Sunday, September 29, 2013

Osprey - A Unique Bird of Prey

Osprey migrating over Putney Mountain in SE Vermont
The e-mailer was driving along Route 142 near the Connecticut River when she saw a bird just above the water. She wrote: “This bird was big! Very light, mottled feathers, mostly white, but what really caught my eye was the distinctive black eye ‘patch’. As I watched, the bird made a very tight circle, folded it's wings, and dove straight into the water! It flew back out, apparently unsuccessful, because I did not see anything in it's talons.”

She saw an Osprey, also known as the Fish Hawk. With its recovery from the devastation caused by DDT, the Osprey is again a common bird along the New England coast, and may be seen anywhere in Vermont where there is water - along our rivers, lakes, and large ponds.

The Osprey’s diet is almost exclusively fish, and from what I have been able to determine, almost exclusively fresh fish. It hovers 30-100 feet above the water surface looking for fish near the surface. Finding its prey, it plunges to the water, sometimes completely submerging save for wing tips. Terres in Encyclopedia of North American Birds completes the description of the Osprey’s fishing: “Rises from water with fish gripped in both feet, pauses in midair to shake water from plumage, and to arrange fish with head pointed forward, which reduces its resistance to air, flies with it to habitual perch to eat or to nest to feed young. Reported to carry fish up to 4lbs or more.” This dull description only hints at the excitement generated when you are able to watch the real thing.

Osprey hunting over Texas wetland

The Osprey is the only bird which fishes in this manner. Gulls plop on the surface. Many aerial sea birds, like pelicans or gannets, plunge dive, capturing fish in their beaks. The Bald Eagle, also a “fish hawk,” plucks fish near the surface with its talons.

The Osprey and the Bald Eagle pose interesting contrasts. The Osprey rarely eats dead fish; the Bald Eagle enjoys dead fish, and dead anything else. The Osprey is a tireless fisher. It will consume its catch, then go hunting for more. The Bald Eagle does as little work as possible. When in the mood for fresh meat, rather than carrion, it is content to let the Osprey catch a fish and then steal it.

Osprey feeding in a New Jersey salt marsh

An older naturalist, like Edward Forbush, always wrote of the benefit or harm that a particular bird posed to humans. In contrast to many other hawks, Forbush could write of the Osprey that all “the evidence available points to the conclusion that the Osprey is harmless to poultry, birds and game, and that most of the fish that it takes are species of little value to mankind. Fishermen usually welcome it as a guide to good fishing. All things considered, this great, handsome, picturesque and interesting bird must be regarded as a subject for perpetual protection.”

In the nineteenth and early twentieth centuries, an even greater contrast in attitude was found among coastal farmers. Where most people in those times considered hawks vermin to be exterminated (most hawks, given the opportunity, would take a barnyard chicken), coastal farmers and fishermen actively protected Osprey. They watched Ospreys aggressively protecting their nests, eggs, and young. The farmers’ young chickens ran free during the summer; it was assumed that the Osprey protected the chickens from other hawks. Coastal farmers were anxious to have Osprey nesting close to their farmyard, so they  set up nesting platforms for them - a tall pole with a wheel fixed on its top.

Osprey "home repairs" in May at Forsyth NWR, NJ

However, John James Audubon was the more complete observer of the Osprey. In the mid-nineteenth century he described the Osprey, or Fish Hawk as he knew it, as having a mild disposition: “Not only do these birds live in perfect harmony together, but they even allow other birds of very different character to approach so near to them as to build their nests of the very materials of which the outer parts of their own are constructed. I have never observed a Fish Hawk chasing any other bird whatever.”

He also debunks the coastal farmers belief that the Osprey protected the barnyard chickens from other hawks. Rather than staying away from the Ospreys, the other hawks simply went away; they went inland “for the purpose of rearing their young in security.” When the shorebirds and waterfowl returned to the coastal marshes, the other hawks returned as well. By then, the Osprey had completed its nesting and had begun moving south.

Osprey aerie atop a pinnacle in Grand Canyon of the Yellowstone
The Osprey is one of the most widely distributed birds in the world, found on every continent in the world except Antarctica and even on some remote Pacific Islands. In the western hemisphere it nests in North America; northern populations migrate to warmer climates for the winter.

