Sunday, February 28, 2016

Bird Season

 Spotted a pair of pair of downy woodpeckers flitting about in the front yard.  This is the male.

My first love, trees, are mostly still pretty sleepy; meanwhile, the birds are busier all the time--mating season has begun.  Birds are perhaps the easiest group of large animals* to watch, or at least the most obvious, and they're virtually everywhere.  And for the next month or two--birds will be at their most visible: trees will not begin leafing-out until almost May.  

Even though I am no kind of birder, I will be observing and learning as much as I can over the coming weeks.  I have used several websites to identify and learn about birds, but the Cornell Lab of Ornithology is the premier site--especially for learning bird songs.  Songs are valuable because we often hear birds that we can't see.  A skillful birder I know can identify many birds with her eyes closed.  

Looking through the Cornell site a day or so ago, I came upon a great way to learn to identify birds by their songs.  If you want to go out better prepared, here is a great place to start. Within something called the Bird Academy, I found Bird Song Hero.  This is a couple of interactive lesson/quizzes that teaches you to "see" birdsong.  And after you've finished it, you get a free download of backyard bird songs that you can study and keep for reference.  (There's also a nifty-looking online lecture course you can take, but it costs money.)

Other sites are easy to find in a search.

*Okay, maybe they're medium-sized animals.  But on the grand scale of things, most animals are the size of insects.  (Come to think of it, most animals ARE insects!)  Of course, we are bigger than the average bird, but you might not realize that we aren't that far from the top of the animal size range.  Blue whales are about 2000 times heavier than a human, a human is about 1000 times heavier than a robin, which is in turn about 3700 times heavier than a lady bug. 

Monday, February 22, 2016

In the winter a young bird's fancy lightly turns to thoughts of love

 Appropriately enough, I first noticed loud, urgent birdsong of several different kinds around Valentine's Day.  (I'm not able to identify more than a few birds by their songs, though I would dearly love to learn.)  I had imagined that spring was mating time for local birds, but some, at least, get a head start much earlier. 

In most birds it is the male who sings to attract a mate, and the female who does the choosing.  For the same reason, the male is often the more brightly-colored.  (Females are more often dull: they don't need to show off.)  The male may sing, "keep out! this is my territory!" to other males, while to the females he sings, "Am I not the most beautiful guy you've seen, and with the most impressive song? and wouldn't you like to raise a large brood of fine, strong chicks with me on this wonderful territory?"

The coloration and singing are textbook examples of sexual selection.  This is a variant of natural selection in which characteristics such as bright plumage are selected for, not by directly improving survival or reproduction, but indirectly--the males most attractive to the females are more likely to succeed in getting a mate and contributing those very genes conferring bright color to the next generation.  It makes evolutionary sense that females, which make the enormous resource investment of gestating the young, will be very choosy about who their partner is.  (This choosiness of female holds true in a great many other animal species as well--likely even in humans.)

 A well-attired White-Breasted Nuthatch on February 19th.  
These birds walk up, down and around the tree trunk looking for food.

On February 19th I spotted a handsome pair of white-breasted nuthatches working their way around the gnarled limbs of an old red maple.  If I'd had any doubt they were lovers instead of mere dining companions, my copy of the Sibley Field Guide to Birds of Eastern North America set me straight: "usually solitary."   

 This Downy Woodpecker is probably the female; the male looks the same
but with a prominent red patch on the back of the head.  These birds brace their tails
against the tree while they hammer their beaks into the bark probing for insects.

Today, February 22nd, the sound of gentle, companionable tapping drew my eyes to a pair of downy woodpeckers searching for food in the bark of some dead oak branches.  Later my wife called my attention a pair of tufted titmice in a big Norway maple tree in the backyard.  

It's worth mentioning that these three particular birds don't differ much from male to female, though the male downy woodpecker does have a bright red patch not shared by his mate.  And in the tufted titmouse, at least, both male and female sing.

I will look and listen more carefully in the coming days.

