Thursday, September 21, 2017

Black-bellied Whistling-Duck

We have seen Black-bellied Whistling-Ducks in Texas and Florida, where the species is common and expanding its range. This duck is also found in other southern states and in Arizona. Whistling-ducks used to be called tree-ducks, but the Black-bellied is far more often found in trees than are other species of whistling-ducks. Elsewhere in this blog I discussed how birds can sleep with one eye open. I wonder if the opposite eye of each of these birds is closed or open.

Black-bellied Tree Ducks were abundant in western Costa Rica. These two guarded one of the Tarcoles ponds. These ducks range south to northern Argentina (Dale and Thompson 2001).

Wednesday, September 20, 2017

Tikal Spreadwing

A Tikal Spreadwing on 3 July 2017 at one of the Tarcoles ponds in Puntarenas Province, Costa Rica. The second photo is of another we saw later on our trip, on 15 July, at La Selva Reserve in Heredia Province. Tikal is the location of famous Mayan ruins in Guatemala, and this species is found from southern Mexico to Panama. This spreadwing is common in many locations across its range

Tikal Spreadwings are found along shallow ponds and marshes in forested areas. They prefer regions that enjoy marked dry and wet seasons. Prolonged drought, however, and deforestation might adversely affect this species (IUC Red List).

Tuesday, September 19, 2017

Claret Pondhawk


Claret Pondhawks (Erythemis mithroides) are rarely recorded in the lower Rio Grande Valley in Texas. This dragonfly is found across much of South America, with an isolated population in Central America (Mexico, Guatemala, and Honduras). At one time, the northern population was thought to be a different species. But subsequent study revealed that Claret Pondhawks are simply variable across their range (Paulson, per. com.).

Claret Pondhawks patrolled the Tárcoles ponds we visited on 3 July. This pondhawk and others we observed usually faced toward the pond centers—better to see prey and competitors. I am not sure to which population these Costa Rican pondhawks belong.

Monday, September 18, 2017

A Squadron of Pelicans and a Red-banded Gull

What do you call a flock of pelicans? Google suggests a squadron. Considering the smell of a pelican colony, I find that answer somewhat fishy. How about a whiff of pelicans? 14 September found Erika and me at nearby Circle Lake as we took photos of American White Pelicans. A few gulls, Franklin’s and Ring-billed, loafed in front of the pelicans. I noticed one sported red bands on its left leg. A post to the Minnesota Birding FaceBook group drew this response: "Todd Froberg Hi All, I'm a graduate student at the University of Minnesota working on this project. Thanks very much for the report on RBGUs with red bands. They are part of a University of Minnesota study on presence of non-pathogenic avian influenza in gulls. Birds were banded at 3 colonies and at various landfills in MN. We have had reports of gulls we banded as far as Lake Erie and Lake Michigan so far this late summer/fall. The bird in the photo was probably banded at the Rice county landfill. One aspect of the study is to learn about gull movement among different locations in the state, particularly in relation to poultry farms, so your reports and photos are of great help and interest. For more info, send questions/reports to Francie Cuthbert (cuthb001@umn.edu).”

Sunday, September 17, 2017

Shadow Darner

During the last week, a large, dull darner hovered over our water feature. Each time, I ran for my camera, only to have the dragonfly disappear. Friday, 15 September 2017, I caught an image. This observation is not my first for a Shadow Darner in the backyard. In an earlier post, I commented about this species’s cold tolerance.

The species deposits eggs into “wet, rotting wood of a floating log or a partially submerged log” (Mead). This day the darner behaved strangely. It repeatedly returned to the dry, mossy edge of our artificial pond and appeared to deposit her eggs along a crease along the pond wall, The eggs seemed to be placed deep into the mossy mat about four inches above the high waterline.

Saturday, September 16, 2017

Band-winged Dragonlet

Band-winged Dragonlets were fairly common along the Tárcoles ponds on 3 July 2017. This observation was not the first time we’ve seen this dragonfly. The first was in southern Texas on 18 March 2012. Judging by their numbers in Texas, Band-winged Dragonlets may be partially migratory. They are abundant in the tropics, from Argentina north into the United States (to Ohio, Georgia, and Florida). Look for them low in the grass or as they fly over ponds (Paulson).

