Sunday, May 31, 2015

Vesper Sparrow

On 27 May 2015, John Holden and I were greeted by this singing Vesper Sparrow. “Vesper” probably comes from an archaic meaning, referring to evening. John Burrows (1837-1921), American naturalist and conservationist, wrote that this sparrow sings “into the twilight of vespers, after most other birds have become still” (quoted in Jones and Comely 2002). Burroughs, as did Thoreau, probably knew this species as the Bay-winged Warbler. A close look at the bird in the grass below clearly shows this sparrow’s bay shoulders.
Vesper Sparrows were once fairly common birds across its range. Today populations, at least in the East, are declining as fallow fields either return to forest or become urbanized. Further west, this species depends on uncultivated lands near row crops or open rangeland.
Vesper Sparrows usually dust-bathe. In fact, Jones and Comely (2002) give only one citation for this sparrow’s bathfing in water. Ron Dudley blogged and shared photos quite similar to ours. His photos also show a Vesper Sparrow with its head touching the water. His, however, appears to be wetting the top of the head. Ours appears to have the whole side of the head under water—we wondered how the bird did not drown! Do you suppose the bird held its breath?
Finally our Vesper Sparrow took notice of us and suddenly took flight straight up out of the water. One of the dangers of bird baths is supposed to be that, unlike when they are dry, wet birds are more vulnerable to predators. Our wet Vesper Sparrow seemed to have no difficulty taking wing.

Saturday, May 30, 2015

White Ibis

White Ibis are fairly common along the Texas Coast at Rockport. The species prefers aquatic crustaceans, amphibians, small fish, and insects (although I have a photo of a Florida bird eating bread). This bird was consuming a crab (much more expected fare).

Friday, May 29, 2015

Common Whitetail 2

Female Common Whitetails joined their males today, 28 May. I blogged about this dragonfly two posts ago. The females look similar to Twelve-spotted Skimmers, but have yellow dots across the lateral sides of their abdomens. The skimmers’ sides have a yellow stripe.

Thursday, May 28, 2015

Little Blue Heron

I have previously blogged about how Little Blue Herons are unique in having different color phases for first-year (white) and adult (dark) plumages. The species seems relatively uncommon compared with other egrets and herons, but they tend to be secretive and solitary, so censusing them tends to be difficult (Rogers et al. 2012). I am always surprised, however, to find Little Blues perched on treetops, like this one Erika and I photographed in Rockport, Texas, last March. My first thought is usually “Green Heron,” which this bird clearly is not.

Wednesday, May 27, 2015

Common Whitetail

Two juvenile, male Common Whitetails on 25 May are the second and third odes of 2015 in Erika’s garden. The first was a shy damsel a couple of weeks ago who refused to be photographed. As this dragonfly matures, the tail will become a chalky bluish-white. The broad, black wing bands and the jagged, yellow lateral abdomen stripe are both good identification marks. As you see here, Common Whitetails often perch on the ground.

Male Common Whitetails are highly territorial. Subordinate males male share territory space, the these males are not allowed access to females. Larger males hold bigger territories, and mate more often than smaller individuals. Copulation lasts three seconds. Females, while guarded by their mate, may lay up to 1000 eggs at a rate of 25 per second Paulson.

Tuesday, May 26, 2015

Sandhill Crane

Last week, John Holden and I saw three Sandhill Cranes in the vicinity of Sprague Lake in southwestern Rice County. Cranes are becoming increasingly common in the region—even compared to ten years ago, these majestic birds have become steadily more easy to find. These birds were common in Minnesota in the mid-1800s, but may have been reduced to about 50 individuals by the 1940s (Minnesota Department of Natural Resources).

Current populations of Sandhill Cranes in Minnesota have not been censused (MNDNR). An interesting phenomenon is occurring as the numbers and range increase. Historically cranes in northeastern Minnesota belonged to a mid-coninent race, while birds in the central part of the state were classified as being an eastern subspecies. The two populations are now beginning to overlap and their interactions are well worth further study.

Monday, May 25, 2015

Common Grackle

I wish I remember where I read that the Common Grackle is “the poor man’s bird-of-paradise.”  If anyone knows who wrote this, please let me know. Grackles are, indeed, beautiful birds. Yet they are despised by many bird feeder enthusiasts. Grackles do tend to take over feeding stations. Our neighbor asked what to do about the grackles at her feeder. I replied that she should learn to love grackles—probably not much help.

