Tuesday, July 25, 2017

Rufous-naped Wren


I think that when I wrote, “we birded in the garden in the back of the Bougainvillea Hotel,” that you do not have an appropriate vision of how luxuriant it was. In the 30 minutes we had on our first evening between rain showers and an hour on Sunday morning, we saw six bird species—and 16 the next morning. 

One interesting bird was the Rufous-naped Wren. This species often nests near wasps, which provide the nesting birds with protection against predators. Rufous-naped Wrens are found from southern Mexico to northern Costa Rica. Compared with more northern populations, the Costa Rican birds are hardly marked below and have the rufous on their napes extending onto their backs. Their calls also differ. Many ornithologists now consider them to be a separate species, the Rufous-backed Wren. In any event, this bird was common in most of the northwestern Costa Rican locals we visited.

Monday, July 24, 2017

Clay-colored Thrush

Our first Costa Rican bird was this Clay-colored Thrush in the garden of our first hotel, The Bougainvillea on the outskirts of San Jose. We arrived late, after our airport ordeals. Many of our companions were surprised that this thrush, despite all the stunning birds of the country, is the National Bird of Costa Rica.

This thrush is found from the Rio Grande Valley south through Central America to northern South America. The males’ songs are like those of American Robins, but “smoother, clearer, mellower, and more melodious” (Handbook of Birds of the World—Alive). In Costa Rica, Clay-colored Thrushes are commonly kept as cage-birds, despite their being the National Bird.

Sunday, July 23, 2017

Costa Rica

We visited our kids in Texas on our way to Costa Rica. Many of you know that we hate airplanes. Flying from Dallas, at least, allowed us a nonstop flight. We spent the first 18 days of July with a tour under the auspices of Sunrise Birding, led by Dennis Paulson, one of the world's foremost dragonfly experts, and Steve Bird, a tour guide with awesome bird identification skills. 

This tour was a first for us. We enjoyed being tour clients. No worries about itineraries, reservations, or navigating Costa Rican highways. The tour focused on dragonflies, which meant arriving during the rainy season, the best time for Odonata. But to our delight, we also chased birds and anything else we could discover. Posting my photos from the tour will take many months. I will interrupt my report with local observations.

Flying to Costa Rica did not cure our fear of flying. Thunderstorms in Dallas forced us to fly over Louisiana, before we turned south. Much of Central America lost power as we tried to land in San Jose. We made an aborted landing to avoid a plane on our runway. All the computers in the airport were inoperative, leaving a line of about 1000 people in front of us. Matters could only improve, which they definitely did, beginning with our being met by a patient Steve Bird when we finally escaped customs.

Saturday, July 22, 2017

Texas Odes

On 30 June, we explored a small, artificial pond in Denton County just north of Dallas, Texas. Like our photos from Kansas two days earlier, all were well known to us in Northfield, Minnesota. I was excited when I found the first dragonfly. It was flying about thorny bushes fairly distant from water. But, instead of something exotic, it proves to be a female Blue Dasher.
The second is a male Widow Skimmer. Except the Rocky Mountain west, these dragonflies are common across much of North America. The second photo is of a female Eastern Pondhawk, abundant across most of eastern North America. (We also saw an Eastern Amberwing, like the one from Kansas in my last post.)

Friday, July 21, 2017

Kansas Odonata

Our adventures last June began with a quick trip to visit kids in Dallas. Texas in the summer heat may not appeal to all, but I looked forward to seeing a few new dragonflies. Our first afternoon was in Andover, Kansas. We stayed at a Holiday Inn Express that boasts a small duck pond. We found a number of dragonflies. Unfortunately, none was new. The first photo is of a male Eastern Amberwing.
Flying over the pond was a Prince Baskettail. Hard to photograph, but occasionally seen in Northfield.
This third photo is a Blue Dasher, abundant in many parts of the country.

This last damselfly is probably a Skimming Bluet. Note the lack of blue rings on the abdomen. The lily pads upon which it perched is also typical habitat for this species. (Thanks to Scott King for help identifying this one.)

