Review of Field Guide to the Dinosaurs

By in Book Reviews, Uncategorized

Over the course of the last 500,000 years of earth’s history, paleontologists have identified five relatively brief periods when many species went extinct  about the same time.  These events are called mass extinctions.

The most recent mass extinction occurred about 65 million years ago.   The dinosaurs, the pterodactyls, and the plesiosaurs (long-necked,  marine reptiles) failed to make it through this mass extinction.

We have some good insight into the reason for this mass extinction.  A geologist, Walter Alvarez, discovered a thin layer of sediment at sites around the world that had high concentrations of the metal iridium.  Iridium is a rare element on earth but is much more common in asteroids and meteors.  Alvarez was able to date the age of this iridium-rich layer to about 65 million years ago.  Alvarez suggested that an asteroid hit the earth then and that the effects of the impact wiped out the dinosaurs and other species.

Alvarez’s hypothesis was a controversial one.  But support for his explanation grew later when the outlines of a large crater, over 100 miles, were found in the Caribbean just off the coast of the Yucatan peninsula.  The smoking gun had been found!  Dating of the sediments showed the crater was formed 65 million years ago.

The collision of such a massive object was 20 million times more powerful than the largest atomic bomb ever detonated.  The impact would have created tsunamis that would have destroyed coastlines.  The red-hot debris thrown up into the atmosphere would have created fiery clouds hot enough to ignite fires and heat animals and plants to death.  Dust from the blast would have persisted in the atmosphere for years, plunging the earth into a long, dark winter.  Throw in acid rain and pollution and the post-impact earth was an inhospitable place.

Many children become captivated by dinosaurs.  The success of films like Jurassic Park attests to the drawing power of the dinosaurs.  Many of us would love to see dinosaurs in the flesh.

Perhaps we can. Paleontologists have collected evidence to support the idea that birds and dinosaurs are closely related.  Dinosaurs may be living today in the form of our feathered friends.

What is the basis for claiming that birds arose from the dinosaurs?  First, we know that some dinosaurs had feathers.  The likely dinosaur ancestors of birds (the theropod dinosaurs) shared with birds a distinctive wristbone that allows the hand to swivel, important for birds in powered flight.  The collar bones of both were fused (making the wishbone).  The shoulder blades of both were strap-like, quite different from the typical scapula of other land vertebrates.  Finally, scientists were able to extract some protein from a Tyrannosaurus bone and found that the protein was very similar to the modern chicken.

A fantastic new book on dinosaurs, The Princeton Field Guide to Dinosaurs by Gregory Paul, has recently been published by the Princeton University Press.   Paul is an accomplished illustrator and expert in all things dinosaurian.

The first 60 pages of the book provide an introduction to dinosaur biology. morphology, and techniques for studying these fossils.  The information on how the limbs of dinosaurs articulated is particularly intriguing.  Using fossil evidence as well as comparisons to living vertebrates, Paul discusses the digestive tracts, respiratory systems, vocalizations, diseases, reproduction and social activities of dinosaurs.  His fine illustrations provide nice accents to the text.

The meat of the book is the coverage of individual dinosaur species.  The guide is arranged in taxonomic order, beginning with the avepods (Tyrannosaurus and other predatory, bipedal dinosaurs) and continuing on with the sauropods (like the Brontosaurus that used to be on the logo of Sinclair gasoline signs) and the genasaurs (including the Triceratops, Stegosaurus, and duck-bill dinosaurs).

Species are illustrated with multiple drawings.  Some species are known from only a few bones while we have complete skeletons for others.  For species with fragmentary skeletons, Paul is careful to indicate the limits of our knowledge of these species.

Paul discusses the mass extinction that eliminated the dinosaurs.  He offers some speculation of how our world would be different if dinosaurs had survived to the present.  The earth would probably still be dominated by reptiles rather than the mammals that took over after the extinction of the dinosaurs.  Paul argues that humans would not have arisen in the presence of the dinosaurs.

The delightful book can be read on two levels.  It is a concise treatise on our knowledge of dinosaur biology and diversity.  But is it also a book where the illustrations impel our imaginations to flights of fancy with these diverse and fascinating creatures.

[FIrst published on November 14, 2010]

Osprey Conservation

By in Bird Conservation, Reproduction

I recently received a letter from a reader who asked an intriguing question about Ospreys.  Noting that Osprey populations are rebounding from their dramatic crash from DDT contamination, the reader has noticed that Ospreys often nest on telephone poles, powerline towers and even channel markers along our coastal waterways.  He asked if we should be making artificial nest platforms to help the Osprey populations continue to grow.

