The Audubon Christmas Bird Counts were started in 1900. Conducted annually, these counts provide a tremendous resource for ornithologists and environmental scientists. The CBC program is the longest-running community science bird project in North America.

The CBC data are freely available on request to researchers. Hundreds of ornithological articles have used CBC data to advance our ornithological knowledge. Articles I have published on the winter movements of Red-breasted Nuthatches, Purple Finches, Pine Siskins, Common Redpolls and American Goldfinches would not have been possible without CBC data for all of North America.

The counts provide a way to assess changes in abundance of winter bird populations. To be sure, many species have increased or decreased over the past 122 years since the program began.

A recent paper published by National Audubon Society biologists, led by Sarah Saunders, takes a deeper dive into the North American CBC data. They begin by acknowledging that many species have shown significant increases or decreases. The biologists seek to learn why those changes have occurred.

The team analyzed the impacts of two human-related changes: global climate change and changes in land use/land cover. The former is the undeniable fact that temperature has been on an upward trajectory since the beginning of the Industrial Revolution. Changes in precipitation patterns are also occurring.

For land use changes, one does not need a long memory to realize how rapidly natural habitats are changing in our country. Human development eliminates natural habitats. Forests are cut and invasive plant species may find our altered landscapes to their liking.

Taking the longer view, agricultural land was at its maximum in Maine around 1900.  At least some of this former farmland has reverted to forest.

The authors expected that groups of species are responding to climate change and changes in land use in different ways.  We might expect forest birds to respond differently than waterbirds or grassland birds.

The authors strongly make the point that we need to understand how these two impacts affect birds if we are to develop effective conservation plans.  These plans should not merely address winter abundance but year-round abundance.

This study restricted CBC data to areas east of the 100^th meridian (from the Great Plains eastward). CBC coverage west of the 100^th meridian was sparse and would have resulted in large areas with no CBC circles. They also used only data since 1930 when CBC protocols were standardized. Altogether, 109 CBC count circles formed the grist for the mill, including several Maine counts. A total of 89 bird species were used. These birds were assigned to one of nine groups. For instance, woodpeckers, waterbirds, and large forest birds.

As a measure of climate change, the authors used the annual average minimum winter (October to December) temperature and cumulative precipitation from October to December for each year.

For measures of land use, the authors used the percentage of land within the circle devoted to urban or agricultural development and the percentage of preferred natural habitat for each species. So, for woodpeckers, the percentage of forest was used.

The statistical analysis showed that climate change affected the geographical distribution of all nine groups of birds.  Land use changes were even stronger for species with specific habitat requirements. Land use changes had twice the effect of climate change for these species.

I was a bit surprised by this result. Knowing that land use changes have stronger effects on abundance than climate change should inform conservation plans going forward, particularly for habitat specialists like grassland birds or waterbirds.

So, the take-home message is that climate change drives changes in abundance and in geographic distribution of the 89 species of birds. Land use changes have at least as strong an effect on generalist species but even stronger impacts for habitat specialists.

Maine is doing well for most groups of species except for waterfowl, which have declined between 1930 and 2020. Shrubland birds, woodpeckers, mixed-habitat birds and shrubland birds have all increased modestly.

In the previous post, we saw how birds can withstand bitter winter weather by puffing up their feathers, huddling, choosing favorable roost sites and violent shivering through the night. I want to continue with a couple of other remarkable adaptations.

Have you ever wondered why most birds lack feathers on their lower legs? A narrow, cylindrical leg has a high surface-to-volume ratio so quickly loses heat. It turns out those naked legs are designed to lose heat of a bird when it is flying.

When a bird flies, it increases its resting metabolic rate up to eight-fold. That high metabolism produces a huge amount of heat that would raise a bird’s temperature to lethal temperatures if that excess heat was not dumped. So, a flying bird pumps a lot of blood to its legs where the heat is lost to the surrounding air.

The downside is that a standing bird will lose heat to cold air that the bird cannot afford to lose. One trick that birds use is to stand on one leg with the other tucked into the body feathers. Other birds may sit, minimizing the exposure of naked legs.

Just as a flying bird increases blood flow to the legs, a sitting or standing bird decreases the blood flow to the legs. The result is that the temperature of the legs falls well below the central body temperature. The coldest part of the leg is the foot, the most distant part of the leg from the warm blood pumped into the leg.

