Winter Irruptions

Watching birds can do lots of good things for you, including expanding your vocabulary. Or at least, it has expanded my vocabulary. Until I had the time to pay attention to seasonal changes and movements of birds, I did not have the word, “irruption,” in my working vocabulary. I knew “eruption,” which involves something bursting out, like lava from a volcano. Irruption refers to something bursting in, or surging up. It is the word used by ecologists to describe a sudden, rapid, and irregular increase in an animal population. It typically involves some kind of change in the natural ecological checks and balances.

In the bird watching world, irruptions are hoped for events, especially as winter imposes its grip. Winter birding can be rather monotonous - the same old, same old, unless one or more irruptions occur. “Bird Source,” the website of National Audubon and Cornell Lab of Ornithology, puts it this way: “Every winter, bird watchers across North America anxiously await the possible incursion of birds that don't normally winter in their areas. These periodic bird irruptions add a dramatic level of excitement to winter birding.”

Snowy Owl - Brattleboro, Dec, 2011

Last winter (2011-12) was an irruptive year for Snowy Owls. These large arctic predators were reported in record numbers across the northern states, often in places where they have rarely, or never, been reported. Sightings extended deep into the Great Plains and even as far south as Texas. The Snowy Owl irruption was driven by a crash in the lemming population in the Arctic; the lemming is the owls’ principal food source.

When a Snowy Owl was reported in mid-December, 2011, in the corn field behind the marina in Brattleboro, the word spread quickly through the birding community. Within an hour of the first report, a dozen birders were focusing their scopes on the white object among the corn stalks. More observers followed in a steady stream.

Finch species which inhabit the northern forests are the most common irruptive birds, and this winter has been a banner year in our area. During October, large flocks of Pine Siskins (closely related to the American Goldfinch) moved through New England and the mid-Atlantic states. The flocks which visited my bird feeders numbered 200+; they put a serious strain on my bird seed budget.

Common Redpoll have irrupted in New England this winter

The siskin flocks moved on, to be followed by the Common Redpolls (also closely related to goldfinches). Throughout December and January, and on into February, there have been breathless reports about the sudden appearance of these small finches.

What makes the winter irruptions both exciting, and frustrating, is their unpredictablility. As the birds irrupt into New England, they do so in flocks - often large and typically very nomadic. So you hear about all of these redpolls being seen, and you are frustrated, because you have not seen a single one. And then you are snowshoeing through an old hill farm, or walking along a frozen lane, or sitting in your kitchen watching your bird feeders, and suddenly you have a surfeit of redpolls, scratching the snow, squabbling over seed, and taking hurried flights into the hedges.

Winter finches are notorious for quickly exhausting a food source and then moving on. The epitome of this practice is the Evening Grosbeak. Long time bird feeders describe the Evening Grosbeaks’s winter presence with ambiguity. They are delighted to have these large, colorful, and handsome finches at their feeders, but they cannot avoid the additional use of adjectives such as voracious and greedy to describe their presence. This winter Evening Grosbeaks seem to have taken their blitzkrieg feeding habits further south; I have seen few winter reports from our area.

Evening Grosbeak flocks are notorious for emptying bird feeders & moving on during winter.

 The winter finches which are typically more common in our area have been hard to find this year. In addition to the siskins and grosbeaks which have moved on, Purple Finches and goldfinches are scarce.

Pine Grosbeak - Brattleboro, December, 2012

But then there are the frustrating reports of other winter finches - frustrating because you would love to see them, but they do not make it easy. For a couple of weeks in December, a flock of Pine Grosbeaks fed on the yew berries in front of Center Church in Brattleboro. There were females and young males. (The adult males apparently stayed home to defend their territory through the winter). When the berries were exhausted, the flock moved on. If you have not seen the Pine Grosbeaks, you may still have the opportunity. Be alert, because they could be anywhere. On the Christmas Count, we came across several getting grit and salt on a road in Dummerston. If you miss the Pine Grosbeak this winter, I am sorry to tell you that you may not have another opportunity for several years. But, that’s bird watching.

White-winged Crossbill (l) & Red Crossbill (r), December, 2012

On the New England coast, this has been a good winter for Red Crossbills and White-winged Crossbills. I made a trip to Salisbury Beach on the New Hampshire coast and had my best crossbill day ever.