The situation is not aided by the grackle’s being “the most significant agricultural pest species in North America” (Peer and Bollinger 1997). Grackles also attack other birds and their young. In much of their range, however, in the eastern United States and southern Canada, grackle numbers are declining—up to 32 percent in the late 1990s. Reasons for this decrease may include human control measures and competition from Great-tailed Grackles, whose range is expanding across parts of the South.

Sunday, May 24, 2015

Bay-breasted Warbler

On 21 May, I banded this female Bay-breasted Warbler in Northfield, Minnesota. I have seen this species here in Rice County in the spring, but, in Minnesota, during the spring migration, this is the first one I’ve banded. I have ringed this species many times in the fall. Elsewhere in this blog, I shared a photograph of the strikingly gorgeous spring male that I once banded in South Dakota. The female is more subtly plumaged, but no less beautiful.

The species breeds across much of northeastern and north-central Canada and parts of the adjacent United States. Breeding numbers depend on the abundance of spruce budworms. Wintering grounds are in northern South America and southern Central America. The warbler is a nocturnal, trans-Gulf migrant. The migration covers much of the eastern United States, although it rarely crosses the Southeast.

My paucity of spring banding records set me to wonder if spring and fall Bay-breasted Warbler migration routes might differ. A careful reading of Venier et al (2011) indicates that, although young fall birds may migrate further east than do adults, the overall spring and fall paths do not differ. Apparently this warbler is a late spring migrant. This timing results in a quicker migration, with shorter stopover times as the birds head north. Fall migrants must travel a bit more leisurely, giving banders more opportunity to catch birds. 

Friday, May 22, 2015

Underwing Caterpillar

The other day I noticed something strange on one of the garden stepping stones. After poking to see if the object was alive, I discovered that it was a caterpillar. Googling “purple-bellied caterpillar” quickly bought me to the Ilia Underwing moth. This identification is not positive, but likely. Ilia Underwing moths are fond of oaks, and two of these trees grow nearby in our front yard. The moths are found across much of eastern North America as well as California and Arizona. Scott King suggested that I raise the caterpillar to an adult moth, but, when I returned to the stepping stone, the caterpillar disappeared, perhaps eaten by a nearby, hungry robin.

Thursday, May 21, 2015

Prothonotary Warbler

If you visit Rockport, Texas, as we did last March, an interesting (and unlikely-looking) site to visit is the Demo Bird Garden and Wetlands Pool maintained by the city and the Texas Department of Transportation. A short boardwalk winds across several ponds and through a small woodland patch. We had stopped here on previous visits during draught, but knew the location had potential in a wet year.

This year, one of the first birds we found was this Prothonotary Warbler, found in Southeastern swamps and even venturing into southern Minnesota. Despite the bird’s being common, this photo is my first of the species. This warbler is named after prothonotaries, yellow-robed papal clerks in the Vatican. Prothonotaries are our only warbler that breeds in tree cavities, often using holes made by Downy Woodpeckers.

My mentor, John Trott, told the story of how a Prothonotary Warbler resulted in the allegation of Alger Hiss's being a communist spy. Petit (1999) retells the tale. Briefly, a man named Whittaker Chambers accused Hiss of being a spy. Hiss claimed not to know Chambers. Chambers countered that the two men did know each other, and that Hiss, a birder, told Chambers than he had seen a Prothonotary Warbler along the Potomac River. Hiss independently told the House UnAmerican Activities Committee about seeing the warbler, confirming his lying about not knowing Chambers. This discovery was partially responsible for the political rise of one of the committee members, Richard Nixon.

Wednesday, May 20, 2015

Field Sparrow

 
Field Sparrows are common in brushy fields, but tend to avoid urban and suburban habitats. Consequently, these sparrows have declined in numbers. This year I heard a Field Sparrow before I banded one—presumably the individual I heard. The song is an accelerating series of whistles that end in a trill. The species is common across the eastern United States and southern Canada.

Tuesday, May 19, 2015

Black-bellied Whistling-Duck

Erika and I have seen Black-bellied Whistling-Ducks during previous visits to Rockport, Texas, but they seemed down-right abundant in mid-March. This observation is perhaps not too surprising, since, unlike sedentary Latin American populations, northern birds are migratory. Our previous trips were earlier in the year.

