Spoonbills & Sayonara

For newbie Floridians or the uninitiated, the first sighting of a Roseate Spoonbill is a memorable event.  You might hear, “Look at that Pink Flamingo”, or from the more observant, “Look at that Pink Flamingo with that deformed flattened bill”.  A gentle correction is in order.  Our Spoonbill, the Roseate, is one of six in the genus “Platalea”.  These include the Eurasian, the African, the Black-faced from Eastern Asia, the Royal from Australia and New Zealand, and the Yellow-billed from SE Australia.

Roseate Spoonbill, Platalea ajaja

The Roseate Spoonbill is a year-round resident of Florida and the SE Gulf States of the U.S., but also found in the Caribbean, and in large areas of Central and South America.  These large striking waders are active feeders, usually found in shallow fresh or brackish water, swinging their submerged bills side-to-side.  Along with the color, it’s the peculiar spatula bill that catches your eye.  It is lined with sensitive sensory nerves that causes it to snap shut involuntarily when it detects the unfortunate fish or crustacean.  The chicks hatch with a straight bill; the spatula shape develops with maturation.

A “bowl” of Roseates at Ding Darling

Roseates were pursued close to extinction by the plume hunters of the early 20th century, but they survived and have made a comeback since.  They seem to be more numerous now, even compared to when I first started coming to Florida regularly, a dozen years ago.  A “bowl” of Spoonbills are often found feeding along the berm, close to our home and have given me many close-up photo ops–they’ve adapted to the morning parade of human walkers and gawkers near their feeding pools.

click on any photo to zoom to full screen

The pinkness of the bird is determined by the amount of carotenoids in the ingested crustaceans.  The juveniles are less pink and lack the more intense coloring seen at the shoulder in the adults.

It’s about time to say sayonara to Florida; our seasonal sojourn is drawing to a close and we are about ready to migrate northward with the other “snowbirds” and genuine aves.

Without breaking a sweat our Florida seasonal bird count has reached 97 this year, with a couple birding days still left.  These are primarily resident birds, as the spring migration seems less evident down here.  Oh, you do notice the newly arrived Swallowtail Kites soaring above and the occasional colorful warbler passing through, but for most they ask, “why leave”?  This is the land of sunshine, plentiful food, beaches, and swamps, where the living is easy, even for the birds.

Chasing a closely related, White Ibis

But there are new adventures waiting up north along the Chesapeake.  I know the migrating Geese, Ducks, Swans, and likely the Loons will have left and the annoying non-migratory resident Canada Geese will have already built their nests at the shoreline.  Bald Eagles and Osprey will be far along their reproductive pathways and the Osprey will become the most boisterous voice, calling warnings from their nesting platforms.

Osprey, Pandion haliaetus

The monotonic but rhythmic call of the White-throated Sparrow will no longer be heard, but the Mockingbirds, Red-winged Blackbirds, and Chipping Sparrows will have joined the chorus.  I’m looking forward to seeing the acrobatic Swallows, Swifts, and Martins, as well as the Kingbird staking out his territory in the back yard.  And I must quickly break out the Hummingbird feeders before these unique migrators pass me over and all settle in my friend Barbara’s yard–she keeps many more feeders than me, all filled and ready.  I believe she has the local “record” for the most Hummers seen simultaneously at her feeders.  Wasn’t it twelve, Barb?  Keep up the good work, but leave a few for me.

Ruby-throated Hummingbird, Archilochus colubris

The Birds & The Bees

 

Great Blue Herons, Ardea herodias

 

Birds do it, bees do it,

Even educated fleas do it.

Let’s do it, let’s fall in love.

Cole Porter

You don’t have to be an astute observer to notice that something’s up in the avian world right now.  It’s springtime and once the birds have recovered from the stress of migration or the burdens of winter, their raison d’etre becomes reproduction. The hormones from brain and adrenal glands rule the roost and result in both physical and behavioral changes, all focused on reproducing and preserving their species.

Rose-ringed Parakeets, Psittacula krameri

Claiming a territory is step one in this process.  In my neck of the woods this is most noticeable with the boisterous Red-winged Blackbird, perched on the tallest reed, sporting his bright red and yellow epaulets, warning other males to stay clear and beckoning females to come and check him out.  He hopes they are attracted by his beauty, health, and strength.

Red-winged Blackbird, Agelaius phoeniceus

There are numerous avian signs of courtship, some common and others quite bizarre.  The common include colorful breeding plumage, such as the striking migrating Warblers and their melodious songs, all evolved to attract a mate.  The more bizarre include the Magnificent Frigatebird’s inflation of his giant red throat (which other jealous males attempt to puncture), the water ballet of courting Grebes performed in perfect unison, or the Baryshnikov-like leaps of the Sandhill Crane.

Burrowing Owls, Athene cunicularia

There are the gentle offerings of food and mutual grooming, or the spectacular flight and airshows of the Hawks, or the lower nighttime air dance of the Woodcocks.  I don’t quite get the courtship practice of the male Parrot vomiting into the mouth of the female, allowing her to sample the prospective mate’s taste in food, nor do I condone the Mallards’ gang rape of a cornered female, so common with that specie.  But these are all signs of spring, evolved over millions of years to recreate and preserve life.

American Wigeons, Anas americana

As a Radiologist I have a special interest in the comparative anatomy of humans and birds.  First for the male, the avian testes, the producers of sperm, are located high in the abdomen, near the upper poles or the kidneys–male birds have no scrotum.  The sperm travel down through the deferent duct and seminal vesicles and empty into the cloaca at mating.  As with mammals, sperm require lower than normal body-temperatures to mature.  Birds solve this by lowering their body temperature at night and by storing sperm in the cooler seminal vesicles in the lower pelvis.

Copulating Black-necked Stilts, Himantopus mexicanus

Most male birds have no penis.  Mating occurs with “kissing cloaca”, the brief and often repeated contact of the male and female cloacae.  But a few male birds including Ducks, Storks, Flamingos, and Ostriches do have an erectile penis arising in the cloaca.  In the mating duck this is quite large and has a corkscrew configuration while the complementary female anatomy has a reverse corkscrew shape to accept it.  Some have said that these birds, who often mate in water, use this penetrating copulation to prevent water from washing the sperm away.

Red-shouldered Hawks, Buteo lineatus

The most interesting aspect of bird anatomy is that most female birds have only left-sided internal genitalia–the right sided structures are involuted or completely absent.  There are a couple potential explanations for this.  It may serve to reduce body weight and make flight easier, and it also prevents bilateral ovum forming simultaneously with opposing eggs obstructing each other in their passage to the lower genital tract.

Cactus Wrens, Campylorhynchus brunneicapillus

The ovary is positioned high in the abdomen, similar to the testes, and its eggs pass to the cloaca via the oviduct, uterus and vagina.  Grossly these three structures appear to be a continuous tortuous tube, but microscopic anatomy reveals differing functions.  At ovulation the soft ovum enters the upper oviduct and becomes coated with albumin and keratin as it proceeds downward.  The limey shell and egg coloration is added in the uterus and the finished egg is stored in the vagina.  It appears that the fertilization with sperm occurs in the upper oviduct.  The entire process from ovary to cloaca takes about 24 hours.

Greater Yellowlegs, Tringa melanoleuca

The structure and function of the avian egg is a fascinating topic by itself, but best left for a later posting.  Just as a trailer however, consider that a bird’s egg must be strong enough to withstand the weight of the incubating parent but fragile enough to allow the hatching chick to escape.  It must be a protective barrier, but also porous enough to allow oxygen transport and respiration.  It must also contain all the nutritional and energy requirements of the developing embryo.

Hooded Mergansers, Lophodytes cucullatus

So as you head out this spring remember the raging hormones have expressed themselves in many ways, some visible and some unseen.  The males are carrying testes that have increased their volume 100 times and are trying to find and impress a mate in any way possible.  The female, her own genitalia markedly enlarged for the season is the egg producer, primed and ready, hoping to find a worthy mate.  If successful, the real work will have just begun.

Osprey, Pandion haliaetus

Book Review: The Heart of the Valley by Nigel Hinton

Published by Harper & Row, copyright 1986, 236 pages.  Cover art by Pam Stephens.