Winter irruptions are driven by conditions in the northern forests. Scientists and naturalists in Ontario and the Maritime Provinces have been studying the preferred food sources of various species for years. Based on their collected data, fairly accurate predictions are possible about which species will irrupt. When they document the shortage of a food that a particular species prefers, they predict an irruption. Winter survival depends upon getting enough food. When local food sources are scarce, the birds go elsewhere.

Red-breasted Nuthatch

Finches are the most common irruptive species during winter, but not the only ones. It is easy for us to miss an irruption of the Red-breasted Nuthatch, since this species also nests in the higher elevations of our area and may be seen year-round. Harder to miss when you come across them are the Bohemian Waxwings. When you find Bohemians among the flock of their cousins, the Cedar Waxwings, then you have counted a coup among bird watchers. And when you meet a waxwing flock dominated by Bohemians, you have certainly encountered evidence of an irruption. And, you will be breathless.

Bohemian Waxwing, Putney, 2011

For any of these winter irruptions, I have two pieces of advice if you are not a hard core birder: First, I am sorry to say, don’t hold your breath. The winter flocks are nomadic and erratic. Hard core birders sometimes spend days trying to chase them down, not always successfully. Second, when you do stumble on one of these flocks, or when one of these flocks stumble on you, don’t forget to breathe!

Good birding!

Crossbills

Yesterday was a crisp, clear, bright day - a marvelous day for birding and wonderful light for photography. I drove to the Massachusetts shore. Crossbills were being reported in the campground at Salisbury Beach.

The cone-laden pine trees hosted flocks of White-winged Crossbills and Red Crossbills, the most concentrated winter irruption of these boreal species that I have seen. Here is an early sampling. I'll post additional photos soon.

White-winged Crossbill (male)

Red Crossbill (female and male)

 Crossbills usually travel in single species flock (Sibley), but there was a mixed flock (or two separate flocks which decided to forage in the same trees), as seen in this photo ...

White-winged Crossbill (l) and Red Crossbill (r)

Red-breasted Nuthatches were clearly another irruptive boreal species, with numbers almost rivaling the crossbills ...

Red-breasted Nuthatch

 As I stood with two other birders was watching the crossbills feeding, my binoculars picked up a Common Redpoll. I casually named the bird. A few moments later, one of the birders said, "Thank you. That's a life bird." It is always gratifying to help others add to their observations.

Common Redpoll

 In the estuary near the campground, Bonaparte's Gull provided an accesible display of their tern-like hovering ...

Bonaparte's Gull

At Plum Island, a scan of the ocean produced a rare Western Grebe, plus Horned Grebe, Common and Red-throated Loon, Razorbills, Surf and Black Scoters, Common Eider, and Red-breasted Merganser, all fairly close to shore but too distant for photography. At the waters edge was a flock of Sanderling and Dunlin ...

Sandering (l) and Dunlin (r)

A day of Good Birding!!

Sandia Crest - Rosy-Finches - 2

Sandia Crest east of Albuquerque is one of two must visit winter sites in New Mexico. (The other is Bosque del Apache; I am still processing photos from Bosque, but will be posting some soon).

We drove to the summit (10,600 ft) on a Sunday morning. Only problem was that we arrived too early. The lodge did not open until 10am, so we had to spend about 20 minutes outside watching birds - (life can sometimes be difficult).

During the winter months when the Rosy-Finches are present, the Rosy-Finch Project does bird banding on Sunday, so we had a considerable additional plus to our day.

One of the banding team assesses the health of a Mountain Chickadee ...

Mountain Chickadee

A Brown-capped Rosy-Finch is about to receive a radio transmitter which will enable researchers to track its movements and where it roosts at night ...

Brown-capped Rosy-Finch

Birds are not caught in mist-nets, as is typically done when banding songbirds. They are trapped in a manually triggered metal cage. This Black Rosy-Finch has already been banded. Re-trapping banded birds over years helps to determine life span, and within a single season and from year-to-year assess the health of individuals and populations.

Black Rosy-Finch

A banded Brown-capped Rosy-Finch considers whether it can grab a seed from inside the cage and get out before slow human reflexes can trip the trap.

Brown-capped Rosy-Finch

Red-breasted Nuthatch wears aluminum jewelry, compliments of the bird banders ...

Red-breasted Nuthatch

Stellar's Jay begs for anthropomorphizing - intelligent, curious, cautious, sassy - but definitely gorgeous ...

Stellar's Jay

Two more photos ... just because ... Black Rosy-Finch ...

Black Rosy-Finch

Brown-capped Rosy-Finch ...

Brown-capped Rosy-Finch

 Good Birding!

