Thursday, December 30, 2010

Winter Crane Fly

Today (30 December 2010), our second day above freezing (40 degrees F), I was surprised to see two dozen small, blackish "bugs" flying about the side of the house and landing on the ice dam along the edge of the roof. Pat Beauzay writes, "Nice find!  This is a winter crane fly species (Diptera: Trichoceridae), probably the genus Trichocera, though I would need the specimen to determine its identity. I collected Trichocera sp. one month ago on a mild day at the MSU-Moorhead Science Center. Trichocera is a widespread Holarctic genus, with 27 species in North America. They can be an important winter food source for birds. Here is a link to an image on bugguide.net:

http://bugguide.net/node/view/166869/bgimage "


They must be short-lived, as more typical Minnesota weather is quickly approaching...  According to Seabrooke Leckie, the larvae are scavengers, primarily of decaying vegetation. Adults overwinter in logs or cozy nooks and crannies, and in the spring males will hang about in mating swarms in front of caves or hollow trees.

Wednesday, December 29, 2010

Snow Bunting 2

On the Red Wing (Minnesota) Christmas Bird Count, Erika and I tallied 46 Snow Buntings.  I was surprised by their bright rusty sides, especially compared to the birds I saw near Northfield in November.  The bird on the far left, on the other hand, seems exceptionally pale.

In my November post, I mentioned that Snow Buntings nest in rock cavities. Ideal nesting sites are in short supply.  To claim their sites, males return to the arctic in April, at least a month before the females.  The males use the nest site to attract the females.  The nest cavities are relatively safe from predators, but they are cold.  Consequently, once incubating, the female is fed on the nest by the male.  This care allows the female to fledge young both relatively quickly and successfully (Bruce and Montgomerie 1995).

Monday, December 27, 2010

Pileated Woodpecker Pilfers Hackberries

The highlight of the Red Wing (Minnesota) Christmas Bird Count for Erika and me was this Pileated Woodpecker.  The bird teetered along the outer branches and twigs of a Hackberry tree.  The woodpecker acted like a tightrope walker, with both wings stretched out for balance. Notice that the bird's left foot is extended forward as the bird makes his way along the branch.
A novice tight rope walker.  Occasionally the bird slipped upside down, grabbing onto icy branches that were too narrow for obtaining a secure footing.
The Pileated daintily fed on Hackberry fruit, selecting one berry at a time.  Often the bird fed upside down as it stretched for a new morsel. 
We had never seen Pileated Woodpeckers picking fruit (perhaps because this species, unlike in Minnesota, is very rare where we lived in South Dakota.)  Bull and Jackson (1995) cite a study reporting that up to 27% of this woodpecker's diet is vegetable matter, including hackberries. Bull and Jackson (in the AOU's The Birds of North America) write little or nothing about Pileated Woodpeckers' fruit-eating behavior.  The authors do include, however, a line drawing of a woodpecker feeding on fruit.  The portrait depicts behavior similar to what we witnessed.

Thursday, December 23, 2010

Ring-necked Pheasant

Ring-necked Pheasants were introduced to Minnesota between 1905 and 1915.  The first hunting season occurred in 1924.  Populations peaked between 1940 and 1960.  Since then populations have fallen, probably due to intensive farming (Janssen, Birds in Minnesota).  According to the Minnesota Department of Natural Resources, "keeping a stable pheasant population is difficult in Minnesota. There aren't enough grasslands for the birds to nest in and not enough cattail marshes where they can hide from cold winter weather. Pheasant die-offs are common during extreme winters."  Nevertheless, Minnesota hunters annually harvest some 350,000 pheasants.

I flushed this hen pheasant from a roadside near Northfield on a chilly, 15 degree F 19th of December.  The bird flew from the roadside and into corn stubble, where it hunched down in the snow.  I suspect it was trying to be inconspicuous.

