Thursday, July 31, 2014

Variegated Meadowhawk

During a long and relatively unproductive hike through Santa Anna National Wildlife Refuge on 23 February 2014, we did come upon this gorgeous Variegated Meadowhawk along the Spring Lake Trail. I have posted about this dragonfly on a number of occasions in this blog. Readers may recall that this species is highly migratory, often appearing in the northland well before other species of emerged from their aquatic winter abodes. Their migration can be spectacular. Paulson writes that, along the American Pacific Ocean, “maximum numbers [can be in the] thousands or even tens of thousands, passing coastal points at rates of up to 500/min."

Wednesday, July 30, 2014

Golden-fronted Woodpecker

In the United States, Golden-fronted Woodpeckers are most common in mesquite brushlands of south Texas. Erika and I often saw this species as we explored the Rio Grande Valley last February. I also blogged about this bird in May 2012.

These woodpeckers are as fond of fruit and nuts as they are of insects (Husak and Maxwell 1998). Unfortunately, they are fond of pecan fruit in the fall. They seldom drill wood when they do consume insects, although they do excavate roosting and nesting cavities.

Tuesday, July 29, 2014

Red-tailed Hawk

At the Mission Nature Park and Bike Trail on 23 February, when we spied this raptor, we thought we found our quarry, a Hook-billed Kite. It seemed russet-breasted and slender. But closer examination of my photos proved this to be a western Red-tailed Hawk adult, intermediate between light and dark morphs. I had never before observed this plumage.
This Red-tailed Hawk race breeds across most of western Canada. Some individuals are dark, others pale, and some intermediate, with still others intermediate between these three morphs. Why do Red-tailed Hawks come in different color phases? One hypothesis is that prey species learn to identify what a Red-tailed Hawk should appear. This learning makes the prey vulnerable when a different morph appears. If the odd morph becomes more common, due to its hunting success, then the prey learns the new plumage patterns, and another morph will be favored.

Monday, July 28, 2014

Greater Roadrunner

When we searched for Hook-billed Kites along the Mission Nature Park and Bike Trail on 23 February, we did not see the raptor, but did watch a Greater Roadrunner hunt along the trail. Roadrunners are curious, terrestrial cuckoos. They feed on “snakes, lizards, spiders, scorpions, insects, birds, rodents, and bats” and, in times of food shortages, its own young (Hughes 2011). Roadrunners are monogamous and maintain long-term pair bonds. Both sexes incubate their eggs and feed their young. Roadrunners have been increasing in numbers and moving north and east from their traditional southwestern range, which includes Texas and Louisiana.

Sunday, July 27, 2014

Neotropic Cormorant

This Neotropic Cormorant is identified by its relatively small size and by the white line behind its lower mandible. Erika and I found this cormorant, on 23 February, a day we devoted to unsuccessfully searching for two rare birds, the Hook-billed Kite and Fulvous Whistling-Duck. We discovered this bird at Lake Edinburg, only to discover that the lake is closed on Sundays, making the whistling-duck search impossible.

For reasons unknown, Neotropic Cormorants greatly declined during the 1960s in the United States, but have resurged since that decade. Recently the species has been even reported in the Dakotas and elsewhere in the Upper Midwest, as well as Canada and Pennsylvania. Normally Neotropic Cormorants breed from south Texas through much of Latin America. This species is relatively tolerant of human activities and can survive diverse habitats and climates (Telfair and Morrison 2006).

Friday, July 25, 2014

Roseate Skimmer

This gray-sided dragonfly turns out to be a female Roseate Skimmer. We also found this species species in 2012 when we last visited Estero Llano Grande State Park in south Texas. This pose is typical for the species, which perch on twigs with their abdomens below the horizontal (Paulson).This author describes Roseate Skimmer copulation as aerial, and lasting only some 10 seconds. Females either deposit their eggs directly into the water or splash water onto adjacent banks.

Visiting this park later in the spring or summer would probably yield a great number of dragonflies. The park consists of a network of wetlands, ideal for both insects and birds.

