Monday, January 25, 2010

Florida: Artificial Wildernesses

Every naturalist knows that Florida is a wonderful place to see glamorous water birds, alligators, and other creatures up close. What every naturalist does not know is that you don't have to go to the Everglades or the Florida Keys (wonderful as they are) to have that experience. I fact, if you visit Palm Beach County you can find entirely man-made wildernesses where some of the best of Florida's wildlife will come, entirely on its own, to you.

Each winter, for a good many years now, my parents have been fleeing the Canadian winter for the suburbs of Boca Raton. When I visit, one of the first things I do, most mornings, is to drive about 20 minutes north to the Wakodahatchee Wetlands (and here I am, with my new Nikon D300s). Wakodahatchee's fifty acres must be one of the best places to see water birds in Florida - but only a few decades ago it didn't even exist. Even its name, which means "created waters" in Seminole, is a testament to its artificial nature.

Wakodahatchee is not the property of the Florida Fish and Wildlife Service, the National Park Service or even a private conservation foundation. Instead, it belongs to, of all things, the Palm Beach County Water Utilities Department. It started life (and continues to this day) as a water reclamation facility, into which the Utility pumps some two billion gallons of treated water a day. Its role as a haven for wildlife was, in fact, an afterthought, and a remarkably successful one - after plantings with everything from palm trees to duckweed, Wakodahatchee has become a home for alligators, marsh rabbits, turtles, birds (some 140 species have been recorded there) and a choice selection of insects.
This November, Eileen and I discovered a new "constructed wetland", as these things are called, only a short distance from Wakodahatchee. Green Cay Wetlands is newer, a lot bigger, and boasts a new nature centre and a much longer boardwalk. Both places wonderful for wildlife, and are very popular with people, too, who can be easily spotted lugging vast telephoto lenses or strutting about on their morning constitutionals.We alternated between the two every morning for several days, and greatly enjoyed both; the following photographs feature wildlife you can see, usually with great ease, at either site.

I would normally be extremely proud of myself for having taken a closeup like this one of a Tricoloured Heron (Egretta tricolor), were it not for the fact that the birds practically do everything but push the shutter for you. Eileen demonstrates the principle in the next shot:

See what I mean?

And here is the result from her point-and-shoot!

The White Peacock (Anartia jatrophae) is a widespread tropical butterfly that just makes it into the United States in Florida and Texas.

Skippers abound in the wetlands. This is a Long-tailed Skipper (Urbanus proteus), another widespread tropical and subtropical species.

Skippers are notoriously difficult to identify, and I'm pretty hopeless with them. I believe that these two are Brazilian Skippers (Calpodes ethlius). If there are any skipperologists out there, though, help would be appreciated!

I have no idea what this little guy is, beyond noting that it is a moth caterpillar of some sort. Possibly a Virginian Tiger Moth or Yellowbear (Spilosoma virginica)? Anybody?

A little pond on the central boardwalk at Green Cay proved to be a good spot for dragonflies. This is a Blue Dasher (Pachydiplax longipennis) in a typical "obelisk" pose, with its abdomen straight up in the air. This is supposed to reduce their exposure to sunlight, but they do it in the shade, too.

I think this one is a female Needham's Skimmer (Libellula needhami), but it could just as easily be one of its close (and almost indistinguishable) relatives. [Nov. 6, 2011: Probably not Needham's, but a Golden-winged Skimmer (Libellula auripennis); see here for identification points]

This is a male Eastern Pondhawk (Erythemis simplicicollis), identifiable by its combination of pale blue body and bright green face. The female is totally different, bright green and black (I saw one hover in front of me, but failed to get a photo).

And this is a Pin-tailed Pondhawk (Erythemis plebeja), a tropical species unknown in Florida before 1971. Sidney Dunkle, in his Dragonflies of the Florida Peninsula, Bermuda and the Bahamas, calls it "wary and active", and it was not easy to photograph (as the quality of this picture, I'm afraid, shows).
The woodsier parts of Green Cay supported vast numbers of this highly attractive web spider, one of two species of the genus Leucauge (long-jawed orbweavers, Family Tetragnathidae) in Florida. Going by some images of the two on the very useful BugGuide site, I believe this to be Leucauge argyra.

This, as far as I can tell, is a Pig Frog (Rana grylio), one of the few large frogs to range throughout the state of Florida.

Turtles have found their way into both wetlands. This is the commonest and most obvious species, the Florida Red-bellied Turtle (Pseudemys nelsoni). If you look carefully at this male, you can see the extremely long, straight foreclaws on his front feet. They are used, oddly enough, for courtship. A courting male swims above the female, positions his foreclaws beside her face, and strokes her face (or the water near it) some three to ten times, at a rate of 10.8 vibrations per second (according to the 2nd edition of Turtles of the United States and Canada, by Carl Ernst and Jeffrey Lovich). Perhaps, for the female, the sensation is somewhat akin to the pulsations of a whirlpool bath.

Of course, the animal everyone comes to see is the American Alligator (Alligator mississippiensis), and Wakodahatchee boasts a few pretty hefty specimens. Alligators breed here; I have occasionally come across a female guarding her babies.

On to the birds! We'll start with a Snowy Egret (Egretta thula)...

This is a Great Egret (Casmerodius albus or, if you prefer, Egretta alba, or Ardea alba, take your pick), the North American form of a nearly cosmopolitan species (though the birds from eastern Asia and Australasia are frequently split off as the Eastern Great Egret (C. modestus, or E. alba, or A. alba, or... oh, forget it).

