Yellow Warbler, Setophaga petechia
Note: this post, while published, is a work in progress, as are all posts in this series, My Photo Life List. My goal is to photograph every species of bird that is seen on a regular basis here in Michigan, working from a list compiled by the Michigan chapter of the Audubon Society. This will be a lifelong project, that I began in January of 2013, and as I shoot better photos of this, or any other species, I will update the post for that species with better photos when I can. While this series is not intended to be a field guide per se, my minimum standard for the photos in this series is that one has to be able to make a positive identification of the species in my photos. The information posted here is from either my observations or the Wikipedia, the online free encyclopedia, however, I have personally shot all the photos appearing in this series.
Yellow Warbler, Setophaga petechia
The American Yellow Warbler is a New World warbler species. They make up the most widespread species in the diverse Setophaga genus, breeding in almost the whole of North America and down to northern South America.
Depending on subspecies, the American Yellow Warbler may be between 10–18 cm (3.9–7.1 in) long, with a wingspan from 16 to 22 cm (6.3 to 8.7 in). They weigh 7–25 g (0.25–0.88 oz), varying between subspecies and whether on migration or not, globally averaging about 16 g (0.56 oz) but only 9–10 g (0.32–0.35 oz) in most breeding adults of the United States populations. Among standard measurements throughout the subspecies, the wing chord is 5.5 to 7 cm (2.2 to 2.8 in), the tail is 3.9 to 5.6 cm (1.5 to 2.2 in), the bill is 0.8 to 1.3 cm (0.31 to 0.51 in) and the tarsus is 1.7 to 2.2 cm (0.67 to 0.87 in). The summer males of this species are generally the yellowest “warblers” wherever they occur. They are brilliant yellow below and golden-green above. There are usually a few wide washed-out rusty-red streaks on the breast and flanks.
Their song is a musical strophe that can be rendered “sweet sweet sweet, I’m so sweet”, although it varies considerably between populations. The call is a soft or harder chip or ship. This is particularly frequently given by females after a male has finished his song. In territorial defense, they give hissing calls, while “seet” seems to be a kind of specialized cowbird alert. Other calls are given in communication between pair-members, neighbors, or by young begging for food. These birds also communicate with postures and perhaps with touch.
The breeding habitat of American Yellow Warblers is typically riparian or otherwise moist land with ample growth of small trees, in particular willows. The other groups, as well as wintering birds, chiefly inhabit mangrove swamps and similar dense woody growth. Less preferred habitat are shrubland, farmlands and forest edges. In particular American Yellow Warblers will come to suburban or less densely settled areas, orchards and parks, and may well breed there. Outside the breeding season, these warblers are usually encountered in small groups, but while breeding they are fiercely territorial and will try to chase away any conspecific intruder that comes along.
These birds feed mainly on arthropods, in particular insects. They acquire prey by gleaning in shrubs and on tree branches, and by hawking prey that tries to fly away. Other invertebrates and some berries and similar small juicy fruits are also eaten, the latter especially by American Yellow Warblers in their winter quarters. Caterpillars are the staple food for nestlings, with some – e.g. those of geometer moths preferred over others.
These New World warblers seem to mob predators only rarely. An exception are cowbirds, which are significant brood parasites. The Yellow Warbler is a regular host of the Brown-headed Cowbird, with about 40% of all nests suffering attempted or successful parasitism. Upon recognizing a cowbird egg in its nest, the warbler will often smother it with a new layer of nesting material. It will usually not try to save any of its own eggs that have already been laid, but produce a replacement clutch. Sometimes, the parents desert a parasitized nest altogether and build a new one.
As usual for New World warblers, they nest in trees, building a small but very sturdy cup nest. Females and males share the reproductive work about equally, but emphasize different tasks: females are more involved with building and maintaining the nest, and incubating and brooding the offspring. Most of the actual feeding is also done by them. Males are more involved in guarding the nest site and procuring food, bringing it to the nest and passing it to the waiting mother. As the young approach fledging, the male’s workload becomes proportionally higher.
The clutch of the American Yellow Warbler is 3–6 (typically 4–5, rarely 1–2) eggs. Incubation to hatching usually takes 11 days, but may take up to two weeks. The nestlings weigh 1.3 g (0.046 oz) on average, and are brooded for an average 8–9 days after hatching, and leave the nest the following day or the one thereafter. Almost half of the parents attend the fledglings for some time after these leave the nest. This post-fledging care can extend for two additional weeks or more, and sometimes the pairs separate early, each accompanied by one to three of the young.
Some 3–4 weeks after hatching, the young are fully independent of their parents. They become sexually mature at one year of age, and attempt to breed right away.
On to my photos:
This is number 114 in my photo life list, only 236 to go!
That’s it for this one, thanks for stopping by!