Bulletin 202 - Panama #10 - Trogons, Finches, Iguanas

The trogons are a small worldwide family of 43 colorful birds, 2/3 of whom are in the Americas. They are medium-sized birds and have long square tipped tails (except for a few exceptions). They tend to sit motionless on branches until they fly out to snag an insect, or pluck fruit off a branch. Two species just make it into the USA in extreme southeast Arizona.

We saw and photographed 2 species on our trip. The first was the 12.5" Slaty-tailed Trogon (Trogon massena). The male has a green back and breast, red belly, gray tail and wings, and red bill and orbital ring.


Slaty-tailed Trogon - male

The female is duller with the green replaced by gray.

Slaty-tailed Trogon - female

The 9" Gartered Trogon (Trogon caligatus) is one of 3 species split from Violaceous Trogon for those of you unfamiliar with the name Gartered Trogon. The male has a green back, purplish head and breast, yellow belly and eye ring and striped undertail.

Gartered Trogon - male



The female is similar, but the back and head are gray and the eye ring is white.

Gartered Trogon - female



On another occasion, we watched a pair of these trogons attacking a mud nest of Aztec ants. These bell shaped ant nests are in the trees. The pair flew from their perches nearby and landed on the nest. They pulled pieces off to get at the ants inside. Here is the female hanging on the bottom of the ant nest.

Gartered Trogon - female on nest of Aztec ants

Some of the nomneclature of birds can be confusing. I find this especially with 4 families, the tanagers, finches, cardinals and new world sparrows. I suppose this arose as the discoverers of the new world species called them as to what they resembled in Europe. And now with DNA analysis, we can more closely find related species and put them in the proper relationship.

Because of that, we can have birds with the similar names, but they are not in the families of the that name. For example, we have birds called tanagers in both the cardinal and tanager families. We have birds called finches in the finch, cardinal, and sparrow families. There are cardinals in the cardinal and sparrow families. There are grosbeaks and buntings in the cardinal and finch families.

We saw 2 members of the finch family on the trip. Both are small bright yellow birds. The first was the Yellow-crowned Euphonia  (Euphonia luteicapilla). This is a tiny (3.5") bird. The male dark above and has a yellow breast and crown.

Yellow-crowned Euphonia - male

The female is dull yellow.

Yellow-crowned Euphonia - female

The other was the Thick-billed Euphonia (Euphonia laniirostris). It is a little larger at 4". The male is all yellow underneath and dark on top. The only one we saw was this juvenile male who has an olive back rather than black. The female is all olive and yellow.

Thick-billed Euphonia - juvenile male

One of the things that has always fascinated me as I have done more reading and research on nature is the geographical distribution of species. Animals of the same genus, tend to be close together geographically. This sort of make sense from a evolutionary perspective, if they evolved from an ancient species. Perhaps God placed these initial species around the globe and let evolution proceed from there or He placed all the different species, no one knows for sure.

To give you an example, there are 11 species of Piranga tanagers of which 5 occur in North America (Scarlet, Summer, Western, Hepatic and occasionally Flame-colored). The other 6 occur in Mexico, central America and northen South America.

The term iguana is very confusing as there is a suborder iguania that includes many primarily arboreal lizards such as chameleons in the Old World, New World iguanas, and anoles. The family iguanidae is narrowed down to New World lizards (anoles, spiny lizards, horned lizards) as well as Madagascar iguanas and a few others. Below that classifiaction is the subfamily iguaninae. There are 8 living and 4 extinct genuses in this family with a total of 47 living species. All of them are in the Americas and Caribbean Islands except for a few. There are 4 species in the Galapagos including the unique marine iguana.

Where it gets interesting is that there are 3 species in Fiji and Tonga Islands in the South Pacific. As well there were 2 more species there, that have gone extinct. These lizards are 6,200 miles from their nearest relatives and this has caused a biogeographical enigma. 2 hypotheses have been proposed to explain this distribution. The first was that some lizards rode debris from South America to Fiji on the South Equatorial Current, sort of like the Kon-Tiki Expedition.

The other is that there was an Old World precursor of the iguanas that spread across the Pacific Islands and also crossed the Bering land bridge into the Americas. However, no fossilized remains of this lizard have been found in the Old World. Also for me, I find it hard to believe a cold-blooded lizard could cross the Bering land bridge in the arctic. My theory is that God has a sense of humor and placed them there to puzzle us humans.

We saw 2 members of the iguanidae family. The Black Spinytail Iguana (Ctenosaura similis) is a large (up to 5') lizard that is gray in color with black bands circling his body. The range is southern Mexico to northern Columbia. Of interest, the Guiness Book of World Records lists this lizard as the world fasted lizard. They can run at 21 mph. We saw this one at the top of a chain-link fence with barbed wire above. We stopped and watched, and were concerned that he may have been impaled on the fence, as he wasn't moving. We got out to help him, and took some pictures. But as we got close to him, he jumped down and ran away.

Black Spinytail Iguana

The second was the Common Basilisk Lizard (Basiliscus basiliscus). This is one of 4 similar species popularly known as Jesus Christ lizards for their ability to run short distances on top of the water. They grow up to 2.5 feet in length. They are brown with a cream stripe on the sides and another on the upper lip and throat. The adults have a dorsal fin and the males have a crest as well. They are able to run on water as they have large hind toes with flaps of skin, that open in the water to increase the surface area of the foot.

Here is a juvenile. Notice he has no dorsal fin, but one can see the flaps on his hind toes.

Common Basilisk Lizard - juvenile

Happy birding and photography,

David McDonald dkmmdpa@gmail.com

photos copyright 2006 - 2014 David McDonald

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