A bird carefully controls the amount of blood pumped into the legs. The temperature of the underside of a Herring Gull foot can get as low as 32° Fahrenheit but does not freeze because just enough heat is provided. More blood has to be pumped into the legs as the air temperature falls.

Mechanical engineers use a clever idea to make heating systems of large buildings efficient. The furnace is situated in the center of the building. Air is brought into the furnace in an intake pipe that is half the length of the building. The exhaust pipe is erected adjacent to the intake pipe.

Here’s what happens in the winter. Cold air enters the intake pipe and is pumped into the furnace. The air in the exhaust pipe is at room temperature. By putting the pipes next to each together, heat is exchanged all along the pipes from the warm exhaust air to the cold air in the intake pipe. By the time air gets to the furnace, it is already warm and needs relatively little extra heating by the furnace. Meanwhile, the air exiting the building has given up most of its heat so little heat is lost to the outside. Genius!

Engineers call this particular arrangement a counter-current exchange system. Birds beat the engineers to this principle by tens of millions of years. The arteries and veins of a bird’s leg are arranged as a counter-current, helping the bird lose as little heat as possible as it pumps blood to the cells of the bird’s leg to provide nutrition and oxygen.

We know that the rate of heat loss between the air and a solid structure is proportional to the differences between the two temperatures. Some birds gain a marginal decrease in heat loss by allowing their body temperature to fall at night. Black-capped Chickadees have a normal temperature of 108° F but allow their temperatures to fall as low as 86° F at night. So the difference between air temperature and body temperature is a bit lower, resulting in less heat transfer. Like the regulation of leg temperature, this nocturnal hypothermia is tightly controlled. Death can result once the body temperature dips below 86°.

Given a bird’s arsenal of adaptations to tolerate the cold, the limiting factor for a bird is finding sufficient food. If food is adequate, a bird can scoff at the Maine winter climate.

One of the marvels of avian biology is the adaptations that allow birds to live through brutally cold winter weather. Birds use a multi-pronged approach. To understand the ways that birds accommodate the cold, we will delve into some physics, geometry and biochemistry.

Like mammals, birds maintain a constant body temperature in the face of varying environmental temperature. In the winter, birds lose heat from their surface to the cold air or water. To keep their temperature constant, their cells must produce enough heat to balance the heat that is lost to the environment.

Virtually all of a bird’s cells have organelles in their cells called mitochondria. The organelles are used for cell respiration. The reactions that occur therein also release heat. So these tiny mitochondria act as furnaces.

Imagine you are in a cabin heated with a wood stove in winter. Like a bird, the cabin is losing heat to the outside air. You feed your wood stove to balance that heat loss. As the temperature falls, you have to toss a few more logs into the wood stove to keep your cabin comfortable.

You might think a bird would do a similar process, increasing its heat production as the temperature falls. Surprisingly, birds keep their heat production constant over a broad range of temperature with the lower limit sometimes below freezing. This range of temperature with a constant metabolic rates is called the thermoneutral zone.

How can that be? Aren’t we violating the laws of physics? Heat will be lost as the temperature falls but birds aren’t cranking up the furnace in cooler weather to compensate.

The resolution of this paradox is a bird’s plumage. Birds can raise and lower their feathers. By raising the feathers, air is trapped and forms an insulating blanket. At the higher portions of the thermoneutral zone, the feathers are lowered to decrease their insulation to prevent overheating.

Birds appear very puffy when they have their feathers fully erected. Some years ago, I was studying a population of color-banded Black-capped Chickadees at the north end of Flagstaff Lake. Each chickadee had two color bands on one leg.

One morning, I began the day when the temperature was -28 F. The chickadees were so puffed up, I couldn’t see either band. The lower band was visible when the temperature got up to -15 and both appeared once the temperature got to zero.

Geometry is cruel to small birds. The surface-to-volume ratio of a small bird is meager compared to that ratio for a large bird. The surface is where heat is lost and the volume has all the cells whose mitochondria produce heat. Chickadees and kinglets are more on the edge than eagles or owls.