The Little Blue Heron (Egretta violacea) is white as an immature, adding confusion to the identification of white herons in Florida; this, though, is an adult.

I can remember when the Cattle Egret (Bubulcus ibis) was a rare and exciting novelty in North America. Originally an Old World species, the birds arrived, apparently on their own steam, in South America around the turn of the twentieth century. They took to the New World rapidly (thanks to our habit of replacing forest with cattle pasture), and spread north, reaching Florida by the 1950s. Now they are abundant here, and as they are not as tied to wetlands as the other herons, they have become a common roadside bird.

These are Green Herons (Butorides virescens); the D300S makes flight shots a lot easier!

The white streaks on the head of this Glossy Ibis (Plegadis falcinellus) are a sign of non-breeding (or first-winter) plumage. Like the Cattle Egret, the Glossy appears to be a fairly recent arrival in the New World; the ancestors of this Florida bird may have been wind-blown strays, carried across the Atlantic a century or two ago.

Perhaps even more than the herons, the Anhinga (Anhinga anhinga) is one of the symbols of Florida's wetlands. This bird, in a typical wing-drying posture, is either a female or an immature (The male has a dark head and neck).

Common Moorhens (Gallinula chloropus) are abundant at both sites, and in November there are a great many immatures accompanying their parents. As usually recognized, the moorhen is an almost cosmopolitan species, only absent from Australasia where the very similar Dusky Moorhen (G. tenebrosus) replaces it. However, things may not stay this way. On one of our last trips to Green Cay, we ran across a group of European birders on a Florida tour. Their leader was an old acquaintance of mine, Arnoud van den Berg. Arnoud is now one of the three leaders of The Sound Approach, a dedicated band of bird recordists engaged in cataloging the details of bird vocal repertoires (and publishing some unique books on the subject). He has been studying the vocalizations of moorhens, and he told me, much to my surprise, that the voices of European and American birds are so different that they may actually belong to different species. Once Arnoud publishes his findings, we may have to go back to calling our birds Florida Gallinules (as we used to when I was a boy). "Moorhen" does seem an odd name for a bird that never sees a moor in its life ("Gallinule", which sort of means "little chicken", isn't much better).

The American Purple Gallinule (Porphyrula martinica) is a lot more spectacular than its cousins the moorhens, and behaves rather differently; you are less likely to see it swimming than clambering about the stems of water plants, feeding on flower buds.

Moorhens and gallinules, which are members of the rail family, are almost invariably mistaken for ducks by beginning birders. For contrast, then, here are some real ducks. These Black-bellied Whistling-Ducks (Dendrocygna autumnalis) are among the newest of Florida's bird immigrants. Though a group of these ducks, which are normally native to tropical America from extreme south Texas to Argentina, escaped from Crandon Park Zoo in Key Biscayne back in 1968, they failed to thrive. The increasing numbers in Florida today appear to be genuine wild birds, arriving from, probably, Mexico, early in the 1980s.

This is a Mottled Duck (Anas fulvigula), the Florida and Gulf Coast equivalent of the Mallard (Anas platyrhynchos). Unlike Mallards, the plumage of the sexes is alike; the male and female differ mostly in bill colour. This female has a mosly orange bill; the male's bill is yellow.

Here is a pair, cunningly hiding their bills among the duckweed so we can't tell which is which!Blue-winged Teals (Anas discors) are abundant fall and winter visitors to the wetlands. As the second photograph shows, they can be rather aggressive.

Songbirds, with a few exceptions, are far less obvious in the wetlands than waterbirds. in winter there are always a few Eastern Phoebes (Sayornis phoebe) about, stirring their tails and occasionally calling out their own names (fee'-bee!).

Far more secretive is the gorgeous Painted Bunting (Passerina ciris). At Green Cay a feeder lures these shy birds into view, but you can't get too close to it. This is an adlt male; he was accompanied by up to four female-plumaged birds, either females or first-year males.

The Painted Bunting is, alas, a species in decline over much of its range (see this account in the Audubon Watchlist). Its sheer beauty is part of the problem. Though it is illegal to trap or keep Painted Buntings in the United States, that is not true in Mexico, Central America or the Caribbean where much of the population winters. Thousands are trapped on their wintering grounds for shipment to pet dealers around the world. In 2004, the United States and Mexico proposed listing the Painted Bunting under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The proposal, unfortunately, was not adopted -- a real disappointment for me and my colleagues, who were at the CITES meeting lobbying in its favour. You can read the proposal here.

Much more obvious, and certainly noisier, than the buntings is the Red-winged Blackbird (Agelaius phoeniceus). Almost everybody knows the male, but the female seems to be one of the most confusing of birds for beginners. She is not only completely unlike the adult male in plumage, but is smaller in size, rather different in behaviour -- and certainly less showy and aggressive.

For sheer aggressiveness, obviousness and personality, though, the Red-wing must give place to its cousin the Boat-tailed Grackle (Quiscalus major). Like the Red-wing (but unlike the Common Grackle (Q. quiscula) that also shows up in the wetlands), it is sexually dimorphic; the cinnamon-brown females are smaller than the males. Rival males will often challenge each other on the railings of the boardwalk while you watch from a few meters away; here, to demonstrate and to finish this already long post, are some photos by Eileen: