Saturday, January 30, 2010
Cracking the Hard Shell
All along the coast, diving ducks are common during the winter: eiders, buffleheads, goldeneyes, scoters, mergansers, harlequins. They ride the waves, disappear beneath the surface, then pop back up like so many corks. Occasionally one comes to the surface with something in its bill, pauses a moment, swallows, then resumes doing its duck thing.
I watched a female Common Eider come to the surface with something that looked like a flattened egg. It was dark, appeared solid, and was about as wide and almost as long as her bill. Only later did I realize that she had brought a shellfish to the surface.
She was diving to find food. A favorite food for diving ducks is mussels, those two to three inch long, dark, oblong shellfish. They dive to the bottom, and rip the mussel, shell and all, from the colony. The eider I was watching brought to the surface an intact, tightly closed bivalve, something related to the mussel, but larger. I began to wonder: How did she get through the hard sea shell to the nutritious food on the inside?
A lot of food is protected by a hard outer shell. Plants and animals have developed defenses against those things which would eat them. The hungry foragers in turn have developed ways to breach the defenses.
Let’s take a look at our bird feeders. If you do much bird feeding, you know that sunflower seeds are favored by many, perhaps most, of our feeder birds. The edible and nutritious part of the sunflower is inside its small, hard shell. Have you ever tried to open a sunflower seed? Putting aside the fact that we are big and clumsy when it comes to handling something that small, it is nevertheless a very difficult task to break open the seed.
Many birds have no trouble. The grosbeaks and cardinals can perch on the sunflower feeder or stand on the platform and shell half a dozen sunflowers seeds in the time it takes me to write this sentence. They have powerful beaks to crack apart the hard casing. Many smaller birds are equally adept. The finches, for example, will fill the nine perches on the sunflower feeder and consume seed after seed, scattering the husks to the ground beneath them.
Not all of our feeder birds are as adept at opening the sunflower seeds. These birds have beaks more suited to gleaning insects along tree trunks, branches, or leaves. But they are opportunists, and our feeder food is handy. Chickadees and titmice carry the seed to a branch, hold it between their feet, and drill it open with their sharp beaks. The seeds do not yield the tasty meat easily. These small birds have to pound repeatedly before the shell cracks open. Nuthatches have a similar problem, but are not designed to hold the seed between their feed. They carry it to a tree trunk, jam it into a crack, and then pound it open.
As big and muscular as the Blue Jays appear to be, they also do not have a beak designed for opening seeds. I often see them carry a seed to a branch, hold it between their feet, and pound it open. The jays also have another way of dealing hard shelled seeds. They store them in their crop. I often see a jay’s throat swell as it scarfs seed after seed. The seeds which are stored in the crop get softened up in a kind of pre-digestive soaking.
There are a lot of different ways that birds have found to crack the hard shell of a nut. My favorite is the brainy solution used by native crows in New Zealand. They drop their favorite nut on a busy road, then wait for a car to run over the nut and crack it open. To avoid the danger of speeding automobiles, some crows drop the nut in a pedestrian crosswalk, and then wait for the light to change.
But what about those hard shelled mussels favored by diving ducks? When I did some research, I learned that opening a mussel requires a special blade and considerable adeptness. Or, the mussels can be steamed; the bivalve opens and the tasty meat is then readily accessible. I remember one time on the Maine coast when we enjoyed a dinner that consisted of a huge plate of steamed mussels. However, the combination of place, occasion, companion, and the aphrodisiacal quality of mussels banished any curiosity I might have had about how diving ducks might get at the tasty meat, or whether it contributed to a duck randiness.
Omnivorous gulls occasionally exhibit an epicurean taste for mussels and other shellfish. They carry the tightly closed shellfish aloft, then drop it on rocks - or a roadway. They repeat this exercise until the shell finally opens, or breaks. Then they dine.
