May 2010

A Trip to the Galápagos Islands

By in Trip Report, Uncategorized

This column is the second of two on my recent trip to Ecuador.  The first column detailed some of the highlights of a visit to Amazonia.  In this column, I will cover our three-day excursion to the Galápagos Islands.

A visit to the Galápagos has been a dream of mine for a long time.  Charles Darwin visited these shores in 1835 on his around the world cruise on the H.M.S. Beagle.  His experiences with Galápagos mockingbirds, tortoises and finches were instrumental in his development of the theory of natural selection.  To see these animals and to walk the same land that Darwin trod was a tremendous thrill.

Our group flew from Guayaquil, Ecuador’s largest city, 500 miles west to the Galápagos archipelago.  We landed on the small island of Baltra.  A U.S. Air Force base was established there during World War II and now serves as one of two commercial airports in the Galápagos.

After clearing security and paying the required $100 visitor’s fee, we boarded a bus for a short ride to a ferry dock.  The passenger ferry took us just a few hundred yards to the large island of Santa Cruz, one of the four human-inhabited islands.

Brown Noddies (a type of tern), Brown Pelicans and Audubon’s Shearwaters flew above the water as we motored across the narrow channel.

Boarding another bus, we worked our way south towards the town of Puerto Ayora where we would spend three nights.

One of the two Los Hemelos (click to embiggen)
One of the two Los Hemelos (click to embiggen)

Our first stop enroute was Los Gemelos (The Twins), two huge volcanic depressions in the highlands of Santa Cruz.  Admiring one of these two sinkholes, I noticed a bird out of the corner of my eye.  It was a Warbler Finch, one of the 13 species collectively referred to as Darwin’s finches.  Within a few minutes, we had seen four others: Woodpecker Finch, Large Ground-Finch, Small Ground-Finch and Medium Ground-Finch.  I was thrilled!

With few natural predators, the animals of the Galápagos are well known for their fearlessness.  As our group stood around one of Los Gemelos, a Galápagos Dove perched only feet away from us.  This species is widespread in the archipelago but is declining.  Our tour guide told us we were lucky to see this species.  It is really a striking bird.

The dominant trees belong to the genus Scalesia and are members of the sunflower family.  Without seeing the flowers, I would never have suspected the Scalesia are related to our daisies.

Our next stop was Rancho Primacia.  A walk through this reserve yielded our first Galápagos tortoises as well as White-

Galápagos Tortoise
Galápagos Tortoise

cheeked Pintails, Galápagos Mockingbird, Yellow Warblers (the males have red feathers on their head) and a Common Moorhen.

The following day, we boarded a boat for a trip to Floreana, a two-hour cruise from Puerto Ayora.  We saw Nazca Boobies, Magnificent Frigatebirds, Audubon’s Shearwaters and

Marine iguanas on Isla Floreana
Marine iguanas on Isla Floreana

Elliot’s Storm-Petrel during the crossing.  Arriving at Floreana, we saw Galápagos sea lions and marine iguanas on the rocks near the dock.

We boarded a bus for transport to the highlands of the island.  I was particularly keen to see the Medium Tree-Finch, endemic to this island, but was skunked.  We did see lots of tortoises, Galápagos Flycatchers and a brief glimpse of a Galápagos Hawk.

Galápagos Flycatcher on Isla Floreana
Galápagos Flycatcher on Isla Floreana

We cruised to Devil’s Crown, a rocky outcrop just offshore.   Two Galápagos Penguins were perched on the shore with a Swallow-tailed Gull close by.  A Great Blue Heron was roosting there as well.

Blue-footed Boobies
Blue-footed Boobies

On Devil’s Crown, many Blue-footed Boobies and Nazca Boobies were roosting.  A couple of spectacular Red-billed Tropicbirds circled the boat.

The next day we sailed north for three hours to the small island of Bartholomé, adjacent to the large island of Santiago. Bartholomé is a young island, a little less than a million years old.  The soil is very poor; plants are sparse and well adapted to the arid environment here.  Geologically, Bartholomé is fascinating with lava tubes and magma formations.  Ornithologically, the island has little to offer so no new species were added to our list.  The snorkeling just offshore was spectacular with many fish species and sea turtles seen.

On our final morning, we visited the Charles Darwin Research Center in Puerto Ayora.  Walking in, we saw our last

Common Cactus Finch, Puerto Ayora, Isla Santa Cruz
Common Cactus Finch, Puerto Ayora, Isla Santa Cruz

Darwin’s finch species of the trip, Common Cactus-Finch.

At the institute, eggs of the 13 species of Galápagos tortoises are incubated and the young turtles raised for five years before release into their original habitat where the eggs were collected.  We saw Lonesome George, the last member of his species, found only on the small island of Pinta.

[Originally published on May 1, 2010]

A Trip to the Tibutini River, Ecuador

By in Trip Report, Uncategorized

I have just recently returned from nearly two weeks in Ecuador.  I was a participant in a faculty seminar in environmental science, sponsored by IES Abroad.  We were based in Quito but had time for excursions to the Ecuadorian Amazon and to the Galápagos Islands.  In today’s column, I will describe some of the Amazonian highlights.

The Tibutini Biodiversity Station (hereafter, TBS) was our destination for our Amazonian excursion.  The station, maintained by the University of San Francisco at Quito, is located along the Tibutini River, a tributary of the Amazon.  The Amazon is the largest river in the world and drains more water than the next ten rivers combined.  The Amazonian watershed encompasses 40% of the area of South America.  Amazonia is well known for its biodiversity.   But the TBS and the adjacent Yasuni National Park are exceptionally diverse.  One can argue that this region is the most diverse habitat on earth.  The area is at the center of a small zone where amphibian, bird, mammal, and plant diversity all reach their maximum levels within the Western Hemisphere.

To say that the TBS is remote is no exaggeration.  To get there, we flew south from Quito to Coca, a small town on the Napo River.  A couple of White-fronted Toucans gave us great looks in trees along the river.  White-winged Swallows, a close relative of our Tree Swallows, hawked insects over the water.

We continued our journey by boarding a large motor-powered canoe for two hours down the Napo River to a landing at a parcel of land, currently leased by a petroleum company.  After passing through the security check, we waited for a bus for the next leg of our journey.  Birding at the landing, we found Smooth-billed Anis, Purple Martins (soon to depart for North America, no doubt), a Roadside Hawk, a Palm Tanager, a Blue-gray Tanager and a pair of Chestnut-bellied Seedeaters.

The open-air bus carried us for two hours to the Tibutini River where we boarded another canoe for another two-hour trip to the landing at TBS.  As we docked, a Drab Water-tyrant, a flycatcher, hawked for insects along the riverbank.  Climbing the stairs to the dining hall, we had a nice look at an aptly named Sicklebill, a large hummingbird with a strongly curved bill, perfect for extracting nectar from the Heliconia plants growing near the dining hall.

TBS maintains a canopy walk and a canopy tower to facilitate the study of plants and animals high in the canopy of the dense forest.  On our first full day, we split into two groups, spending half the day on the canopy walk and half on the

tower.  I did the canopy walk in the morning.  It was wonderful to be 120 feet high and

Canopy Walk, Tibutini Biodiversity Station (click to embiggen)
Canopy Walk, Tibutini Biodiversity Station (click to embiggen)

above the canopy.  Scarlet Macaws, Blue-and-Yellow Macaws and Mealy Parrots flew above the trees.  I was surprised at the diversity and abundance of butterflies in the canopy.

In the afternoon, we climbed the tower alongside a huge ceiba or kapok tree, walking across to a solid platform 130 feet high.  Unfortunately, it rained most of the afternoon so soaring birds

Canopy Tower, Tibutini Biodiversity Station
Canopy Tower, Tibutini Biodiversity Station

were scarce.  We did get nice looks at Violaceous Jays, Dusky-capped Flycatchers, a Brown-throated Cotinga and a pair of striking Black-tailed Tityras.  On the hike back to the station, we had Rufous Motmot and Slate-colored Hawk.

The following morning was clear.  With high expectations, we boarded the canoe early for a float trip down the Tibutini River.   This trip was a wonderful way to see birds.  Highlights were Yellow-headed Vulture, Double-toothed Kite, Great Black Hawk, Bicolored Hawk, Black Caracara, Bat Falcon, Cobalt-winged Parakeet, Dusky-headed Parakeet, Tiny Cuckoo, White-breasted Nunbird, White-eared Jacamar, Ringed Kingfisher, Black-tailed Trogon, Purple Fruit-crow, Red-capped Cardinal, and Yellow-rumped Cacique.  White-banded Swallows, with steel-blue bodies and a conspicuous white band across the breast, were abundant.  Several were always in view, capturing insects above the river.

