FAMILY THRAU PIDAE 



441 



Adult female, head and throat dark brown; upper back dark brownish 

 red, brightest on upper tail coverts; wings and tail blackish brown; rest 

 of undersurface light brownish red. 



Immature, like female, but duller. 



Figure 35. — Crimson-backed Tanager, Sangretoro Comim, Ramphocelus dimi- 

 diatus, male (above), female (below). 



The Crimson-backed Tanager is widespread and common in the low- 

 lands (except in continuously forested areas) and in partially cleared 

 areas in foothills of both slopes of Panama. It is more abundant on the 

 Pacific slope, and on the Caribbean side is absent from Bocas del Toro. 

 A separate race is found in the islands of the Pearl Archipelago, and 

 another on Isla Coiba, off the Pacific coast of Veraguas. In the past, 

 populations from mainland Panama have been divided among three 

 races: nominate dimidiatus, supposedly in Darien, albirostris (—palli- 

 dirostris Hellmayr ) of Chiriqui, and isthmicus in between. In the large 

 series now available at the Smithsonian, it is evident that age and indi- 

 vidual variation account for the differences previously attributed to 

 geography. Herein all the birds of mainland Panama are referred to 

 the nominate form, which ranges to Colombia and western Venezuela. 

 Similarly, it also appears that the race molochinus (de Schauensee, 

 Proc. Acad. Nat. Sci. Philadelphia, vol. 102, 1950, p. 136) of the upper 

 Magdalena Valley of Colombia may be indistinguishable from the 

 nominate form. 



This species inhabits forest edge, shrubby areas, clearings, and gar- 

 dens; at Balboa, Canal Zone, I have seen several feeding at a ripe mango 

 on the ground and coming to drink at a dripping faucet. In the wild, 

 especially in the islands, they are shyer and more likely to be found in 



