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.

Tuesday, November 30, 2010

Southern Cassowary

Although my vote for favorite bird during our 1990 Australian expedition is the Tawny Frogmouth (see last post), my family picks the Southern Cassowary. Cassowarys mainly eat fruit. Indeed, they are ecologically important. Fruit seeds are dispersed as they pass through cassowary digestive systems.  The birds also consume a wide variety of other vegetable and animal prey.  Although usually shy, they can be dangerous when defending their nests or young.  Notice the young cassowary to the right of the adult. The function of the horn is unknown--perhaps a sexual ornament or maybe a defensive armament.

We found this cassowary in the rainforest near Mission Beach, Queensland.  We asked our motel clerk where to find them.  He replied, "The Chamber of Commerce won't approve of what I am about to tell you.  The best place to find them is in the town dump."  That's where we took this photograph.  Discovering the Cassowary was like finding a living dinosaur strolling among the rusting cars and rotting garbage. 

Monday, November 29, 2010

Tawny Frogmouth

As we flew to Australia in 1990, an Aussie on the never-ending plane trip told us not to miss the Koala Park in Melbourne.  "Your kids will love it."  He was right.  On the way out of the parking lot, Erika exclaimed, "I think you'd better stop the car--there is a cool bird perched on a pine bough over the road!"  There sat a Tawny Frogmouth, my favorite bird of our trip.  (The rest of the family's vote will appear in my next post.)

Frogmouths are in the family Podargidae  They are in the same order as nightjars. They are not closely related to owls. Frogmouths are found in southeast Asia and Australia.  The Tawny Frogmouth is a nocturnal omnivore--it eats most anything, including mice, birds, and lizards--although mainly arthropods.  Frogmouths usually drop from their perches and capture their prey on the ground. They accomplish their capture with their bills, not their talons.  Occasionally they will sit motionless, snapping up passing insects (Nightjars, Potoos, Grogmouths, Oilbird and Owlet-nightjars of the World).  Although this frogmouth is locally common to abundant, we saw no others.

Saturday, November 27, 2010

Kea

In 1990, Erika and I presented our antbird parasite research at the International Ornithological Congress in Christchurch, New Zealand.  One of the advantages to working at a small college--Northern State University allowed us to teach our classes an extra half-hour during the semester and we gave our final exams at Thanksgiving.  We packed up our family and spent a week in New Zealand and over a month driving up Australia's east coast.  Needless to say, we enjoyed numerous adventures.

On our last day in New Zealand, we rented a car rather than pay for one of the congress's excursions. (We should have struck out on our own from the beginning!)  Despite driving on the left side of the road, we found ourselves at Authur's Pass, high in the New Zealand Alps.  Our goal was the Kea,  the world's only alpine parrot and restricted to New Zealand's South Island.

We arrived at the pass at noon. A park official informed us, "Your timing is rotten, mate.  Keas are only seen at dawn and dusk."  Crestfallen, we continued a short distance away from the pass and parked at a roadside rest.  Suddenly a Kea flew over and landed on a nearby rock.  I inched my way toward the bird, taking photos as I approached.  A bus full of Japanese tourists stopped and they began taking photos of the birder getting closer and closer to the large parrot (I am not sure they were that interested in the bird). The photo below is uncropped.  I am not sure I wanted to get any closer to that beak!
Keas are omnivorous--they will eat almost anything, animal or vegetable.  Unfortunately that includes sheep, an animal you do not want to poach in New Zealand.  The government paid a bounty on Keas until 1970.  By then, only about 5000 Keas remained.  Full protection was afforded to the Kea in 1986.  Since 1999, Kea numbers have again fallen, presumably due to nest predation by possums.  Today the bird is considered to be endangered (Wikipedia).

Keas have an odd predilection for rubber.  The bird I was photographing flew up, and was joined by a second bird.  Both landed on our rental car and began tearing at the window sealant--much to our younger son's consternation. He had remained in the car, being once again embarrassed by his father's bird chasing.  Keas are known to slash car and bike tires and make moon-roofs out convertible tops. Keas will also carry off any belonging left unguarded.  When we returned our car to the rental company, we did not mention the Kea attack.

Thursday, November 25, 2010

Bird Art


Last May I blogged, "When I see Rose-breasted Grosbeaks, I am reminded of my favorite artist, Louis Agassiz Fuertes." One of his sketches of grosbeaks is just stunning.

One of my photographs from Florida last January also reminds me of Fuertes.  In this case, the long plumes on the head and neck on a Tricolored Heron reminds Fuertes' 1929 portrait of feathers on an Egyptian Vulture.  You may recall that I wrote that Fuertes was killed at a railroad crossing in 1927.  There are times when we birders should keep our attention away from birds! A biography and a collection of his paintings is to be found in A Celebration of Birds and in the following link to  Cornell University.

I think my favorite living bird artist is Lars Jonsson, whose work crosses that line between superb illustration and great art. He has published a collection of recently completed work. This book also discusses his technique. The book is worth perusing if you are interested in bird art.

Tuesday, November 23, 2010

Snow Bunting

Today I saw hundreds of Snow Buntings in several flocks near Nerstrand Big Woods State Park in Rice County, Minnesota.  Between the busy state highway and relatively uncooperative birds--not to mention the 18 degree F temperature--I did not get very good photographs.  In fact, the photo above of a Snow Bunting that I took several years ago.  Today's photos were more like the one below.
Snow Buntings breed in Alaska and across Arctic Canada where they nest in rock cavities. They winter from southern Canada to the central United States.  Although they can be of sporadic occurrence, and numbers vary from year to year, these buntings can be locally abundant, and are often seen along Minnesota highways.

