Birds of spring 2005 (5)

这是一个Common Yellowthroat，也是Warbler的一种，乍一看，跟咱们国宝挺相像的。 另一个侧面像： 看看birds.cornell.edu的介绍： Common Yellowthroat: “Upperparts of both sexes are olive gray to olive brown. The throat, breast, and undertail coverts are bright yellow in males, and paler in females. The belly is whitish. The exact extent of the yellow and white of the underparts varies geographically. Males have a broad black mask across the forehead, enveloping the eyes. The band of whitish gray above the masks varies geographically and is yellowish in some races. Females lack the mask and have a faint buffy eye ring. The male Common Yellowthroat has a black mask that varies in size depending on the individual. A recent study showed that males with large black masks were more likely to win mates than males with small black masks. Males with larger masks were also more likely to sire young by copulating with other females, in addition to their own mate (Animal Behaviour 62: 435-446).” 这么看，我拍到的是个male。 “Male Common Yellowthroats perform song flight displays, especially during the late afternoon. The male gradually ascends into the air, calling to a height of 20 feet or higher, whereupon he utters a number of short sputtering notes, followed by song. He then drops back to the ground.” 不知道male common yellowthroat还能做这样的空中花样杂技。 “The female constructs a nest usually on or very close to the ground at the base of a shrub or clump of grasses. Sometimes she suspends the nest over water, attaching the nest to the stems of grasses, reeds or cattails. Occasionally, she extends loose material from the rim into an overhanging. The female incubates the eggs for about 12 days. Young yellowthroats leave the nest just eight days after hatching. They fly a few days later. Both parents tend to the young for an extended period up to 20 days. When a pair attempts to raise a second brood, as is common, the male sometimes assumes care of the first brood. Common Yellowthroats are frequent cowbird hosts. If a cowbird lays an egg in a yellowthroat’s nest, the yellowthroat sometimes builds a second nest on top of the parasite's egg and lays a new clutch. ”