Wednesday, July 19, 2017

Scissor-tailed Flycatcher

We have been away from the Internet for the past three weeks. Our adventures began with a quick trip to Dallas to visit grandchildren. My target bird for this first leg of our journey was the Scissor-tailed Flycatcher. I lacked a good photo in my collection and also missed seeing a vagrant flycatcher in Minnesota in June. These flycatchers are common in Texas and the southern Great Plains, They specialize in eating grasshoppers and beetles. Individual tail length is variable, although males generally have longer ones. 

Monday, July 3, 2017

Four-spotted Skimmer

Four-spotted Skimmers are found across Canada and the northern United States (further south in the West). They also inhabit Europe and Asia, where they are known as Four-spotted Chasers. I caught this individual backlit in Erika’s garden on 8 June 2017. Some populations are migratory, and can be found in large aggregations. The prey upon other dragonflies, even those of similar size (Odonata Central).

Friday, June 30, 2017

Blue Dasher

Our first Blue Dasher of the year, 24 June 2017, in Erika’s garden. Blue Dashers are often abundant across most of the United States. Only Montana and Wyoming lack records in Odonata Central. They perch with their wings slanted downward from treetops to almost ground level. They often return to their perches, making photography somewhat easier. 

Blue Dashers are fierce predators. They take over 10% of their body weight in prey every day. They are aggressive towards competing males, often raising their blue tails at them. Females lay up to 700 eggs in only 35 seconds. Odonata Central, from whom most of this information is gleaned, maintains that Blue Dashers are largest in the spring, and get progressively smaller in the summer and fall. I thought, however, that this one seemed relatively small as it was.

Tuesday, June 27, 2017

Eastern Forktail

I agree with Scott King, who once mentioned that Eastern Forktails, were they not so common, would be a highly sought after damselfly. Sort of the Blue Jay (actually a quite handsome bird) of the dragonfly world. Males have bright emerald bodies and azure-tipped tails. Most adult females are a lovely shade of blue. Immature females sport a bright cinnamon color. I took these photos on 2 June 2017 in the Dakota County Lebanon Hills Regional Park.

Saturday, June 24, 2017

Red-eyed Vireo

The Red-eyed Vireo’s persistent, clear whistle is often heard in North American forests. The song seems to ask a short question and then give a short answer. A folk name is Preacher Bird. One observer commented, “I have always thought that whoever dubbed this vireo the ‘preacher' could have had no very exalted opinion of the clergy” (Bradford Torrey in Bent 1950).

The word vireo comes from the Latin “greenfinch.” Most vireos are greenish birds (Gruson 1972). Whatever the name, this photo clearly shows this vireo’s red eye. Erika and I found this bird in Carleton College’s arboretum in May 2017. This species breeds across much of Canada and the United States. They winter east of the Andes in the Amazon jungle. When migrating, this bird orients to the earth’s magnetic field (Cimprich et al. 2000).

Thursday, June 22, 2017

Eastern Pondhawk

Eastern Pondhawks are abundant across much of eastern North America. This one is from Erika’s garden yesterday. I think this is a young pondhawk. Adult males will become all blue. The tail is just changing—a rather regal image in my opinion. Pondhawks are fierce predators. Several have been zipping around the garden this spring.

Wednesday, June 21, 2017

American Redstart

American Redstarts are abundant in many eastern and northwestern forests. I had high hopes of catching this warbler’s “flash pattern” as it hopped through the forest sunlight and shadows. Wouldn’t you know that this individual appears to be missing his central tail feathers? During the flash pattern, the redstart fans his tail and droops his wings. This behavior attracts mates and warns competitors. The action may also flush its small insect prey from nearby vegetation (Sherry et al. 2016).

