NO. 5 MAMMALS OF PANAMA — GOLDMAN 1 39 



SCIURUS GERRARDI CHOCO Goldman 



Darien Squirrel 



[Plate 29, figs. 1, 10] 



Sciurus variabilis choco Goldman, Smiths. Misc. Coll., Vol. 60, No. 22, 

 PP- 4-5, February 28, 1913- Type from Cana, eastern Panama (altitude 

 3,500 feet). 



The Sciurus gerrardi group of tree squirrels, widely dispersed in 

 northwestern South America is represented in Panama by two forms, 

 one of which ranges as far north as the Canal Zone. They are 

 recognizable by the varicolored tail, the intense rusty reddish general 

 hue of which contrasts strongly with the broad black tip. In general 

 shade of coloration they are not very unlike the smaller species, 

 5". hoffmanni, which inhabits western Panama, but the latter has the 

 tail uniformly washed or broadly edged with ochraceous buff to 

 the tip. 



6". g. choco of the Darien region in eastern Panama is closely allied 

 to S. g. mornlus of the Canal Zone, but is distinguished by darker 

 color throughout; a deep black median dorsal stripe, usually con- 

 tinuous from near the shoulders posteriorly over the upper base of 

 the tail, is absent or only faintly indicated in 6". g. morulas. The 

 underparts of the body are a darker rusty reddish shade ; the under 

 side of the tail is marked by a broader, more distinct black sub- 

 marginal stripe. Variation from the usual rufescent coloration of 

 the underparts is shown in one individual by limited areas of pure 

 white near the armpits, on the pectoral and inguinal regions, and a 

 very narrow stripe along the median line of the abdomen ; in another 

 the white is reduced to a few hairs near the armpits and on the sides 

 of the lower part of the abdomen. These white areas may indicate 

 gradation of this subspecies toward the South American forms of 

 the 5\ gerrardi group in which the underparts are normally white. 

 Specimens from 800 to 2,500 feet altitude, on Cerro Azul near the 

 headwaters of the Chagres River, are somewhat intermediate 

 between S. g. morulus and the Darien form, the black dorsal stripe 

 being somewhat indistinct, but in the rich coloration of the under- 

 parts they agree with the latter form. S. g. milleri from the moun- 

 tains of southwestern Colombia seems to be a nearly related form 

 with the same pattern of coloration, but it differs in darker, more 

 rusty reddish hue, the darkening due in part to the much narrower 

 subterminal bands of the hairs on the shoulders and flanks. 



These squirrels are generally distributed throughout the region 

 visited, ranging upward in the forest from sea level in the Tuyra 



