1917.] Chapman, Distribution of Bird-life in ColomMa. 25 



The Cauca Valley near Cali. — The Cauca Valley from Call to Cartago 

 has a uniform altitude of 3500 feet and an average width of possibly twenty- 

 five miles. 



The rainfall is not high, ranging from thirty-five to fifty inches, and 

 forests apparently occur only where they receive natural subsurface irriga- 

 tion from the mountain slopes. The Cauca River, which is navigable for 

 small steamers from Cali to Cartago, except during very dry seasons, is 

 bordered by marshes, bamboo thickets and savannas and, in places, by 

 heavy forests. Approaching the mountains, on each side, dryer savannas 

 with acacias and large tracts of grazing and cultivatable land predominate 

 and extend to the bare, rounded foot-hills which lead upward to the lower 

 borders of the cloud forest of the Subtropical Zone. 



About Cali we collected in the savannas and marshes; at La Manuelita 

 in the pastures, cacao groves and fallow fields grown with scrub and bordered 

 by trees. At neither place did we find first-growth forests such as exist 

 in the vicinity of Guengiie east of Florida, where, however, circumstances 

 shortened our stay. Miller and Allen later collected in primeval forest at 

 Rio Frio, but I feel that more work could be done to advantage in the forests 

 of the valley. 



The Central Andes above Palmira. — Our location at Miraflores (alt. 

 6200 ft.) on the western slope of the Central Andes above Palmira, was much 

 like that in which we had lived at San Antonio. The comfortable bungalow 

 which Mr. Eder so kindly placed at our disposal is situated near the junction 

 of the Tropical and Subtropical Zones. Above us was the lower border of 

 the luxuriant subtropical forest; below, the bush-grown or bare hills leading 

 to the valley. If, therefore, we went down the trail we encountered chiefly 

 tropical forms but if we climbed upward we were soon among the birds of 

 the subtropics. Where the change in fauna also implied change in haunt 

 the difference between the bird-life below and above our home seemed 

 natural. Thus Ground Doves and Seedeaters were to be expected in the 

 open grassy country toward the valley, just as Tanagers and Trogons were 

 to be looked for in the forests higher up the mountain side. When, however, 

 in the belt of timber bordering the Amina River, a thousand or fifteen- 

 hundred feet further down, one found Ostinops decumanus, a strictly tropical 

 species, and in not dissimilar haunts a few hundred feet above the bungalow, 

 encountered Ostinops salmoni a strictly subtropical species, one was more 

 impressed by the influence of temperature in determining life-zones. 



The summit of the ridge on which Miraflores is situated has an altitude 

 of 8000 feet, and the forest growth increases in luxuriance as one mounts 

 toward the crest. Nowhere have I seen a greater profusion of creepers, 

 parasitic and epiphytic growth. • ■ Tree ferns here were estimated to reach 

 a height of fifty feet. 