I usually call whistling-ducks by an older name, tree-ducks. Black-bellied Tree-Ducks are more arboreal than other whistling-ducks, and often nest in tree cavities or duck boxes. This species appears to be moving northward from its haunts in Texas, Louisiana, Arkansas, Florida, and Arizona, with recent records from South Dakota, Minnesota, Ontario and elsewhere.

Monday, May 18, 2015

Black-throated Green Warbler

On Saturday, 15 May 2015, I banded a gorgeous Black-throated Green Warbler in Northfield, Rice Co., Minnesota. At the time, I noticed the black post-auricular spot.  I also was aware of faint black streaks on the bird’s back. After researching the afore-mentioned spot, I slowly concluded that this warbler is probably a hybrid between a Black-throated  Green and Townsend’s warbler. Black-throated Green and Townsend’s warblers hybridize in the limited area where their ranges overlap in central British Columbia (Toews et al. 2011).

Here is why I thought this bird was odd:

1) The black post-auricular spot started my unease with my initial identification. Most field guides don’t show this mark. A few photos on the Web of birds identified as Black-throated Green Warblers do show similar dark spots. The stripes on the sides of this bird’s face, however, are darker than expected on a typical Black-throated Green Warbler.

2) In the field, I noticed the faint black streaks on this bird’s back. A Black-throated Green Warbler’s back should be completely unstreaked. Male Townsend’s Warbler’s have dark-streaked backs.

3) After reaching the conclusion that my bird might be a hybrid, I returned to my photographs and found the photo below. Although a pure Townsend’s Warbler should have a black crown, unlike the green one on a Back-throated Green, notice the black feathers along the upper edge of this bird’s yellow supercilliary stripe.

I should have stopped my research there. But, instead, I continued on to Stephenson and Whittle’s definitive book, The Warbler Guide. There I found photos of Black-throated Green Warblers showing all the field marks I have discussed. They write that the back has little or no streaking (the emphasis is mine). Several photos show black post-auricular spots, and a couple of them show black-lined, yellow supercilliary stripes. Well, “easy come, easy go” is all I have to say.  I just had hybrids on the brain after my apparent hybrid between an Audubon’s and Myrtle warbler.

Sunday, May 17, 2015

Brown Pelican

Brown Pelicans are common around Rockport, Texas. Their aerial dives into the water are entertaining. Laughing Gulls, hoping the steal or scavange the pelican’s catch, often accompany the pelicans.

The photo below really should be credited to both of us. Erika found a pelican sleeping on a pier. The bill is completely hidden in the back feathers. “Take a photo, Dan,” Erika said, “that is certainly a Kodak moment!” Notice the half-open eye. Birds (and some aquatic mammals) are able to sleep with one eye open and half of their brains awake. The ability, termed “unihemispheric sleep” allows them to sleep, while, at the same time, be alert for predators (Mascetti and Vallortigara 2001).

Saturday, May 16, 2015

Yellow-headed Blackbird

I have posted a number of times on the Yellow-headed Blackbirds of Dakota County’s 180th Street marsh. See, for example, a posting from last June. When John Holden and I listed this blackbird once again last Wednesday, I could not resist posting yet two more photos of this dragonfly-eating omnivore.

Friday, May 15, 2015

American Pipit

American Pipits breed across the Canadian Arctic, most of Alaska, and south through Rocky Mountain tundra into the United States. They winter in the southern United States, Mexico, and northern Central America. In Minnesota, they are uncommon spring and common fall migrants (Eckert). Last Wednesday, John Holden and I found this pipit at the 180th Street Marsh in Dakota County.

American Pipits vary in the amount of breast streaking. Non-breeding birds tend to be much heavier streaked than birds in breeding plumage. See my 2012 post, showing a heavily streaked bird I photographed near La Jolla, California. In that post, I commented that American Pipits used to be named Water Pipits, when our birds were considered to be races of European birds. Our birds received new nomenclature when ornithologists decided our birds are not races of the European pipits, but a species of their own.
Four races of American Pipit are currently recognized—one breeds above treeline, from northern Alaska to Newfoundland; a second breeds from Alaska south through the Rockies to Oregon; and a third breeds further south in the Rockies of the United States. The fourth race of the American Pipit, the Asian Pipit, breeds in eastern Siberia and winters from northern India to Japan. They only accidentally wander into the New World. Asian Pipits show a number of subtle plumage differences, and have pink legs (Hendricks and Verbeek 1012). In his field guide, Sibley illustrates an Asian Pipit.

