Friday, February 7, 2014

ID: Gnatcatchers of San Diego

Blue-gray Gnatcatcher
Blue-gray Gnatcatcher. Escondido, California. January 1, 2014. Greg Gillson.
In Oregon, Blue-gray Gnatcatchers barely reach the southern edge of the state. So I rarely saw them, living as I did in the NW corner. Active and perky, these birds are like more long-tailed and long-legged Bushtits that mostly occur as pairs. So I love the chance to see them more often now.

Gnatcatchers as a whole tend to prefer brushy habitat, so, yes, there's always a pesky stick in front of them ruining that perfect shot!

As for identification, the Blue-gray Gnatcatcher is... wait for it... blue-gray above, almost white below. The tails on gnatcatchers are key to their ID. On Blue-gray Gnatcatchers the outer tail feathers are white. This causes the underside of the tail when held normally (not spread) to be nearly entirely white, with dark restricted to the inner underside of the tail.

The call is a soft, almost insect-like, drawn out "speee."

This species likes riparian and is often found in weedy or brushy river bottoms but also chaparral and even juniper woodlands in the West. In San Diego County they are found throughout the county, including quite near the coast, but below the mountains, and only along water courses in the eastern desert areas.

Black-tailed Gnatcatcher
Black-tailed Gnatcatcher. Anza-Borrego Desert, California. January 26, 2014. Greg Gillson.
Black-tailed Gnatcatchers replace Blue-gray Gnatcatchers in the desert. However, near water both species can occur in desert habitats.

In comparison to the Blue-gray Gnatcatchers, Black-tailed Gnatcatchers are darker gray, still with  contrasting paler underparts. The inner and basal portions of the tail are black on the undersides, but there is a considerable amount of white in the outer portion of the end of the tail.

The call is rather harsh in comparison with Blue-gray Gnatcatcher, but not loud; it is a doubled or tripled "chee-eee."

In San Diego County Black-tailed Gnatcatchers are found in the extreme eastern portion in the Anza-Borrego desert.

California Gnatcatcher
California Gnatcatcher. Lake Hodges, California. February 2, 2014. Greg Gillson.
Found only in the disappearing coastal sage scrub habitat of the coastal slope from southern Ventura County to southern Baja California Sur, the Endangered California Gnatcatchers are similar to Black-tailed Gnatcatchers, from which they were split in 1993.

They are rather dark gray all over, including the underparts, and the tail is nearly entirely black underneath.

One of their calls is a soft cat-like mewing. They also have a harsher call similar to Black-tailed. I've had some difficulty finding this species by voice, as House Wrens also winter commonly in coastal sage scrub and give a similar harsh call note in addition to their more familiar rattle. I've chased a lot of soft harsh calls thinking I was going to find a California Gnatcatcher and ended up with a House Wren instead.

Two locations in San Diego County where California Gnatcatchers are fairly easy to see is San Elijo Lagoon and Lake Hodges.