One trick that small birds use, particularly when roosting at night, is to huddle. Essentially, a number of birds convert themselves to one large bird with a more favorable surface-to-volume ratio. Imagine the surprise of a Londoner who looked in a 4 x 5 x 5 inch nest box in the morning after a particularly cold night to find 61 wrens!

The choice of roosting site can provide an incremental gain in heat balance. Roosting in a conifer or in a roost cavity reduces the amount of heat lost to the wind. Roosting against a tree trunk takes advantage of the infrared radiation that the tree emits. This same radiation causes the melting of snow around the base of a tree.

These behaviors that birds use to reduce heat loss ultimately fail when the temperature gets too low. The lower end of the thermoneutral zone is called the lower critical temperature. Below this temperature, a bird has to raise its heat production,

It does so by shivering, rapidly contracting its flight muscles. Shivering is used at night since a bird cannot shiver and fly simultaneously. A chickadee may burn 40% of its body weight in a single night. Its job in the morning is to find food to replace the fat that was burned. Talk about rapid weight gain and loss!

This post is the last of three, reviewing highlights of Maine Christmas Bird Counts (CBCs), sponsored by the National Audubon Society. Each count was conducted on a day between December 14 and January 5 within a circle with a 15-mile diameter.

The Greater Portland CBC usually has the highest bird diversity of all the Maine counts. That pattern was true again this season as the December 18 count produced 100 species.

The 22 species of waterfowl were an extraordinary number. Lingering puddle ducks helped to get the species count up. Seven Gadwall, one American Wigeon three Northern Pintails and a Green-winged Teal joined the more abundant Mallards and American Black Ducks.

Both scaup species were present: 12 Greater Scaup and 7 Lesser Scaup. One Barrow’s Goldeneye appeared.

Northern Gannets are sometimes seen just offshore in the winter along the southwestern coast. Five were present this year.

Three sandpipers were tallied: 280 Sanderlings, six Dunlin and 78 Purple Sandpipers on intertidal rocks. The only alcids were 20 Razorbills and 28 Black Guillemots.

Notable birds of prey included three Snowy Owls, one Merlin and two Peregrine Falcons.

The relatively mild climate along the southwestern coast keeps water open a little longer than in other parts of the state so aquatic birds can linger. This list of birds included 12 Great Blue Herons and eight Belted Kingfishers.

Hardy lingering land birds included three Turkey Vultures, eight Northern harriers, one Killdeer, one Yellow-bellied Sapsucker, five Northern Flickers, three Winter Wrens, a Marsh Wren and five Hermit Thrushes.

A Chipping Sparrow, a Savannah Sparrow and a Swamp Sparrow made for a nice trio of unusual sparrows for this time of year.

Members of the blackbird family do not usually overwinter in Maine. Four species were pushing their luck this year with two Red-winged Blackbirds, a Common Grackle, a Brown-headed Cowbird and a Baltimore Oriole counted.

Northern finches were represented by a single Purple Finch.

A western stray, a Western Tanager, put the icing on the cake.

All birds count so we should acknowledge the abundance of three introduced species. This CBC yielded 819 Rock Pigeons, 910 European Starlings and 830 House Sparrows. These three species accounted for 20.3% of all the individuals on this count.

The York County CBC was held on December 20 and yielded a fine count of 90 species.

Sixteen species of waterfowl graced this count. Three Snow Geese were a nice find as well as three Northern Pintails and six Green-winged Teal.

Seven Northern Gannets were close enough to shore to be seen. Both species of cormorants were found: 42 Great Cormorants (our normal winter cormorant) and two lingering Double-crested Cormorants.

Seven species in the hawk family were present including a Red-shouldered Hawk, seven Bald Eagles and a rare Golden Eagle. Three owl species were present including an Eastern Screech-owl and a Snowy Owl.

The two Dunlin and 91 Purple Sandpipers are expected sandpipers in the winter but not a Wilson’s Snipe. A great sighting! The five gull species included one Black-headed Gull.

Lingering birds included seven Turkey Vultures, five Belted Kingfishers, four Northern Flickers, three Hermit Thrushes, a Pine Warbler, a Chipping Sparrow and five Savannah Sparrows (including one of the Ipswich subspecies that breed solely on Sable Island, Nova Scotia).

Four Purple Finches were the only northern finches present this year.