Saturday, February 20, 2016

Warm Afternoon Walk in Hockomock Swamp

Hockomock Swamp is a different place on a warm February day with no snow.  I was out there with my son for a few hours today.

 Prince's pine is a lycopod, remnant of a group of plants that formed the first forests
--long before the dinosaurs, and before flowering plants or even conifers evolved.

 This scrub black oak is more characteristic of dry hilltops than swamps.

 One of many culverts that allow water to pass beneath the rail bed.

For some reason, I can't walk past open water without taking a photo. I just gravitate to it, I guess.  Though it is fifty degrees and sunny today, and has been well-above freezing for days, some ice still remains--especially in the shade.

 My son is at an age where he cannot pass by ice without testing it
--as long as someone is close by to pull him out, at least!

 Atlantic white cedar (Chamaecyparis thyoides) is a significant tree in this swamp.

 There are several conifers with scale-like needles.  I know this one is 
Atlantic white cedar because of the ball-like cones on this bent-over tree.

 Paper birch is often bent over by the weight of snow, sometimes breaking,
sometimes bending over to form graceful arches over the roadbed.

 Eastern hemlock (Tsuga canadensis).  I only noticed it by spotting
a fallen twig and looking to see where it had fallen from.

 My son lifted a stone and discovered this blue-spotted salamander
that had been sheltering from winter.  We replaced the rock as best we could.

 yellow birch (Betula allegheniensis) has the shreddy bark of some birches,
but in a yellow-gray color.  Around here, this is a tree that says, "wild."
 My son spotted several large pieces of railroad ties that showed the roadbed to have been
beside the current track, rather than on it.  Although most parts of this bed are overgrown,
you can see how level and board-flat the exposed parts are.

Monday, February 15, 2016

Eight (or so) Trees You Can Readily Identify in Winter

With the leaves gone, the upswept branching pattern of sugar maple trees is more striking than ever.  This got me wondering if I could do a "tree silhouettes" post.  But as I walk around, I find no other trees as easy to distinguish at a glance as sugar maple.  Without their leaves, identifying trees can be tricky.  Nevertheless, some trees have peculiarities that make it easier.  Here are some easy calls, beginning with conifers.

1. White pine (Pinus strobus) is very easy to distinguish, with its long, thin needles (in groups of 5), feathery branches, and a typically blue-green color.  They are distinctive enough to be identified at highway speed--even more so in winter, since they keep foliage year-round.

 The white pine above is losing needles (as they do in fall), which makes it
look yellowish rather than the usual blue-green. (I see dying needles
on the highway, as well.)  Up close, the needles are two-colored.

Other common pines in the area are red pine, an alien which has distinctly reddish bark and coarser needles,  and pitch pine, with its more yellow-green color, thick, stiff needles leading to a "bottle brush" appearance, and the fact that this drought-tolerant pine is most often found on well-drained sandy soils.

 Pitch pine (Pinus rigida) has sparser, thicker, stiffer needles than white pine.  Its cones are small and round rather than long, and pointed, and the scales are armed with very sharp spines.

2. The alien invasive Norway spruce (Picea abies), with its dangling branchlets, and big, long, cylindrical cones is easy to spot.  This tree is common in yards despite the deep shade it casts, and the near-impossibility of growing much of anything under it.  Birds do love its shelter in winter, though.

 Beside the very distinctive drooping branchlets,
Norway spruce has large cones that taper abruptly at the tip.

3. A third conifer is eastern hemlock (Tsuga canadensis).  It has short needles, but the branchlets don't hang the way Norway spruce does.  The needles are flat and striped beneath.  In the wild, eastern hemlock is a stately tree, but homeowners ignorant of its true nature sometimes condemn to be a mere bush or hedge, tortured regularly with pruning shears.

 Another easy-to-recognize conifer is the stately eastern hemlock, with its short, flat needles decorated beneath with light-blue racing stripes, and cones no bigger than your little finger end.

Flash photography brought out the "racing stripes" in these eastern hemlock needles.