No Respite from Winter

Alas, the whole of the United States seems to be reeling from one storm after another. For all of the anticipation heaped up by the media, when it finally reached us here in Vermont it was not too bad - about 10 inches (25cm), with some mixture late of sleet and freezing rain. The snow pack in the back yard is now 30 inches (75 cm).

The storm may not have been too bad for us, but I am getting tired of winter.

After the big flock moved through a few days ago, four Wild Turkeys are continuing in the near vicinity.

While eating lunch, I saw big black things high in the willow tree. We don't think of turkeys as flying machines, but they are quite adept.

The winter finches have moved elsewhere - no grosbeaks, redpolls, siskins. But the neighborhood residents are still present, including at least five cardinals ... and a Red-breasted Nuthatch returned briefly to the suet.

Northern Cardinal, female

Northern Cardinal, male

Red-breasted Nuthatch

Portraits during a Blizzard

Individual portraits of a few feeder birds which visited during Monday's blizzard.

Common Redpoll

Evening Grosbeak

Blue Jay

Northern Cardinal

Red-breasted Nuthatch

Good Birding!

Nuthatches - Agile Acrobats on the Tree Trunk

Just when I think I have gotten a bird nicely figured out, I see one of its kind do something completely out of character. This time, it was the nuthatches, and specifically, the Red-breasted Nuthatch.

Nuthatches are stubby, stocky little birds with short tails; they have strong legs and feet, and long toes with sharp claws. These are all adaptations for life on a tree trunk, a niche they share with woodpeckers and the Brown Creeper. Their body style bears a superficial resemblance to these other arboreal species, but that is as close as their relationship comes - superficial. Nuthatches parted evolutionary company with the woodpeckers long ago. The somewhat similar traits in a similar habitat are the result of what scientists call “convergence.”

The woodpeckers and the creeper, supported by their stiff tail feathers, climb up a tree trunk. The nuthatches also climb up the tree trunk, but they are just as likely to climb down the tree trunk head first. The tree trunk, and the tree branches, are where the nuthatches earn their living. They forage for insects and assorted invertebrates in the bark crevices. Their short tail enables them to move as easily down as they do up. By contrast, the longer tail of the woodpeckers would get in their way if they tried to move downward.

Science has not been able to figure out why nuthatches climb down a tree. Research seems to suggest that it is more efficient to forage in the manner of the woodpeckers and creepers - fly to a low spot on the trunk and then move upward. Perhaps the nuthatches are able to see prey when they are moving down that the upward feeders miss.

The natural habitat of the nuthatches is mature forest. The White-breasted Nuthatch will make its home in the broken “forest” between river and farm field, or in a town or village, providing the “forest” has large trees. The Red-breasted Nuthatch prefers mature coniferous forests. With suitable habitat nearby, these nuthatches will often forage for seeds at bird feeders where sunflower seeds are their preferred choice.

Bent’s Life History calls the White-breasted Nuthatch droll, earnest, sedate, and lacking in a sense of humor. Adjectives applied to the Red-breasted include happy, jolly, quick and agile. I rather prefer “acrobatic clown” for the White-breasted; it perches on the feeder, upside down, with head extended at a right angle from its body, daring any chiropractor to set its spine straight. The smaller Red-breasted may be jolly, but it is also feisty, sometimes aggressive toward larger birds. “Irrepressible woodland gnome” is appropriate even when the Red-breasted ventures out of the woodlands and to our feeders.

That the nuthatches are feeder birds tells you that their diet is varied. They may be adapted to foraging on tree trunks for invertebrate protein, but vegetable matter in the form of nutrition rich seeds is prevalent in their diet. Seeds and small nuts give them their name, “nuthatch.” At our feeders, nuthatches are like chickadees and titmice; they grab a sunflower seed and fly off to crack it open. Chickadees and titmice hold the seed between their feet and pound it open with their bill. Nuthatches, by contrast, take a sunflower seed, fly to a tree, and jam the seed into a crevice. Then they pound it open with their bill to release the nutritious kernel.

Nuthatches have been finding food in this manner long before we started putting out bird feeders. We watch them forage from the warm comfort of our homes, which, you must admit, is a very indolent way to observe nature. When observation of nature required walking in the woods (or more likely - working, hunting, harvesting, and foraging), the nuthatch was frequently seen hacking open seeds or small nuts with its bill. Hence its name: nuthatch. “Nut” from its food - probably nothing so large as a hickory nut or walnut, but a small pod which contained seed ... and “hatch,” which is an earlier form of “hack,” from its practice of hacking a seed too large to swallow whole into small pieces.