But how does the hen eider which I saw with a shellfish in her bill get at the meat. First of all, she swallows it whole. After a recent meal, I felt like the food I had consumed was resting in my stomach like a solid lump, a heavy brick weighing me down. But a mussel or mollusk, shell and all? That must really feel like a brick.
And yet, mussels are the favored food of diving ducks, and some dabbling ducks. The shellfish is swallowed whole and then the double stomach takes over. Complex contractions move the food back and forth between the glandular stomach (proventriculus) with its acids and enzymes which dissolve and digest, and the muscular stomach (gizzard) with its grit and stones which grind, pulverize, and mix. A study done on black ducks demonstrated that they can completely digest and pass a blue mussel in 30 - 40 minutes.
The hen eider which I watched with the large shellfish in her beak was unusual. Generally, they prefer smaller mussels which have less nutrition but which pose fewer problems when being swallowed.
Finally, I should add a disclaimer. Here and elsewhere I refer to the “tasty” meat, or morsel, inside the hard casing of a seed, nut, or shellfish. We may dine on mussels for their epicurean delight, perhaps their stimulus to the libido, and maybe their nourishment of the body. The hen eider which I watched was only concerned about the latter. Her complex and efficient digestive system quickly dissolves and grinds the hard shell and digests the meat. What taste buds she may have play no role in her menu selection. The diet of the eider has been determined by the remarkable and complex stomach which can digest a stone - or at least, food which looks like a stone on the outside.
Good birding!
Friday, January 29, 2010
Diving Ducks Identified
Diver #1 - Red-breasted Merganser
Diver #2 - White-winged Scoter - I am not sure it was fair including this one since the white-wing was not at all visible, but then it is not visible in the companion photograph below which is a good thing to know when looking at black ducks. It took me a lot of searching to discover finally that the Surf Scoter also has red legs, but not the Black Scoter. If anyone knows how to distinguish White-winged & Surf in the diving photo, I would love to hear from you. I had the distinct advantage of watching the lone White-winged Scoter, so IDing the photo was not a problem
Diver #3 - Common Eider
Diver #4 - White-winged Scoter
Good birding!
Wednesday, January 27, 2010
Monday, January 25, 2010
Diving Ducks
Sunday, January 24, 2010
January Thaw
Saturday, January 23, 2010
Along the Rock River
“River” is a bit of a misnomer. River implies something large and long. The Rock River is neither. I am only a few miles from its headwaters. It flows past me for a few miles and then joins the more appropriately named West River and eventually the Connecticut. During Spring melt and following torrential rains, the Rock River rages like a river for a day or two. Then it settles back into its placid mode. In all seasons, it would be better described by “brook,” “creek,” or “stream,” but whoever made the entry on the geographical maps preferred the alliteration of Rock River.
So Monday morning I waded through the new snow to the river bank to look at the river. The day after Christmas, rain washed out the ice, heaving large chunks onto each bank and leaving the water open. Now, three weeks later, the ice has returned. In most places it spans between the river banks, giving animals a dry bridge across the frigid water. Tracks crisscrossed the snow covered ice giving evidence that life has continued its activity even as I lay abed, enjoying the snow muffled quiet of the winter morning.
Where the river flows swiftly, there are still open places, but if a frigid January returns, it will quickly close up, forming an ice cover of eighteen or more inches. It happens most winters. A few winters, I have been able to snow shoe down the middle of the river for long distances.
On those winters when the Rock River is completely frozen over, it then becomes a gauge by which the return of Spring can be measured. As the sun acquires more warming power and the temperatures begin to moderate, the river slowly opens up, with a patch here and a patch there.
About ten years ago, the river had frozen completely. Around the beginning of March, hints of Spring began to be felt in the air and the ice slowly began to retreat on the river. By the middle of March a couple of pools had opened up and the flowing water could be seen for the first time in weeks.