A final edit, and one more conifer.  Taking to the highway today, I realized that oldfield juniper (aka eastern, aka etc.) shared the roadside with white and sometimes pitch pines.  But it's usually easy to distinguish by its silhouette.

Eastern juniper (Juniperus virgianiana) is a tree common to oldfields and roadsides
and is rather seldom planted.  On the highway, you can easily tell its by its narrow,
tapering or tear-drop silhouette from broader, more open crowns of pine.

Some, but not all, oaks hold some of their dead leaves through the winter (a trait called "tardily deciduous").  Other than that, oaks cannot (in my experience) be distinguished in winter at a distance.   Up close, you might notice that the tips of oak twigs are crowded with buds.  

4. One oak that can be distinguished is white oak (Quercus alba): its bark is light to medium gray, and up close often looks a little like overlapping vertical shingles. I don't know whether white oak got its name from the having lighter bark, or from the light color of the undersides of its leaves.  The crown varies in shape.  

  Above are two white oaks, below are two other (probably black) oaks for comparison.

If you can reach a twig, white oak buds are small, round, fat and hairless. 

Here are the crowns of a few white oaks to give you an idea of their gnarlyness and range of shapes.  Notice that the two are holding dead leaves low in their crowns, as is most typical.  Here is white oak during the growing season.

Maples are easily distinguished from most other locally common trees by having opposite leaves and buds--rather than alternating from side-to-side as oaks (for example) do.  Red and silver maples have large enough buds that you can often see this even when a branch is too high to reach.  

5. Sugar maple (Acer saccharum) is told at a distance by the gracefully upswept branches that divide low on the tree, so that there seems to be no clear central trunk for most of its height.  Within the maples, sugar maple has bark that breaks into plates in the mature trunk, while most others have vertical ridges that form a net pattern.  Red maple is in-between: the mature trunk bark somewhat platy but not as much so as sugar maple.

Three sugar maples in a row are clearly identified by the upswept branches 
and absence of a central trunk.

Buds of silver maple (above) and red maple (below).  Easier to see than paired buds in the silver maple, some twigs are also paired (see especially the little twig in the bottom right corner above). 

 Paired buds of ash-leaved maple.

Here are the trunks of a few maples.  And here is sugar maple during the growing season.

The deeply-ridged and platy bark of older sugar maple.

 The bark of red maple is fairly distinctive in mature trunks (above), 
but not young trunks (below).

 Norway maple trunks have a network of ridge (above), as do trunks of unrelated white ash (below).

6. Shagbark hickory (Carya ovata) has very distinctive bark that peels off mainly in winter in long, stiff, jagged pieces.  Not a very hug-able tree!

7. While not all birches have smooth, white bark, two that do are paper birch (Betula papyrifera) and gray birch (Betula populifolia).  If the old bark low on the trunk doesn't look convincingly white, look aloft at higher limbs.  The two species are hard to distinguish at a glance, but paper birch grows larger, and gray birch tends to have dark triangles that are the scars of fallen branches.  In summer their leaves give them away: paper birch are more rounded, gray are more triangular with long, tapering points.

The three photos below are all of the same paper birch, the fourth is a different individual.

Below, for comparison, are two different gray birches.  The dark markings where branches emerged are generally more pronounced in gray birch, but the distinction isn't that easy.  Better to wait for the leaves

 Gray birch (Betula populifolia).

8. American sycamore (Platanus occidentalis) is a large native tree.  (Okay--now this really IS my last edit.)  Spotting some sycamore trees in downtown Providence reminded me that I know of two sycamores in my neighborhood--and sycamore is certainly easy to identify.  If the jigsaw puzzle-like bark isn't obvious, you might notice the lollipops hanging from the branches.  These spherical clusters began dispersing seeds dangling from dandelion-like parasols back in the fall, but they aren't done yet.  You might spot the clusters of downy seeds on the ground (as I did in Providence) before noticing the trees themselves.

Multicolored bark that peels off in pieces that look like jigsaw puzzle pieces instantly mark
this as sycamore.  Lollipop-like fruit structures may drop tufted seeds far into winter.