The Osprey is a unique bird of prey. It belongs to the Order: Falconiformes - the diurnal birds of prey. But the Osprey has been on its own evolutionary path for a long time. Taxonomic classification constantly changes. At one time the Osprey was in a Family by itself; the other Families being Hawk Family and Falcon Family. Current classification puts it in a sub-Family of the Hawk Family, making it a little more closely related to the hawks and eagles than to the falcons, but not by much. It is the only member of its sub-Family.

The point is, there are things about the Osprey that are unique among the diurnal birds of prey. For example, the Osprey has long, strong claws, curved about one-third of a circle. The claws are round. The toes are equal length. The lower surface of the toes are covered with spicules (small, bony spines) which help hold slippery fish. The outer toe is reversible (like an owls’) so that it can hold prey with two toes in front and two in back. Its plumage is compact which reduces wetting when it plunges into the water. These are only some features of the Osprey which make it unique among the hawks.

The scientific name for the Osprey is Pandion haliaetus. The genus name refers to the complicated Greek legend of Pandion, king of Athens, and his two daughters. The rules of taxonomic nomenclature require that once a name has been applied, we are stuck with it, even if it is wrong. This is one of those cases; there is no reasonable, or even unreasonable, reason for applying the name “Pandion” to the Osprey. The best that can be said, is that this was a flight of mythological exuberance. The species name, haliaetus, does a little better; it means “sea eagle” from the Greek.

Osprey feeding young
How the name “Osprey” came to be applied to this “Fish Hawk” is a mystery. “Osprey” probably derives from the Latin, meaning something like “bone breaker.” The original “bone-breaker” known to the Romans was the Lammergeier, or “lamb vulture,” which dropped bones from a height in order to break them. No one seems to know how “osprey” came to be applied to the bird we know. However, translators of the King James Version (1611) do refer to “the eagle, the ossifrage, and the ospray.” An early commentator on this translation explains that the ossifrage is a “species of eagle” and the osprey is “the black eagle.” Clearly these theologians were a bit confused, especially since Shakespeare a few years earlier had written (correctly) in Coriolanus: “As is the osprey to the fish, who takes it by sovereignty of nature.” This suggests that for reliable observations of the natural world, you may be better served by a poet than by a theologian.

Good birding!

Thursday, September 26, 2013

Random Images from a Hawk Watch

When the Broad-winged Hawk migration over Putney Mountain concludes, somewhere around the September 20-23, there is usually a lull until other species begin moving seriously around October 1. But there are always a few stalwart watches who make sure that those slow days are covered, and the few birds counted, and  just in case ....

But most of the action takes places other than in the skies overhead. Here are a few random images from Putney Mountain during the last few days ...

Hermit Thrush
Whittling away the watch hours

Migrating Blue Jays often pass overhead in significant numbers

School groups visit Putney Mountain, and sometimes serenade the watchers
Northern Flicker migration has begun
Golden-crowned Kinglet

Good Birding - wherever you may be!

Monday, September 23, 2013

The Universe is Unfair ...

... and nice guys don't always get the girl, or win the prize, or whatever. Today I took a 20 minute detour on my way to Putney Mountain in order to get cider donuts for the stalwart hawk watchers. I was being a good guy.

I arrived at the hawk watch site 2 minutes after the hawk watchers watched a Peregrine Falcon dive into the woods, then reemerge with a Blue Jay in its talons and begin eating on the wing. So no photos of the drama. Alas!

So today I had to be content with a few medium height hawks (out of photography range), and a family of ravens playing on the wind.

Common Raven

Yesterday (Sunday) was a bit better. The second season of hawk watching is underway with the accipiters beginning to come in numbers. And they do so with attitude. Our plastic owl attracted the attention of several birds, almost always young, inexperienced birds ...

The Plastic Owl

This Sharp-shinned Hawk made a close pass at the owl ...

Sharp-shinned Hawk (hatch year)

... while this young Cooper's Hawk made repeated attacks ...

Cooper's Hawk diving at the owl
Cooper's Hawk - note the full crop
Cooper's Hawk - compare head size with the Sharp-shinned Hawk
In addition, Bald Eagles continued their steady run, while song birds occasionally are found in the edges around the watch site or in the woods on the walk up ...

