FAMILY FREGATIDAE 73 



FREGATA MAGNIFICENS Mathews: Magnificent Frigatebird; Tijereta 



de Mar 



Figure 14 



Fregata minor tnagnificens Mathews, Austr. Av. Rec, vol. 2, no. 6, Dec. 19, 1914, 

 p. 120. (Barrington Island, Galapagos Archipelago.) 



Size large ; wings long, angular ; tail long, deeply forked. 



Description. — Length 810 mm. to a meter. Male black, glossed 

 above with violet; throat sac large, bright red in breeding season, 

 shrunken, dull orange at other times. 



Female, black, with breast and sides white. 



Immature, head and neck white. 



Measurements (from specimens from the Pacific coast of Central 

 and South America). — Males (22 specimens), wing 587-648 (622), 

 culmen from base 105.6-116.4 (109.0) mm. 



Females (15 specimens), wing 615-695 (648), culmen from base 

 115.3-135.8 (122.8) mm. 



Iris brown ; bill dusky neutral gray ; tarsus and toes dull black ; 

 throat sac of male bright red in the breeding season when capable of 

 inflation, changing to dull orange in the post breeding, contracted 

 state. 



Resident. Common along the coasts, particularly in the Bay of 

 Panama. Often seen soaring far inland; found regularly over the 

 Panama Canal and Gatun Lake. 



The known breeding colonies in Panamanian waters are as fol- 

 lows : The western one of two small islets immediately north of Isla 

 Uva, in the Islas Contreras, which lie to the north of Isla Coiba ; 

 Isla Iguana, north of Punta Mala ; Isla Bona ; Farallon del Chiru ; 

 Isla Villa ; islets near Isla Taboguilla ; Isla Chame ; Isla Pacheca, 

 Isla Saboga, Isla Cangrejo in the Islas Caracoles (to the north of 

 Isla del Rey), and Isla Galera, in the Archipielago de las Perlas. 



The frigatebird, with its narrow, angular wings and deeply forked 

 tail, is a familiar sight anywhere along the sea, as the birds are 

 constantly on the wing, often high in air. Seen regularly over the 

 coastal towns and cities, they also swing inland, particularly during 

 periods of storm, and so it is not unusual to see one high overhead 

 through some forest opening far distant from the sea. They cross 

 the isthmus constantly from side to side over the canal. 



Frigatebirds are notorious for robbing their neighbor terns and 

 boobies of their fish. The brown booby particularly is unfortunate 

 in this, though it often manages to escape. I have seen royal terns 



