Naturespeak A naturalist's view of the world

August 9, 2008

Just Add Sun

Filed under: Uncategorized — wykes @ 6:56 pm

  It is not entirely correct to say that Indigo Buntings really aren’t blue, though this is a favorite trivia fact imparted by naturalists. It is true that their color results from the refraction of sunlight off the micro structure of their feathers and that there are no blue pigments anywhere on this species. In the absence of light, therefore, these Buntings appear nearly black.

  But, considering that these creatures inhabit the sunny edges of woodlots and open brushy fields, there are very few times that you see them without their proper dose of lighting. Indigo Buntings are as true blue as the sky – just add sun to either and voila, you have blueness.

 These birds pull an especially incredible shade of sea blue out of the solar spectrum. Scientifically they called Passerina cyanea which means “true blue sparrow” in Latin. As the photo above shows, the male of the species deserves every bit of that name (see above). The females are brown -true brown- and slightly streaked.  They are the primary caregivers and have no need to be flashy.

  I came upon a pair of these buntings in brushy field the other day (as seen here -the female is on the upper left). They were especially nervous about my presence and were anxiously flitting about the perimeters of a thick cluster of blackberry vines in mid field. Everything about their demeanor indicated that they were protecting a well hidden nest within. The agitated parents were sounding off (indigo_sdr_0008wav) as they continually re-located from stem to stem.

  The couple chose their nest site well, however, and the thicket proved to be an impenetrable barrier for this particular intruder. Buntings build their structures fairly low to the ground and it would have taken a lucky angle to spot it.  I attempted to peer into the shadows, but gave up after a short while – out of respect for parental psyche. 

  This nesting situation was fairly late in the season – these birds normally start breeding in early May. Summer is now getting long in the tooth and the time to rear a successful brood before arrival of the migration season is getting slim.  No doubt this is a second brood for the couple.  It is possible that their brood was destroyed by a predator and they were able to get off one more attempt before the seasonal barn door closed for good.

  My fretting couple went silent as soon as I put some distance between them and me. At the far end of the field, another worry-free male bunting was in full singing mode and I was able to record him (indigo_sdr_0011wav). His distinctive bunting banter consisted of a lilting chorus of “sweet, sweet..chew, chew..sweet, sweet.”  

  Indigo Buntings generally stop talking by mid-August and gradually slip away to the southlands by September’s end. This call, then, could be considered as one of the season’s last. It is an ode to the sun with which they share kinship.

August 6, 2008

Don’t Take My Word For It

Filed under: Uncategorized — wykes @ 9:13 pm

  I’ve been keeping my eye out for an albino deer lately. The ghostly creature has been spotted on a number of occasions but the descriptions have varied from all white to partially white.  To those who have seen it, I tell them to keep a camera handy for the “next time.”  A photo, even a bad one, will go a long way toward solving the mystery.  

  All this leads me to my sighting of a partial albino cowbird the other day. I had my camera ready, but I wasn’t ready and I had to settle for a bad photo as my documentary proof (see above). Allow me to explain myself.

  Earlier in the afternoon, I led a public nature walk to the lotus beds at Lake Erie Metropark. I brought along a pair of waders so that I could wade into the plants and cut a few examples for show and tell.  Unfortunately, my old waders have a pin-hole leak in the left boot which soon let in a refreshing torrent of cold water – immediately soaking my pant leg and sock. 

  I squished my way through the remainder of the program, and the day, before heading home.  As I drove down the road the thought occurred to me that I could take off my wet sock and hang it out of the car window to dry.  As long as I held on tight, the thing would flap around in the wind like a red-neck’s squirrel tail and dry out in no time.

  You might expect me to say that the sock ripped out of my hand at some point and, after turning around to retrieve it, I spotted an albino cowbird standing next to it.  Well, not exactly.  You see, I was flying down the road – left sock in hand and bare footed to match – and something caught my eye.  A white bird flew across the road and landed on a fence to my right. I had just enough time for the sight to register as something unusual before I was able to pull off the road and peer back though the rear window.

  I couldn’t make out what it was, but also couldn’t (or wouldn’t) step out of the car while doing my shoeless Joe Jackson imitation.  The mystery bird flew back across the road before I could get my camera out.  It landed out of sight beyond a big spruce tree in someone’s front yard. I did a 180 and zipped down to where I saw it vanish.  As I turned into what I hoped would be the correct driveway I spotted a small cluster of cowbirds in the grass. Right smack dab in the middle of the group was my white bird. 

  The front door of the house was open and it looked like someone had just parked their truck in the drive. Here I was a stranger with a camera sitting in someone’s driveway.  I expected someone to come walking out at any moment. I should have been able to quickly jump out, take a few quick focused shots, and then take off.  But, no, I was shoeless and would have looked especially odd – even dangerous – had I chosen to get out. I wasn’t ready to explain that I just wanted to take a picture of a white blackbird as the owner’s glance drifted downward to my single bare foot.

  The situation demanded that I take a few quick shots through the windshield before speeding off.  I guess you could call this incident a drive by naturalist shooting. There is a lesson in this affair somewhere, but I’ll leave that deduction to you.