This hatching requires certain physical adaptations similar to those of the woodpecker - a sturdy bill and muscle strength for pounding. This in turn allows most nuthatches worldwide (there are 25 species) to excavate a nest cavity. The Red-breasted Nuthatch excavates a cavity, and often smears sticky pitch around the entrance hole, probably to discourage other creatures from entering. Our White-breasted Nuthatch is an exception; it uses existing cavities.

Nuthatches are one of the few birds that use a tool. Some will hold a piece of bark and look for food by flaking off other pieces of bark.

So that summarizes the adaptation of the nuthatches to life on the trunks and branches of mature forest trees. These intelligent and agile little birds make their living by acrobatically gleaning invertebrates and gathering seeds and nuts from their arboreal home. They are not aerialists; they fly, awkwardly it often seems, from one food source to another.

A week ago, I was in a stand of pines on the edge of a coastal marsh looking for shorebirds. The tide was out, so the shorebirds had gone to the rich mud of the tidal estuary and I had to notice other things. What I noticed was a flycatcher sallying from the pines, making a quick circle over the marsh grasses, and returning to the pines. I had glimpsed a tail-wagging phoebe and assumed that the flycatching bird was a phoebe doing what it is designed to do. In the absence of shorebirds to watch, I decided a good look at a phoebe would be in order. I continued to watch the swooping flycatcher bird until I finally saw it return to an overhead branch. But the bird had no tail and instead of perching upright, it clung to the side of the branch. I thought I had missed the return of the flycatching phoebe. Everything about the bird I was looking at said Red-breasted Nuthatch, including the repeated, thin notes: “eeeen, eeeen, eeeen.” It stayed still long enough for me to focus my binoculars.

Then the Red-breasted Nuthatch flew out over the marsh grasses in a quick circle and returned to the pines. Over and over and over it sallied through swarms of insects. Once it alighted, and paused, so that I could see in its beak the insect which it had adeptly snatched in mid-air.

My first thought was - the Red-breasted is not adapted to flycatching. But then I realized that the most important adaptation for the Red-breasted, or any species, is the ability to adapt. The flycatching Red-breasted saw those swarms of rich protein over the grasses and exploited their availability. It did not care that it had not evolved as a flycatcher. Back on the branch, it clung acrobatically upside down while it ate its fly.

Good Birding!

Late Summer Sightings at the Feeders

First the birds that have not been in my backyard lately. The blackbirds - they showed up early in the Spring and were regular until early August. By then their nesting and breeding were complete and they abandoned my yard to gather in their huge flocks, and I suppose for some of them, to begin their migrations. Red-winged Blackbirds, grackles, cowbirds, and starlings may be around your area, but they are no longer visiting my feeders.

The Cedar Waxwings which were buzzing so persistently through the tree tops just a couple of weeks ago have apparently taken the kids, who should be old enough now to feed themselves, and gone to join up with others of their kind. Their large, gregarious, nomadic flocks will now wander about our neighborhoods, carousing on fermented fruit through the winter months.

I have not seen the resident nesting Common Yellowthroat. The young are on their own, and the parents no longer have territory to defend or nests to care for. If they are still around, they are skulking quietly.

So what birds are around? All of the expected year-round residents are here: chickadees, titmice, Hairy and Downy Woodpeckers, doves and pigeons. They seem to have concluded their young rearing for the year. Some, like the doves and pigeons have raised multiple broods. The young of all of these are evident, not so much by plumage as by their naivete. They are still slow to take flight, not yet fully aware of the dangers lurking around the yard.

The adult cardinals still come by in the early morning and late evening. One male cardinal is very scruffy - either he is a young bird molting into adult plumage, or a adult changing his plumage. Cardinals may raise three or four broods in a season, and I suspect that the resident pair is still busy with nestlings. Last year there were recently fledged cardinals in mid- to late-September; plumage of the juvenile is much like the female, but the bill is dark.

As recently as last Saturday, an Evening Grosbeak was feeding its young in the backyard. As a nestling, the grosbeak is fed regurgitated insects. I watched the adult crack open sunflower seeds with its powerful beak and feed them into the open bill of the fledgling. These young grosbeaks are undoubtedly a second brood.

Song Sparrows also raise multiple broods during a breeding season, and one of the resident pair is still finishing up with their latest brood; they were feeding young in the yard early this week.