By happenstance, I was watching the river from my kitchen window when two birds flew upstream along the river highway and landed in the first open pool. One was a drake Common Merganser, his large, bright white body, breast, and neck prominent against his dark back and green head. The other was a hen merganser with her gray back and rusty-brown head. They rested for a few moments, and then both dove. When they surfaced, it was about ten yards upstream in the second open patch in the river. They paused again for a few moments, then took flight and headed swiftly upstream.
I see Common Mergansers along the Rock River waterfowl highway several times every year. In the spring, a pair flies rapidly upstream a few feet above the water. Sometimes an hour or so later, I will see a pair fly rapidly downstream. Less often, when I am especially lucky, I may see one or two swimming down the river. The mergansers are very wary. When they even sense my presence, they take to the wing.
In March and April when the mergansers fly up the Rock River, I know what they are doing. They are in search of a nest site. Looking through my records, I found that there was one year when I recorded a Common Merganser on January 18. I think it was a mild winter and the river was open. Even so, that seems like a very early date for one to be wandering so far from good fishing grounds.
Common Mergansers prefer deep, clear lakes and rivers where they can pursue their foraging-by-diving lifestyle. You will often see them on the waters of the Retreat Meadows, lower West River, and Connecticut River. They are hardy birds, and in winter some will go no further south than the nearest open water.
Fast moving shallow water is not the Common Merganser’s preferred habitat except when there are other overriding urges. Early last May along the West River I watched four drake Mergansers courting a single hen. They swam in a tight circle, posturing before one another. Occasionally a powerful kick from a drake’s foot sent a spurt of water 3 or 4 feet long. The splash was the merganser variation of sexual display. He was showing off his bright red foot, and the power contained in it.
One June I was in an evergreen blind along the Rock River when a pair swam downstream. The bright red feet of the drake were clearly seen through the clear water. He had won her over, and they were returning from their upstream inspection of nesting sights.
I know that mergansers nest along the Rock River somewhere upstream from my home. Their nest is probably in a hollow tree; it could also be on the ground. When Audubon found their nests, they were on a marshy island, but most accounts describe nest holes. When I see a pair of Mergansers going upstream, or downstream, I know that journey is related to breeding. However, as soon as the eggs are laid, the drake disappears. The hen does the incubating and cares for the young alone.
In the mid-summer, the hen leads her young brood down the Rock River to the deeper waters of the real rivers downstream. Bobbing downy fluff balls float with her on the river’s current. She is as wary as ever, and when she senses my presence she speeds up, paddling her feet so rapidly that she almost walks on the water. Her young, desperate that she may disappear ahead of them, follow her in a near panic.
The Rock River behind my home is still partially open, but I do not expect to see any mergansers for a couple of months. For the time being, this rocky mountain stream flows gently, mostly hidden by the covering ice.
In our culture of instant gratification, the frozen river reminds me to be patient, and to accept what the day brings. A merganser pair is not going to be flying upriver on this day. It will be many months before a brood of young mergansers goes bobbing downstream. Today’s gift is new snow, a clearing sky, and sun sparkling on frozen water crystals. I am gratified ... and grateful.
Wednesday, January 20, 2010
Monday, January 18, 2010
Red-bellied & Robins
Flocks of American Robins have been passing through the neighborhood as well. They have been feeding on the apples and crabapples ...
Good Birding!!
Saturday, January 16, 2010
Field Guides Begin to Go Electronic
In 2000, David Sibley published the Sibley Guide to Birds. The volume revolutionized the printed bird guide world. It contained descriptions and clear illustrations of 810 species. The multiple illustrations included breeding, non-breeding, juvenile, and intermediate plumages The birds are shown in flight., and sometimes in characteristics poses. At 6"x9", it was not published as a field guide, but it was so useful that birders found various ways to carry it into the field when they were birding. A couple of years later, smaller and more field friendly Eastern and Western versions were published.
Also in 2000, Kenn Kaufman published his Birds of North America, another revolutionary guide. Conventional wisdom said that photographic guides were much inferior to illustrated guides for bird identification. The two thousand photographs in Kaufman’s guide were digitally enhanced, creating a field guide that rivaled such classics as the Peterson or Golden guides. For many years when I still had the humility to admit that I needed a field guide close at hand, I chose the Kaufman guide for the very practical reason that it would fit into the rear pocket of my jeans – and it was good.
In the last decade the publication of bird guides has mushroomed with new editions of the superb National Geographic guide, photographic guides from Stokes and Smithsonian, and many specialty guides (e.g. shorebirds, seabirds, gulls,) both illustrated and photographic. This presents a dilemma - what are you going to carry in your pocket, or backpack, or store in your backseat, or carry in your luggage, when you go birding?
Last January, I hiked up a remote canyon in the Santa Rita Mountains near Tucson. A Rufous-capped Warbler, a Mexican bird that on rare occasions sneaks across the border and stirs up the birding community, was being seen. I carried the Kaufman guide.
I found several other people also looking for the bird. The question of its song and call came up. Someone produced a small, hand held devise, fiddled with it briefly, and we heard the song and call. My interest was piqued. Up to that point, if I was going to have access to a resource for bird songs in the field, I needed a back pack, a portable CD player, a 3 or 4 CD set of birds songs, and the indexed booklet which would guide me to the appropriate CD, and then appropriate track. Cumbersome, to say the least.
Back home in Vermont in February, with nothing to do except keep the wood stove filled and the snow shoveled, I began reading the advertisements in birding magazines with particular interest and attention. I won’t take you on the full journey, but here is a summary of what I have discovered and a review of those results.
It is now possible to go into the field birding with multiple field guides and audio resources that can be held in the palm of your hand and slip easily into a breast pocket. You can review songs, calls, and identifications of every bird that has ever been seen in North America.
All of the applications reviewed below (“Apps” as they are known) work with the iPhone or iPodTouch. Many work on the many other devises available.
Here are the birding Apps currently available:
“birdJam Maker” is usable with most iPods. This application organizes a bird song collection into playlists so that you can quickly find and play the song of a particular species. The most comprehensive collection is “Stokes Field Guide(s) to Bird Songs,” Eastern and/or Western Regions. Unless you buy a preloaded iPod from the vender, this is the most complicated App to set up. However, “birdJam Maker” provides very clear instructions on how to do it. The end result is that you have all seven CDs from Stokes in the palm of your hand and can find any song in about a half minute. (They claim 15 seconds.)
“iBird Explorer Plus” is the future of the electronic field guide. Currently providing information on 934 species, birds can be browsed by first name, last name, or family. For each species there are illustrations, photographs, range map, and detailed information on identification, including description, range, habitat, breeding, nesting, foraging, feeding, and more. Song and call can be played. “Facts” provides interesting information and trivia. If there is wireless internet available, there is a link to Birdipedia. The downside to this App is that the illustrations often are not very good, and the number of photographs are often sparse. (The developers continually update with donations from photographers.) “iBird Explorer” is a work in progress, but a good work, and at present is the standard against which other electronic field guides should be measured.
All of the electronic guides provide description, voice, and range. What makes any guide useful is the visual help it gives in identification. “National Geographic Handheld Birds” is based on the field guide, and uses the excellent illustrations from that guide. For some species the illustrations are very limited and small. Its design (user interface) is different from the previous one, but easy to use.
“The Audubon Guide - Birds” relies on photographs. The number of photographs varies, and unfortunately they have not been chosen for how well they will assist field identification. I would not want to rely on this App for identifying little brown sparrows. It retains all the problems of the old photographic guides.
There are three Apps based on the Peterson Guides: “Birds of Prey,” “Warblers,” and “Backyard Birds.” Beyond the Peterson illustrations which are sometimes too small to be of any help, the limited number species and small amount of information and description make these Apps marginal at best.
The electronic field guides can all be downloaded and automatically installed via computer or wireless connection.
A new App which has just become available is “BirdsEye.” It is integrated with Cornell Lab's Project eBird, the online database for reporting sightings. According to reports, with this App “you can instantly find out what birds are being seen in your area, how recently, and exactly where, and you can go straight to the spot and see them for yourself.”
Often when using a field guide, you want to look at similar species. “iBird Explorer” and “Audubon Guides - Birds” provides a quickly accessible list of similar species. Only “iBird Explorer” provides quick access to birds with similar voice. With a simple touch you can listen, for example, to Willow Flycatcher, then Alder, then Acadian, then back to Willow - exceptionally useful!
The ideal would be for “iBird Explorer” to contract with the publishers of, for example, Sibley, Kaufman, and Stokes guides to use their paintings and photographs. Perhaps someday. Electronic guides are still in development. They will not replace the traditional printed guides. They are useful aids, and they eliminate a lot of weight when you are in the field.
Good birding!
Thursday, January 14, 2010
January Birding
However, in the last three days, I have surged, adding four species with the result that my January total soared to 46!! In keeping with full disclosure, only 17 are from Vermont, partly a reflection of semi-hibernation. The photos below are from my archives.
A small flock of 5 Evening Grosbeaks visited the platform feeder briefly on Tuesday ...
Going out for the mail yesterday, I heard a Common Raven calling over a nearby hill ...
In the open water below the Vernon Dam on the Connecticut River, there were Hooded Mergansers ...
... and Common Mergansers ...
... and all of those contribute to Good Birding!
Saturday, January 09, 2010
Best New Birds of the Decade
But not without first doing a Don Quixote by tilting at a windmill. The passing of 2009 was not the end of the decade. That will not occur until the current year, 2010, is a year of the past. The current system of numbering years was devised in 525. The “Current Era,” (abbreviated C.E. and also known as A.D., “Anno Domini,” the “Year of the Lord”) begins with the year “1.” “Before the Common Era” (abbreviated B.C.E. and also know as B.C., “Before Christ) ends with the year “1." There is no year zero. The numbering of years goes from 1 BCE to 1 CE - or if you prefer the old system, from 1BC to 1AD. That means that the first decade ran from 1CE to 10 CE, and that every decade since ends in a “zero” year. We are currently in the 210th decade of the Common Era.
For some reason or other, media people decided that decades should be figured on the numeral in the “ten” spot, so the current decade-past in their reckoning ran from 2000 to 2009 (‘00-’09) and the next decade will run from ‘10-‘19. I guess that means that the first decade of this Common Era only had 9 years, running from years 1-9, there being no year zero. I would like to fight the battle for some accuracy in the media and among all of us who lap up their offerings, but I doubt anyone would show up.
However, I bet I can provoke some fights if I begin with a list of the 10 worst birds. Nearly everyone would agree that the list should be headed by Rock Pigeon, European Starling, and House Sparrow. These are introduced species in North America; they are invasive, displacing many native species from nesting sites. All true. But is it the fault of these birds that they were released in the western hemisphere? All found their way to the continent with deliberate human help. Should we fault them for then being adaptable and prolific in their new environment?
Most would put Brown-headed Cowbird on the list of worst species; it is ugly, with no redeeming vocal abilities, and a parasitic breeder. Preferring farmlands, hedge rows, and forest edges, it victimizes more and more beautiful songbirds as it follows power lines and development roads through the forests. Adaptable and opportunistic, the cowbird exploits habitats created and extended by another adaptable and opportunistic species, scientifically known as homo sapiens.
Plenty of people, especially conservationists, would add the Canada Goose and Mute Swan to a list of ten worst birds. The adaptable Mute Swan is in the same category as the pigeon, starling and House Sparrow - deliberately introduced and now invasive - with the single redeeming quality of being a graceful and gorgeous bird which many people love - and associate with love. The equally adaptable Canada Goose rarely nested in the lower forty-eight until wildlife managers, in “all their wisdom,” decided to help them out.
That’s six birds that have made it onto my ten worst list, and all of them are our fault, which isn’t exactly fair to creatures that are just very good at surviving. So I’m going to end this list and go elsewhere.