This question caused me to think about the way we use our limited conservation dollars.  I’ll address some of these general thoughts before giving my view on the question of the need for Osprey platforms.

Wildlife conservation can be boiled down to two approaches.  First, a tract of land or body of water with outstanding diversity may be purchased and protected in perpetuity.  Often, a charismatic animal of the community serves as the ambassador of the habitat to the public at large.  Who can resist a giant panda or a Spotted Owl?  By setting aside diverse habitat, all of the species in the area, including inconspicuous ones like insects, spiders and other invertebrates are all protected along with the more obvious vertebrates and plants.

The alternative approach is to develop and implement a conservation approach tailored to a single species.  This approach requires detailed information on the factor that limits the population.   Consider a bird that is limited by food availability.  Providing nesting sites or cover to cut down on predation will not be effective conservation practices.  Food provision is the way to allow the population to grow.  Understanding the limiting factor of a population takes lots of time and effort.

Here’s a cautionary tale.  Loggerhead turtles have been on the Threatened Species list since 1978 so are a concern to marine conservationists.  Female loggerhead turtles come ashore on sandy beaches to lay 100 or more eggs above the high tide level.  The eggs incubate beneath the sand, warmed by the sun, and hatch out later in the summer.  The hatchlings then find their way down to the water’s edge and begin their lives at sea.

Raccoons, dogs and other predators may destroy loggerhead turtle nests.  Hatchlings are at risk to bird and mammal predators as they seek to move down the beach to the sea.

In an effort to help the populations, beach patrols have been set up along beaches in the southeastern and Gulf states.  Volunteers map the location of nests, transplant eggs to safer places if necessary and guard the hatchlings as they make their way down the beach.  Some beach patrols report that 90% of the eggs laid along a stretch of beach produce hatchlings that make it to the water.

About 20 years ago, some population biologists started to collect survivorship information for different ages of loggerhead turtles, from the egg stage to the oldest adults.  The same sort of technique is used by insurance companies to develop actuarial tables.  Those tables need to be pretty accurate or an insurance company will go bankrupt.

From the turtle model, the biologists found that the bottleneck for the species was the 5-7 year old subadult turtles that were often drowned when caught in the nets of shrimp trawlers.  That finding led to the development of Turtle Excluder Devices (TED’s) that must be used by shrimp trawlers in the Gulf of Mexico.

The authors found that even if 100% of all loggerhead turtle eggs survived, the population would still show a decline.  Sure, the beach patrols do help increase loggerhead turtle survival but conservation dollars and time might be better spent helping protect the 5-7 year old turtles.

Returning to Ospreys, we do not presently have definitive information on the factor that limits Osprey population growth.  Some have argued that either food or nesting sites is likely the limiting resource.

We do know that Ospreys readily adopt artificial nest platforms.  Such platforms are generally more stable and safer than the natural nesting areas (usually dead or living trees).  Nesting success is generally twice as high in nests on artificial sites compared to natural sites.

Erecting artificial nest platforms is an effective way to get Ospreys to nest in areas where they had not nested previously.  Because Ospreys are not territorial, it is possible to establish colonies pretty quickly.

Still, we do not know if nest sites limit the populations.  Ospreys may choose artificial nest platforms for nesting because they are superior to natural sites.  However, that does not mean that natural sites are not sufficient for the population.   Pending further research, I am skeptical of the need to invest significant funding for artificial nests for Ospreys.

[FIrst published on October 31, 2010]

Hoarding

By in Uncategorized

As we harvest the last of the vegetables from our garden, I think about birds putting food aside for the winter.  Hoarding food is a way for some landbirds to tough it out in a northern winter.  The benefits of not having to migrate are huge.

Black-capped Chickadees are well known for their food-hoarding behavior.  Usually seeds are hoarded although insects and spiders may be stored as well.  Insects and spiders are prepared before storage by removing the head.  Chickadees readily cache sunflower seeds and pieces of suet from bird feeders.  A chickadee removes the husk of a seed before caching it.

Chickadees do most of their hoarding in the fall, particularly in October and November.  The number of seeds stored is staggering.  Over a thousand items may be stored in a single day and, over the course of autumn, 50,000 to 80,000 spruce seeds may be cached.

Sites for food storage are varied.  Typical hiding places are cracks or crevices in woody vegetation, under bits of bark (particularly birch bark), in clusters of conifer needles, in the ground and even in the snow.

Tufted Titmice, members of the chickadee family, regularly hoard seeds.  Nuthatches, classified into their own family but closely related to chickadees, also store food for use at a later time.

