Zosterops (ZOS-ter-ops). Girdle eye, from the Greek zoster, girdle, and ops, eye.
Their common name of white-eye or speirops (Greek spiera, circle, and ops) aptly describes the birds of this genus, with their wide ring of feathers around the eyes. There are 98 species of Zosterops, one of the largest genera in the bird world.
They live in regions of sub-Saharan Africa, Asia/Indonesia and Australasia. Once thought to be related to nectar-feeding birds like honeyeaters because of their brush-like tongue, recent DNA evidence puts them closer to Old World warblers.
These small birds, only 3-4 inches (10-12 centimetres) long and 0.3-o.5 ounces (10-12 grams) in weight, have been very successful in a variety of habitats, climate zones, and altitudes.
They are very good colonisers and easily invade disturbed habitats. The greatest number of white-eyes is found on the Solomon Islands, which are home to 11 species, but only one or two species exist on each island.
White-eyes are very social, congregating in flocks as they move through habitats in search of food while constantly calling to each other. Members of the flock apparently develop close relationships; ringing/banding studies have captured many of the same birds in a flock year after year. Flocks are sometimes small, but up to 500 birds have been counted in a single group.
One of the reasons for white-eyes’ success is their ability to enter a state of torpor at night, dropping their body temperature to about 410F (50c), resulting in a halving of their metabolic rate. At dusk white-eyes gather in small groups, but as darkness approaches, these small groups coalesce into a larger group.
From Latin for Bird Lovers by Roger Lederer and Carol Burr, Timber Press, 2014, 224 pages, $24.95, hardcover.
Photo: Silvereye. Sourced from https://en.wikipedia.org/wiki/Silvereye