Friday, September 15, 2017

Three-striped Dasher

These male (above) and female (below) Three-striped Dashers are from the Tárcoles district of Costa Rica. This dragonfly ranges from the southern tip of Texas to northern South America and from southern tip of Florida through the West Indies. They tend to perch in the shade, often with their wings drooped down. Their breeding biology is poorly known—males are found at or over water, while females stay further away. Pairs copulate in woodlands away from water (Paulson).

Thursday, September 14, 2017

Northern Jaçana

Almost every day during our Costa Rican trip, we saw at least a few new dragonflies (as to be expected on a dragonfly tour). Several days, however, were outstanding. The afternoon of 3 July was one of those mega-days. We explored two freshwater ponds in the Tárcoles District near the Pacific Ocean. The ponds were quite different, one surrounded by forest and the other beside a motel in the outskirts of the village of Tárcoles. I have combined these locations in my posts.

But first a bird—Northern Jaçanas greeted us at the motel pond. Everything about jaçanas is interesting. The cedilla hanging below the c in jaçana is often found in French and is pronounced like an “s” rather than a “k,” as in façade or garçon.

Northern Jaçanas range from coastal Mexico south to Panama. Occasionally they stray into eastern Texas. Note the yellow spurs, outgrowths of their wrist (carpometacarpus) bones. These are displayed during courtship. These structures are not unique to jaçanas, some plovers also have them.

Female jaçanas are larger than their males and their sex roles are reversed. Males build the nest, incubate, and bood their young. Females rarely brood the chicks. The females mate simultaneously with up to four males. The females defend their mates' nests against other females and other male jaçanas. This polyandry occurs in rich habitat. In poorer habitat, male territories tend to be larger, the result being their females may mate with fewer or just one male (Birds of North America).

Tuesday, September 12, 2017

Lemon-tipped Helicopter

As I recall, Netta Smith saw a Lemon-tipped Helicopter (Mecistogaster ornata) first thing at Carara National Park, but nobody else saw it. After our lunch, she found it again. Photographing Lemon-tipped helicopters, as these damselflies row lazily through the air, is nearly impossible. No structure is visible to the camera’s autofocus. I took this photo with manual focus.

These elegant odes are sometimes called Ornate Helicopters or Yellow-tipped Helicopters—no official common names exist for most Costa Rican dragonflies. They range in tropical woodlands from Mexico to northwestern Argentina. Like the Blue-winged Helicopter, these dragonflies are web-spider specialists. Apparently the yellow wing spots distract the spiders before they are captured. Lemon-tipped Helicopters also eat insects trapped in spider webs. These damselflies lay their eggs in water-filled holes in trees (ICN Red List).

Monday, September 11, 2017

Blue-eyed Setwing


Back at the tour bus for a picnic lunch on 3 July at Carara National Park. With our bee allergies, picnicking can be a bit dicey. We ate quickly and searched the parking area for more dragonflies. This Blue-eyed Setwing (Dythemis nigra) perched at the forest edge. The species is known from northeastern Mexico (almost to the United States) south through most of Brazil. This habitat is typical for the species. Males perch on dry stems and survey their territories (Benoit.Guillon).

Sunday, September 10, 2017

White-whiskered Puffbird

Also attending the army ant swarm on 3 July at Carara National Park was a male White-wiskered Puffbird. Puffbirds are neotropical birds related to Jacamars and, more distantly, to woodpeckers. The White-wiskered Puffbird inhabits forests from southeastern Mexico to Ecuador. Males are more rufous than females. Puffbirds perch quietly, occasionally capturing insects, frogs, or lizards. White-wiskered Puffbirds are known to join mixed species flocks around army ant swarms (Cornell).

