98 BIRDS OF THE REPUBLIC OF PANAMA PART 2 



Costa Rica through Panama and northern South America, south to 

 eastern Peru, Bolivia, and north-central Brazil. Those of Central 

 America differ slightly in depth of blue on head and breast, in darker 

 green of the back, in amount of red on the lower foreneck, and in 

 average smaller size, from the population of southern Colombia 

 southward. The differences noted are variable but are evident when 

 specimens from Panama and Brazil are compared. The northern 

 race covers northern Colombia, while in central and southern Colom- 

 bia there is a broad area of intergradation in which size usually is 

 large like the southern race, but color in the main is like that of the 

 northern group. Wing measurements in typical menstruus range 

 from 178 to 187 mm. 



PIONUS SENILIS (Spix): White-crowned Parrot; 

 Casanga Cabeciblanca 



Psittacus senilis Spix, Av. Spec. Nov. Bras., vol. 1, 1824, p. 42, pi. 31, fig. 1. 



(Veracruz, Mexico.) 

 Pionus senilis decoloratus Griscom, Amer. Mus. Nov. No. 379, October 17, 1929, 



p. 6. (Pozo Azul de Pirris, Costa Rica.) 



Similar to the blue-headed parrot, but forehead and crown white ; 

 rest of head and breast greenish blue. 



Description. — Length 230-245 mm. Adult male, forehead, feath- 

 ered anterior lores, and anterior half of crown white; throat and 

 upper foreneck buff to brownish white ; rest of head, lower foreneck, 

 upper hindneck, and upper breast greenish blue, each feather edged 

 with dull blue ; back, rump, and upper tail coverts green, with some 

 of the feathers partly blue basally ; lesser, middle, and greater coverts 

 green basally, tipped with brownish olive, in part spotted with buff 

 to olive-buff; greater coverts and inner secondaries green externally, 

 blue on concealed portions; primaries and outer secondaries dark 

 blue, with outer webs of outer primaries green at tips ; upper surface 

 of tail with central feathers green, the others blue; lower breast, 

 abdomen, sides, and flanks rather dark green, in some edged in part 

 with dark blue; edge of wing narrowly buff; central under wing 

 coverts blue ; outer under wing coverts, under primary coverts, and 

 under surface of wing green ; outer webs of primaries dull black ; 

 under tail coverts and base of tail red ; in some, abdomen and flanks 

 suffused with red. 



Adult female, usually with green and blue colors somewhat duller. 



Immature, forehead and anterior crown edged and tipped with 

 white to buffy white ; throat buffy white ; general color green with 



