Thursday, February 27, 2014

Bohemian Waxwing

A Bohemian lives a vagabond life, and so it is with the waxwing of the same name. This bird forms winter flocks that search for fruit, which tends to be an unpredictable resource. Therefore the waxwing's winter range is also unpredictable. I saw them regularly in the winter in South Dakota, where I took this photo, but, in Minnesota, they seem to be found more often in the northern half of the state.

This love of fruit has some interesting consequences. Fruit tends to be abundant but local in distribution. Often waxwings do not return to the previous year's breeding grounds. Waxwings do not hold territories. They do not sing. Individuals seldom fight and, in fact, often feed each other fruit. As they search for food, waxwings usually travel in large flocks, which are perhaps better for discovering trees with fruit.

Monday, February 24, 2014

Galapagos Hawk

DNA studies indicate that Galapagos Hawks diverged from a single colonization event by Swainson's Hawks. Consequently their genetic diversity is remarkably low, perhaps lower than in any other bird species (Handbook of the Birds of the World-Alive).

Galapagos Hawks are one of only about a dozen bird species with a cooperative polyandrous mating system. Up to seven unrelated males may copulate with a single female. All the males help with incubation and feeding the one young and also defend a single territory. Monogamous males raise more young per individual, but males in groups live longer than monogamous males.

Saturday, February 22, 2014

Bare-throated Tiger-Heron

Bare-throated Tiger-Herons are found from Mexico to northwestern Columbia. I took this photo in eastern Mexico in the 1960s. Unlike many other egrets and herons, this species is a solitary breeder. This bird prefers coastal areas and is often found salt or brackish water. It is also found along rivers and streams away from the coast.

This heron is thought to be common across most of its range. Species has been recorded once in southern Texas.

Wednesday, February 19, 2014

Ash-throated Flycatcher

On the same trip as when we saw the Canyon Wren in New Mexico (May 2003), we photographed this Ash-throated Flycatcher in the El Malpais National Monument. This flycatcher is in the same genus as the Great Crested Flycatcher and looks similar. Note, however, the whitish throat and the fact that the rusty color on the underside of the tail does not seem to reach the tip.

Ash-throated Flycatchers are common summer residents in most of the western United States. They survive high temperatures and do not need to drink water. The Mal Pais environment certainly fits a bird with these qualities. These flycatchers nest in holes made by other species and also in nest boxes and hollow fence posts. Consequently, Ash-throated Flycatcher populations are expanding (Cardiff and Dittmann 2002).

Monday, February 17, 2014

Canyon Wren

I took this Canyon Wren photograph in May 2003 at the Catwalk Recreation Area run by the Forest Service near Glenwood, New Mexico. Due to fires and landslides, the area is now closed. This situation is a shame, because this park, largely consisting of a stairway up a narrow, rocky canyon, is intriguing—perfect habitat for Canyon Wrens.

Canyon Wrens are found across the western United States. They are often hard to see in their rocky environment, but their echoing, descending calls are distinctive. Their habitat is generally inaccessible, thus their biology is little known.  Only the female incubates but both adults feed the young (Jones and Dieni 1995).

Saturday, February 15, 2014

Masked Lapwing

The Masked Lapwing is eastern Australia’s ecological counterpart of our Killdeer (just a bit bigger). This plover prefers pastures and wetland edges and is common in urban areas and wetland edges.

 Masked Lapwings are increasing their range. They were rare in Tasmania in the late 1800s, but are now common. They arrived in New Zealand in the early 1900s, and have also become common there. In fact, this species was responsible for 22% of all plane accidents in 1991—airfields are ideal habitat.  Consequently,the species is controlled at New Zealand airports, by nest destruction, shooting adults, and habitat alteration (Handbook of the Birds of the World—Alive).

Thursday, February 13, 2014

Bay-breasted Warbler

I mentioned the importance of backing up files in my series of posts on digital photography. The subject is worth mentioning again. I back up all my files twice on two external hardrives. I save my RAW, TIFF, and JPG files. 

Why save RAW files after they have been processed? In one of my previous posts, I warned about technology advancing, leaving your old files behind. This photograph of a male Bay-breasted Warbler is a good example. In 2001, when I began taking digital photographs, I saved all my photos as GIF files. I was told that such files were the most robust. I did not save the other formats. Now I wish I had saved them all. Note the choppy patterns in the background. Now I wish I could backtrack and produce higher quality images.