I think the American Pipit is poorly named. To call the Siberian birds “American” seems absurd. It makes as much sense as naming the whole species “Siberian Pipits.” Buff-bellied Pipit, occasionally used at the subspecies level, might be a better species name.

Thursday, May 14, 2015

Whooping Crane

One reason to visit Rockport, Texas. is that the town is close to where the world’s wild Whooping Cranes winter. This crane is one of the rarest birds in North America. Over 250 birds compose the wild flock (USFWS). The best way to see the birds is to take a boat tour from Rockport, as Erika and I did in 2010. But boat trips cost money, and a visit to the Aransas National Wildlife Refuge will likely meet with success. In recent years, we have discovered Goose Island State Park, just across the bridge north of Rockport. The photo above was taken last March in Goose Island, near the The Big Tree.

The Texas cranes are vulnerable to pollution, competition with people for water, and natural disasters such as hurricanes. By releasing captive birds, biologists have attempted to establish secondary flocks of Whooping Cranes. Programs along the Rocky Mountains and in Florida have be abandoned. Birds raised and Wisconsin and taught to migrate to Florida suffer repeated nest failures. A new release, to reestablish a nonmigratory Louisiana population, began in 2010.

The birds in my photograph appear to be a family group of two adults and one young. Whooping Cranes care for their young for up to a year, and young birds learn their migration routes by following their parents. Usually only one hatchling survives their two-egg clutches. Taking single eggs for propagation programs, therefore, does not affect the wild population. Wild birds may live to be 25 years old; captive birds can live over 40 years. They do not mate until they are three or four years old (in the wild) or as old as eleven in captivity (Urbanek and Lewis 2015).

Wednesday, May 13, 2015

Herring Gull

This Herring Gull image is the last of three photos Erika and I took in Rockport, Texas, last March of bathing birds. Herring Gulls often bathe while resting on water, ducking their bodies under water and then shaking their feathers. After bathing, these gulls will often preen (Pierotti and Good 1994). You might not think that a gull would get dirty enough to need a bath. The behavior probably both cleans and helps control feather parasites such as mites.

Tuesday, May 12, 2015

Eastern Forktail

On 7 May, I encountered this damselfly on a path along the Minnesota River Valley National Wildlife Refuge’s Bass Ponds. In the field, I identified it as an Eastern Forktail, one of the most abundant forktails in most of its range. Back home, I was less sure.  With its chestnut thoracic stripe and pale, emerald tail, I could not find anything quite like it in my guides. My ode guru, Scott King, confirmed my initial identification—this young female is acquiring the blue pruinosity of an adult. I have posted an entry showing photos of both young and old individuals.

Damselflies sure can be frustrating to identify. You can have males, young females, old females, and andromorphs—females that look like males. How is a fellow supposed to remember all that?

Sunday, May 10, 2015

Long-billed Curlew

In Rockport, Texas, last March, a lone Long-billed Curlew bathed among the Laughing Gulls (see last post). When bathing, this large shorebird lowers itself into the water until the breast is wet. Then it dips head into the water and quivers its wings, like in the upper photo. Then the bird stands, shakes, and preens, like in the lower photo (Dugger and Dugger 2002).

Saturday, May 9, 2015

Laughing Gull

After leaving Dallas, Erika and I spent two days in Rockport, Texas—a favorite destination because of easy access to birds. Thousands of Laughing Gulls breed in the Rockport City Park. Whooping Cranes can be seen at Aransas National Wildlife Refuge and usually at locations even nearer to Rockport. And, as this was as far south as we intended to travel this year in Texas, who knows? Perhaps we would encounter our first living dragonflies of the year. (You may recall the dead one in the grackle’s mouth reported in a recent posting).
I have posted photos of these gulls from a previous trip. Conditions were much wetter this year—heavy rain fell during our first night, and we saw many bathing birds. Laughing Gulls bathe often, in both fresh and salt water. For up to 20 minutes, the gull dips its head under water, and then raises the head quickly to pour water over its back. The gull flops its wings, like the one in my photo, while dunking its head in and out of the water. Afterwards it preens, often up to another 20 minutes (Burger 1996)

Friday, May 8, 2015

Red-headed Woodpecker

Erika and I usually find Red-headed Woodpeckers at the Nerstrand Big Woods State Park, as we did last Tuesday. Numbers, however, vary from year to year, and we do not list this species on every visit. Populations are apparently dependent on the abundance of the local acorn crop, which also varies annually. The woodpeckers collect and store acorns during the fall.