Sunday, November 21, 2010

Winter Reading

One of the books that inspired me to become a birder was Wild America by James Fisher and Roger Tory Peterson.  The book recounts the authors' 1953 road-trip across North America and northern Mexico.  At the time, their list was the record for birds seen in one year in North America.


I am currently reading Scott Weidensaul's Return to Wild America. This book gives the reader a history of American conservation challenges over the past half-century. The author retraces Fischer and Peterson's route and discusses fifty years of environmental change and growing public support for environmental causes.  Despite urban sprawl, not everything has gone downhill since the 1950s.  Since then, many of the hallmark environmental laws have been passed and many acres have been preserved for wildlife. The result is that bird populations have changed, often for the worse, but occasionally for the better.  A small drawback is that Fisher, Peteron, and Weidensaul all avoided the upper Midwest.

I picked up Return to Wild Ameica because I enjoyed Weidensaul's Of a Feather, a well-written and entertaining history of North American birding.  I can recommend this book to anyone wishing to learn about the history of ornithology and birding in the United States.

Thursday, November 18, 2010

American Crow

 
American Crows are abundant across North America.  Picking what to write about crows is difficult. They are intelligent.  They employ a number of information-laden calls, they recognize individual people (although few people can recognize individual crows), and, generally speaking, crows are less wary in cities than in the countryside. I encountered these crows as they foraged in a Northfield field (the day before the snow arrived).

For the past several years, we enjoyed a huge winter crow roost in our backyard.  The birds reminded us of the flying monkeys in the Wizard of Oz.  I do not know why the roost was abandoned this year.  Crows seem to be exceptionally prone to West Nile Virus.  This Old World disease appeared in New England and spread across the country.  I once wrote a paper demonstrating that banding returns show that crow populations are are not isolated, but potentially can come in contact with infected birds across the continent.

Young crows help their parents raise subsequent broods, sometimes for two or three years.  Not all young are helpers, and we do not know why some young help while others raise their own offspring.  Do the baby-sitting helpers eventually become better parents? Do parents pass genes to some offspring that effectively enslave some young, thereby increasing the parents' reproductive success compared to crow families without helpers?

Tuesday, November 16, 2010

Muskrat

I encountered three muskrats on one of our last, warm November afternoons.  Muskrats feed mainly on aquatic vegetation.  They are not dormant during the winter, and must eat every day. Muskrats, rats and mice belong to the same family.  Muskrats owe their name to their musky scent glands with which they mark their territories.

Muskrat populations expand and contract through a 6 to 10 year cycle. The muskrats in this photo are likely a family group. They burrow in bank-sides of lakes or streams or they build lodges with underwater entrances.  Muskrats also build platforms for feeding.

Sunday, November 14, 2010

Sharp-shinned Hawk

Because this forest-inhabiting hawk subsists almost entirely on small birds, this Sharp-shinned Hawk was probably attracted by the activity at our feeders.  I banded it on 8 November.  The hawk flew up from our water feature, where it may have been drinking.  At the time, no small birds were evident.

Male Sharp-shinned Hawks are much smaller than the females.  The size of the sexes do not even overlap.  This bird, with a wing chord of 203 mm, is a female.  Her yellow eye and brown back indicate she is a young bird.

Several hypotheses exist to account for female hawks being larger than their mates. Perhaps females need to be larger to protect themselves from dangerous, aggressive males. Alternatively, perhaps to reduce competition between the sexes, males and females specialize in different sized prey. Apparently, for whatever reason, the more a raptor specializes in taking small birds, you expect to see a larger difference between the size of the sexes.

Friday, November 12, 2010

Cackling Goose

While taking photographs of Canada Geese (see first photo) in the Cannon River within the city of Northfield, I noticed that about a quarter of the flock were smaller and tended to stay away from the larger geese.  The smaller birds' bills are relatively shorter and stubbier, giving the bills a triangular appearance (see middle photo).   Additional field marks add up to the small birds being Cackling Geese. 
1. In the photo at the end of this post, a Cackling Goose swims in front of two Canada Geese.  The head is not as round as in the middle photo above, but not as wide as in the Canada Goose.  (The Cackling Goose in the bottom photo shows kind of a squarish, rather than round, head--but that is OK.)

2. The forehead of the Canada usually has more of a slope to it than does the more angled Cackling forehead.

3. The Cackling Goose tends to have a relatively shorter neck--a field mark that is apparent in the lower photo, but murky if the bird is stretching its neck out as in the middle photo.

4. Cackling Geese show slightly darker breasts than do Canadas, a mark that can be seen in the photo below. 
Until recently, Cackling Geese were considered to be a small race of the Canada Goose.  Genetic studies indicate that the two forms are distinct species.  Paul Hertzel, Ross Silcock and Stephen Dinsmore have published a website that further discusses identification issues with these geese. They warn that not every Cackling Goose, especially when solitary, is easily identified.

Wednesday, November 10, 2010

Tundra Swan 2


Do any field guides depict ducks dappling?  For today's quiz, name these ducks!   The swan is not difficult.  Its meter-long neck allows the Tundra Swan to feed in relatively deep water on plant stems and roots.  Often the feet are used to dig up plants. This swan also feeds in agricultural fields in the winter and arctic meadows in the summer (Limpert and Earnst 1994).

Moments after I took the photograph above, all three waterfowl came up for a breath--and I took the next photo.  You can see the answers to the quiz--Tundra Swan, Mallard, and Northern Pintail.  This post is the last from our trip to Brownsville, Minnesota. For finding birding spots in Minnesota, Kim Eckert's A Birder's Guide to Minnesota is indispensable.