In the afternoon, we visited an oxbow lake in search of Hoatzins.  These birds are distant relatives of cuckoos and are the avian equivalent of cows.  The esophagus of a Hoatzin is modified as a fermentation chamber where symbiotic bacteria break down the leaves that the Hoatzin eats.  We took turns in a dugout canoe, paddling to the dense shrubs the Hoatzin prefers adjacent to the shore.  All of us had nice looks at these bizarre birds.  We also saw a pair of Greater Anis.  Locals refer to these birds as cooker birds because their group choruses sound like a pot of boiling water.

Before departing the next morning, we admired a pair of roosting Crested Owls.

[originally published on April 18, 2010]

Eastern Phoebe

By in Migration, Reproduction, Species Accounts

Fee’-bee!  Fee’-bee! You are probably hearing this buzzy song of the Eastern Phoebe in your neighborhood now.  These flycatchers spend the winter in the southeastern United States and return to our area to breed.  It’s good to have them back!

Unlike most flycatchers that have a single, stereotyped song, Eastern Phoebe males sing a second song.  The essence of the song can be captured as Fee’-b-be-bee.  In both songs, the first note is exactly the same.  For the Fee’ bee song, the second note is raspy.  The second portion of the Fee’-b-be-bee song is not as harsh and seems like stuttering.

Don Kroodsma found that Eastern Phoebe males alternate the two song types when they are singing at a high rate (about 40 songs/minute).  At 25 songs/minute, only three of four songs are Fee’-bee songs.  Males sing virtually only the Fee’-bee song if the singing rate falls below 20 songs/minute.  The pattern is clear; the reasons for the pattern are unknown.

Eastern Phoebes are easy to identify.  They have the upright stance of flycatchers as they sit on their perches.  The head is dark brown with dark eyes.  Phoebes lack the conspicuous light eye-ring of many of our flycatchers.  The upperparts of the body are olive-brown, slightly lighter than the head.  The wings have no wingbars.  The throat is white and the rest of the underparts are a buffy-white.  A distinctive behavior of Eastern Phoebes is their tail-wagging.  The tail is rapidly flicked downward and then slowly raised to its original position.

Eastern Phoebes like habitats that are only partly enclosed.  Suburban yards, roadsides, stream banks and orchards are all good habitats.  Within their nesting territories, phoebes have several perches that they habitually use.  A phoebe will sit on its perch, looking for an insect in flight.  When a potential meal is seen, the phoebe will sally forth and grab the insect in flight, returning to a perch.

These birds seem particularly fond of beetles although wasps, ants, grasshoppers and flies are taken on the wing as well.  Sometimes, millipedes and spiders may be taken from the ground.

Nests of Eastern Phoebes are cemented to a vertical surface and are made of an outer layer of mud and a softer, inner lining of grass and other soft materials.  Before European settlement, Eastern Phoebes probably nested on cliffs and ledges.  As Europeans colonized eastern North America, Eastern Phoebes easily adapted.  They now readily nest on rafters and under the eaves of our houses and barns.  In the 19th century, common names for the Eastern Phoebe  were Barn Pewee and Bridge Pewee.

Phoebes will use the same nesting site from year to year, often building the new year’s nest on top of the old one.  Their faithfulness to a nesting site was first shown by John James Audubon who tied some silver wire to the legs of nestling birds captured at their nesting site in Pennsylania.  Sure enough, two birds returned to the same area the next year.  Aubudon was apparently the first bird bander in North America!

Audubon’s results were fortunate ones.  Other biologists have shown that Eastern Phoebes are seldom faithful to the area where they were hatched and fledged (the natal site).  In Indiana, none of 3,594 nestlings were found in the area in subsequent years.

Like most perching birds, adult Eastern Phoebes do show strong fidelity to a nesting site.  Nearly 90% of pairs use the same nest site for second clutches.  The fidelity from year to year is equally strong.  Lots of other birds show similar behavior with low natal site fidelity and high nesting site fidelity.