Saturday, September 9, 2017

Bicolored vs White-cheeked Antbirds

Bicolored Antbirds are common across their range. This bird is an obligate army ant follower. As the ants move through the forest, they stampede a host of invertebrates in front of the swarm. Army ant followers pick off the stampeding invertebrates, leaving the army ants alone. Bicolored Antbirds also take small frogs and lizards.
Two disjunct populations exist—one from Honduras south to northern Colombia and western Ecuador; the other in upper Amazonia, from southeast Colombia to north-central Peru. Erika and I worked with Bicolored Antbirds in Ecuador. I am surprised I have not shared a photo of the Ecuadorian bird with this blog. Note the bird in the second photo. Unlike the Costa Rican bird in the first photo, the Amazonian bird is white below the eye; behind the eye is black, not brown; the upper-parts are richer chestnut; and the calls are different. Genetic studies show that the two populations are not closely related.

eBird, presumably following the American Ornithological Society, now classifies my Ecuadorian bird as the White-cheeked Antbird (Gymnopithys leucaspis) and the Costa Rican one as the Bicolored Antbird (Gymnopithys bicolor). When we saw our Costa Rican bird at the furthest point of our jungle hike on 3 July at a bridge over a small river, we had no idea we were adding a life bird to our lists. One thing for sure, the ground was swarming with ants!

Friday, September 8, 2017

Broad-winged Hawk and Darners

On Thursday, 7 September, Erika and I strolled in the Carleton College arboretum in Rice County. Swarms of darners flew over the prairie. Most, as one might expect, were migratory Common Green Darners. One, however, was the Green-striped Darner in the second photo. This record is only my second for this species. Curiously my first sighting was only several hundred yards disrtant, and almost exactly two years ago. We also saw several Red Saddlebags, but they proved impossible to photograph.
A Broad-winged Hawk circled above the darner swam. These hawks are opportunistic feeders, and they are known to take various insects. To my surprise, dragonflies are not mentioned as being among the hawk’s prey in The Birds of North America. Hawk Mountain’s website, however, informs us that “During migration, broadwings will feed opportunistically on insects, including migrating dragonflies…”

Thursday, September 7, 2017

Blue-winged Helicopter

My readers have patiently read my complaints in the last couple of posts about viewing wildlife in the jungle. Dragonflies were no exception. We were in Costa Rica in July because odonates are most abundant in the rainy season. But dragonflies withdraw when it is raining or even cloudy. What a conundrum!

My dragonfly chasing is only a half-dozen years old. I did not know much about Costa Rican dragonflies. I did know that Blue-winged Helicopters are perhaps the largest living odonates—at least in terms of wingspan. Definitely one of my target species—imagine my delight at our finding one on our third day in Costa Rica!

Some entomologists hypothesize that the Blue-winged Helicopter color mimics a foul-tasting butterfly, and thus birds tend to avoid them. As this creature flies through the forest, its dark wingtips look almost like spinning helicopter blades. These damselflies are web spider specialists. Apparently the spiders are distracted by the hovering black wing tips and never see the damselfly’s mandibles. Scientists, without distracting black spots, try to capture spiders with a remarkable lack of success.

Wednesday, September 6, 2017

Green-and-Black Poison Dart Frog

During our Costa Rica, 3 July, trek through the Carara National Park jungle, we kicked up a Green-and-Black Poison Dart Frog (Dendrobates auratus). The frog’s (as is the case with many in the genus) bright coloration serves to warn predators to stay away. Indeed, unlike many other frogs, Poison Dart Frogs are diurnal and, lacking predators, tend to be conspicuous. The frog absorbs toxins from its prey—perhaps ants. Some Native Peoples use frog skin secretions on their arrows. Monkeys that survive being hit by arrows can thus be brought down. Handling the frogs is not dangerous per se, unless you have cuts on your hands or you rub your eyes after touching the amphibians. The frog in the second photo, taken two days later, hopped about our front porch at the Villa Lapas eco-lodge.

Tuesday, September 5, 2017

Northern Tamandua

I mentioned in my last post that a drawback to jungle hiking is that the understory tended to be too dark to take really good photographs. But wonderful creatures were to be seen. Northern Tamandua are a species of anteater that range from southern Mexico to northern South America.

Tamanduas are mainly nocturnal, but are also active during the day. They spend about 40% of their time in trees. They are active for about eight hours, sleeping the rest of the day in hollow trees. They are generally solitary. They eat ants and termites, and consume up to 9000 insects per day. They search by smell and dig into, but do not completely destroy, ant nests with their claws. They avoid soldier ants and look for non-noxious workers. They use their long, sticky tongues to capture prey. They also eat bees and honey (Wikipedia; Encyclopedia of Life).