Tuesday, December 21, 2010

Cold Turkey

Since the mid-1960s, Wild Turkeys have been repeatedly released in southeastern Minnesota.  These birds have come from captive and wild stock, the latter mainly from Missouri.  The species is now fairly common in most of the southern half of Minnesota.  Indeed, the Department of Natural Resources now allows both spring and fall hunting seasons.  The general consensus is that Wild Turkeys, due to overhunting and habitat destruction, disappeared in the state in the 1880s (MN DNR). I was surprised to read in Roberts' The Birds of Minnesota that "there is no absolutely positive evidence that the Wild Turkey ever existed in Minnesota."  The early explorers of the region make no reference to turkeys, although possibly these large birds rarely wondered north or west from Iowa or Wisconsin. 

Europeans first called these birds turkeys when the birds were brought from the New World in the mid-1500s.  The word was used to describe any strange, foreign import. Although the term was vague, it referred to Asia Minor in general even though people knew turkeys originated from the Americas (Gruson's Words for Birds).

Turkey Vultures, on the other hand, were so named for their superficial similarity to turkeys.  As you can see from this Florida vulture below, the similarity is not such a stretch!

Sunday, December 19, 2010

Broad-winged Hawk

As I write this blog, another five inches of snow has fallen on the 14 inches already on the ground.  Surely this Broad-winged Hawk has completed its southward migration back to Mexico, Central or South America. (Erika and I observed Broad-winged Hawks on the edge of a coffee plantation along the eastern Andes in Peru.) A few young also winter in south Florida.  This photo is left over from last spring, when Gene B. and I encountered this rather tame Broad-winged Hawk just south of Northfield.

Broad-winged Hawks are common across their breeding range in deciduous forests in the eastern United States and across southern Canada to the Rocky Mountains.  They migrate, often in huge flocks called kettles.  Breeding birds usually hunt from within the forest canopy, where they take a variety of insects, amphibians, reptiles, mammals and birds (Goodrich,  Crocoll and Senner. 1996).  To have an individual cooperate by perching out in the open is uncommon. 

Thursday, December 16, 2010

Alan Phillips and Purple Martins

Alan Phillips was a famous, if eccentric, ornithologist who lived in Mexico. He was fond of quotes.  He often trilled, "If ever I am accused of destroying the crops, I would certainly want an ornithologist to defend me."  I think of him every time I see Purple Martins.  Birders often claim that they keep mosquito numbers in check.  Look closely at the female martin on the left.  These martins are eating dragonflies, which, in turn, prey on mosquitoes.  So, if you are lucky enough to have martins nesting in your yard, chances are, because of reduced dragonfly numbers, you have more mosquitoes! This photo was taken several years ago near Watertown, South Dakota.

I met Alan Phillips when I worked at the Smithsonian as a college student. In January 1967, he agreed to take me on as an intern. I prepared and labeled specimens for him. Alan Phillips took me on my first ornithological expedition to the Laguna de Tamiahua, a huge lagoon south of Tampico. That winter (1967) was one of the coldest on record, with snow in El Paso and Mexico City. The result in semitropical Tamiahua was a huge lake full of dead fish. At first we thought someone was dynamiting them. But it was just the cold, not even freezing temperatures. Mangrove Swallows dropped from their perches. We found all sorts of different birds. Crimson-collared Grosbeaks skulked in the bushes and Rose-throated Becards perched in the small trees. Most exciting were Black-headed Saltators that lacked their characteristic black breast bands. Were these undescribed species, subspecies, plumages? To this day I do not know. But my future in ornithology was set.

Tuesday, December 14, 2010

Pine Siskin

Pine Siskins are an irruptive, nomadic winter visitor.  The hypothesis is that these population irruptions are correlated with the relative abundance of seeds upon which siskins feed. We have observed a few Pine Siskins at our feeders for the last couple of weeks.  Suddenly they are abundant--we banded 21 on 10 December.

During my 25 years of banding in Aberdeen, South Dakota, I banded 13,239 Pine Siskins, more than any other single species and despite their being absent during some winters.  Some summers, after abundant winters, siskins bred in the area. Two recoveries illustrate their nomadic nature--one banded in Aberdeen on 10 March 1985 was found in Connecticut on 11 March 1988; another Aberdeen siskin, banded on 12 December 1992 was recovered near San Francisco, California, on 5 January 1995.

