Archive for the 'Fieldnotes' Category

The day in birds

My day in birds began just after 5 a.m. when I woke to the pre-dawn chorus of the local House Sparrows. Argh! I grumbled something and rolled over. Between rain clouds, I went out to Jamaica Bay Wildlife Refuge in the middle of the day. Some thirty-seven species of birds and three mosquito bites. Many Tree Swallows, above, who nest in the boxes set up for them there, including one set up underneath an Osprey nest. Saw one Barn Swallow among all these acrobatic swallow-fliers. I watched this juvenile Black-Crowned Night Heron groom from a blind for a while. Eventually, it broke off a stick and flew away with it. It was probably going to use it as a fishing lure. Yes, they do things like that.

I also saw a Peregrine cruise overhead as I was about to cross Court St. It landed on one of the arms of the cross atop SS Paul & Agnes, the highest thing south of Atlantic Avenue in my neighborhood. It’s a regular perch for raptors.

Premature Juneberries

Some of the local Amelanchier (a.k.a. Shadblow, Serviceberry, etc.) berries are purple-ripe. Others are coming along fast:Gowanus street top, Brooklyn Bridge Park bottom.

Horseshoe Moon

Can you feel it? The Horseshoe crabs (Limulus polyphemus) sure can. It’s spawning season. Here, looking like rocks, are some males awaiting females and clusters of males attached to, and surrounding, females.

Could it be their multiple optical systems, including compound eyes and UV sensors? Could it be their one hundred thousand cuticular receptors, allowing them to feel their way along? Or the chemosensory pores that connect their dendrites to the water? Whatever it is, they can smell the pheromones…A huddle of males around female mostly-buried in the sand under the clump of seaweed. Horseshoes started their evolutionary journey something like 450 million years ago. They predate the dinosaurs, and, needless to say, the species that chops them into bait, grinds them into fertilizer and chicken feed, and sucks their blood for human medicine. There are four species, three in the Indo-Pacific (where they are also eaten by H. sapiens), one in the Atlantic. Related to the trilobites and the arachnids, they are not crabs; they survived the Permian-Triassic Extinction that killed off nearly all other ocean life. It is fashionable to call them “living fossils,” but that suggests a simplicity that the reality belies. The full and new moons of May and June bring them in-shore to mate and lay their eggs in the sand at the high tide line up and down the east coast. NYC is no exception. Jamaica Bay has been prime nesting habitat since the retreat of the ice.
Not all of them return to the sea. There are more than a dozen dead in this photo. Legion are the hazards of being a Horseshoe crab.Between the devil (you will know him by his works) and the deep blue sea, there are a lot fewer Horseshoes than there used to be, a situation which has ramified throughout littoral habitats and their food chains. As a result, the animals are much studied, with censuses conducted up and down the coast this time of year. This tag, one of five we saw among the several hundred crabs about an hour before high tide, had only been attached two nights earlier by a team from NYC Audubon.
Pointing out some anatomy on the underside, where the appendages, including the chelicerae, and book gills make for a fascinating contrast to the helmet-like topside. Note blade of Spartina in hat band… but that’s a whole other story. Thanks to Traci for the photo.

C. serpentina

Over the weekend, I saw three big Snapping Turtles (Chelydra serpentina) in Green-Wood Cemetery. This is the time of year they emerge from the murk of ponds and lakes to reproduce, the female often travelling long distances to find soft earth, dirt, or fine gravel in which to bury her clutch of eggs. Unlike in most turtle species, male Snappers are actually larger than the females.Growing to platter-sized, these animals can live nearly five decades in captivity, but the rigors of the wild reduce that to about 30 years. One problem is that the type of ground they dig their nests in is now often found on driveways and dirt roads, hazardous both because cars can crush the animals and destroy the nests through compaction. Also, they must cross paved roads to find these places. Here’s a video on how to help a Snapper cross the road (don’t pick it up by the tail). Snappers have spread into Europe through the pet trade. A 44-pounder was captured in a canal near Rome last year. As with the other turtles, mortality is very high; few of their young survive to adulthood, but some old vets live long and deep. Baby snappers, especially in their northern range, will hatch in September and October, but stay in the nest through the winter, only emerging the following spring, when they make their sometimes long, instinctive journey towards water. Other species follow the same strategy: remember the baby Painted Turtle I found one early spring on Nantucket?The Snapper’s common and species name serpentina both allude to their strong jaws and long necks. They have a surprisingly small plastron, or bottom shell, and can’t retreat into their shell like other turtle species, so their best defense is a strong offense. Their claws are also formidable, about an inch long in this case. They are turned up here because this animal has its feet pointing backwards. Snappers have a fearsome reputation, more hype than reality in my experience, but can be aggressive in response to interference. I mean, if you lose your finger because you poke one, don’t blame the turtle. So, as with all wild things, you shouldn’t approach too closely and you shouldn’t touch (unless you’re helping it off a road).The other two snappers, which looked just as big, were in the water. Note those little nostrils at the very tip of the face; they can stick just the tip of their snout above water to breath, and you probably wouldn’t notice them at all. The animals in the water seemed as curious about me as I was about them.