Thursday, July 24, 2014

Least Grebe

In 2012 during our last visit to Texas, we saw many Least Grebes. Last February we only saw this one, at the Estero Llano Grande State Park. Texas had suffered from several years of drought, which probably adversely affected grebe habitat.  Least Grebes have high reproductive rates and generalized feeding habits, so are able to recover from adverse weather trends. Although not migratory, this species is able to fly considerable distances in search of appropriate habitat (Storer 2011).

Tuesday, July 22, 2014

Buff-bellied Hummingbird

Buff-bellied Hummingbirds breed along the coast of the Gulf of Mexico, north to southern Texas and south to Belize and Guatemala. In Texas this species is common from March to August, becoming rare in the fall and winter. Like many hummingbirds, undoubtedly some post-breeding Buff-bellies migrate south. But, uniquely, a few disperse into the southeastern United States. Records exist from most southeastern states, from Arkansas to Florida and North Carolina. At least in Louisiana, winter records may be on the increase (Chavex-Ramirez and Moreno-Valdez 1999, Rubythroat.org).

Erika and I were delighted to photograph this Buff-bellied Hummingbird at the Estero Llano Grande State Park. Hummingbirds were not abundant during February, but patience in front of one the the park hummingbird feeders paid off. We listed this species during our March 2011 visit to Santa Ana National Wildlife Refuge, but then we only saw one uncooperative individual.

Monday, July 21, 2014

Ruby-throated Hummingbird

Also at the hummingbird feeder at the Estero Llano Grande State Park, perched a bird I could not initially identify.  Turns out to be a Ruby-throated Hummingbird. This was late February, when, typically, Ruby-throats molt their body feathers. This molt begins towards the bird’s bottom end and proceeds towards the head. Thus this bird is molting in its bright throat feathers. Weidensaul et al. (2013) also note that, especially in the winter, males occasionally have orangey throats. The cause of this orange color is not well understood.

This spring in Northfield, Erika and I enjoyed seeing many Ruby-throated Hummingbirds in more typical plumage, such as the bird below.

Sunday, July 20, 2014

Black-chinned Hummingbird

Black-chinned Hummingbirds breed across much of western North America and central Mexico. In the United States, they winter north only into southeastern Texas—that is, until the 1980s, when they began to be reported across much of the southeastern United States. This change is not well understood—where they always there, but undetected? Have they moved in because of habitat change? Is it the result of more people keeping winter hummingbird feeders?

Erika and I photographed this male Black-chinned Hummingbird Hummingbird at the Estero Llano Grande State Park. The bird fed at a hummingbird feeder at the park headquarters, making visits about every 20 minutes. Fortunately a bench was strategically placed nearby.

Saturday, July 19, 2014

White-faced Ibis

Erika and I added the White-faced Ibis to our February trip list at the Estero Llano Grande State Park in south Texas. I have previously posted a note on how to differentiate between White-faced and Glossy ibis. The White-faced Ibis is the more likely species in most of Texas. The species breeds in the western United States and winters in Mexico, western Louisiana, and eastern Texas. Also note the red facial skin on this ibis. This area is dark or blue in Glossy Ibis.

The two ibis have interbred in captivity, but are not known to do so in the wild. Thus, for the time being anyway, they are considered to be distinct species (Ryder and Manry 1994).

Thursday, July 17, 2014

White Ibis

White Ibis inhabit coastal areas of the southeastern United States, Mexico and Central and South America. The birds inhabit both estuarine and freshwater swamps. These ibis shift their roosting and colony sites in response to water availability and to concentrations of crustaceans and small fish. Curiously young birds do not survive when fed crustaceans from salty water. Therefore, White Ibis depend on freshwater breeding sites (Heath et al. 2009). 

This aversion to brackish water crustaceans probably does not affect these White Ibis that Erika and I found on 22 February 2014 at Estero Llano Grande State Park. I have previously posted notes on this species.

Wednesday, July 16, 2014

Black-bellied Whistling-Duck

On 22 February, after we left Santa Ana National Wildlife Refuge and headed out towards Estero Llano State Park. Along the way we searched for Fulvous Whistling-Ducks, but all we found was a solitary Black-bellied Whistling-Duck. This odd duck appeared to have been asleep in a cultivated field.