One of my claims to fame was my discovery on 27 December 1981 of an odd bird at my feeder in Aberdeen.  Richard Zusi of the National Museum and I determined that this was the only known hybrid between a Pine Siskin and a Red Crossbill.  We speculated that this instance of hybridization suggests a common origin of the two species.  Clicking here will download a copy of the paper we wrote.

Sunday, December 12, 2010

Trumpeter Swan

The highlight of Erika and my trip to Prescott, Wisconsin, were about a dozen Trumpeter Swans asleep on the ice of the St. Croix River in nearby Minnesota.  We noted that most of the swans, and the other waterfowl, rested with their eyes open.
The Trumpeter Swan, our largest native North American waterfowl,  is a restoration success story.  Originally abundant from Illinois (and perhaps further east) to Alaska, by the end of the 1880s, this swan was near extinction.  Although adult birds were tough and tasted poorly, the swans were harvested for their feathers.  Habitat destruction also contributed to their demise. They were gone from Minnesota by 1880.  In 1935, only 69 individuals were censused in the Red Rock Lakes area of Montana, but flocks of unknown numbers also inhabited parts of Alaska and Canada. Due to conservation and restoration efforts, 34,803 wild individuals are now known, and numbers are increasing. 


Restoration in Minnesota began in the 1960s, with birds from Red Rock Lakes released near Minneapolis.  Through the 1980s and 1990s, the Minnesota Department of Natural Resources actively collected eggs from both wild and zoo stock to propagate wild populations of swans.  The first releases occurred in 1987. By 2004, Minnesota populations exceeded 2000 individuals. See The Trumpeter Swan Restoration Project website published by the Minnesota DNR for more details and from which most of this data comes. Kim Eckert in A Birder's Guide to Minnesota, however, warns "this population may not yet be fully viable since it is still being augmented by introductions and is often locally reliant on hand-outs from humans." The species is of regular occurrence in Minnesota, with both migratory and resident populations. Active state restoration programs have also been successful in South Dakota, Iowa, Wisconsin, Michigan, Ohio and Ontario. 
Upon my approach, a few of the swans stood up, preened, and, like this bird, stretched before sitting back down on the ice to continue their nap.  Because Trumpeter Swans are so heavily managed, we were surprised this bird was unbanded.  In any case, a natural down coat and feet adapted not to lose heat must be good things to own during a Minnesota winter.

Thursday, December 9, 2010

Red-breasted Merganser

The two birds awake on the ice are Red-breasted Mergansers.  Their field marks are basically opposite those of the Common Merganser I blogged about yesterday.  First, their brown heads fade into their grayish or whitish breasts--a sharp line of demarcation is not present.  Neither bird shows a distinct white throat patch.  Although a bit hard to observe at this distance, especially the bird to the left has a much narrower bill than sported by a Common Merganser.  These mergansers have slightly different colored heads.  I suspect the darker one on the right is a nonbreeding adult.  The paler bird on the left may be in juvenile plumage.

As I mentioned yesterday, Red-breasted Mergansers, although common during migration in Minnesota, are only casual away from Lake Superior in the winter (Janssen, Birds in Minnesota).  Most spend the winter off coastal North America.  Both species of mergansers mostly eat minnows (up to 70%, in the case of Red-breasted Mergansers) and, to a lesser degree, crustaceans. The Common Merganser tends to take larger prey than does the Red-breasted. As top predators on the food chain, mergansers are  adversely affected by pollutants and are therefore indicative of the ecological health of the lakes and streams where they feed. 

When Erika and I arrived at the Minnesota park opposite Prescott, Wisconsin, we were somewhat surprised that all the waterfowl were napping on the ice.  In this photo you can see Canada Geese and two male Common Goldeneyes.  Closer to shore, a dozen Trumpeter Swans dozed.  I will blog about the swans in my next post.