We’ll finish by heading downeast to Moose Island-Jonesport where the December 18 CBC produced 58 species.

The 22 Harlequin Ducks were the most notable of the 13 waterfowl species present.

This part of the state is good for Spruce Grouse and one was found as well as one Ruffed Grouse.

One Black-headed Gull was a nice find among four more common gull species.

Lingering land birds were few and far between. Two Chipping Sparrows and a Red-winged Blackbird were the only ones.

The finches present were seven Purple Finches, six Common Redpolls and 49 American Goldfinches.

This post is the second of three, reviewing highlights of Maine Christmas Bird Counts (CBCs), sponsored by the National Audubon Society. Each count was conducted on a day between December 14 and January 5 within a circle with a 15-mile diameter.

It’s interesting to compare CBCs located close together. The Bangor-Bucksport CBC produced a list of 49 species on January 1. Five species of waterfowl were headlined by 448 Mallards.

Red-bellied Woodpeckers continue to push northward in Maine; three were found this year. A Merlin was a nice find.

Bohemian Waxwings have been scarce so far this winter so the 23 in Bangor-Bucksport were notable. Lingering birds included a winter wren, five Carolina Wrens, 14 Eastern Bluebirds, four Northern Mockingbirds and a Chipping Sparrow. The only northern finches were three Pine Grosbeaks.

The Orono-Old Town CBC is just a few miles north where 50 species were found on December 18. The best of the six species of waterfowl were six Barrow’s Goldeneye.

Lingering migratory species included a Carolina Wren, ten Eastern Bluebirds, three Northern Mockingbirds and a Pine Warbler.

In striking contrast to the Bangor-Bucksport CBC, Northern Finches put on a great show in Orono-Old Town: five Pine Grosbeaks, ten Purple Finches, five Red Crossbills, two White-winged Crossbills, 140 Common Redpolls and 68 Pine Siskins.

Let’s head a bit south and west to Unity. On December 18, CBC participants there tallied 50 species. Seven species of waterfowl included two surprises, a Ring-necked Duck and two Lesser Scaup.

White-winged gulls seem scarce so far this winter so the Glaucous Gull in Unity was a nice find.  Five species of woodpeckers included five Red-bellied Woodpeckers and a lingering Northern Flicker.

Lingering half-hardy birds included eleven Eastern Bluebirds and a Northern Mockingbird. The only irruptive finches were six Purple Finches and a Pine Siskin.

Let’s go 15 miles southwest to the Waterville CBC circle. On January 2, 50 species were tallied. Waterfowl diversity was excellent with 10 species including an American Wigeon, a Lesser Scaup and two Barrow’s Goldeneye.

Lingering land birds included four Northern Flickers, two Carolina Wrens, a Northern Mockingbird, two Brown-headed Cowbirds and a Red-winged Blackbird. Six Common Redpolls and a Purple Finch were the only Northern Finches this year.

Off to Hartland we go, about 30 miles north of Waterville. The CBC there on December 26 yielded 50 species. Waterfowl were particularly good with a Green-winged Teal and five Greater Scaup in addition to five common species. A Great Blue Heron and a Belted Kingfisher were toughing it out, surely long gone now to warmer climes.

Few Northern Shrikes have pushed into the state so far this winter so the one in Hartland was notable as were the 17 Horned Larks and 53 Snow Buntings..

Lingering birds from the fall included an Eastern Bluebird, a Brown Thrasher and a Savannah Sparrow. The only irruptive finches were one Purple Finch, one Common Redpoll and five Pine Siskins.

The Bunker Hill CBC on December 20 yielded a count of 54 species. This area includes the towns of Alna, Whitefield, Nobleboro and Damariscotta Mills. Nine species of waterfowl included two Red-breasted Mergansers.

The four species of diurnal raptors included a Northern Harrier and a nice count of 21 Bald Eagles. Lingering land birds included a Yellow-bellied Sapsucker, a Northern Flicker, 53 Eastern Bluebirds, Savannah Sparrow, and a Lincoln’s Sparrow. The highlight of the count was a Bullock’s Oriole, a western species, hanging out at a feeder with a Baltimore Oriole.

Finches included 14 Pine Grosbeaks and 14 Evening Grosbeaks.