In the winter of 1995/1996, I was doing some research on the effect of bird feeders on chickadees and nuthatches in a remote area east of Flagstaff Lake.  To my surprise, a Tufted Titmouse (north of their current range) appeared at one of the feeders in December and continued to visit through March.  The titmouse was considerably more timid than the chickadees and nuthatches coming to the feeder. On several occasions, I saw the titmouse watch a Red-breasted Nuthatch hoard a seed under the bark of a conifer. When the nuthatch left, the titmouse would come over and remove the seed from the hiding place.  A clever thief!

The jay and crow family contains over 100 species, many of which store food.  Blue Jays are energetic hoarders, storing acorns and other nuts but even invertebrates, small vertebrates or bits of meat.  Favored storage sites are cracks and crevices of tree trunks, amid the needles of conifers and in loose soil.

A Blue Jay can carry up to five acorns at once to be stored.  The acorns are swallowed and stored in the upper part of the esophagus.  The acorns can then be regurgitated intact when a suitable hoarding site is found.

Gray Jays, common in the mountains and the northern half of Maine, are unusual in their method of hoarding.  Gray Jays have enlarged salivary glands that secrete a very sticky, saliva.  This salivary glue is used to cement together food items, like insects and scraps of meat, into food packets measuring about 3/4 inch long and 3/8 inch wide.  These packets are lodged into the bark or needles of conifers where the saliva in the food packet dries, cementing the food into place.

Two members of the jay family from western North America, the Pinon Jay and Clark’s Nutcracker, rely heavily on hoarding to get through the winter.  Both species store pine seeds, which they laboriously remove from the pinecones.

A single Clark’s Nutcracker can store up to 100,000 seeds in the fall.  Both nutcrackers and Pinon Jays do not raid their hoarded seeds until most of the fall seed crop is depleted.  One researcher has determined that up to 90% of the winter diet of Piñon Jays comes from stored seeds.

The largest members of the jay family, American Crows and Common Ravens, store food as well.  Stored items include carrion, mice, fish, frogs, salamanders and dung.  Most of the food stored by these two species is perishable and therefore must be recovered within a day or less after caching.

Of the 198 species of woodpeckers, only ten are known to hoard food.  Downy Woodpeckers and Hairy Woodpeckers are among those ten but store food only infrequently.  The champion hoarder among the woodpeckers is the Acorn Woodpecker.  Family groups of Acorn Woodpeckers excavate thousands of holes in a dead tree, called a granary.  Each hole takes about an hour to excavate.  A woodpecker will fill the hole with an acorn.  Some granaries have 50,000 holes, each filled with an acorn.  The family group defends the granary tree against all competitors seeking to use the acorns.

Shrikes store food in an interesting way.  Small mammals or birds are killed and then impaled on a thorn or barbed wire fence for later consumption, hence the reason for calling these hoarders butcher birds.

[FIrst published on October 17, 2010]

Review of Mariposa Road by Bob Pyle

By in Uncategorized

The concept of the Big Year has a long history in birding.  During a Big Year, a birder seeks to identify as many birds as possible in an area of interest.  That area might be a county, a favorite patch of birding habitat, a state or even a continent.

Book CoverThe first well-publicized Big Year was done by Roger Tory Peterson and his British colleague, James Fisher in 1953.  Peterson wanted to show his friend the diversity of the North American avifauna.  Over 100 days, the two traversed the continent from Newfoundland down the east coast to Florida, Texas and the desert Southwest up along the Pacific coast to Alaska. Fisher and Peterson wrote Wild America, an engaging account of their trip.

Scott Weidensaul repeated Peterson and Fisher’s trip on its 50th anniversary.  Return to Wild America chronicles the changes in our bird fauna since the Wild America trip.

A notable North American Big Year was Kenn Kaufmann’s effort in 1973 when he managed to find 666 species.  Kaufmann did his trip on the cheap, thumbing his way back and forth across the continent.  Kingbird Highway is his account of that Big Year.

One other notable Big Year book is Mark Obmascik’s The Big Year in which he describes North American Big Year efforts in 1998 by three birders, one of whom found an eye-popping 745 species.

Just last month, a book describing a different kind of Big Year hit bookstore shelves.  Robert Pyle did a North American Big Year in 2008 for butterflies!  Mariposa Road is the lively and charming account of his adventures.  Mariposa, by the way, is Spanish for butterfly.

Pyle is an accomplished nature writer.  His fourteen books include Wintergreen, the winner of the 1987 John Burroughs Medal for Distinguished Nature Writing.  He has been studying butterflies since his childhood in Colorado.  He has a Ph. D. from the Yale School of Forestry where he studied under Charles Remington, one of the foremost butterfly biologists of the twentieth century.

Pyle has had a varied career (The Nature Conservancy, visiting faculty member at a number of colleges, scientific consultant and museum curator) but the two themes that span his career are butterfly conservation and nature writing.

In 1971, Pyle established the Xerces Society, a conservation organization devoted to invertebrates.  The organization is named after a butterfly, the Xerces Blue, a now extinct butterfly that used to live on dunes near San Francisco.  Urban development caused the extinction of this species.

Inspired by the birding Big Years of Peterson and Kaufmann, Pyle decided a grand tour of North America to gauge our butterfly populations was in order.  His Big Year resulted in $45,000 for the Xerces Society through a Butterfly-a-thon in which donors pledged money for every species seen.

Pyle and his wife live modestly in Washington State so expenses had to be carefully monitored.  Most of the driving was in Pyle’s Honda Civic named Powdermilk (over 350,000 miles on the odometer) and plane tickets came from speaking engagements around the country.  In all, he plunked down about $16,000 for his yearlong adventure.

His Big Year carried him on several cross-country junkets as well as a trip to Alaska.  He visited Hawaii (seeing 15 of the 18 species that occur there).  Of the roughly 800 species in North America, he saw 478 species.  He was hoping to crack 500 but unexpected health problems of his wife forced him to abandon some of his trips (he regretted not visiting Vermont or Nova Scotia).  He briefly visited Maine, getting to see the Clayton’s Copper near Winn.

Even if you don’t know a hairstreak from an elfin, reading this book can give great joy.  There is the exhilaration of seeing a rare butterfly or of particularly beautiful common ones with the disappointment of missing hoped for species.  Fickle weather plays a big role in butterfly hunting; butterflies are not active during inclement weather.  Pyle notes the birds, snakes and other wildlife he sees, too.

Pyle is a gregarious person, so we get to meet many butterfliers around the continent.  Pyle is quite a character himself.  His tendency to be late and his forgetfulness make for a number of riveting anecdotes.  As an example, he left a yogurt container of some of his specimens at a restaurant and had to go dumpster diving days later to search for them.  Fortunately, he found the specimens.

I admire his graceful writing style, filled with clever allusions and puns.  I grinned when he wrote about an expedition to find Behr’s Sulphur.  Checking his equipment, he was loaded for Behr’s.

[First published on October 3, 2010]

Molting

By in Migration, Physiology

The spectacle of migration is well underway.  Warblers, vireos and thrushes are streaming south in good numbers now through Maine.  The sparrow migration will pick up speed in October.

Migration, even for short distances, is an arduous task that demands a high expenditure of energy.  Two other events in a bird’s life demand equally high energy costs: reproduction and molting.  The costs of each activity are so high that no bird can do two of them at once.

There are about 10,000 species of birds in the world so exceptions always arise when one tries to make universally true comments about some aspects of birds.  That is certainly true of molting; one size does not fit all.  Nevertheless, we can make some general observations on molting and then look at some of the interesting variations on the theme.

Generally, birds undergo one complete molt every year.  During that molt, every contour feather on their body is replaced.  For a bird like a Song Sparrow, that entails replacing about 2,000 feathers.  A Tundra Swan will have to replace over 25,000 feathers.  No wonder molting is so expensive.

The usual pattern is for the complete molt after nesting has been completed but before any migration is begun.  The bird then enters its basic plumage (sometimes called winter plumage or non-breeding plumage).

This sequence of nesting to molting to migration has obvious advantages.  After the breeding season, food is generally abundant enough to allow a post-breeding bird to find enough energy to fuel its molt.  Then, it is ready to migrate on fresh, efficient flight feathers.

A typical bird will have a second, partial molt near the end of the winter.  Some of the body feathers will be replaced, transforming for example a drab, greenish male American Goldfinch into a stunning yellow bird.  However, the flight feathers on the wing and tail are generally not replaced.  So, the northward migration must be done on worn feathers.

Some birds do undergo two complete molts a year.   Extremely long distance migrants and species that live in abrasive habits (thorn scrub or coarse grass) replace all their feathers twice a year.  In Europe, the Short-toed Lark only has one complete molt per year in the summer but an Asian race of this species that lives in sand-blown deserts has a second molt in the spring.

Molting can improve a bird’s physiological condition.  The Salt Marsh Sparrow undergoes two complete molts each year.  Seaside Sparrows, nesting in the same marshes, have a complete molt in the fall and a partial molt in the spring.  Seaside Sparrows have more bird lice than co-occurring Saltmarsh Sparrows.

