Saturday, October 31

Could migrant Ammodramus Sparrows be found by ear?

The Ammodramus sparrows are extremely secretive and elusive during migration, acting like mice in often extensive grassland or weedy habitat. I've never found one by ear, but they do vocalize away from the breeding grounds, and conceivably they could be discovered this way if a suspicious sounding call was heard.
The flight calls are distinctive, Le Conte's being a long, descending tinny call, like a lengthy Savannah. Henslow's is a longish trill, that sounds a bit like an American Robin to me. Grasshopper Sparrows have a rising call; the only other clearly rising sparrow calls in the east are Vesper and White-crowned (and the rare Clay-colored). Saltmarsh/Nelson's (Sharp-tailed) have high (higher than Song Sparrow), level, tinny calls.
Of course, in the field, it would be extremely difficult to pick out one of these birds by its call, amongst all the other calls by more common species. Having said that, we need all the help we can get, and challenging as it might be, I'd say it behooves us to learn their calls to perhaps increase the odds of finding these little guys.
Le Conte's Sparrow (Feb, PA)

Henslow's Sparrow (Oct, PA).

Grasshopper Sparrow (Oct, NJ).

Sharp-tailed Sparrow (Nov, NJ)


JR said...

A friend and birder here in northern Mississippi can reliably locate and identify wintering Le Conte's Sparrows by ear. My high-freq hearing is not good for finding LCSP, but he located my lifer LCSP by ear (and we subsequently flushed it after a chase) in a grassland near Oxford, MS. So, there's no doubt they can be found and identified by ear.

Paul Driver said...

Excellent! I guess when I posted I was thinking of my region where these birds are very rare migrants. Where they are more common it would be somewhat easier.