In North America, this species breeds along the coasts of Mexico and in Southern Texas. The species’ range is expanding in the United States. Unlike birds further south, most, but obviously not all, of these ducks migrate to Mexico. As I have posted before, Black-bellied Whistling-Ducks form life-long pair bonds but often lay their eggs in their neighbors' nests.

Tuesday, July 15, 2014

Northern Parula

A small denizen of the eastern North American forests is the Parula Warbler. This species winters in eastern Mexico and in the West Indies. This bird was named Blue Yellow-backed Warbler by early ornithologists, and Finch Creeper by its discoverer. Parula Warblers glean insects and spiders from the tree canopy. I found this one in the Cannon River Wilderness Area of Rice County this past May.

Monday, July 14, 2014

Clay-colored Robin

Throughout my birding career, I figured, since birds do not recognize international boundaries, why should I? So, if I saw a bird in Argentina that also occurs in the United States, I checked it off on my North American list. Now, however, I use eBird to keep track of my records—and this app only allows birds seen in North America (north of Mexico) to be counted as such. Thus my rather respectable North American list of 717 birds took a heavy hit with eBird’s advent, and now stands at 578.

This Clay-colored Robin is a case in point. It inhabits forests, other woodlands, orchards, and even city parks from northern South America through Mexico. It is usually a common bird, but this thrush is a scarce resident in southern Texas. Erika and I found this individual in trees above the bird feeder at the entrance of the Santa Ana Wildlife National Wildlife Refuge in the Rio Grande Valley. Thus I recovered one of my lost North America “ticks."

Curiously the Clay-colored Thrush is not covered in the AOU’s monumental Birds of North America.  The AOU checklist assures us that the species breeds casually in southernmost Texas. This thrush is, however, coveted as a cage songbird and has also been introduced to some parts of Mexico.

Sunday, July 13, 2014

Blue-fronted vs Blue-tipped Dancers

I think I have a handle on identifying Blue-fronted and Blue-tipped dancers. These small damselflies are often very common on roadsides and forest paths. They are usually hardly noticed by casual hikers. I found both of these dancers along the road next to the river at the Cannon River Wilderness Area in Rice County, Minnesota.

Dancers are a large group of New World odonates. These two species are in the genus Argia. They are recognized by scientists by their long tibial spines.  I generally look for their habit of holding their wings high above their abdomens.

The top two photos are of Blue-fronted Dancers. On the blue male, note the very thin black stripe both on top and on the sides of the thorax. The last three abdominal segments are blue. Look closely at the eighth segment—it has a small black notch on it, a field mark often, but not always present on Blue-fronted Dancers. The female is harder to identify.  You may have to enlarge your view of the photo on your computer to note the pale tan stripe that runs across the sides of the last couple of abdominal segments.

The last two photos are of Blue-tipped Dancers. The male is “easily” identified by his broad purple thoracic stripes, whitish sides, and only having the last two abdominal segments blue. The female is tougher. Note that her last abdominal segment is pale.  Then look for a tiny tan triangle at the back of her dark thoracic stripe.

Just when a fellow thinks he has this identification riddle solved, along come blue-form females of both species. I will, for the time being, ignore those! In any case, both species fly for most of the summer, from June through August. Two good books for identifying damselflies are Bob Dubois’ Damselflies of the North Woods (if you can find it) and Ed Lam’s stunningly illustrated Damselflies of the Northeast.

Saturday, July 12, 2014

Western Wood-Pewee

I discovered this photograph of a Western Wood-Pewee (and a couple of Northern Rough-winged Swallows) among my computer files. Erika and I took this photo years ago near Missoula in western Montana. As is the Eastern Wood-Pewee that I blogged about yesterday, the Western is found in woodlands. The two species can be separated by call and usually by range. Unlike the “Pee-a-wee” of the Eastern species, the Western’s call is described as “Pee-er” or “deer-me." Like the Eastern, populations of Western Wood-Pewees appear to be declining. Bemis and Rising (1969) suggest the lower numbers are due to cutting of western riparian habitat or other, unknown factors in their wintering range.

Friday, July 11, 2014

Eastern Wood-Pewee

On 8 June 2014, Erika and I photographed this Eastern Wood-Pewee. This flycatcher is common across its breeding range in eastern North America. Its plaintive “pee-a-wee” song is often heard in our woodlands.

