Tuesday, August 22, 2017

Golden-hooded Tanager

Golden-hooded Tanagers are in the genus Tanagra, bright and varied tropical birds. About ten species are found in Costa Rica. This species occurs from southern Mexico to Columbia and Ecuador. It favors jungle edges, clearings and gardens. This tanager seemed to be common almost everywhere we visited in Costa Rica.

The closeup photos on the bottom was taken in the eastern part of the country on the last day of our trip. The first picture was taken on 2 August, the first full day of our travels. A pair of Golden-hooded Tanagers hopped about in front of a large, grass, domed nest. The female entered and exited from a hole in the side of the nest. What is strange is that this tanager’s nest is supposed to be an open cup (Cornell). It seems unlikely that these tanagers were using some other bird's nest. Possibly they were foraging for food in another species's nest.

Monday, August 21, 2017

Firetails

Two firetails were stunning dragonflies at the Villa Lapas frog ponds. (I use the word dragonfly to include damselflies.) Hyacinth Firetails (Telebasis levis) were abundant—and well named in English by Dennis Paulson, since water hyacinths clogged the small pools.

I was startled to find a firetail with striped sides. I called to Dennis, who identified the new damselfly as a Striped Firetail (Telebasis filiola). These two, in a “wheel” position—the male grasping the female’s neck and thus guarding her from competitors, while the female collects the male’s sperm—were the only Striped Firetails we saw. Both species range from Mexico to Panama.

Sunday, August 20, 2017

Cherrie's and Passerini’s Tanagers

Walking through the grounds of the Villa Lapas eco-lodge in western Costa Rica, we were delighted when an all-black tanager perched on a tree branch in front of us. Then the tanager spun around and displayed its scarlet rump. Aside from being beautiful, Cherrie’s Tanagers are taxonomically interesting. They used to be named Scarlet-rumped Tanagers. But these birds were split into two species— Cherrie’s along the Pacific coast of Costa Rica and Panama and Passerini’s on the Caribbean cost, from southern Mexico to northeastern Panama. 
The males of the two species are virtually identical. The last photo is of a Passerini’s Tanager taken later in our journey in eastern Costa Rica. The dull female Passerini’s Tanagers are actually easier to tell apart. They are brighter in the east than in the west. The two species, however, have different gene sequences. They do not hybridize, even in the only place where they come into contact in northwestern Costa Rica. (Since the males are so difficult to tell apart, I am not sure how ornithologists’ determined that the species don’t interbreed.) Cherrie’s Tanagers are named after George Cherrie, who explored the Brazilian River of Doubt with Theodore Roosevelt in 1913. Passerini was an Italian entomologist who lived in the early 1800s.

Saturday, August 19, 2017

Black Dasher

So far I am still posting about our first full day in Costa Rica, 2 July 2017. This dragonfly is a male Black Dasher (Micrathyria atra). This species occurs from Mexico to northern Argentina. We found several at the frog ponds at the Villa Lapas eco-lodge. The dasher appeared to watch us leave the ponds as we made our way back across the lodge grounds, searching for dragonflies and birds.

Friday, August 18, 2017

Familiar Bluet

On 11 August, Erika and I attempted a stroll in the St. Olaf College Wildlands. We did not last long before being beaten back by hoards of mosquitos—far worse than anything we experienced in Costa Rica! We managed to take one photograph along the trail—a Familiar Bluet.

Familiar Bluets are common, but local, damselflies across much of North America, south through Central America to northern South America. I have encountered them in south Texas. Curiously, this record is my first from Minnesota. We may be near the northern edge of their range. Others have recorded this species from the campus.

The species is similar to a number of other species. Note the projections on the back end. The little spines are triangular and almost as long as the last abdominal segment. Thanks to Jim Johnson for helping me with my identification.

Thursday, August 17, 2017

Harnessed Tiger Moth

On 11 August 2017, I was strolling dutifully behind Erika in the lumberyard of our local Menard’s when a striking moth caught my eye. I took this photo with my cell phone. It is a tiger moth. According to bugguide.net, at least four species of tiger moths and they are difficult to tell apart. The only way is to dissect and check out the genitalia. Clearly I did not do that, and I wonder if the moths carry microscopes with them when they go out to mate. 

I suspect this moth may be a Harnessed Tiger Moth, found from southern Canada to Florida, and west to Texas and South Dakota. The larvae feed on clover, corn and dandelion (Bugguide).

Wednesday, August 16, 2017

Eastern Kingbird

The local Eastern Kingbirds have brought off this year’s clutches. This first photo was taken on 7 August 2017, in Rice County in the Carleton College arboretum. This young bird seems to be contemplating its upcoming journey to South America. The second photo is of a recently arrived kingbird taken last May in the county. I have been experimenting with a new photo development program, Topaz Studio. I am pleased with the results. The app replaces Adobe Photoshop. If for no other reason, it is worth trying because the basic program is free.

Tuesday, August 15, 2017

Proboscis Bat

More bats in the Villa Lapas belfry. Proboscis Bats live in groups of up to 10, sometimes more. They have regular feeding areas, preferring small ponds like where we searched for dragonflies and frogs. They form harems and breed all year. These bats are found from northern South America north to southeastern Mexico.

Monday, August 14, 2017

Tent-making Bat

On 2 July 2017 alongside the Frog Ponds at the Villa Lapas eco-lodge in western Costa Rica, we found a Tent-making Bat hanging in a garden bush, These bats make their own abodes. The bats chew the ribs and veins of plants until the leaves fold over, creating a tent. On the plus side, this behavior means that the bats do not have to search for shelter in caves (which can be uncommon in the jungle) or other cavities in trees or in buildings. The disadvantage is that the leaves wither and die, and the bats have to make new tents every couple of weeks. One consequence is that Tent-making Bats tend to be more nomadic than more typical bats. (Wikipedia).

Look in the bat’s ears. The shiny, brown structure in each ear is not an eye, but a tragus. The tragus is a fleshy structure that aids bats in echolocation. The tragus collects sound from behind the bat. The result is that a bat has enhanced perception of its surroundings. The black eyes are further down the head nearer to the bat’s nose.

Sunday, August 13, 2017

Hourglass Frog

Hourglass Treefrogs, or Dendropsophus ebraccatus, are tiny, yellow frogs. They are Central American amphibians and are tolerant of ecological disturbance. They differ from other frogs (and, perhaps, all other vertebrates)—they can lay their eggs in the water or on land. If little shade exists, they go for the water. With shade, they lay their eggs on land. When in the water, the tadpoles are eaten by dragonfly nymphs. To escape the dragonflies, the frog larvae can change their tail color (Wikipedia).