It’s easy to see evidence of molting in the flight feathers of a flying.  The flight feathers are usually replaced in a sequence so that only a few feathers are missing at any time.  The innermost primary feathers and the outermost secondary feathers are molted first. In a molting bird in flight, you can see gaps or shorter feathers showing the current stage of wing molt.

Geese, swans and ducks as well as loons opt for the fast track during their flight feather molt.  All of the primary feathers are shed at once.  Until the feathers regrow, these birds are flightless.  The birds find sheltered wetlands with enough food to allow them to hide and feed as their primaries grow.

To get to such a favorable habitat, many waterfowl stage a molt migration.  After the breeding season, lakes with lots of vegetation may be populated with thousands of flightless waterfowl that flew there for the express purpose of molting.  Canvasbacks that nest in the northern United States stage a molt migration north(!) to the Prairie Provinces of Canada after breeding.  After their molt, the Canvasbacks then migrate south for the winter.

Anna’s Hummingbirds have a molt migration as well.  These birds nest in the chaparral of coastal California in the spring, move to the summer in the high mountains to take advantage of the abundant nectar where they molt, and then migrate to Arizona or Mexico for the winter.

In 1983, the AOU Check-list Committee lumped the Baltimore Oriole and Bullock’s Oriole into a single species, the Northern Oriole because these two forms hybridize where they overlap in the Great Plains.   These forms have now been re-split into two species.  Part of this decision stems from the finding that Bullock’s Orioles stage a fall molt migration to the southwestern United States and northern Mexico before molting and then continuing their fall migration.  Baltimore Oriole’s, even in the same habitat, molt before beginning their fall migration.

[First published on September 25, 2010]

Bird Banding

By in Banding, Migration

Fall migration is an exciting time for birders and also for bird banders.  A number of banding stations are gearing up in anticipation of a flood of regular migrants and who knows what surprises.

The Bird Banding Lab, a federal agency in the U. S. Geological Survey, coordinates banding activities of native North American birds.  To band native birds, one must obtain a Banding Permit, possible only after extensive experience in assisting a licensed bander.

Bird banding has provided a major tool for the study of birds.  The first banding of birds we know of was done by John James Audubon in eastern Pennsylvania. He tied some aluminum wire to some nesting Eastern Phoebes and found that the birds returned the following year to nest.

Licensed banders contribute to our understanding of bird migration, reproduction and population dynamics.  Banding allows the individual identity of birds to be known.  In the United States, a bander is issued aluminum rings, each with a unique nine-digit number.  Birds are captured, either with special live traps or mist nets that birds do not see and get tangled in. With the bird in hand, a band is opened, placed around a bird’s lower leg and then closed with specially made pliers.  Data on age, sex, fat score, wing length, parasite presence and other information are recorded.  The bird is then released.

For larger birds like geese or eagles, the band number can often be read directly with a spotting scope so that a bird need not be recaptured to identify it individually.  However, the bands for most birds are so small that it is impossible to read the number at any distance.  To identify the band number of a small bird like a nuthatch, the bird must be recaptured.

The Bird Banding Lab serves as the central repository for all banding information.  A bander submits her or his banding data (band number, species of bird, age and sex of bird, banding location) to the lab.  If another bander captures a banded bird or if someone finds a dead bird with a band, a call to the Bird Banding Lab will allow the observer to know when and where the bird was banded.  The Bird Banding Lab also notifies the original bander that one of her/his birds was re-encountered.

The millions of banding records and the thousands of recapture records are available to interested parties.  I have used banding data on Pine Siskins, Common Redpolls and other finches to examine changes in the southward winter migration as affected by an increase in bird feeding over the past quarter of a century.

Many banders now use color bands in addition to the required aluminum bands that are placed on captured birds.  Color banding requires special permission from the Bird Banding Lab to insure that banders in the same area are not duplicating banding combinations.  By using unique combination of color bands, one can identify individual birds without having to recapture them and read the number off the aluminum band.  I use this technique with Black-capped Chickadees and Red-breasted Nuthatches.

Here are a few of the ornithological discoveries that have been made possible by banding birds.  Arctic Terns are known to migrate from pole to pole, twice a year.  By following the disappearance of banded birds (presumably because they died), we know that most small songbirds have a 50% chance of dying every year.  We know much about where different populations of birds winter.  For instance, Palm Warblers do an interesting criss-cross in migration.  Populations breeding in the upper Midwest and Prairie Provinces migrate southeast to winter in Florida while our eastern Palm Warblers migrate southwestward to winter along the Gulf Coast.