Sunday, June 18, 2017

Hagen’s Bluet

Hagen’s Bluets are among a suite of damselflies that are difficult to identify—unless you are an expert in a lab with a microscope. Yet these creatures are pretty and I find myself taking photos even though the prospects for naming them are slim. I shared this photo, taken on 16 June 2017 at the Minnesota Landscape Arboretum in Carver County, with my dragonfly guru, Scott King. To my surprise, he replied that this damselfly is a Hagen’s Bluet. Scott wrote, “the upper appendages slope downward, giving it a kind of wedge shape.” (The appendages are the structures at the very end of the abdomen.) You can enlarge this photo and almost see this trait.

Hagen’s Bluets are common near ponds and lakes across much of northern North America. They are named after Hermann August Hagen, a 19th century German entomologist. In 1867 he became curator of Harvard’s Museum of Comparative Zoology, where he enjoyed the title of Professor of Entomology.

Friday, June 16, 2017

Ebony Jewelwing

On 8 June 2017 I was checking my bird net when I kicked up a male Ebony Jewelwing. (Females have white spotted wing tips.) These damselflies are often abundant along area rivers and streams. I ran into the house to fetch my camera. By my reckoning, this individual is the 18th species of Odonata we have photographed in Erika’s garden.

Wednesday, June 14, 2017

Wood Frog

Of the Wood Frog, the Minnesota Department of Natural Resources writes, “Who is that masked frog?” The frog’s color ranges from brown to black or reddish-brown. I found this individual in our water feature on 3 June 2017. My first reaction was, “Whoa, that isn’t a Leopard Frog!”

Wood Frogs breed in the spring, often even before the snow melts. This frog is remarkably adapted to life in the Northwoods. They overwinter in leaf litter. They tolerate partial freezing of their body fluids. In the winter, according to the DNR, they stop breathing and their hearts stop beating. They produce antifreeze to keep their cells from freezing. As a result, this is the only frog found north of the Arctic Circle. Their range slides southeast from Alaska and most of Canada to northern Idaho, central Minnesota, and much of the northeastern United States.

Tuesday, June 13, 2017

Pale Beauty

Despite the heat and wind of 10 June in Northfield, Erika and I took a short walk in the St. Olaf College campus. We came upon this relatively large, white moth. Googling “large white month MN” quickly led to the moth’s identity: Campaea perlata—Pale Beauty.

This moth is very common across northern North America. Adults are usually nocturnal. Perhaps this individual was blown by the wind from a perch. Their larvae consume a variety of trees and shrubs.

Monday, June 12, 2017

Canada Goose and Mallard Chicks

The local waterfowl have fledged their young. These photos, of a Canada Goose and Mallards, were taken on 8 June 2017 on local Northfield ponds.

Sunday, June 11, 2017

Dusky Clubtail

On 2 June 2017, Erika and I visited one of our favorite dragonfly spots. The Lebanon Hills Regional Park in Dakota County consists of about a dozen lakes nestled among urban sprawl. The lakes are surrounded by forest and the water seems be in fairly good condition, thus the dragonfly diversity. This day brought us a fair number of dragonflies, but relatively few species.

One I had only seen once before was this Dusky Clubtail. The first time was on 2 June 2015 in Washington County. At first this dragonfly perched on a branch at about eye-level. Then it flew almost to the forest floor. The species is known to perch on or near the ground. It proceeded to raise its abdomen skyward, until it appeared to be almost standing on its head. This behavior is probably a form of obelisking, in which odes attempt to keep cool during hot days by pointing their abdomens to the sky. At 90 degrees F, this day was, indeed, hot.

Friday, June 9, 2017

Summer Tanager

On 8 June I banded a Summer Tanager in our backyard in Northfield. Summer Tanagers are rare in Minnesota. This is only the second I have seen in the state. It is not the first Summer Tanager that I have banded. I caught two in South Dakota. Summer Tanagers breed across the southern United States. In the spring males are regularly reported north of the breeding range. Less often they are found in the north during the fall. Although fond of various fruits, Summer Tanagers have a predilection for bees and wasps.

