Friday, September 20, 2013

Birding tip: noisy Acadian Flycatchers


The Acadian Flycatcher belongs to arguably the most difficult to identify group of birds in North America, the flycatchers in the genus Empidonax.  They are all small (warbler sized), have wingbars, are colored in subtley different hues of olive and gray above, and are white below, usually with yellowish tinges.  Many Empidonax seen in the field are not identified to species, especially if they are silent.

The Acadian is the only species in the group that nests in our area, and is common in shady bottomland forests such as in Jean Lafitte Park and the Honey Island Swamp.  It can be located in the nesting season (May-June) by listening for its sneezy song, and then peering patiently at the subcanopy for the bird to move perches since it is difficult to pick out in its shady habitat if it just sits tight.

Oddly, this species goes through a season of enhanced vocal activity in the late summer (now!), when they notably utter a rather bold whee! call.  On many occasions, they will string these into series that commonly reach a dozen or two utterances, spaced about a second apart.

Hearing this call gives away the presence of the species, easier than at any other season.

Today I heard one whee-ing away in a shady spot of the Jefferson batture, redeeming an otherwise migrant-less visit.  It uttered 20 of these phrases in a steady sequence before I stopped counting.  This bird was passing through as a migrant- they don't nest in the batture.

My bird today shows that they sometimes do this away from breeding sites, but my general impression is that the best chances of hearing one uttering this call at this season is in bottomland forest areas such as the ones they nest in.  For instance, some birders at Honey Island Swamp yesterday reported 9 in 3-4 hours. Another visit there on Sep 5 produced 16 in 4-5 hours, and 17 were reported on Aug 20 in 5 hours.  In all three cases, I would predict that most were detected by their uttering this call.

Good birding,

Peter

for a copy of Birding Made Easy- New Orleans, make a personal check out for $24 (incl $4 shipping) payable to Gulf South Environmental Investigations LLC, and mail it to
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330 Jefferson Heights Ave
Jefferson, LA 70121

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