Occasionally Rock Pigeons are seen with one or more bands.  Because pigeons are not native species, one does not need a banding permit to band those birds.  So, 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.

[Originally published on September 12, 2010]

AOU Check-list Changes

By in Field Guides, Taxonomy

The fifty-first supplement to the American Ornithologists’ Union Check-list of North American Birds has recently been published in the ornithological journal, The Auk.  This check-list is the standard guide to common and scientific names of the birds of North America.

The committee reviews the published literature and decides if species should be split, lumped or renamed.  The consideration of DNA evidence and morphological evidence may result in changes in the higher taxonomy (such as the family level) of birds.

This supplement is the tenth one since the publication of the most recent Check-list in 1998.  This supplement is based on committee deliberations between January 2009 and March 2010.

Many of the changes involve tropical species or other species found well outside of Maine.  In this column, I will restrict myself to birds that occur in Maine, at least as passage migrants.  I will consider birds in the standardized check-list order.  You may wish to enter corrections into your field guide.

First, the common name of Greater Shearwater is changed to Great Shearwater.

The order Pelecaniformes formerly contained the pelicans, cormorants, gannets and boobies, and the tropicbirds.  All of these birds have totipalmate feet; webbing is found between all four toes.  All other bird with webbed feet only have webs between three toes.  The hind toe has no webbing.

However, DNA analysis indicates that the tropicbirds are not closely related to other members of the pelecaniforms.  Therefore, a new order, the Phaethontiformes, has been erected for the tropicbirds.  A new order for the Red-billed Tropicbird that has been seen around Seal Island the past few years during the summer.

Even with the tropicbirds removed from the pelecaniforms, DNA evidence indicates that the remaining families are a hodge-podge of distantly related groups of birds.  In fact, the herons, spoonbills and ibises are very closely related to some families of pelecaniforms.  So, now the herons (family Ardeidae) and spoonbills and ibises (family Threskiornithidae) are moved from the Order Ciconiiformes into the Order Pelecaniformes.  Now, the Order Ciconiformes contains only the storks (Family Ciconiidae).

We’re not done with the pelecaniforms yet.  The cormorants and frigatebirds are moved from the Order Pelecaniformes to a new order, the Suliformes.

The species we have been calling Black Scoter occurs on both sides of the Atlantic.  However, differences in courtship behavior and feathering of the bill indicate the European and American forms are different species.  Now, Black Scoters in North America are described as new species (Melanitta americana); the common name of Black Scoter remains the same.  The European birds are  referred to as Common Scoters (Melanitta nigra).

DNA comparisons show that the hawks and falcons, formerly united in the Order Falconiformes, are not closely related.  Now the Order Falconiformes includes only the falcons (Family Falconidae).  A new order, the Accipitriformes, is erected to contain the New World vultures (Family Cathartidae), hawks. kites and eagles (Family Accipitridae) and the Osprey, now placed in its own family, the Pandionidae.

Whip-poor-wills occur in eastern North America as well as Arizona.  The Arizona forms have been split off as a new species, the Mexican Whip-poor-will.  Our species is now called the Eastern Whip-poor-will.

Our Winter Wren, Troglodytes troglodytes, nests in coniferous forests throughout northern North America.  This bird also occurs in Europe, the only wren in the Old World.  Research indicates there are actually three species in what we called Winter Wren.  Two new species are recognized in North America.  The Winter Wren occurs in Maine but is now classified as Troglodytes hiemalis.  The wrens that occur in the west are classified as a new species, the Pacific Wren (Troglodytes pacificus).  If you have seen Winter Wrens in the Far West, you have just picked up a life bird!

The gnatcatchers are now placed in their own family, the Polioptilidae.

The scientific name of the Blue-winged Warbler is changed from Vermivora pinus to Vermivora cyanoptera.

The Tennessee Warbler, the Nashville Warbler and the Orange-crowned Warbler are all moved from the genus Vermivora to the genus Oreothlypis.

The Northern Waterthrush and the Louisiana Waterthrush are moved from the genus Seiurus to the genus Parkesia.

Analysis of the DNA of larkspurs and snow buntings has revealed that they are not very closely related to the sparrow family, the Emberizidae, in which they were formerly classified.  A new family, the Calcariidae, is established for these birds.  Regularly occurring members of this new family in Maine are Lapland Longspurs and Snow Buntings.

If you would like to see the full report of the Check-list Committee, the article appears in the July 2010 issue of the Auk, Volume 127, pages 726-744.