Eastern Phoebes are industrious parents.  It is normal for a pair to raise two broods in a summer.  Each brood usually has five babies, although broods as high as eight have been reported.  Unfortunately, phoebes are often the victims of female Brown-headed Cowbirds which lay a cowbird egg in a phoebe nest, fooling the phoebes into raising a greedy cowbird chick along with their own chicks.

Data from the Breeding Bird Survey (begun in 1966) indicate that Eastern Phoebe populations are holding their own.  The overall density of this species is highest in the New England states.

The species winters from Virginia to Texas and eastern Mexico.  The center of the wintering population is in eastern Texas and the panhandle of Florida.

The replacement of square concrete culverts and small wooden bridges with circular, corrugated metal pipes has made such sites unusable for nesting.  Biologists have discovered that flat nesting platforms placed in circular culverts are readily accepted as nest sites by Eastern Phoebes.

[originally published on April 4, 2010]

Two New Bird Books and Ospreys in Maine

By in Book Reviews

A couple of new bird books have crossed my desk that I think will be interest to birders.  The first is a new field guide to the birds of the eastern part of our continent.  Sterry_SmallPublished by Princeton University Press, this guide is titled Birds of Eastern North America: A Photographic Guide, written by Paul Sterry and Brian Small.

The old saw that a picture is worth a thousand words certainly applies to nature guides.  The most important part of any bird field guide is the illustrations.  Most field guides reply on paintings or drawings by skilled artists.  The artist can draw or paint a bird from an angle to best show its distinguishing characteristics.  Nonetheless, some people may consider even the best paintings to fail to capture the living quality of a bird.

Alternatively, photographs are true representations of how a particular bird looks under the lighting and background conditions when its picture was snapped.  Some birders find it far easier to match an unknown bird with a photograph rather than a painting.

Acquiring suitable bird photographs for a field guide is a challenge.  Birds don’t pose for the camera, lighting may wreak havoc on the true color depiction of a bird and getting close enough to a bird for a crisp, close-up is tough.  Despite these challenges, Sterry and Small have produced what I believe is the finest photographic field guide of eastern birds.

Both authors are highly skilled nature photographers.  Small is the Photographic Editor for Birding magazine and I have admired his photographs for years.  The photographs in this guide are crisp, informative and, in many cases, stunning.

The book is organized like most field guides with a brief introduction to bird anatomy and plumages.  The majority of the text is composed of species-by-species descriptions of birds in the currently recognized checklist order.

The left page has text on two or three species, giving, in telegraphic style, information on identification features, different plumages and similar species.  Information is provided on the status of the species and tips on how to find each species.  One or two small photographs for each species are given on the left-facing page.  A distribution map is provided as well.  The right-facing page is devoted solely to photographs; many seem to leap out of the page.

At the end of the guide, you will find a section called Out of the Ordinary where vagrants to the east, like Barnacle Goose and Ivory Gull, and exotic waterfowl, like Mandarin Duck and Common Shelduck, are briefly covered.

Bright Wings: An Illustrated Anthology of Poems about Birds is a charming book.  The book is edited by Billy Collins, former Poet Laureate of the United States.  The poems chosen span two millennia, from the Roman poet Catullus through brightwingsChaucer, Henry David Thoreau, Thomas Hardy, and Emily Dickinson to more recent poets like Gray Snyder, Wallace Stevens, Jane Hirshfield, Mary Oliver and Billy Collins himself.

I had to smile when I realized that the bird poems are arranged in checklist order, just like a field guide!

But the poetry is only a part of the charm of the book.  For many poems, David Sibley has provided a lovely portrait of the bird featured in that poem.

Osprey Egg Contamination

The Biodiversity Research Institute in Gorham has released its troubling report on contaminants in the eggs of Casco Bay Ospreys.  Polychlorinated biphenyls (PCBs) and other organic contaminants were found at levels known to adversely affect chick development in chickens.

You can download the whole report at http://www.briloon.org/contaminants/index.php

Maine Butterfly Survey

The Maine Butterfly Survey, a five-year project to map the distribution and abundance of the butterflies and skippers of Maine, is beginning its fourth year. This project relies heavily on volunteers. The first three years have yielded over 4300 records (specimens or photographs). Volunteers have established four new state records and a large number of county records in the first three years of the project. You can see all of the records to date at the MBS website: http://mbs.umf.maine.edu/

Please contact me if you are interested in becoming a member of the MBS team.

