25)(26)(27). Colborn et al draw a conclusion that decrease in sperm count in human males in some geographical regions over the last 50 years (28) may be a reflection of the increase in estrogenic pollutants in the environment.…”

Feminization in common terns (Sterna hirunda) : relationship to persistent organic contaminants

“…Furthermore, the incidence of supernormal clutches tended by female pairs approached 15% on the contaminated Santa Barbara Island population (Hunt, Wingfield et al 1980), much higher than observed in other gull populations (Hunt and Hunt 1977;Shugart 1980;Nisbet and Drury 1984). Western gull and California gull (Larus californicus) eggs injected with amounts of DDT comparable to levels found in eggs at Californian gull colonies resulted in the development of ovotestes and oviducts in male gulls, and indicated Jbat these gulls were more sensitive to feminization by estrogenic compounds (10-50 times) than chickens, quails, and finches (Fry, Toone et al 1987).…”

Poliginia em Sicalis flaveola brasiliensis (Gmelin, 1789) (Passeriformes, Emberizidae)

“…Larus argentatus pode apresentar poliginia ocasional, provavelmente quan· do o número de fêmeas é maior que o de machos (Shugart, 1980). Powell & Jones (1978) sugerem que a reduzida competição intra-específica seja a responsável pelo aparecimento de um caso de bigamia em Geothlypis trichas.…”