Eastern Wood-Pewees are late spring migrants. Because they nest high in trees and build cryptic nests, relatively little is known about their reproductive biology. The Eastern Wood-Pewee is quite similar to the Western Wood-Pewee. Both were once considered to be races of a single species. But their ranges hardly overlap, their songs differ (see tomorrow’s post) and no hybridization is known to occur (McCarty 1996). The same author writes that Eastern Wood-Pewees have declined significantly in numbers during the past 25 years. He speculates that this decline may be due to heavy browsing of forests by White-tailed Deer.

Thursday, July 10, 2014

Common Pauraque

On 22 February 2014, during our Texas trip, Erika and I drove to one of our favorite birding locations, the Santa Ana National Wildlife Refuge. We arrived just in time to accompany a bird walk led by refuge volunteers. We do not often take group bird walks, but we sure were happy we did this time. We would never have seen two Common Pauraques sleeping by the side a trail. Even as our guides pointed them out, the birds were difficult to see. I could see the odd, bold wing pattern, but not the bird’s shape.  It was just so cryptically camouflaged—and the bird was only a few feet away from us. Note the bird's long tail!

The Common Pauraque is found from southern Texas south to South America. Pauraques are relatives to whip-poor-wills and are, indeed, common—they are just very hard to see. Consequently little is known about this species’ biology. Males are unusual among nightjars in that they share incubation duties. They feed low to the ground at night, jumping up to catch flying arthropods. The word “pauraque” may be derived from one of its calls, which sounds like “para que” in Spanish. In any event, pauraques are well represented in Latin American folk lore. Pauraques lead women astray and occasionally make virgins pregnant (Latta and Howell 1999).

Wednesday, July 9, 2014

Red Saddlebags

In February, of the few dragonflies we encountered in south Texas, we found Red Saddlebags most frequently. Often we saw males patrolling lake edges, like in the first photo taken at Llano Estero Grande State Park. These odes defend large territories, up to 3000 square feet (Paulson).
The second photo is of a male defending territory some distance from a local pond north of Edinburg. Paulsonwrites that Red Saddlebags are often found far from water. I was surprised to find both this and the last individual (a female) perched on or near the ground. Often saddlebags perch on treetops. The last photo is of a female, who, by the look of her abdomen tip, had just finished ovipositing. We found her on a dike some distance from an irrigation ditch at the Mission Nature and Bike Park.
Red Saddlebags are common in much of the eastern and southwestern United States. They range south to northern South America. Minnesota is about as far north as this species is found, and are usually rare here (see my previous post). Red Saddlebags may be migratory in the far North.

Monday, July 7, 2014

Bobolink

Gene Bauer, Gerry Hoekstra and I checked out a prairie being restored by the Nerstrand Big Woods State Park in Rice County. Bobolinks bred in the grassland. Bobolinks are relatively common nesting birds in our part of Minnesota, yet these first two photos are my first for the female of the species. Perhaps their relative drabness compared to the striking black and white males diverted my attention. Both sexes gave curious wing quivering behaviors (shown in all but the first photo), flapping their wings without flying.  I am not sure if this action is aggressive or territorial, or if it was directed at other bobolinks or at me. I have seen similar displays by other grassland birds like Henslow’s and Grasshopper sparrows.
Bobolinks are polygynous, with males breeding with multiple females. Males defend their territories until they begin feeding nestlings. At this time, males without territories establish territories of their own and often attract females that have been unsuccessful at breeding. Female Bobolinks almost never defend areas against other females within their male’s territory (Martin and Gavin 1995). Thus my photo of the female giving a wing display may well be intended to distract me from the nesting area.
Bobolinks are long-distance migrants, wintering in southern South America, a round-trip distance of about 12,500 miles. A banded female Bobolink was recaptured after nine years, thus “presumably made this trip annually, a total distance equal to traveling 4.5 times around the earth at the equator” (Martin and Gavin 1995). Studies indicate that Bobolinks orient using magnetic clues.