Monday, September 4, 2017

Barred Antshrike

After we finished at the parking lot of Costa Rica's Carara National Park on 3 July, we hiked a couple of miles into the jungle. We enjoyed being back in the tropical forest. For us the forest seemed relatively tame. Unlike in Peru and Ecuador, were we explored barely visible hunting trails, the park paths were wide, cleared, and occasionally wheelchair accessible.

This enterprise proved to be fairly frustrating. With our guide and dragonfly expert at the front of the line, three-fourths of us missed seeing dragonflies. We were supposed to rotate our positions in line, but that tended not work so well. Our bird experts were better at moving along the line, but the birds were not very cooperative. For one thing, it was not breeding season. Birds were not on territory and did not respond to calls.

The jungle was dense, making seeing birds even more difficult. Take this male Barred Antshrike. That’s my best photo. Barrred Antstrikes are found from eastern Mexico south through most of Amazonian South America. These birds are omnivores. They consume both plants and small animals. According to Koloff et al., “Barred Antshrikes are found in dense areas with highly tangled foliage and consequently are heard more often than seen.”

Sunday, September 3, 2017

Common Woodskimmer

Little information exists in Interlandia about Common Woodskimmers. They are sometimes named Tropical Skimmers, but all members of its genus, Uracis, are tropical. Records exist from southern Mexico to northern Argentina. One sighting was made in eastern Cuba. Lasley writes, “The Tropical Skimmer (Uracis imbuta) is a widespread and common species in parts of South America.” We found this male on 3 July at the entrance to Carara National Park in western Costa Rica.

Saturday, September 2, 2017

Boat-billed Flycartcher

Boat-billed Flycatchers look superficially like Gray-crowned Flycatchers or Great Kiskadees. Their huge bill sets them apart. Like the Gray-crowned, the Boat-billed often inhabits forest edges, plantations, and clearings. With such an outsized bill, it is not surprising to learn that they take large insects like cicadas. They even take small vertebrates, but are not adverse to figs, berries and seeds. The species is found from Mexico to much of northern South America.

Friday, September 1, 2017

Gray-capped Flycatcher

Gray-crowned Flycatchers are common in Central and northern South America. They look similar to about a half-dozen other flycatchers, but can be identified by their gray crowns and relatively short eye stripes.

A couple of these flycatchers hunted for insects over the Carara National Park entrance on 3 July. This species inhabits areas of secondary growth, agriculture, and even residential areas. They prefer more humid habitat than do other, closely related species. This day was fiercely hot and humid.

Thursday, August 31, 2017

Banded Peacock Butterfly

Butterflies flitted around the Carara National Park in western Costa Rica. Banded Peacocks (Anartia fatima) are abundant from Panama to Mexico. They inhabit disturbed areas—fields, orchards, and secondary growth. Their caterpillars are fond of weeds in the mint order (bugguide.net).

Occasionally this butterfly wanders north to central Texas, where they may breed. One record exists from Cincinnati, Ohio. The record is a bit dubious. In any case, the photograph of this individual shows one beat up critter.

Wednesday, August 30, 2017

Steely-vented Hummingbird

On the morning of 3 July 2017, we visited Carara National Park near our eco-lodge, Villa Lapas. The park contains the northern remnant of the western Costa Rican rainforest. Well marked trails run into the jungle from the park headquarters.

We waited at the headquarter’s parking lot while our leaders negotiated our entrance fees. Surrounding the lot and headquarters was a swampy, weedy field—perfect for both dragonflies and birds. This Steely-vented Hummingbird greeted us at a patch of flowering bushes in the middle of the lot.

These hummers are found from southern Nicaragua to Costa Rica and in western Colombia and Venezuela. They inhabit shrubby areas, forest edges, gardens and secondary growth. They appear to be absent from Panama. The resulting isolation of the northern population, and because their calls are different from South American birds, makes some ornithologists suggest they are a distinct species (Handbook of Birds of the World Alive). 

Tuesday, August 29, 2017

Jesus Christ Lizard

Along the Villa Lapas streamside Common Basilisk lizards basked. These reptiles are found from Nicaragua to northern South America, usually near streams. In Costa Rica, most are found on the Pacific slope (which is where we were on 2 June 2017).

They are also known as Jesus Christ Lizards. When disturbed, they run on their hind legs across the water surface. They have flaps of skin on their hind toes, which maintain their buoyancy. The lizard also runs at about 5 mph, fast enough to keep from sinking. Old lizards are heavier than young ones, and often sink, after which they swim away from pursuers (Wikipedia).

