Monday, June 23, 2014

Bulletin 201 - Panama #9 - Antbirds, Ovenbirds, and Rodents

Two families of new world birds may be unfamiliar to most people that haven't spent time in the tropics. The first is the antbirds and their relatives. The other is the ovenbirds. There is a warbler in North America named the Ovenbird, but this isn't related to the family of ovenbirds.

The antbirds and their relatives are small songbirds in 4 different families. They got their name as many of them feed by following army ant swarms and catching insects that fly off to avoid being devoured by the ants on the forest floor. Some of these birds resemble or behave like other birds, so have been named to show their resemblance. Thus we have antshrikes, antvireos, antwrens and just antbirds in the antbird family with 224 species. 3 other separate familes are the antthrushes with 12 species, gnateaters with 11 species, and the antpittas with 51 species. In general the males of these birds are black or gray with various white barring or spots. The females are brown with the white accents. They are confined to Central and South America.

In general these birds are hard to see as they tend to be in dense jungle, however the most likely one for someone to encounter is Barred Antshrike (Thamnophilus doliatus). This cute 6" bird is widespread throughout Central America and can be found in populated areas. They have hooked beaks like shrikes, bushy crests and yellow eyes. We photographed this pair in a town on the main street and also saw another pair by the beach. They are very noisy and pump their tails when calling, so are comical to watch. This bird is a favorite of many birders.

Barred Antshrike - male

The only other antshrike we saw was the 5.5" Western Slaty-Antshrike (Thamnophilus atrinucha). A pair of them kept flying back and forth, in response to the tape, over the path we were on, but we didn't get any good looks. Another time, at a lodge, where we got many of the hummer photos at feeders, I was watching the feeders and just had my camera set when a dull brown bird flew into the field and I got a single photo. When I showed the guide, he said it was the female of this species. Again, the hooked beak can be seen.

Western Slaty-Antshrike - female

The most common of the antwrens is the 4" Dot-winged Antwren (Microhopias quixensis). Its range is from Mexico to southern Amazonia. This was the only species of antwren we found and we saw it several times. The male is black with a white bar and dots on the wing and white on the tail.

Dot-winged Antwren - male

As expected, the female is similar but gray and rufous.

Dot-winged Antwren - female

The other 3 smaller families, antthrushes, gnateaters and antpittas, are secretive birds that walk along the forest floor searching for insects. We did not see or hear any, and in fact, I have never seen any of them in a half dozen tropical trips.

The ovenbird family is another huge tropical new world family of small to medium sized songbirds with 307 species. They are insectivorous and tend to be drab brown or rufous with varying spots and streaks. Many are named for their foraging habits, so we have treerunners, treehunters, foliage-gleaners, streamcreepers, and leaf-tossers. Others are named for plumage characteristics such as spinetails, barbtails, and tuftedcheeks. One group, which behave like woodpeckers by hitching up tree trunks to search for insects, are called woodcreepers. The woodcreepers used to be a separate family, but now are included with the ovenbirds. In general the sexes are similar in all these birds.

The Cocoa Woodcreeper (Xiphorrhynchus susurrans) has extensive streaking on the breast and back of head and upper back.

Cocoa Woodcreeper

Rodents and especially squirrels are often the most common mammals seen on birding trips. Here is the Variegated Squirrel (Sciurus variegatoides). It is a large tree squirrel with a range from southern Mexico to Panama. It has a dark back and light underside. Here he is taking a siesta.

Variegated Squirrel

The other rodent we saw was the almost tailless Central American Agouti (Dasyprocta punctata). It is a large (7-9 lb) rodent related to guinea pigs. It has shorter front legs than back. Their range is from southern Mexico through to Venezuela and Ecuador. They have been introduced to the Cayman Islands and Cuba. They were quite cute, and when disturbed they made a funny barking noise as they ran rapidly from the danger.

Central American Agouti

Happy birding and photography,

David McDonald

Photos copyright 2006 - 2014 David McDonald

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