Sunday, July 6, 2014

Ichneuman Wasps

Giant Ichneuman Wasps, Megarhyssa atrata, are our largest wasps. As they are not venomous, thus they are no danger to people. They insert their long ovipositors into rotten wood and deposit their eggs inside Pigeon Horntail larvae, which burrow into trees. The wasp’s larvae proceed to devour the hosts from the inside out. Adult wasps are short-lived and have only about a month to mate and find their host. How they find their host larvae is a mystery. Presumably the wasp uses smell or sound (University of Michigan). The wasps remain as larvae through the winter, leaving their burrows and pupating in the spring.

Scott King and I found several of these wasps in the forest at the River Bend Nature Center near Faribault, Minnesota.

Saturday, July 5, 2014

Tree Swallow

Last week, Erika and I were walking through the forest edge of the Carleton Arboretum when I heard musical chirping above us.  I looked up to see a first-year Tree Swallow looking down at us. At first I thought it was a Bank Swallow.  The breast band, however, is pale and lacks a downward running point. Thanks to Matt for pointing out my error.

Friday, July 4, 2014

Three-spotted Fillip Moth

As Scott King and I walked through the forest in the River Bend Nature Area in Rice County, Minnesota, we happend upon the Three-spotted Fillip Moth. This moth’s caterpillars feed on maples. I do not know the derivtoion of the word “Fillip."

Thursday, July 3, 2014

Great Horned Owl

Not far from the pygmy-owl (last February in Texas) sat a Great Horned Owl—what a contrast in size! Great Horned Owls mostly hunt at night, but sometimes also during the day. Ninety percent of its prey is mammalian, and only 10% are birds. A small number of other creatures are also taken (Houston et al. 1998).

Great Horned Owls are found across North America, from Alaska and northern Canada to southern Central America. They enjoy a wide ecological range—including deserts, grasslands, suburban, forest, and marshland habitats. I have previously posted a photo of this species’ nesting in the middle of the Florida Everglades.

Wednesday, July 2, 2014

Le Conte’s Haploa Moth

A week ago, In the River Bend Nature Area near Faribault, Minnesota, Scott King and I found two Le Conte’s Haploa Moths. Just by looking at these two photos, you can see that this moth is a variable creature (some can even be all white, others much more complexly patterned). Often the species looks similar to other closely related moths. I base my identification on a photo from the Fontenelle Forest Nature Association website, which I consider to be reliable. The website mentions that this moth’s caterpillars favor a variety of herbaceous and woody plants, including apples and willows. The caterpillars overwinter and pupate in the spring.
Haploa moths are sometimes called Crusader Moths, as their black back markings are often graced with black crosses like on crusader's cloaks. Haploa is the moth’s genus and comes from the Greek for simple or single. I assume Le Conte is the same individual for whom Le Conte’s Sparrows are named.

Tuesday, July 1, 2014

Ferruginous Pygmy-Owl

Ferruginous Pygmy-Owls are common throughout most of South and Central America. At the northern end of this range, in southern Arizona and southern Texas, however, the species is rare or endangered. In Texas these owls suffered from the clearing of 90% of Honey Mesquite-Live Oak woodlands between 1920 and 1945. A look at eBird shows only a few dozen records ranging from Kingsville to the lower Rio Grand. This may be misleading, since, when I submitted this record, eBird advised me to keep the record hidden. The fear was that, when birders learn of Pygmy-Owl locations, the birds are often besieged by over-eager listers. One thing for sure, south Texas was crawling with more birders than I have ever seen in one place.

While visiting our friends north of Edinburg, they asked if we would like to see a pygmy-owl. “Sure,” we replied, with low hopes for our success. But our hosts bought their ranch because it contains small patches of mesquite forest. In one of these, our friend played a pygmy-owl call on his phone. Within couple of minutes, this owl replied. I called out that the phone could be turned off. “I did a while ago,” was the reply. What I took to be the recording was actually a living owl.

Although under seven inches long and weighing 2.5 ounces, the Ferruginous Pygmy-Owl is an opportunistic predator. Insects, reptiles, amphibians, birds and small mammals all are included in this owl’s diet. Pygmy-owls are most active at dawn and dusk, but are also active during the daylight (Proudfoot and Johnson 2000).