Graceful Pelicans

I was fascinated watching the aerial maneuvers of White Pelicans at the Don Edwards National Wildlife Refuge at the south end of San Francisco bay.

Breakfast time was over, and now it was time to preen those feathers and get them back into their best condition.
A lone Pelican was still swimming around looking for something to eat (?), but usually these Pelicans, which do not dive for their food unlike Brown Pelicans, forage in huge groups, paddling their feet to scare fish up to the surface. For example, in the photo below…
White Pelicans were “group fishing” on a lake in southern Minnesota last year. Great Blue Herons stood by to catch whatever the Pelicans missed.
But their real grace is in their effortless flight — catching the updrafts for lift on those long wings…
or moving more quickly with slow, deep flaps in order to get up speed to glide.
Even their landings are pretty graceful as they daintily lower their big webbed feet to the ground while back-pedalling with their wings to slow their descent.

A cruise on the Delta

Five rivers feed into the 200,000+ acres of wetlands that make up the second largest river delta system in the U.S. just north of Mobile Bay in southern Alabama. The Mobile-Tensaw delta’s expanse of swamp, bog, natural rice paddies, canals, and rivers makes this area of Alabama a real biodiversity hotspot where you can find more species of fish, turtles, snails, crayfish, and oak trees than anywhere else in North America. Harvard ecologist E.O. Wilson has called it North America’s Amazon, and so it was a real treat to venture out on a small boat to explore some of the smaller waterways of the delta for ourselves.

Wild rice and Phragmites reeds grow along the edges of the river, almost closing off the small waterways in the labyrinth of corridors throughout the delta.
A variety of snails colonize the floating vegetation in the swampy bogs.
Clumps of rice seed fell into the bottom of the boat as we passed through narrow canals. A Yellow Warbler might not be interested in the seed, but there are plenty of insects in this vegetation.
We must look carefully on the river banks before stepping out of the boat — there are plenty of alligators in the delta waters.
Cruising up the Tensaw river we entered a cypress swamp where the trees grow right in the water, completely independent of any land surface.
Cypress forests are a haven for all kinds of birds — small migratory warblers as well as large waders like a Great Blue Heron.
In the Spring, these waterways are lined with brilliant flowers.
Spanish moss hangs from the Cypress’ lower branches, and odd vertical stumps arise from the tree’s roots. Their function is not certain, but they might assist in collecting more sediment to buttress the tree roots in the soft, muddy river bottom.
Honeybee nests can be found where large branches have broken away from the trunk. This is a “honey” tree.
Not only is there great diversity of vertebrate animals in the delta, but there are hundreds of species of insects as well. And some are really big — like the praying mantis..
and this 4-inch lubber grasshopper (which is not fully mature yet).

The southeastern U.S., and the Mobile delta in particular, was a refuge for species driven south during the ice ages of the Pleistocene glaciation. Warm temperatures year-round and plenty of rainfall (averaging 70 inches per year) ensure the most equitable conditions for life to survive, and so it has in this cradle of biodiversity.

Amazing sand beaches of Dauphin Island

We took a car ferry to Dauphin Island which sits at the mouth of Mobile Bay, and then drove west to Pelican Point beach for a (hot) walk in the late morning sun. The beaches along the gulf coast of this part of Alabama are composed of finely ground, minuscule particles of quartz that originated in the Appalachian mountains, were ground down by erosion and river action before being transported to the gulf, where minerals were further reduced in size by wave action over tens of thousands of years. The result is an eye-blinding, fine, white sand that actually squeaks as you walk over it.

It’s hard to decide which is whiter — the sand or the puffy cumulus clouds. Little islands of sea oats grasses and herbaceous perennials help stabilize the dunes. But this is harsh habitat for these plants that have few mineral nutrients and precious little fresh water resources and must deal with a lot of salt water spray.
Farther away from the ocean, more perennial grasses can establish mats of vegetation.
In salt water pools behind the beach, one might find a few shorebirds foraging for food. We were surprised to find a tiny Least Sandpiper poking around in the vegetation at the water’s edge.
Even farther away from the ocean, the vegetation is much thicker and more diverse with all kinds of perennial grasses and forbs growing on the sandy matrix. I surprised a Great Blue Heron and Black-bellied Plover as I came around the corner of this small pond.
A flock of Red-winged Blackbirds (all females and immature males) were feasting on the sea oats.
The Dauphin Island fishing pier ends far short of the ocean now, due to sand buildup between Pelican Point (which used to be an island) and Dauphin Island.
Looking toward the interior of Dauphin Island, you can see the successive ridges of white sand dunes deposited over time, and colonization first by grasses, then various species of shrubs, and finally dense stands of pines and oaks, the species best adapted to growing in dry, sandy conditions.
In the interior of the island, you can find huge, old live oak trees, covered with mosses and epiphytes, and surrounded by saw palmetto and a variety of flowering plants. These are impressive giants, both in their size and in their survival in a climate of intense heat, periodic drought, and occasional hurricane landfall.

Alabama’s gulf shores are an ecological wonder!

The Invader

Florida has the distinction of being the epicenter of invasion of non-native reptiles, introduced by collectors who intentionally or unintentionally let non-natives escape, or by accident when eggs or small hatchling reptiles are carried into this country on imported plants.