Some of my neighbors in Newfane have enough coniferous forests around their homes that the Red-breasted Nuthatch is a regular, year-round visitor to their feeders. In my backyard, I have come to expect them to show up in the late summer. They are regular for about a month. Then they are a sporadic feeder bird through the Fall and Winter. Smaller than its cousin, the White-breasted Nuthatch (which visits my feeders every single day of the year), the Red-breasted Nuthatch is an active little comic - tame, acrobatic, inquisitive. A delight to have around.

The bee-balm is starting to fade, but the Hummingbirds are still here, now feeding on the phlox and drinking nectar from the hummingbird feeder. There are always two or three around, and I have counted as many as seven. But the hummingbirds in my yard pale compared to those of a friend on Newfane Hill. Her feeder is twice the size of mine and she fills it twice a day. Most of the hummingbirds appear to be juveniles. The male has given up defending his territory from other males, females, and his offspring; he’s probably on his way south. I’ll keep the humming bird feeder out until late September.

The goldfinches are common. They are one of the last birds in our area to nest, often not beginning until mid to late June, but often managing more than one brood anyway. They’re beginning to form into their winter flocks. One or two pair were visitors to the backyard during the early summer; now there are a dozen or more. The bright-yellow males are showing feather wear, looking sort of tattered. They will soon molt into their winter olive drab.

Occasionally joining the goldfinches are a couple of their close relatives, the little brown Pine Siskins. The siskin can be easily mistaken for a sparrow. The siskin bill is thin and pointed, unlike sparrows. A trace of yellow in the wings is very unsparrow-like.

A walk through my yard shows feathers scattered everywhere. The doves and jays, in particular, are molting feathers. I saw a dove yesterday with a day feather sticking out at an odd angle. When it flew, the feather was shaken loose and floated to the ground. When Mourning Doves perch, the tail feathers usually form a long, neat point. The pointed tail of a dove on my feeder consisted of one feather.

A few days ago, I was taking in clothes from our solar clothes dryer. (Older readers might know it as a clothesline - the most energy efficient, cost effective, environmentally friendly, and underused laundry appliance.) From somewhere in a nearby bush I heard movement and rustling, like a cat or groundhog might make if it were barging through the understory. A chickadee called sharply. I looked toward the disturbance. A hawk was beneath the bush, banded tail spread wide. It flew. My glimpse, not much longer than the time it will take you to read this subordinate clause, was of a young Sharp-shinned Hawk, brown-backed, not gray like the adult. By the relatively large size, it was probably a female. I could not see its talons as it flew off so I don’t know whether it had hunted successfully. I suspect not. Its whole manner had seemed clumsy.

After the hawk disappeared and I returned to my solar dried laundry. My mind finally woke up to the Blue Jays’ cacophony in the distance. They called their warning before the hawk attacked, but I had paid no attention. They were continuing to signal the danger. When I looked toward the feeders, the birds were gone. There was silence from the surrounding trees.

And yes, the Blue Jays are around. A dozen at a time sweep in on the feeders. They shovel seed to the ground for the ground feeders, then pick out one seed, then repeat the shoveling before eating another seed. They tussle among themselves. They are not the unmitigated bullies some people imagine them; grosbeaks hold their own against the jays. So do the timid appearing, passive appearing doves. I suspect that even the birds which appear to be bullied by the jays don’t really mind. The Blue Jays, after all, are the neighborhood’s guardians. In the constant movement, the jays are usually the first to notice danger, raise the alarm, and marshal forces to drive off predators. The young hawk will have a better opportunity to practice its hunting skills if it can find a neighborhood free of Blue Jays.

As you may have gathered, during the late summer there is a lot of good birding in my backyard.

Backyard Birds

The backyard feeders have been busy. But first, what has not been here - no blackbirds since early August. Red-wings, grackles, cowbirds, and starlings have moved from their breeding dispersal, gathering in flocks elsewhere.

In the backyard as of Saturday, September 1 - Evening Grosbeaks were feeding young.


Pine Siskins have come down from their mountain breeding areas and have been regulars


Some neighbors have the Red-breasted Nuthatch as a regular year-round feeder bird. At my feeders, they show up during August and September, then periodically through the winter. Two or three were around all day yesterday.


Rose-breasted Grosbeaks are less common, but this youngster is beginning to show his true colors.


There have been so many young hummingbirds on the bee-balm, that the resident male has given up trying to defend his territory. I counted six at one time yesterday.


Spotty without his breeding spots is still working the river.


An odd resting stance for the Mourning Dove - looks like its injured, but it was fine.