Turtles have been around for some 215 million years. They are older than their fellow reptiles the lizards, snakes, and crocodiles. A Snapper in particular, lifting its shell high, spiky tail dragging behind, has a dinosaurish look to it when it walks.

While wondering around the cemetery thinking about turtles, it dawned on me that the readiest source of earth there for a nest was a freshly dug grave.

Prospect Park has Snappers, too.

Salamanders in Da Bronx

As part of New York City Wildflower Week, I went up to Van Cortlandt Park in the nether reaches of the Bronx to join Ellen Pehek in turning over some old wood. Ellen is the NYC Parks & Rec Principal Research Ecologist and involved in a study monitoring Eastern Red-backed salamanders (Plethodon cinereus). How do they respond to stressed, invasive-filled woodlands, as compared to relatively healthy forests? Wooden boards, one on top of the other with a little spacer in-between (I called them wood sandwichs) have been set up. The boards are now quite hard to find with the understory layer thickly covering the forest floor (the study checks them in the fall, when it’s easier). So we also turned over some downed tree branches. Red-backed like these cool, damp places, in fact must have them, since they breath through their skin (having no lungs). Of course, the dark and dank also attracts other creatures. We found three individual salamanders: one little juvenile; one the so-called “leadback” type, the same species but without the reddish stripe; and one with the stripe, although this one was was more dull orangish than red.The leadbacks seem to predominate in hotter, dryer habitats.

NYC salamanders have also been the subject of another study that found urban woodland specimens tougher than their country cousins when it comes to battling a pathogenic fungus that’s taking a high toll of amphibians around the world.

Below the bridge

This view is like a dream sometimes.

Also spotted in Brooklyn Bridge Park:

Galls and Crane Fly

A two-fer in this shot of a Witch Hazel leaf:This is a boom year for the Witch Hazel Cone Gall-maker (Hormaphis hamamelidis), an aphid. Read more about these tiny insects and how they force the American Witch-Hazel (Hamamelis virginiana) to create these protective cone forms around their young. For more about the endlessly fascinating galls read here.

The insect perched here looks like a Genus Trichocera Winter Crane Fly. There are some 28 species in this genus in the the U.S. and Canada, and as their name suggests they can be found in the winter months, particularly in caves and mines.

Viburnum Leaf Beetle

If you read this, you are probably also reading Marielle Anzelone’s Spring series at the New York Times. If not you should be. Yesterday’s article introduced us to the Viburnum Leaf Beetle (Pyrrhalta viburni) an invading species which devours Viburnum species, especially Arrowwood (Viburnum dentatum).

Well, yesterday afternoon in Van Cortlandt Park, I met one of these beetles in person, at least in its tiny larval stage. This is just one of the instars, or stages of the beetles’ larval growth:Small, but hungry.

Native Flora Garden

In the Brooklyn Botanic Garden yesterday morning. It was still dripping from the rain under the trees, even though it had long since stopped raining. Our woods in leaf always hold onto the rain. Next to the present NFG, the Garden is working on a major expansion to allow for less shade-dominated habitats found in the region. It will take years, of course, and will be glorious to watch.

Cardinal Chicks

Looking somewhat like Muppets, two Northern Cardinal chicks realize there is no food forthcoming from the camera. Normally at this stage in their careers, they are all about open mouths — wide, wide mouths, like so:These birds will quickly get bigger, feather out, and fledge, or fly out from the nest. (This site gives details on Cardinal plumage colors and molts; technical, but still a great comparision.)

Fledged songbirds stick close to their parents at first — people often find a young bird on the ground and mistakenly think it has been abandoned, but the parents are just hiding from you (read this on baby birds; in general, you should not interfere). Fledged birds will follow their parents and loudly call to be fed. A whole new chorus of bird sounds is now being heard: hungry, insistent youngsters.
This Starling youngster has yet to develop the glossy black plumage of an adult bird.

So some birds are already fledged. Others, having just arrived, like Baltimore Orioles, are only now weaving their suspended nests.

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