We’ll end our tour in Grand Lake Stream in interior Washington County. The winter weather here is quite challenging. The CBC on December 17 produced an expected low number of species.

Those 25 species included a Spruce Grouse, a Gray Jay and a surprising White-crowned Sparrow. Northern finches included a Purple Finch, 10 Red Crossbills, 20 White-winged Crossbills, a Common Redpoll and 70 Pine Siskins.

The 122^nd Christmas Bird Count (CBC) sponsored by the National Audubon Society is now history. On a day between December 14 and January 5, groups of birders spread out to census all the birds in a circle with a 15-mile diameter.

There are over 2500 CBC circles in North America with others in Central America and South America. This annual census is a powerful tool in assessing the changes in winter bird abundance.

This column is the first of three in which I will review the highlights of some of the Maine CBCs. Today we’ll look at four Mid-coast sites and two inland sites.

The Augusta CBC on December 18 produced a count of 59 birds. Six species of waterfowl included a Ring-necked Duck, a White-winged Scoter and a Bufflehead. A dozen Common Loons clearly found enough open water as did three Great Blue herons and a Belted Kingfisher

Counters hit the accipiter trifecta, finding one Sharp-shinned Hawk, Cooper’s Hawk and Northern Goshawk. The Bald Eagle count of 32 was impressive.

Hardy lingering landbirds included three Northern Flickers, a Hermit Thrush ad two Chipping Sparrows. A Clay-colored Sparrow was a rare find.

After last winter’s wonderful irruption of northern finches, we don’t expect to see many of these northern visitors this year. In Augusta, a single Common Redpoll and nine Purple Finches were the only northern finches.

The Lewiston/Auburn count on December 19 tallied 49 species. Unusual waterfowl were a single American Wigeon and 22 Ruddy Ducks. Five Common Loons and a Great Blue Heron were unusual for this late in the season.

For raptors, highlights were a Snowy Owl and a Peregrine Falcon. Lingering land birds were sparse, highlighted by a Northern Flicker. The only northern finches were one Pine Siskin and one Purple Finch.

On December 18, 72 species were found on the Pemaquid-Damariscotta CBC. A whopping 18 species of waterfowl were present including a King Eider, a Harlequin Duck and three Barrow’s Goldeneye.

Eight Red-throated Loons joined the 114 Common Loons. The eleven Great Cormorants were joined by a lingering Double-crested Cormorant.

The only alcids were a single Razorbill and 31 of the common, coast-hugging Black Guillemots. Four species of gulls were found, none unusual.

Upland, two Northern Flickers, a Hermit Thrush and a Pine Warbler were braving the cold weather. House Finches and American Goldfinches were the only finches found.

We’ll move up the coast to Blue Hill where 57 species were spotted on December 19. Thirteen species of waterfowl graced the count with three Barrow’s Goldeneye being the only unusual species.

A single Red-throated Loon was picked out from 28 Common Loons.  Grebes were present in modest numbers: 26 horned and 16 red-necked.

The four gull species were all common species (Herring, Great Black-backed, Riing-billed and Bonaparte’s).

Away from the shore, a Northern Shrike was a nice find. A Hermit Thrush was the only lingering songbird. As with Pemaquid, American Goldfinches and House Finches were the only members of this family.

We’ll hop over Penobscot Bay to Mt. Desert Island where counters on December 18 found 63 species. This total included 15 species of waterfowl. The most unusual were a single American Wigeon and a single Green-winged Teal.

Common Loons were well represented with 159 birds but Red-throated Loons were absent. The 198 Red-necked Grebes made for an impressive count.

Only three species of gulls were present with the 632 Herring Gulls dominating the count. One Razorbill and 25 Black Guillemots were the only alcids.

An Eastern Phoebe may have been pushing its luck by lingering into December in Maine although members of this species will feed on fruit when insects are not available.

Ten Red Crossbills and two White-winged Crossbills were notable.

Just to the west of MDI, the Ellsworth CBC on December 26 yielded 49 species. Highlights were a Barrow’s Goldeneye and a Northern Shrike.

The derivation of January from the Roman god, Janus strikes me as brilliant. Like Janus with faces on the front and back of his head, January invites us to look forward to the new year and look back on years past.

