FAMILY ICTERIDAE 



363 



(175.1), tail 165.4-200.5 (184.2), oilmen from base 40.3-45.7 (43.2), 

 tarsus 43.3-48.8 (45.8) mm. 



Females (10 from Panama), wing 139.9-150.2 (144.1), tail 132.5- 

 155.9 (144.8), culmen from base 31.7-36.8 (34.6), tarsus 36.0-41.6 

 (38.4) mm. 



Resident. On the Pacific slope this species is scarce in Chiriqui, but 

 increasingly common as one moves east toward central Province of 

 Panama and Darien. There are a few records from western Chiriqui: 

 on March 9, 1966, I watched a male bathing in the Canal del Colorado 

 at Puerto Armuelles, and on March 6, 1976, Ridgely (in litt.) saw 50 

 in mangroves and on the seashore at Estero Rico. It is common on most 

 of the islands off the Pacific Coast. On the Caribbean slope, it occurs 

 quite commonly in the town of Changuinola, Bocas del Toro (April 

 1980, Ridgely in litt.), and from just west of the Canal Zone eastward 

 through San Bias and the islands off San Bias. It is most abundant in 

 open residential areas and along the seashore. In Chiriqui and Darien, 

 it seems as yet not to have spread far from its presumed ancestral habi- 

 tat, mangroves and seashore areas. Beyond Panama this race is found 

 on the Pacific Coast of Costa Rica and south to northwestern Peru and 

 the Caribbean coast of Colombia and Venezuela. Other races are found 

 north to southern Arizona and the Gulf Coast. 



Dr. Graham Fairchild of Panama City told me in 1960 that this 

 species has increased greatly in abundance since he first came to Pan- 

 ama 20 years earlier. With the increase in number, the birds are spread- 

 ing back along the Canal. In 1960, I found a dozen at Gamboa; previ- 

 ously I had never recorded any number beyond Fort Clayton and the 

 Miraflores locks. Dr. Fairchild told me that the grackle roosts in the 

 main plaza at Panama once became such a nuisance that the authori- 

 ties finally cut down the trees. In contrast, Thayer and Bangs (Bull. 

 Mus. Comp. Z06L, vol. 46, 1906, p. 221) saw only 1, an adult female, 

 in Panama City in 1904. They wrote that "the grackle is one of the 

 birds relentlessly hunted for food by the natives, and is found, conse- 

 quently, in very small numbers, and is exceedingly shy." 



As might be expected of a bird that expands so successfully when not 

 molested, the Great-tailed Grackle is opportunistic and aggressive. I 

 have seen them feeding along the shore of rivers and oceans, taking 

 fish (sometimes by diving a few inches), frogs, and crabs dead and 

 alive, hawking for flying ants and termites, picking parasites off cattle, 

 extracting insects from the ground, and eating berries. One that I 

 watched eating ripe berries of a royal palm (Roystonea sp.) seized them 