[originally published on March 21, 2010]

An Ornithological Reading List

By in Book Reviews

A reader of this column, Tim McCormack, asked me to suggest a reading list of bird books to provide a good overview of the field of ornithology.  After sending him some suggestions, it occurred to me that other readers might be interested in those suggestions as well.

The number of bird books is huge so the books I discuss below are an eclectic assortment.  I have greatly enjoyed reading all of them and found each informative.

The best college-level textbook on the market is Frank Gill’s Ornithology.  The current edition was published in 2007 so is quite up to date.  Gill’s text is highly readable; it is chockfull of information without being technical.  The book has many figures and photographs to accompany the text.

The Handbook of Bird Biology is a massive reference volume created by the Cornell Laboratory of Ornithology.  The book serves as the text for their long-standing Home Study Course in Biology.  The book can be purchased without subscribing to the Cornell Lab course.

The level of the text is similar to Gill’s Ornithology.  The Handbook is a cooperative effort with each of the ten chapters being written by one or more ornithologists who are specialists in a particular topic.

The beauty of bird song captivates birder and non-birder alike.  There is an embarrassment of riches on this topic.  A good starting point is Don Kroodsma’s The Singing Life of Birds.  Kroodsma is a prolific researcher on bird vocalizations, authoring many technical articles on the subject.  This book, however, is aimed at a lay audience.  Kroodsma explains how our eyes can help our ears by describing sonagrams, computer-generated graphs of sounds.

The text is a collection of narratives of many different excursions that Kroodsma took to record vocalizations.   You will go with him close to his home in Massachusetts to record a Hermit Thrush, to Costa Rica to record Wattled Bellbirds and to Oregon to record Bewick’s Wrens.   In each narrative, Kroodsma explains the particular hypothesis he is testing and presents many sonagrams on the species of interest.  Each narrative is a primer on how to do science.

The book comes with a CD so you can listen to the actual recordings used to generate the sonagrams in the text.

Another fascinating book is Why Birds Sing by David Rothenberg.  The author is a professor of philosophy and a talented jazz clarinetist.  His book explores the interface between bird song and the arts.  By interviewing scientists and composers, he explores the meaning of bird song, both to avian and human ears, to try to determine why birds sing.  I enjoy books that meld different disciplines to construct intriguing connections.  This book succeeds in this regard.

Lots of mammals and insects migrate but none can hold a candle to birds in the extent of their migratory movements.  A wonderful introduction to bird migration is Scott Weidensaul’s Living on the Wind: Across the Hemisphere with Migratory Birds.  Weidensaul is one of our most gifted nature writers.  His lyrical prose takes us to many parts of the world to vicariously experience a migratory spectacle.  We go to see the Sandhill Cranes in Nebraska, Red Knots in Delaware, the thousands of songbirds on the Gulf Express, struggling to get to the shores of Gulf Coast states after a non-stop flight from Mexico, and the river of tens of thousands of Broad-winged Hawks passing over Veracruz, Mexico.  By the end of the book, you will have experienced fully the phenomenon of bird migration.

I enjoy books that focus on a single bird species.  One of my favorites is Susan Smith’s The Black capped Chickadee: Behavioral Ecology and Natural History.  Smith has worked with chickadees for over four decades.  She reviews all aspects of the biology of our state bird in a highly readable style.  Much of the research she summarizes is her own.

To get a flavor of field ornithology in the tropics, you will not go wrong by reading Don Stap’s A Parrot with No Name.  Staps went on an extended expedition to the Peruvian jungle with a number of ornithologists from Louisiana State University.  He takes you to the jungle with all the joy, frustration and anxiety such an experience brings.

Finally, a couple of books on ornithological history.  Joseph Kastner’s A World of Watchers gives a history of ornithology and birding in North America, mostly focusing on the 19th and 20th centuries.  For a fascinating account of the life of John James Audubon, you can’t beat Richard Rhodes’ John James Audubon: The Making of an American.

I’d love to hear of your favorite bird books.

[originally published on March 7, 2010]