Today, I to share some thoughts on the ways birding has changed over the last 50 years. I grew up in the 1950’s and 1960’s in North Carolina. I developed an interest in birds at an early age. My mother was an avid feeder watcher and knew the songs and calls of many birds. However, I did not have a birding mentor growing up. My eyes and ears were opened to ornithology when I began college at the University of North Carolina in 1971. So my column today will cover my perception of the evolution of birding over the past half-century.

Fifty years ago, two field guides dominated the North American market, the guides by Roger Peterson and Chan Robbins. I was a Robbins guy. The Peterson plates were better but the maps were in the back of the book. Robbins covered all of North America and also presented sonograms of vocalizations that I found helpful. Both guides covered only regularly occurring species.

Driven in large part by the formation of the American Birding Association in 1969, competitive listing and interest in rare birds grew. Two important field guides appeared. The National Geographic Guide, first published in 1983, covered all of the birds of North America, including the rarities from far-flung places like the Aleutian Islands. Then a guide by David Sibley upped the ante with the number of plumages shown in marvelous plates and its thorough coverage. Each of these guides is regularly updated.

My first binoculars were bulky, Bushnell binoculars. The image seemed OK but pales in comparison to the binoculars used by birders today. Although the prices are high, the clarity of images by binoculars made by Zeiss, Leica, Swarovski and other brands are stunning.

Fifty years, the most common spotting scopes were the Bushnell Spacemaster and the Bausch and Lomb Balscope. I owned a Spacemaster with a 20-45x zoom lens. It was useful but the crispness and brightness of the image left something to be desired, particularly at higher magnifications.

For me, a game-changer was the appearance of Kowa spotting scopes with much large objective lenses. I bought my first one in 1985. These scopes were originally used for evaluating targets at rifle contests but found a market in birding. I could not have done my research on sandpiper foraging with older spotting scopes.  As with binoculars, healthy competition thrives in the spotting-scope market now.

Fifty years ago, I cherished my two-disk set of LP records on eastern bird sounds, put out by the Cornell Lab of Ornithology. They provided a way to learn to identify birds by ear. A downside was the limited number of recordings for each species. The Birding by Ear recordings in the late 1980’s provided a valuable learning tool, grouping together species with similar songs, like chipping sparrow and pine warbler. Today the Macaulay Library of Natural Sounds and Xeno-Canto websites host thousands of recordings, available to anyone for vocalization study.

Alerting others to the presence of rarities is so easy now. In the early 1970’s we had telephone trees where each member, after receiving a call about an unusual bird, had to call two people below on tree. Not the most reliable arrangement. State birding groups set up rare-bird-alert recordings one could call to hear about local sightings. Now, email and social media make it easy to get up-to-the minute info on rare birds. The rise of eBird has provided huge benefits in communication.

Lastly, digital photography has been a boon to providing solid evidence of correct bird identifications. In my youth, good telephoto lenses were very expensive and a roll of film provided at most 36 images. Now, we can get hundreds of decent images with inexpensive digital cameras or even our cell phones and share them instantaneously.

What amazing changes in birding the past 50 years have brought.

The Maine Bird Atlas is a community-science project to determine the distribution of birds across our state. The project is in its fourth year of five. The project consists of two parts: the Maine Breeding Bird Atlas Project and the Maine Winter Bird Atlas Project.

The fourth year of the Breeding Bird Atlas was a spectacularly successful season. We are well situated now to meet the project goals for coverage of nesting throughout the state. I’ll write more on this project  in the spring as we gear up for the last field season.

The fourth year of the Winter Bird Atlas is just underway and we need your help. Here’s the way this project works. The 7.5 degree topographic quadrangle maps produced by the U. S. Geological Survey provide the framework for the project. Each of these quadrangles is divided into six equal blocks, each about three miles square. Those blocks are the unit of focus for both atlas projects.

At a minimum, the atlas coordinators want to have a winter atlas block completed for every topographic quadrangle in the state. You can see the progress of winter atlasing in your area by visiting this map: https://rb.gy/wap8dq

How is a block completed? The winter season is divided into two parts: an early winter period from December 15 until January 31 and a late winter period from February 1 until March 15. To complete a block, observers have to log at least three hours of observations for both the early and late season.