American Goldfinch

By in Reproduction, Species Accounts

Most of our breeding songbirds have fledged young by now.  One species, however, is just getting started.  That species is the American Goldfinch.

Male goldfinches in their summery finery are well known by all.  However, the more drab, olive-colored female is sometimes confusing.  In the winter when both sexes are dull, misidentifications sometimes occur.

The American Goldfinch is a member of the finch family, the Fringillidae.  Other finches like the House Finch, Evening Grosbeak and Pine Siskin do not undergo a complete molt in the spring.  Not so the goldfinch.  These birds molt all of their body feathers.  Males are transformed from a muted olive color to the beautiful yellow and black of the breeding season.  I am sure you have enjoyed watching the transformation of goldfinches in the spring.  First, a little yellow appears, gradually replacing all of the duller feathers.

Why do goldfinches begin nesting so late in the season? Some ornithologists think their spring molt may be the explanation.  Molting is an energetically expensive activity.  Replacing all of the body feathers is a lot more costly than replacing only some of the feathers, as seen in other North American finches.  American Goldfinches may need some time in the early summer to recover from the demands of the molt process.

Other ornithologists have noted that American Goldfinch nesting seems to be closely tied to the flowering of thistle plants.  Courtship usually begins about the time that thistle flowers appear.  By the time the eggs have hatched, thistle seeds are available for the parents to feed themselves and their young.

In flight, goldfinches have a characteristic undulating flight.  They beat their wings a few times to gain a little altitude and then fold their wings tightly against the body and glide for a bit, losing a little bit of altitude.

During courtship, look for a couple of flight displays that are distinctly different from the normal undulating flight.  One type is called Butterfly Flight.  A male will fly with steady, slow wing beats, maintaining a constant height above the ground.  The male circles over a prospective nesting area, singing its rambling, warbling song.  The displaing male is frequently joined by other males, all circling over a nesting area and singing.  Quite a display to see.

Later in the breeding season, the Moth Flight can be seen.  A male uses rapid wing beats to hover for a short period of time.  This display is seen just before mating.  Sometimes, a female will perform the Moth Flight.

Nests are most often built in scrub habitats, usually in a deciduous shrub.  Both sexes seem to be involved in selecting a nest site but only the female constructs the nest.  Unlike many nesting birds, American Goldfinches do not usually defend a breeding territory for the duration of the nesting season.  A male goldfinch may defend a nest site while the female is building the nest.  Otherwise, males tolerate the incursion of other goldfinches into their breeding area.

Five eggs is the typical clutch size although as many as seven and as few as two eggs have been found in some nests.

The female does all the incubation of the eggs.  The female often spends long periods of time on the nest and is fed by her mate.  Eggs hatch usually after 12 to 14 days.

Both parents feed the nestlings but the male shoulders more of the responsibility.  Some nestlings may leave the nest after 11 days while others may not leave until 17 days after hatching.

Because of the late start to the nesting process in goldfinches, these birds are usually restricted to a single clutch per season.

Although goldfinches are regulars at bird feeders, learning some of their calls will allow you to detect goldfinches flying overhead. A characteristic flight call can be rendered as per-chi-co-ree or potato chip.

Goldinches also have a characteristic, whiny note, which serves as an alarm call.  The scientific name of the goldfinch is Carduelis tristis; tristis means sad and refers to this whiny call.

Goldfinches are widely distributed throughout North America so these wonderful birds are well known to all birders.  In much of the United States, goldfinches are resident birds although sometimes birds will migrate further south for the winter.  In southern Canada, goldfinches are only found in the summer while in the southern tier of states, only wintering goldfinches are expected.

[Originally published on August 1, 2010]

Second Edition of Birds of Peru

By in Book Reviews

Princeton University Press has recently released the second edition of the Birds of Peru by Thomas Schulenberg, Douglas Stotz, Daniel Lane, John O’Neill and the late Ted Parker.  This edition is a revised version of the award-winning 2007 first edition.

This guide covers all of the 1,817 species found in Peru. Subspecies, sexes and morphs are illustrated with O’Neill and Lane’s appealing illustrations.  Twenty-five species not covered in the first edition are included.  Additional plates are included in the second edition as well.

This guide is a model for presenting lots of information in a minimum of space.  The organization follows the usual field guide format with text on the left-hand page and illustrations of those species described on the right.  At the top of each left-hand page, a paragraph is devoted to all the species (usually five or six) on that page.  Each species is then covered with data on length and concise text on distribution, habitat, behavior and identification feature.  Information on voice and non-vocal sounds (like wing whistles in some doves) is provided as well.  A small map is given for each species in the left-hand margin.