Thursday, June 8, 2017

Clay-colored Sparrow

A May 2017 Clay-colored Sparrow from Carleton College’s arboretum. This bird breeds across the Great Plains of the United States and Canada. Grant and Knapton (2012) write, “The Great Plains is the continent's most endangered major ecosystem. The decline in extent and quality of North American prairies coincides with decreasing populations of many bird species that depend on them, including the Clay-colored Sparrow.” Most forms of habitat destruction are fairly clear. Not so obvious is fire suppression, which allows a variety of invasive bushes to survive in the prairies. 

Wednesday, June 7, 2017

Baltimore Oriole

While walking in the Minnesota Valley National Wildlife Refuge’s Bass Ponds on 5 June 2017, Erika and I , along with two other birders, happened upon a Baltimore Oriole acting strangely. It hopped overhead about the boughs of a maple tree.
We figured it must have a nest nearby, especially since it carried two green caterpillars in its beak. The caterpillar with a horn on its back is likely a sphinx moth. The oriole flew into a dense mat of leaves and dipped its head into a nest. In all my years of birding, this was the first active oriole nest I have seen.
For a few seconds, the oriole stood watch over the nest opening. (As you may know, oriole nests are woven, hanging pouches with an opening at the top.) The caterpillars were gone. No doubt a few satiated baby orioles enjoyed their caterpillar-lunch.

Monday, June 5, 2017

Dame’s Rocket vs. Phlox

Erika and I find Dame’s Rocket every spring in the Carleton College arboretum. Dame’s Rocket is an abundant, four-peteled member of the mustard family. Dame’s Rocket is considered to be an invasive species, having been introduced to North America in the 17th century. This weed tends to displace native species. Many sources warn against planting it in gardens or roadsides.

Sometimes people confuse Dame’s Rocket with phlox, which has five petals. On a recent bike ride on 1 June 2017, along the Cannon Valley Trail, we found two species of phlox. I have been playing with a free phone app called Pl@ntNet. Take a photo of a plant and the app identifies it for you. We give the app a solid B in plant identification. Not too bad in the classroom, and, I suppose, better than nothing. We found Wild Blue Phlox, Phlox divaricata, (left) in shady areas, while the brighter pink Downy (or Prairie) Phlox, Phlox pilosa grew in the full sunlight.
  

Sunday, June 4, 2017

Aunt Lucy

A new wildflower for me, Aunt Lucy, Ilsia nyctelea, is in the Waterleaf family. Except for many coastal states and provences, Aunt Lucy is found across much of North America. Scott King and I encountered it in the wood edge in River Bend Nature Center on 26 May 2017. I tried unsuccessfully to use my new app, Pl@ntNet to identify it. Later Scott found it again in the Carleton College arboretum. Aunt Lucy is a native wildflower, which grows in woodlands and disturbed areas. It is considered a weed in gardens, nurseries, and in cities (Illinois Wildflowers).

Saturday, June 3, 2017

Northern Crescent

This elegant Northern Crescent landed in front of Scott King and me as we returned from our unsuccessful 26 May search for a Southern Spreadwing. The afternoon, however, proved to be entertaining. 

Northern Crescents are very similar to Pearl Crescents. Some Lepidopterists consider them to be variations of a single species. Pearl Crescents are found across eastern North America. Northerns are found further north and west, and also south through the Rocky Mountains. A lot of range overlap exists, with little hybridization between the two forms. Brock and Kaufman warn that many individuals can not be told apart. 

This butterfly is clearly a Northern Crescent. Note the row of dark dots against the orange across the back of the hind wing. Immediately above these dots is a broken black line. This line is continuous in a Pearl Crescent.

Friday, June 2, 2017

Tree Swallow

I photographed this Tree Swallow in the St. Olaf College playing fields on 25 May 2014. Males of this species are blue above and white below. I was not sure what to make of the brown edges of this bird’s white underparts. Young Tree Swallows are brown and white. Female Tree Swallows take a couple of years to lose this brown color and can be quite variable. Eventually, they are inseparable from their mates (Winkler et al. 2011).

Another hint that this bird is a female is the crease in the center of her breast—presumably where her feathers part to expose her brood patch. This patch is the bare skin with which she incubates her eggs.