Bald Eagle - not yet a full adult
 Good Birding!!

Sunday, September 22, 2013

Putney Mountain - Hawks and More

After the big flight of Broad-winged Hawks last weekend, the counts tapered off dramatically with hawks often coming few and far between.

Searching the sky for hawks

Even so, there were moments, such as the hour when there were 20 Osprey, and the 20 minutes when there were 5 Bald Eagles ...

Osprey migrating over Putney Mountain
Among the other rather hard-to-come-by raptor highlights, was this beautifully backlit Cooper's Hawk ...

Cooper;s Hawk
 The slow hawk flights gave time to search the ridge for other "things with wings" ... such as a migrating Magnolia Warbler ...

Magnolia Warbler
... and butterflies - American Lady and "Summer" Azure ...

American Lady
"Summer" Azure
 Dragonflies are often seen flying over the clearing, and occasionally being taken by a kestrel or sharpie. One day this week, Shadow Darners were racing everywhere, but seldom resting. Early in the day, I captured one who paused briefly ...

Shadow Darner
Putney Mountain Hawk Watch is occasionally short on hawks, but rarely short on the magic of the Green Mountains ...

... and when things become really lazy, well you just sit down for a period of somnolent contemplation ...

Good Birding!!

Monday, September 16, 2013

Broad-winged Hawks - Putney Mountain

The Broad-winged Hawk flight exploded over Putney Mountain on Saturday (1100+), then continued on Sunday (1300+) and today (800+ when I left at 4:30).

A few images from the last three days at Vermont's only full-time hawk watch ...

Hawk Watchers count a kettle over the Connecticut River Valley
A small kettle of "broadies" - 20 birds ride the thermal up
Broad-winged Hawk
Broad-winged Hawk
Broad-winged Hawk
While the flight of "broadies" continued to be impressive today, the highlight for the day was the passage of five Bald Eagles in a 15 minute period - 4 adults and one hatch year bird ...

Bald Eagle
 It's still too early to be counting Turkey Vultures as migrating. They roost in Brattleboro and Bellows Falls then wander north, south, south, north, or wherever. But these masters of the wind currents are always fun to watch, and today they were flying low ...

Turkey Vulture
Good Birding!!

Saturday, September 14, 2013

Putney Mountain - the early season Hawk Watch

After last year's record hawk watch season, no one has been expecting this year to be nearly as good, and those expectations have been met. The early season has been dismal. Beastly hot weather and rain/thunderstorms virtually shut down the flight this week. Today was sort of a clearing day, and the birds began to move, but they were often distant and required eye strain to find and count.

A few images ...

Bald Eagles - always stunning, always stately and magnificent. This one flew low over the site on Monday ...

Bald Eagle - adult
 Broad-winged Hawks are the predominant species during mid-September, and today they began their flight, although it was not until mid afternoon that numbers started flying, and often they were distant kettles. As of this post, the count had not been totaled, but it will be in the 600+ range. The bird in the next photo was seen on Wednesday - "ratty" in appearance, but apparently because it was still growing its new feathers ...

Broad-winged Hawk
 Early today, a Sharp-shinned Hawk put on an "attitude show" as it made repeated attacks on the plastic owl decoy ...

Sharp-shinned Hawk - hatch year
 Between hawk sightings, there was the occasional butterfly, such as this American Copper ...

American Copper
 In general, the day required persistent searching to find distant kettles ...


... but, as always, there are those times of good conversation, plus the annual sharing of cupcakes for a birthday, and the sweet fruit of the earth's bounty ...

... and finally ... a young hawk watcher looks for hawks ...

Good Birding!!

Friday, September 13, 2013

Dragonflies in Cape May

During the first week of September, the highlight of our day in Cape May was the dragonflies. A sampling of the many opportunities to see and photograph these fascinating creatures ...

Black Saddlebag

Blue Dasher - male

Blue Dasher - female

Carolina Saddlebag

Eastern Pondhawk - male

Eastern Pondhawk - female
Fragile Forktail
Great Blue Skimmer - male

Great Blue Skimmer - female
Neddham's Skimmer - female
Needham's Skimmer
As always with dragonflies, if you think there is a misidentification, please let me know.


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