This photograph is the only one I have of a male Bay-breasted Warbler. I took the photo in 2001 in South Dakota, where it is a relatively uncommon migrant. I am surprised that I have not banded a spring male here in Minnesota, where the species is much more common. I have previously blogged about fall Bay-breasted Warblers, and you can find these notes by entering the species’ name in the search box on the right column of this blog (or by using the index at the top of the page).

Wednesday, February 12, 2014

Photography Update

Some time ago, I published series of posts on my blog on the subject of photography—the series begins with the link, then goes through the subsequent posts in order.  I thought I would bring you up to date on my techniques (although I am not sure this photograph, taken in the Carleton College arboretum, merits being released for posterity).

I use a Canon Rebel XSi. I think if I were wealthier, I would go for one of the more expensive Canons, but the Rebel serves my purposes fairly well.  I went with the Canon because my earlier Canon lenses from the pre-digital age fit the new camera. In any case, I figure you can’t have too many dots-per-inch, especially for far away raptors.

Now I use a fancy Canon 100-400 EF lens. Its a long story, but I managed to fall flat on my face and on top of my old, $600 lens. That lens was insured, so we upgraded. Anyway, this lens contains image stabilizers and I usually hand-hold it. I use a monopod mostly for lugging this heavy toy around.

I also use a Tamron 1.4 tele-extender. I think this pushes my lens from 400 mm to the mid-500s. If you buy a tele-extender, be sure to check if it is compatible with your camera and lens before you purchase it. It might not fit even though it is supposed to. Or it may interfere with auto-focus. My camera and lens takes so long to autofocus and, because I am often unhappy with where the lens chooses to focus (like the bird’s breast instead of the eye), I am often happier manually focusing. Autofocus is also almost always unsatisfactory for dragonflies.

I take my photos in RAW format. I use a computer program called Capture One to convert the image to a .tiff format. Capture One is used my professional photographers and the latest versions are very expensive—they have left me behind, so I use an older version.

Next, I take the image through photoshop. Photoshop is an expensive program, but, there are great academic discounts if you are in anyway connected with an educational institution. Photoshop Elements is also an option. Generally I crop the image, get Photoshop to automatically adjust the curves, and bump the saturation up to 21. I often use a Photoshop add-on called Neat Image, which can do wonderful things by smoothing out the background and sharpening up the foreground. I think there are some free alternatives out there that do the same thing. Google “noise reducing Photoshop plugin."

Finally, for web images, I reduce the dpi to 72 and save the image as a .jpg file. At this resolution, I save the file at optimum size.  Then I use a free Internet program called picmonkey.com for some final tweaking, often just sharpening the image up a bit.

All this sounds like a lot of work, but the process flows along fairly quickly. I am often surprised when my photos do not turn out as I expect, either for better, but more often for worse. Digital photography really requires sunny days, unless you, unlike I, have fancy flash equipment like the pros use.

I would enjoy hearing from any of you who have different ways of handling digital photography. Why not share your systems through the comments section in this post? I am sure other readers will also be interested.

Monday, February 10, 2014

Great Black-backed Gull

In North America, Great Black-backed Gulls were nearly extinct in the 19th century—victims of feather and egg collectors. With legal protection and their love for garbage dumps, their population may now exceed historical numbers. This gull is now a common breeder in the northeastern United States from North Carolina to Labrador and across the Great Lakes. The species winters throughout most of this range, south to the Gulf of Mexico. This recovery is good news for Great Black-backed Gulls, but not so for Herring and Laughing gulls that are being replaced as the former species spreads (Good 1998).

I took this photo several years ago in Martha’s Vineyard. I have listed the species along the Duluth Harbor in February 2012.

Saturday, February 8, 2014

Yellow-shafted Flicker

At first glance, having an ant-eating specialist surviving a Minnesota winter may be a surprise. But Northern Flickers—in this case the yellow-shafted form of the eastern North America—are actually generalists, consuming beetle larvae and a variety of wild berries and fruits during the winter. Obviously they also eat suet at bird feeders and they seem well adapted to human-modified habitats. 

