Tangara TANAGERS ... Dazzling gems from the South American rainforests

Abstract

Introduction

Tanagers have fascinated me since 1961 when I saw my first live specimens of this large family, comprising 240+ species. Inhabitants of rain and cloud forest, the brilliantly colored tanagers are mainly confined to the tropical and subtropical regions of the Americas. Most species are to be seen in South America, with a few species extending their range into Central America and Mexico.

Only four species are migratory - the four Piranga spp. that breed in the USA migrate southwards for the winter. The rest are non-migratory and largely sedentary, with only slight altitudinal movements in search of food.

Ornithological Observations and Notes

Many tanagers are rather lacking in color, but others are unbelievably beautiful, especially some of the 48 species of the genus Tangara. These denizens of rainforest and other thickly wooded areas are the most brilliantly colored and diverse in color pattern. As they have little or no true song, their beauty is mainly in the coloring. In size, they range between 4.4-6 inch-

es Cl 1-15 cm) and the sexes are generally alike. Different species of tanagers can often be seen forming mixed parties with various insectivorous birds, which then work their way through the canopies of trees, feeding mainly on insects and fruit. Insects are gleaned from the underside of leaves and crevices in trees. Bromeliads are home to insects that are much sought after by tanagers, and they can often he seen probing in the leafy structure and flowers. It is enthralling to see these mixed parties operating, and to see how diligently they work from tree to tree.

The question as to how and why different species of tanagers can work together in these mixed parties - when presumably they are competing for the same food source - is easily explained through observation. Some tanagers eat more fruit, while others are more insectivorous, and a few are almost wholly insectivorous. Significantly, one species will seek insects under leaves, another feeds on insects found in thin moss covered branches, and, the crevices in trees and branches is the feeding place for a third species, while

a fourth may seek insects in bromeliads etc. etc. In this manner, each species almost has its own ecological niche, and does not necessarily compete directly with another species!

While photographing with a team of scientists working on a rainforest project in Colombia during 1991, I had an opportunity to study various tanagers in different locations. In the Anchicaya River valley, a hot and humid rain forest area situated some 40-50 km east of Buenaventura, a number of interesting species, including Scarlet and White Tanagers Erytbrotblypis salmoni, Silver-throated Tanager Tangara icterocepbala, and Golden-hooded Tanager T larvata, were seen accompanying honeycreepers, warblers, banaquits, dacnis, and various insectivorous species. By forming small parties, it was more beneficial for all birds involved as, collectively, they were able to disturb more insects which would then be snapped up readily. Some search "head down" beneath branches and leaves. Food plants are predominantly various species of Cecropia and Miconia, the fruits of which feature in the daily intake of Tangara species.

Down in the valley, about 300 feet (100 meters) above sea-level, Lemonrumped Tanagers Ramphocelus icteronotus used to feed greedily on cooked rice brought down from the canteen of the hydro-electric project by the workers, and placed on a stone wall built on top of the river bank. This omnivorous feeding habit, even in the wild, extends into aviculture where species of the Ramphocelus genus are equally omnivorous and will adapt

. more readily to an artificial diet than some of the other genera.

Nesting in the wild is unpredictable because of the climatic variations in the distribution area of certain species. Silver-throated Tanagers breed around January and February, as well as October at the hydroelectric project in the lower Anchicaya River valley, while further up the valley near Cali, at approximately 1000 meters above sea level, the same species has been recorded breeding in June. Silverthroated Tanagers build a mossy cupshaped nest, usually placed in a bush

or tree between 2-12 meters up. The normal clutch is two whitish eggs with heavy brown mottling.

Another species that breeds in the upper Anchicaya River valley between April and September is the Golden or Black-eared Golden Tanager Tartbus.