The Cuban Brown Anole is a 5-9 inch slim lizard, marked with a diamond-shaped pattern on its back. It typically rests in low vegetation, waiting for unsuspecting insects — or other, smaller lizards — to walk by, and then quickly gobbles them up.

Successive invasions of Brown Anoles from Cuba and the Bahamas since the late 1800s have resulted in well established populations throughout Florida that have since moved north and west to Georgia, Louisiana, and Texas, and have also resulted in an apparent coincident decrease in the population of native Green Anoles.

Brown Anoles now occupy the tree trunk-ground niche in their hunt for prey, and occur in very high density in residential shrubbery (sometimes 4-6 to a single bush).
Female Brown Anoles (recognized by the brown stripe down the middle of their back) lay 1-2 eggs in leaf litter or potted plants every few days. Eggs hatch 4-6 weeks later, and the 1-inch long hatchlings move into the vegetation to hide from larger individuals that might eat them.

However, rather than disappearing altogether as a result of the Brown Anole invasion, it may be that Green Anoles simply move out of the low vegetation and up into the tree tops where they can more favorably compete for food and avoid being eaten by the more aggressive Brown Anole.

the demise of the Puffball

A couple of pristine white and almost perfectly round Giant Puffball mushrooms appeared in the wetland behind the backyard about two weeks ago.

The two Giant Puffballs were located a few feet apart and were already 6-8 inches in diameter.

These distinctive Fungi have no spore-bearing gills on the underside like most table mushrooms. They do not have a stalk or stem, and the spores produced internally are released in a cloud of brown dust when the large fruiting body splits apart at maturity or due to some mechanical disturbance (like someone kicking it).

Every couple of days I visited the “twins” to see what changes had occurred in the interim. The figure below captures the progression of changes in the largest Puffball over almost two weeks. Click on the image to get a larger view.

From the first day I found them, both Puffballs got somewhat bigger, then cracks appeared in the surface and they slowly got browner and more crusty. However, both were still intact after 2 weeks and had not broken apart to release spores.

Giant Puffballs can grow to 20-inch diameters, and occasionally the largest ones may be up to 60 inches across and weigh as much as 40 pounds. They are edible when young with firm, solid white tissue inside. But as they mature and begin to decompose, the interior spore development becomes a soft greenish brown as trillions of spores develop.

By day 8 after I first found them, one of the Puffballs had developed a ring of lacy fungus growing on it –the other Puffball remained pristine.
By day 14 after I first found them, someone had kicked the largest Puffball over exposing the solid white base and its small connection to the underground portion of the fungus (highlighted in the soil).

Here’s a fascinating video on the spore production of Puffballs by Sir David (Attenborough) and some nifty time-lapse video of Earth Star fungi that puff their spores out in response to rain…

Early bird catches “worm”

A little Spotted Sandpiper had the entire beach of Vadnais reservoir to itself and moved slowly along the shoreline probing now and then in the mud and under leaves as I stood quietly and watched.

It’s a rather plain looking, medium-sized, chunky-bodied shorebird, missing the spots for which it is named in its winter or juvenile plumage (can’t tell which). But the bird is instantly recognizable as it bobs its tail up and down as it walks, earning it the nickname of “teeter-bob” or “teeter-peep”.
Here and there, the bird probes its bill part way into the mud testing for the presence of buried larvae.
I’m not sure what this behavior is — did the bird hear something, or see something and tilted its head to localize the cue? Spotted Sandpipers hunt primarily by sight, looking for insects or crustaceans in the debris along muddy shores, but they also probe likely looking nooks and crannies where invertebrates may be hiding.
The bird has found something here — it takes a couple of minutes of probing up and down to extract it.
It pulls some yellow and black-striped “worm” from the muddy substrate. The prey might be the larva of a large stone fly or caddisfly.
It looks tantalizing (to a sandpiper) — why not gobble it up?
Nope, have to wash it off — thoroughly! Two or three dunks and swishes should do it.
Now, it’s edible.

Spotted Sandpipers are likely the most widespread breeding sandpiper in North America, nesting from northern most Alaska to the mid-continental U.S. along rivers, lakes, and streams.

And their breeding system is particularly interesting because they exhibit a sex role reversal compared to most other bird species. Instead of the typical female role of incubation and hatchling care, Spotted Sandpiper females “collect” multiple males, laying a clutch of eggs in each male’s nest, which he will then incubate. After they hatch, the male is in charge of protecting and providing food for the chicks, while the female goes off to find another male to mate with.

Female Spotted Sandpipers arrive first on the breeding ground, establish their territory, and then compete with each other for males to mate with. Since females can store sperm from multiple matings for up to a month, the male may be incubating and tending to chicks that are not his offspring! This breeding strategy, called polyandry, is rare among birds but is found in several shorebird species, in Northern Jacanas, occasionally in Acorn Woodpeckers, and in Harris Hawks.

Photobombed!

While I was photographing Ring-billed Gulls fishing for minnows the other day…

I was following this young Ring-billed Gull flying with his fish

When suddenly, a Great Blue Heron flew right in front of my camera.

Apparently I wasn’t following the gull very well at this point, but nevertheless wasn’t expecting to be photo-bombed by a heron flying so close to me that it didn’t even fit into the camera’s view. This is a full screen, uncropped image.