In the last decade I have added 194 birds to my life list. Chronologically, here are the ten that were the rarest birds and/or most satisfying birds that I added to my list.
- Fork-tailed Flycatcher, Ferrisburg, VT, June, 2000 - This bird occasionally forgets to stop in Central America when it is migrating north. The first Vermont record was in 1884; this was its second appearance. Some birders expect it to appear in Vermont again in 2116.
- Gyrfalcon, Plum Island, MA, December, 2000 - This powerful Arctic falcon wanders south on rare occasions. I chased it with a neighbor; we were the first to find it on this day. The bird treated us to a display of its speed and power.
- Harris’ Sparrow, Putney, VT, January, 2001 - This first winter bird spent several weeks around the backyard feeders of a very hospitable Putney resident. It was the second Vermont record.
- Red-footed Falcon, Martha’s Vineyard, MA, August, 2004 - First North America record for this species which is common in Central Asian.
- Black-tailed Gull, Charlotte Town Beach, VT, October, 2005 - First Vermont record for this Asian Pacific gull.
- Black-tailed Godwit, Plum Island, MA, July 2006 - Eurasian species that makes very rare & accidental appearances in North America.
- Western Reef-Heron, Kittery, ME, August, 2006 - The third North American record for this small heron from western Africa.
- Bachman’s Sparrow & Red-cockaded Woodpecker, North Carolina, April, 2007 - Respectively rare and endangered, both of these birds were added to my life list on an early morning visit to a wildlife management area. I tracked the sparrow by its song (never an easy thing for me) and the woodpecker with patience, and had satisfying looks at both.
- Rufous-crowned Warbler - Florida Canyon, AZ, January 2009 - Most of the birders who chased this Mexican species on the same day I chased it were unsuccessful. I was in the right place at the right time and saw it dart through undergrowth before disappearing on the other side of the narrow canyon. The birding gods smiled on me.
- Montezuma Quail, Cave Creek Canyon, AZ, January 2009 - Some birders target this species on multiple occasions, without success. I saw a covey on two successive days and enjoyed good looks at this small quail with the harlequin head.
If you insist that the decade ended on December 31, 2009, then that’s my list of the ten best new birds for me. Those birds, and many, many more, made for a decade of good birding.
Thursday, January 07, 2010
Coastal Birding
About halfway through the morning, I realized that Common Loon was still absent, and made a particular point to look for it. No luck. Perhaps they were out to sea, or went - were blown - south by the recent, and rather strange, coastal storm.
Other than that, the usual suspects were present, though it seemed to be that the numbers were low. Tide was low in the morning, and the birds that were seen were rather far out, so photography was difficult.
On a day when wintering sea ducks, grebes, and alcids were the expected targets, the highlights were quite different.
At Eastern Point Lighthouse, an American Pipit posed briefly ...
... and at Salisbury Beach, a flock of 50+ Snow Buntings swirled around the campground.
Buffleheads were quite common all along the coast. The sharp contrast between the Bufflehead's bright white hood and bright white body with the dark wings, head, and neck have made this a challenging bird to get a good photograph of, and I have yet to meet the challenge. Nevertheless, in the low angle of the winter sun, the head and neck glistened with an iridescence that was stunning. This gentleman quite apparently has his eye on the lady.
The contrasting light and dark plumage on the Harlequin Duck poses the same photography challenge as does the Bufflehead. They were quite common along our route from the Granite Pier to Andrews Point - a reliable area to see these birds if you need them for a life list.
The King Eider was out to sea, or at least our of our sighting, yesterday. Common Eiders were - well, common - though there were no huge rafts as I have often see, and most were too distant for good photos. But this female was near the breakwater at the lighthouse ...
Good birding!
Monday, January 04, 2010
Snow Birds
A few other neighbors came to the bird feeders as well, including the pair of resident White-breasted Nutchatches ...
... and the three pair of Tufted Titmice ...
Happy New Year!