You can’t complete a block by observing your feeder from the comfort of your home. It is paramount that you sample all of the habitats in the block.

The map referenced above indicates the progress toward completion of every block in the state. Some are complete, some have either the early or late period complete, some have few or no data.

Choose an area and go birding. You will enter your data into the Maine eBird site: https://ebird.org/me

Six hours to census nine square miles represents only a modest effort. Completed blocks near you may well be missing fairly common birds. To see the species list of each blocks to date. just click on any block in the progress map and choose Link to Species List,

As an example near me, I see the Waterville_NW block is Complete but the species list does not include red-tailed hawk, red-breasted nuthatch, or common redpoll. I’ll devote a little time this winter trying to target these birds.

Project Feeder Watch (PFW), a citizen-science project maintained by the Cornell Laboratory of Ornithology and Birds Canada, provides a way for you to contribute important data without venturing out into the cold Maine winter. You can find their website at: https://feederwatch.org/

PWF runs from the second Saturday in November until April 30. Their website has clear instructions on how to participate. You enter your feeder data directly on the PFW website. You can also view summaries of the data.

PFW watchers can report behaviors of their feeder birds in addition to their abundance. Since 2016, PFW observers have reported over 100,000 aggressive interactions at feeders. Who are the bullies and who are the wimps?

It turns out that a fairly strict hierarchy of aggressiveness exists. Blue Jays spring to mind when you think about dominant birds at feeders. For eastern birds, they do rank highly but, in increasing order of feistiness, defer to European Starlings, Red-bellied Woodpeckers, Common Grackles and, at the top, American Crows.

Close behind Blue Jays, the hierarchy has American Robin, Red-winged Blackbird, Hairy Woodpecker and Mourning Dove. In increasing wimpiness, we find Northern Cardinal, Downy Woodpecker, White-breasted  Nuthatch, Tufted Titmouse and House Fiinch. The meekest species at our feeders are Red-breasted Nuthatch, Purple Finch, American Goldfinch and the least aggressive of all, our state bird, the Black-capped Chickadee.

The power of citizen science!

One of my favorite fall memories is participating at a bird-banding station  when I was a college student in Baltimore in the late 1970’s. The banding station was located at a park on a peninsula jutting out onto the western portion of Chesapeake Bay.  This point of land beckoned to south-bound migrants seeking landfall as they completed a nocturnal migratory leg over the Chesapeake.

We captured the birds using mist nets. Our nets were 10 meters long and two meters high. Each net has several lines running the length of the net that support loose pockets. The thread of the net is thin and difficult to see. Birds fly into the net and softly land in one of the pockets with their head and wings lightly tangled.

At this banding station, we were running about 20 nets, spread out along the park trails. We opened the nets before sunrise and monitored them regularly so that a bird would be in the net for 15 minutes at the most.

The banding crew then has the responsibility of removing the birds by simply freeing the wings and backing the bird out of the pocket. Some birds like sparrows and warblers are easy to extract, requiring only ten or twenty seconds for a skilled bander. Some birds like cardinals and grosbeaks show their displeasure by biting a finger hard enough to make blood flow. Chickadees are among the most difficult to remove because they wrap their long toes around multiple threads. One has to free the feet before you can tend to the head and wings.

Most birds were captured by eight o’clock or so but we generally kept the nets open until 10 or 11 AM. Fifty to a hundred birds would be a typical catch. I remember one morning when we had a huge fallout of birds. As we were opening nets, a cry went out “close the nets”. In a matter of 10 minutes, we had caught over 100 White-throated Sparrows in just a few nets. Opening all the nets would have overwhelmed us.

Once extracted, a bird is put into a small cloth bag and taken to the banding table. Each bird is fitted with an aluminum band bearing a unique nine-digit number. The bands are provided by the Bird Banding Lab, a federal agency in the U. S. Geological Survey.  With the bird in hand, a band is opened, placed around a bird’s lower leg and then closed with specially made pliers.  The bird is then released. 

At the very least, the species, sex and age of the bird is recorded along with the location and date. Banders may record other data as well such as weight, fat load, wing length and molting status. The species, sex and age data along with the band number are reported to the Bird Banding Lab.

Cliff Otto took many photographs of the banding station at Occoquan Natiional Wiildlife Refuge in northern Virginia, He has kindly made his photographs availble here. The photos provide a primer on the banding procedures.