Birders have long been aware of Red-headed Woodpecker population fluctuations. The destruction of American Beech forests and the disappearance of the Rocky Mountain Grasshopper (upon which the woodpeckers fed in the Midwest), both events nearly brought Red-headed Woodpeckers to extinction.  Populations rebounded, however, with the extinction of the American Chestnut and the dead trees left by Dutch Elm Disease—both plagues leaving plenty of dead trees in which the woodpecker could breed. As these tree carcasses are cleaned out, woodpecker populations are again falling. A tendency to be hit by cars and unsuccessful competition for nest sites with starlings have not aided woodpecker recovery (Frei et al 2015). In many states and provinces, Red-headed Woodpeckers are listed as Threatened Species; Eckert considers these woodpeckers to be uncommon in Minnesota.

Thursday, May 7, 2015

Great-tailed Grackle

Judging from the account by Johnson and Peer (2001), Great-tailed Grackles are opportunistic feeders. They consume a wide variety of arthropods, grain, and even snakes, lizards, frogs, and rodents. Not mentioned are dragonflies, which I am fairly certain is what the female grackle in my photograph is consuming! Imagine my frustration last March, after three days of searching for odonates near Dallas, to find my first Texas dragonfly, species unidentified and grackle bait. 

You may notice that many of the photographs from our trip are in portrait, rather than landscape, format. This formatting is what BirdsEye requests for their collection of bird photos. I was happy to oblige, although sometimes if I encountered a rare bird or dragonfly, I found it hard to remember which way to hold my camera.

Wednesday, May 6, 2015

Cooper’s Hawk

As I have written previously, Cooper’s Hawks are recovering raptors. Because of people shooting them and due to pesticide contamination, these birds’ numbers declined during the 1900s. Many populations have now recovered, and they are found in forestland and even in urban forested areas. Cooper’s Hawks consume medium-sized birds and mammals (Curtis et al. 2006).

This raptor was described in 1826 by Charles Bonaparte and named for William Coopers, a New York ornithologist. Cooper was the father of James Cooper, after whom the Cooper Ornithological Society is named.

We banded this male Cooper’s Hawk on 27 April. Ominously, in mid-April 2015, amidst an outbreak of avian flu among domestic turkey and chicken flocks, the first wild bird in Minnesota confirmed to carry the disease was a Cooper’s Hawk. Hopefully warmer weather will cause the flu to decline and won’t greatly adversely affect our wild birds.

Tuesday, May 5, 2015

Killdeer

Last Saturday, Erika and I visited a plant nursery in nearby Carver County. The large, dirt parking lot was a madhouse of frenzied gardeners. As we searched for a spot to park, I noticed a Killdeer running along the shoulder of the lot, and giving a classic Killdeer broken wing act. While Erika explored the nursery, I returned to the investigate the bird.
I quickly discovered the Killdeer brooding four eggs (the typical number for this species). The nest, called a scrape (since there is not much to it), was only a couple of feet from the parked cars. The Killdeer showed no fear, and even threatened me if I got too close. Both male and female Killdeer build their scape and often build more than one, much in the fashion of House Wrens that build dummy nests.  Both Killdeer sexes incubate the eggs.
Initially the scrape is a bare depression in the ground. As the season progresses, however, Killdeer  add “rocks, bits of shell, weed stems, or other material” (Jackson and Jackson 2000). These authors report that the birds often collect white objects (shells, crayfish parts, cigarette filters, gravel, plastic, plaster) or build their scrape on white ground. One nest even contained bits of human bones. Apparently the Killdeer try to create a mottled background so that their eggs are better camouflaged. By the end of incubation, the amount of white material can be substantial—nests with over 1500 pebbles have been reported, and the scrape is sometimes raised two or three centimeters (Jackson and Jackson 2000).