Thursday, June 1, 2017

Snail-Killing Fly

Scott King showed me this Snail-Killing Fly next to a dead slug. This fly is in the Marsh Fly Family, Sciomysidae. This family is large and most deposit their larvae in slugs or clams. Often their larvae are aquatic and penetrate their hosts. In this case the larva are terrestrial and are injected into live or dead slugs. All I have to say is here is yet another line to avoid when you return to the Reincarnation Center.

Wednesday, May 31, 2017

Ruby-throated Hummingbird

Ruby-throated Hummingbirds are visiting our sugar-water feeder. These hummingbirds breed across eastern North America and winter in Central America. A few winter in southern Florida and southern Texas.

Females, like this one, are slightly larger than males (3.5 vs. 3 grams). Despite their size, many Ruby-throated Hummingbirds migrate nonstop across the Gulf of Mexico. Prior to this flight, birds may double their body mass by fattening on nectar and insects. Little is known, however, about the details of their migration. Ornithologists do not know much about the relative numbers of hummingbirds making trans-gulf migrations versus those that go around the gulf. Nor do we understand regional routes or precise wintering areas (Weidensaul et al. 2013).

Tuesday, May 30, 2017

Common Whitetail

This past week, I made several unsuccessful jaunts looking for Southern Spreadwings. On 24 May along the Big Pond at St Olaf College, Erika and I photographed a strange dragonfly. Thanks to Scott King, we identified it as a young, female Common Whitetail. This species is often abundant in Erika’s garden. We have never seen one, however, with white rays in its wing like this one. Scott explained that recently emerged dragonflies often take several days to acquire their adult appearance. One hardly needs to wonder why dragonfly identification is so difficult.

Monday, May 29, 2017

Horned Clubtail

On 25 May 2017, Scott King and I surveyed a pond at the River Bend Nature Center. We were successful in our hunt for Horned Clubtails. Even as we searched, these dragonflies were hauling themselves on to algae mats in the pond, casting aside their exuvia, and inflating and hardening their wings.

According to Paulson, males remain near ponds. They often perch on the ground or on other flat surfaces. Females, on the other hand, tend to retire to high woodland leaves. The males, when disturbed, encounter the females in their woodland habitat.

Sunday, May 28, 2017

Dot-tailed Whiteface Explosion

On 25 May 2017, Scott King and I surveyed a pond at the River Bend Nature Center near Faribault. His goal was to record Horned Clubtails. I wanted to see a Southern Spreadwing. We discovered clouds of emerging Dot-tailed Whiteface. Over a thousand flew up from the sedges in the pond and a nearby grassy field. 
The first photo shows an exuvia left by a Dot-tailed Whiteface. An exuvia is the cast-off skin of a larval insect, in this case dragonfly. Some insects eat their exuviae, but others leave them behind. The second image is of a teneral Dot-tailed Whiteface perched next to its exuvia. Teneral dragonflies are soft, recently emerged dragonflies. Their colors are often muted and their wings shiny. If they can fly, they often do so poorly. Some teneral individuals have undeveloped wings.
Adult Dot-tailed Whiteface were also abundant at the pond. The photo above is of a male. You can easily see why it is named Dot-tailed Whiteface. Females, like the one below, are handsome dragonflies. They also sport white faces.
This day was one of the first truly warm days of the spring. Temperatures exceeded 80 degrees F. Whitefaces must develop rapidly. Already a few flew in a wheel-shaped wheel position over the pond. The male holds on to the back of the female’s head, preventing competing males access to her. The male then transfers sperm from his genitals at the end of his abdomen to a sperm holding pouch, his seminal vesicle, near the front of his abdomen. The female attaches her abdomen end here and collects the sperm in her abdominal pouches. Males may continue to guard their mates or the males may fly off. Competing males, upon mating with a female, are likely to flush out her seminal pouches. Females can carry sperm from a single mating for the remainder of their lives, fertilizing their eggs when suitable habitat is encountered.