Monday, August 28, 2017

Racket-tipped Rubyspot

I still remember Scott King exclaiming that the American Rubyspot he showed me along the Cannon River here in Minnesota was a tropical vision. He is correct. The American is the only rubyspot found in Minnesota. At least nine species are found in Costa Rica, including the Smokey Rubyspot we saw on our first day in Central America. (Smoky Rubyspots are found north, well into the southeastern United States.)

Racket-tipped Rubyspots range from Mexico to Panama and are not found in the United States. I found the female in the lower photograph on 2 June 2017 at the Villa Lapas eco-lodge in Puntarenas, Costa Rica. Males proved more elusive to capture by camera. We saw males off and on throughout our expedition. One in focus, like in the first photo, was not captured until much further north on 10 July near Aranal.

Sunday, August 27, 2017

Buff-rumped Warbler


As we walked along the river running through Villa Lapas on 2 July 2017, we saw two warblers foraging on rocks in the stream. They flicked their tails up and down like waterthrushes. Their bright, buffy rumps flashed. We recognized these birds—Buff-rumped Warblers—from 45 years ago in Peru and Ecuador. 

Buff-rumped Warblers are common from Central America through western Amazonia. They are always found near water and feed on or near the ground.

Saturday, August 26, 2017

Dusky Dancer

The Dusky is the most widespread dancer. In the United States, it has a relatively narrow distribution from southern New England to southern Texas and the Southwest. The species is then found south to Argentina. We found them on our first full day in Costa Rica and on our last (2 July—Villa Lapas, Puntarenas (top photo); and 15 July 2017—La Quinta Lodge, Heredia, Costa Rica (bottom photo)).

Coincidently, both patrolled swimming pools. Such habitat should be a poor choice for a damselfly. First the poolside is full of pesky people—and there is no way a dragonfly larvae can survive in a chlorinated pool. On the other hand, Dusky Dancers perch on rocks and stream-side vegetation, habitat similar to hotel pools, which probably also attract mosquitos hungry for human blood.

Friday, August 25, 2017

Yellow-rimmed Eighty-eight


Yellow-rimmed eighty-eight (Callicore texa) are found from Chiapas, Mexico, to Colombia. This one perched on a wall of the Villa Lapas eco-lodge in western Costa Rica on 2 July 2017. Callicore species are called eighty-eights (or numberwings) after their wing patterns.

Thursday, August 24, 2017

Yellow-green Vireo

Yellow-green Vireos are drab, little birds that sound like Red-eyed Vireos, but the notes are a bit shorter and faster. Until relatively recently, ornithologists classified the two vireos as two races of the same species. Yellow-green Vireos occur from Mexico to Panama. Occasionally they are recorded from the southernmost United States. They are the only Central American bird that is wholly migratory. All leave the region to winter in South America. They are often found in gardens and plantations and avoid undisturbed forests. We heard and then saw this individual singing on 2 July in the trees of the Hotel Villa Lapas in western Costa Rica.

Wednesday, August 23, 2017

Leafcutter Ants

Leafcutter ants are amazing insects. At least 47 species are known across the American tropics. The ants chew hunks of leaves and flowers out of trees, The ants can carry 20 times their body weight (Wikipedia). Long lines of ants carry their bounty down the tree trunks and tramping highways across lawns and the forest floor. The highways converge at huge, underground burrows.

There the ants use the leaves to grow nutritional fungi to feed the colony. The fungi produce nutritious “fruiting bodies” to feed the ants. Both the ants and the fungi are mutually dependent on each other.

Wikipedia assures us that “next to humans, leafcutter ants form the largest and most complex animal societies on Earth.” Their burrows can become huge, over 100 feet across and may contain eight million individuals. Many leafcutter societies are composed of four casts—fungus gardeners, burrow guards, leaf-cutting foragers, and soldiers.

Watch your step in the jungle or in the eco-lodge lawn. The soldiers will defend their highways and foragers. The ants can also cause agricultural damage. When they cut flowers, however, the resulting line of colors can be astounding. In Ecuador, we discovered, to our dismay, that leafcutter ants are also fond of nylon and can completely destroy tent mosquito netting.

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.