For me, a mark of a great field guide is my desire to pick the guide up and read random pages.  In short, to hold the book.  This guide certainly qualifies in that regard.  It is a treasure.

At 664 pages, the book is a substantial volume.  But at 5.75 x 8.5 inches in size, the book can be taken into the field in a small shoulder or lumbar pack or even in a generous vest pocket.

Having returned recently from a birding trip to Ecuador, I realize now that I should have carried a copy of Birds of Peru with me in the field.  There are only 14 species of endemic birds in Ecuador so the vast majority of the Ecuadorean avifauna is covered in the Birds of Peru.  The Birds of Peru is certainly easier to carry into the field than the voluminous guide to the birds of  Ecuador written by Robert Ridgely and Paul Greenfield.

Early North American Bird Field Guides

By in Field Guides Tags:

1934 was an important year for birding in North America. That is when Roger Tory Peterson published A Field Guide to the Birds, a seminal guide for identifying the birds of eastern North America in the field.

Peterson was an accomplished artist and prepared all the plates used in his guide. However, the revolutionary aspect of the guide came to be the use of arrows on the bird portraits to indicate important characteristics for the identification of each species.

This guide sold its first run of 2,000 copies in less than a week. The importance of these and subsequent Peterson guides can hardly be overstated in improving the skills of birders and in bringing new birders into our fold.

However, the Peterson guide did not spring from a sudden inspiration. There were field guides prior to Peterson, most of which are little known now. Several of these were authored by women.

Florence Merriam lived in San Diego and developed an interest in bird identification near the turn of the 20th century. Her brother, Hart Merriam, headed the federal Bureau of Biological Survey; field biology was a family interest.

At the time, the major guide to North American birds was Robert Ridgway’s Manual of North American Birds. With more than 600 pages and over 100 plates of drawings of the various parts of birds, Ridgway’s guide was a resource to be consulted after a birding expedition, not carried into the field. The text was technical and dry.

Perhaps influenced by the daunting Ridway text, Florence Merriam published Birds through an Opera-Glass in 1889. This guide is much more welcoming than the dense text of Ridgway. If you visit googlescholar.com and search for the title, you can see selected pages of the book. It is delightful and decidedly non-technical. For instance, here is a portion of the account of the Chimney Swift: “And what a noise these swifts make in the chimneys! Such chattering and jabbering, rushing in and scrambling out! If you could only get your spyglass inside the chimney.”

A line drawing served as a visual aid to identification for each species but the drawings were rather crude. Merriam considered her guide to be a failure because she claimed that only about 90% of birds can be identified with an opera-class. The others (like flycatchers and vireos) she claimed needed to be shot to be identified.

Merriam followed up her first book with Birds of Village and Field in 1898. She provided technical material in small type at the beginning of each count and then devoted the rest of the space to anecdotes in a larger, more inviting font. The wood engravings Merriam used as illustrations were quite useful. The full book can be seen on GoogleScholar

Mabel Osgood Wright was a New Englander and a contemporary of Florence Merriam. In 1895, she published Birdcraft, a field guide to 166 species of eastern birds. Wright cobbled together images from Aududon and other bird artists with photographs of fine bird art onto 15 color plates. The color of the plates was reproduced poorly and the illustrations were not detailed enough to be useful for tricky identifications. Nevertheless, this book went through at least nine editions over the next three decades.  The book was too large to serve as a field guide. Rather it was an accessible reference to be conferred after a birding expedition.

Neltje Blanchan published Bird Neighbors in 1897. Blanchan’s guide was a photographic one. However, the photos were of stuffed birds, often in poses that were decidedly not lifelike. Blanchan’s volume was large like Wright’s book, certainly not small enough to carry into the field.

The first successful pocket guide to bird identification was Bird Guide: Land Birds East of the Rockies by Chester Reed . The guide as first published in 1906. Copies are available for download at http://openlibrary.org/. Reed was an artist and his paintings of birds were quite good. For his Bird Guide, he had selected paintings photographed as viual aids to identification..

The account for each species covered identification features, song, nesting structure and the geographic range of the species.

Roger Tory Peterson received a copy of the Reed Bird Guide when he was in the seventh grade. The National Audubon Society was giving copies to all members of the Junior Audubon Club. The Reed guide was Peterson’s first field guide and must have inspired him to produce even a better field guide 28 years later.

The inspiration for this article was a 2009 article by Thomas Dunlap in Forest History Today See his article for a fuller treatment of the topic.

[Originally published on July 18, 2010]

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