Wednesday, December 8, 2010

Common Merganser

On Tuesday, 7 December 2010, Erika and I birded at the confluence of the St. Croix and Mississippi rivers.  With few exceptions we were disappointed with the variety and numbers of birds.  I was just about to complain when this merganser, looking like a snorkeler with his/her face under water, swam close by the shore. 
Mergansers in this plumage can be difficult to distinguish.  Several field marks clinch the identification of this bird as a Common Merganser.  First, the brown head color ends sharply where it meets the gray/white of the breast and neck.  Next, the bill, although long and narrow as in all mergansers, is relatively thick, especially at its base.  Finally, the amount of white in a merganser's face is variable, with juveniles such as this one having much more white between the bill and the eyes than nonbreeding adults.  In all nonbreeding plumages, Common Mergansers' white throats contrast sharply with their brown heads.

The Red-breasted Merganser is the species mostly likely to be confused with a Common Merganser.  We were surprised, when we crossed out of Prescott, Wisconsin, and back into Minnesota, to find two Red-breasted Mergansers.  Red-breasted Mergansers do not usually winter in Minnesota (at least away from Lake Superior).  In my next post, I will show you photos of these birds and review their field marks.

Monday, December 6, 2010

Bird Nostrils

Have you ever wondered why bird nostrils are not at the tips of their beaks?  The answer may lie in the photograph of the Red Knot (above)  This sandpiper is able to breathe even when the bill tip is probing under the wet sand.  I took this photo last January along the Outer Banks of North Carolina.

On the other hand, basal nostrils were no help for the Dunlin below.  Usually Dunlin feed in much more shallow water.  Judging by the bubbles by its head, the bird was exhaling at the time! (I suppose the bubbles may be air escaping from the bottom mud being probed by the bird.) The photo was taken several years ago at Sand Lake National Wildlife Refuge near Aberdeen, South Dakota.

Saturday, December 4, 2010

Sibley Bird Guide Droid App

I was very skeptical when I first heard that Sibley's Guide to Birds was coming out as a Droid Smart Phone App.  After loading it into my phone, however, I am a complete convert! You can look up single species, or compare species pairs.  The photo above shows a comparison between nonbreeding Pacific and Red-throated loons.  You can tap on each portrait and make the picture larger.  You can scroll down each species and see different plumages.  (Unfortunately my sample photo is of black-and-white birds--the portraits are in color!)  If I have my phone with me, I will never again be without a field guide!

Tap the buttons on the upper right on your phone, and you can usually pick from a list of various calls for each species.  The second button brings up a color range map for each species.  The third button allows you to make personal notes for the birds you see.  You can set the app to show only the birds known to be found in whatever state you are in (geographical, not mental).  Brief written species accounts accompany each illustration.

Off hand I can think of only think of two drawbacks.  First, when you play a call, the file can not be set to automatically repeat.  Second, this app is not free--I paid slightly under $30.  With this marvelous app, I can identify unfamiliar birds in the field and even study my ornithology while I wait for Erika in the mall! As a note of disclaimer, I have no ties, financial or otherwise, to Sibley or the sales of his app.  More information can be found at http://www.sibleyguides.com/2010/11/android-eguide-now-available and the app can be downloaded from the Droid Market. (I recommend downloading with the phone on a WIFI connection.)

Thursday, December 2, 2010

Year of the Chickadee

I have posted my banding results from the past three years, 2008 to 2010.  The report can be viewed by clicking the tab near the top of the blog. I will occasionally update this list as I band additional birds.

I am comparing bird populations near Dundas and in Northfield, Minnesota.  The Dundas site is in forest edge near an open fen.  The Northfield site is in my backyard at the edge of a small woodland city park.

I thought 2010 should be called "The Year of the Chickadee," with a whopping 158 individual Black-capped Chickadees banded at my two sites.  The total is higher than the previous two years combined.  Looking at my data, however, 2010 really is "The Year of the Robin."  I ringed 161 American Robins at my Northfield site, mostly caught during October.  I can not explain this influx of birds.  I suspect my luck was the result of being at the right place at the right time--I was banding birds and the migrating robins just happened to be in my vicinity.

You may notice on my list that, with one exception, overall I have caught fewer birds each year.  I trust this decline does not reflect actual trends in bird populations.  With any luck, my research documents natural population fluctuations.  Another decade or so of data will shed light on this problem.  I will continue updating my banding report tab on a regular basis.