The Common Yellowthroat is another bird that looks surprisingly stunning for a bird breeding in a temperate climate. Apparently, it is very common – the Audubon Society claims that “it is found in practically every reed-bed and patch of cattails from coast to coast”.

eBird seems less impressed, calling it a “small warbler, dull olive overall with intense yellow throat” – somehow, I feel if this were an Asian bird, the description would be a bit more enthusiastic. Familiarity breeds contempt? (Never miss an opportunity to advertise a Chills song).

And a friend called it “the Zorro bird”, probably the best description (for the male, at least).

The scientific term apparently is “black facial mask”, and it may be an indicator in the hierarchy of male yellowthroats. One study in Wisconsin found that males with larger black facial masks were dominant over males with smaller masks and preferred by females in mate choice experiments.

However, when aiming to reproduce the results in New York, females preferred males with larger yellow bibs, though those males with larger black masks were still dominant, but not preferred by females. Lesson learned: better not replicate studies, as this may result in understanding the world less than before …

Or maybe, this does indeed result in better understanding. The carotenoids responsible for the yellow bib are more difficult to provide than melanin. So, if environmental conditions are different (e.g., different habitat, different level of parasites), females may have different preferences. For example, food may be easy to obtain but male competition may be high in Wisconsin, putting a premium on dominance, while in New York, the bottleneck is in finding sufficient high-quality food (with success indicated by a strong yellow breast).

Meanwhile, window collisions are a problem for both competitive male yellowthroats and choosy female ones. In a study conducted in Alabama, yellowthroats were the species with the second-highest number of such deaths after ovenbirds (source).

Apart from avoiding windows, modern yellowthroats also seem to be under pressure to change their songs, particularly in urban areas. Indeed, urbanization metrics significantly affected five of the common yellowthroat’s nine studied song features (source).

Fortunately, other threats turn out to be more temporary. While the number of yellowthroats in a forest affected by a non-native beetle shrank considerably, it also recovered relatively quickly after the beetle invasion had passed.

With the word “common” even in its name and eBird describing it as “dull olive overall”, many US birders might quote the Chills song when asked about the Common Yellowthroat. I won’t.