The Bird Banding Lab serves as the central repository for all banding information.  If another bander captures a previously banded bird or if someone finds a dead bird with a band, an email to the Bird Banding Lab will allow the observer to know when and where the birds was banded.  The Bird Banding Lab also notifies the original bander that one of her/his birds was recaptured.

To band native birds, one must obtain a Banding Permit, possible only after extensive experience in assisting a licensed bander.  My experience at that station qualified me to get my own Master Bander Permit. I regularly banded birds in my research projects before I retired.

Because pigeons or Rock Doves are not native species, one does not need a banding permit to band pigeons.  As a result, pigeon fanciers often band their birds with particular color bands so they can be easily identified.  These band combinations are not regulated by the Bird Banding Lab so one must consult pigeon fancier clubs to try to track down the owner of a sighted racing or homing pigeon.

In the next post, we’ll explore the value and limitations of bird banding in learning about our feathered friends.

The Endangered Species Act has been instrumental in the conservation of many bird species as well as other organisms. The ESA was enacted in 1973 by the U. S. Congress in a resounding fashion.  The vote was 92 for and none against in the Senate and 390 for and 12 against in the House. Truly a bill with bipartisan support.

To be sure, business interests and some Republican officeholders fight to weaken or eliminate the ESA but it has withstood those challenges. Over 80% of Americans support the ESA. The ESA is the most comprehensive legislation for the protection and recovery of endangered species of any nation.

The purposes of the ESA are two-fold:  to provide funding for federal agencies to prevent extinction and to develop plans to allow imperiled species to recover.

The federal agencies that administer ESA programs are the U. S. Fish and Wildlife Service and the National Marine Fisheries Service. These agencies are responsible for the creation of the list of endangered species. They also create a list of threatened species that are declining and likely to be endangered in the near future.

It is illegal to collect or hunt any endangered species without a Federal Permit. The ESA provides for the protection of critical habitat for an endangered species. The ESA stipulates that a plan for the protection of critical habitat be developed within a year once a species is declared Endangered.  The critical habitat may be provided by reclassification of existing federal land or the purchase of land. Private land is not subject to ESA claims.

Initially, decisions about which habitats on federal land to protect sought a balance between likely benefit to imperiled species against the economic value of development of that habitat. An amendment to the ESA in 1982 stipulates that the biological effects of protecting critical habitat be the only criterion in assessing the value of that habitat.

Let’s consider some of the happy effects of the ESA. Kirtland’s Warbler mainly nests in jack pine tracts in northern part of lower peninsula Michigan. In 1973, there were only 215 pairs. Now there are over 2,400 pairs and Kirtland’s Warbler was removed from the Endangered Species list in 2019. This recovery was enabled by habitat protection and capturing of Brown-headed Cowbirds that dupe the warblers into raising their young.

Bald Eagles went from 417 pairs in 1963 to over 11,000 pairs in 2007 when it was removed from the Endangered list. The banning of DDT in 1972 accounts for most of the recovery but habitat and nest protection enabled by the ESA certainly helped. Similarly, Peregrine Falcons recovered from the DDT tragedy to be removed from the Endangered List in 1999.

Other species that have been brought back from the brink include the San Clemente Indian Paintbrush (a plant), Black-footed Ferret and Virginian Big-eared Bat.

There are invertebrates on the Endangered Species list. Most of these tend to be larger and more charismatic. Butterflies, beetles, snails, freshwater mussels and spiders are prevalent. There are certainly many smaller invertebrates that are rare but we lack the expertise and time to document their endangered status. The habitat protection afforded by the ESA for more conspicuous species helps protect these tinier species too.

Alas, some species get removed from the Endangered Species list because the battle is lost. The U. S. Fish and Wildlife Service recently released a list of 23 species that are now extinct. This list includes 11 birds, eight mussels, two fish, a bat and a plant.

Do you remember walking on air in April of 2004 when a fuzzy video of a putative Ivory-billed Woodpecker from Arkansas went viral? After much field work, no solid evidence of this species, last seen in 1944, was found. The USFWS just declared it extinct along with Bachman’s Warbler of southeastern cypress forests and nine bird species from Hawaii and Guam.