Inexplicably, although presently abundant, flicker populations are significantly declining. Forest clearing, especially of trees with dead snags, and competition with starlings for nesting holes may be contributing to this decline. Whatever the causes, Breeding Bird Surveys and Christmas Bird Counts both show a 2 to 2.5% annual decline (Weibe and Moore 2008).

Thursday, February 6, 2014

Blue-headed Parrot

Blue-headed Parrots are perhaps the most common parrot across northern South America. The species is spreading north into southern Central America (Birds of the World—Alive). It tolerates disturbed habitat and makes destructive forays into croplands. Despite its numbers, Blue-headed Parrots are not often taken in the wildbird trade.

This bird, nevertheless, was a pet of the Jivaro (Shuar) people who lived near the missionary outpost where we encamped for 14 months as we researched our dissertations. The Jivaro enjoyed a strange relationship with their wildlife. The people enjoyed keeping pets, but they were often cruel to them. Not unlike ourselves, come to think of it. 

In my ornithology lectures, I always used Blue-headed Parrots as evidence that scientists are not without humor. In 1766, Linnaeus named this species Psittacus menstruus. A look at the undertail feathers will explain why.  (Later studies changed Psittacus to Pionus.) Another common name is Red-vented Parrot. 

Tuesday, February 4, 2014

American Black Duck

Having errands to run in Northfield on Monday, 3 February 2014, I looked over the flock of some 350 Mallards loafing about the only remaining patch of open water on the Cannon River. eBirders have reported an American Black Duck from the river and local lakes all winter. I found the duck almost immediately.
American Black Duck field marks include an olive bill, unlike the orange and black bill of a female Mallard. Black Ducks have very dark sides and lack the Mallard's buffy breast. Most similar are eclipse male Mallards, which also have olive bills. But Black Ducks do not have buffy breasts and have much darker sides. The situation becomes more confusing since the two ducks often hybridize. Hybrids, however, often have white in the tail, curly upper-tail coverts, and greenish on the head (see my previous post on these hybrids). The shiny speculum on the bottom photograph seems a bit blue to me, but iridescence color is always an unreliable field mark. The single white line trailing the speculum is occasionally seen in American Black Duck.
American Black Duck populations recently severely declined. Between the 1950s and 1990s, numbers more than halved. Habitat destruction on wintering grounds played a role in the decline, as did heavy hunting pressure. In the 1980s, both the United States and Canada placed hunting restrictions on the killing of American Black Ducks and numbers increased. Hybridization with Mallards does not help the situation. Hybrids may account for over 13% of birds taken along the Atlantic Flyway—but this number is just an estimate, since backcrosses can be indistinguishable from pure American Black Ducks or Mallards. Longcore et al. (2000) warn, “hybridization of an abundant species with a less abundant and declining one can lead to genetic extinction of the species with the smaller population.”  These authors are not overly concerned about hybridization in this case, because the Black Ducks’ numbers are increasing and because the ducks’ 
range is not small or fragmented. 

Considering all of this genetic mixing, I am not sure why American Black Ducks and Mallards are considered to be separate species.  I did note, however, that often, when this Black Duck swam close by the male Mallards, the drakes aggressively chased the Black Duck away. 

Sunday, February 2, 2014

Andean Goose

Andean Geese are found high in the central Andes. They are found to altitudes exceeding 16,000 feet.  Erika and I photographed these geese at about 15,500 feet. We had just driven across Abra Anticona, at the time (early 1970s) one of the highest paved roads in the world—at 15,889 feet in Peru. 

Andean Geese are common throughout their range. They descend to sea level only rarely, apparently the result of bad weather at high elevations (Birds of the World—Alive). This source writes that, although people hunt this goose for food, the species, because of its inaccessible habitat, is not threatened. 

The species does, however, appear in folk-medicine markets. Extracts of Andean Geese may be a cure of gout (Birds of the World—Alive).  These markets are fascinating. Dead Andean Condors hang in the stalls. Erika and I were informed that these huge birds are in some way used to cure colds. We bought an herbal tea that claimed to cure kidney stones. Back in the USA, we presented it to my stepfather who suffered from these stones. The next time he was attacked, he drank a cup on the way to the hospital. Thirty minutes later, his symptoms vanished. His American doctors were impressed, but I doubt they explored the chemical contents of the tea.