 

During a recent bird outing in rural England a Dunnock was pointed out to me.  It was warily perched on the far side of a shrub, as if purposely defeating my efforts to get a good shot.  This was a life bird for me so I inched closer, but it flew, leaving me only some unpublishable blurs.  This common, drab, brown songbird is not a great discovery for an English birder, but reminded me of Nigel Hinton’s wonderful story of a year in the life of a Dunnock.  I read this tale years ago, read it again after this sighting, and have loaned my copy to multiple birders.  It’s received their universal acclaim.

White-throated Sparrow, Zonotrichia albicollis

Hinton chose to write about a common, non-flashy bird, living in common, rural Kent County, in a common valley, near a common Brook Cottage and Forge Farm, inhabited by common folks living typical common lives.  Although common, the trials and tribulations of these lives, both the birds’ and humans’, are gripping and existential.

Carolina Wren, Thryothorus ludovicianus

The main character is the female Dunnock, barely surviving the cold blasts of the particularly hard winter, her first.  The optimistic stirrings of early spring lead to a timid introduction to her first mate, nest-building, and egg-laying.  I know, it all sounds so corny, but the author avoids the pitfalls of some anthropomorphic literature.  These are not talking birds and this is not “Watership Down” or “Bambi”, but rather a compelling and detailed account of life, perseverance, and also of death.

Swallowtail Kite, Elacoides forficatus         (click on photos to zoom)

It’s not all happy.  The initial nest and eggs are destroyed and her mate is run over by a car.  The humans of the cottage and farm are also dealing with aging, stroke, and loss.  In the most compelling part of the novel the harrowing and fantastic migration of a female Cuckoo from Sub-Sahara Africa to the English valley is described.  Just as the reader is celebrating this successful migration, you watch in horror as the Cuckoo sneaks her egg into the unsuspecting Dunnock’s nest.  The egg hatches and this monstrous, ugly, parasitic chick wages its genetically programmed war against its smaller nest mates, duping the unsuspecting foster mother and hogging most of the food.  Even before its eyes are fully opened the Cuckoo tirelessly works to expel its rivals from the nest.  It is evil personified, or maybe “birdified”.

Yellow-billed Cuckoo, Coccyzus americanus

I didn’t realize that the anthropomorphic nature literature was so controversial and hotly debated near the beginning of the 20th century.  The famous and “pure” naturalist, John Burroughs, felt that authors did a terrible disservice by their non-scientific attribution of human emotions and qualities to wildlife.  Among others he singled out the writings of Jack London, William Long, and Ernest Seton, who had just published a book entitled “Wild Animals I Have Known”.  In retaliation James Montague wrote this poem entitled “Proof”:

John Burroughs, who’s a shark on birds

(He classifies ’em by a feather),

Avers that they’re devoid of words

And simply cannot talk together.

He gives the nature-fakers fits

Who picture birds in conversation,

And tears their story books to bits

In scientific indignation.

 

But there’s a wren outside my door

That talks whenever I go near him,

And talks so glibly, furthermore,

That I just wish that John could hear him.

Of mornings, when I stroll about,

The while he hymns his glad thanksgiving,

He interrupts himself to shout.

“Hey!  Ain’t it glorious to be living?”

Field Sparrow, Spizella pusilla

Believe it or not, even the President of the United States weighed in upon this vital debate.  Theodore Roosevelt publicly took the side of John Burroughs and against the “Nature Fakers”, adding more fuel to the raging fire.  And as we all know and agree, if the president says it, it must be true.  Cooler heads finally prevailed and the controversy returned to a simmer.  As for me, I can’t see what harm is done by imagining what a creature may feel or think, fully knowing that it may have little or no capacity for either.

Bronzed Cowbird, Molothrus aeneus

The female Dunnock did survive, at least for one season, as did the Cuckoo chick and one of the Dunnock chicks.  But survival for them hung by a thread and was temporary, as it is for us all.  This book has given me a new insight regarding the lives of these birds.  I’ve been keeping the feeders a little fuller and their baths a little cleaner, and maybe they’ll notice and like me a little more–who knows.