  Now that you know why my picture is so bad (here’s another one) perhaps you can appreciate the subject matter.  At least, in this case, you don’t have to take my word for it. This is a partial albino Brown-headed Cowbird. Such pale creatures, better known as Pie-balds, aren’t nearly as rare as true albinos but are unusual none-the-less. True albinos completely lack the skin pigment known as melanin and are totally white with pink eyes and skin.  Pie-balds are missing this pigment in scattered locations and appear spotty.  Their eyes and skin are mostly dark, or normal, in color.

  Normal male Brown-headed Cowbirds are deep velvety black (see here) while the females are usually an even pale brown hue (see here).  I suspect this individual was a female based on the mellow brown back and inner tail feathers.  

  There is a very good chance that I will not see her again. Nature has a way of weeding out such odd balls. Her coloration will catch the eyes of predators just as it caught mine. Should she survive, however, there is a slim chance that her offspring will express the same sort of partial albinism. The albino trait is recessive, but it does rear up in random generations over time.

  I will make sure that my next pie-bald sighting will be under better circumstances and that I will get you a better shot.

 

August 4, 2008

Milkweed Manor Mates

Filed under: Uncategorized — wykes @ 7:47 pm

  There is little question that the Monarch Butterfly is the royalty of Milkweed Manor. Nearly every discussion of the Milkweed gets around to mentioning this noble butterfly and its lifecycle link to this plant. Unfortunately, lesser occupants such as the Milkweed Tiger Moth and the Red Milkweed Beetle are often ignored as a result. Perhaps it is time to look over this overlook and see what we’ve been missing.

  The Milkweed Tiger pictured above is a member of the Tiger Moth family  Typical of their ilk, they are furry to the extreme and appear to lack a definable head end. They do have a head end, of course, and this can usually be defined as the part nearest the chewed portion of a leaf (here, is an exception to the rule).  This common species chews only on milkweeds and dogbanes. 

  As a milkweed eater, they ingest the cardiac glycosides found in the milky sap of these plants and use the chemical as a predator deterrent.  They try to avoid eating too much of the sap, however, because it gums up their chewing mouthparts (it contains a latex like rubber).

  When young, the Milkweed Tiger is a colonial beast – all the hatchlings stay together and feed together. During this early gregarious stage they carefully skeletonize the leaves and try to keep away from the sappy veins as much as possible. After their third molt, the tiger cubs head off on their own. Older larvae often deliberately cut the main vein, close to the stem, before dining in order to “bleed off” extra sap and make the leaf more palatable. During all this time they ingest just enough poison to keep themselves toxic.

  By the end of the summer these hairy little creatures will descend down into the leaf litter and weave themselves into a nice furry cocoon made up of body “hair” and silk. They will overwinter as pupae and emerge next year as rather plain looking moths.

  Red Milkweed Beetles, the other unappreciated members of milkweed society, are so named because they are (red milkweed eaters, that is). They claim lineage to a group of insects known as longhorn beetles. All members of this group have very long antennae – the so-called “horns” of their type – which emerge out of the forehead uncomfortably close to their eyes. The antennae base on these insects usually overlaps into the eye space, but those on the Milkweed beetle actually divide the eye into two separate parts! Given that there is plenty of room on the head capsule to put these things, it is not certain why this is so. The scientific name of this antennae-eyed creature is Tetraopes tetrophalmus which is Latin double-speak meaning “four eyes.”

  I invite you to pick up a Milkweed Beetle sometime. Hold the creature firmly in your fingers and hold it up close to your ear (see here).  You’ll hear the thing complain about its treatment with a series of raspy squeaks. As long as you maintain your grip they will keep up this mechanical response.  Properly translated, the beetles are probably requesting a return to their food plant and offering some kind of comment on your mother’s ancestry! 

  Milkweed Tiger Moth caterpillars will offer no commentary if similarly handled, but will roll up and attempt to drop to the ground.  Neither beast appreciates the attention – they apparently prefer being overlooked.

 

August 1, 2008

Wren in Need of Sun

Filed under: Uncategorized — wykes @ 7:58 pm

     Perhaps no other bird, other than the Red-winged Blackbird, embodies the spirit of the marsh better than the Long-billed Marsh Wren.  While Red-wings frequently leave the marsh and enter into our everyday world, Marsh Wrens hardly ever leave the reedy realms.  To see and hear them you have to seek them in their places.

  True to their name, these wrens inhabit the thick vertical vegetation found in cat-tail and bulrush marshes. As mouse-sized members of the wetland fauna they spend most of their time hopping about in the shadowy depths of the lower stems seeking insects and cover. During the early summer breeding season they create wonderful ball shaped nests located about mid-way up on the cat-tail stems. These structures have bottom entrances and are, as you might suspect, hard to find amongst the tangle of green and brown.  I’ve personally only seen a few and in those cases I had to go knee deep into the marsh.

  Marsh Wrens are visually secretive. More often than not, their presence is betrayed solely by the movement of the upper plant stems as they perch on them down below. When you do spot one, it is usually only for an instant before they melt away (see here). The most notable feature is their diminutive size, up-right tail, and white eye brow stripe. It probably goes without saying that the bill is relatively long (they don’t call ‘em that for nothing).

  These wrens are not audibly secretive, however.  They are constantly calling and commenting on the world around them. Often, a small swatch of marshland will ring out with the dry twittering call of multiple wrens.  I was able to record one of these song bursts at Crosswinds Marsh (Long-billed Marsh Wren) – you’ll need to listen to this sequence several times to get a sense of a talkative wren in action.  My wren apparently sensed my desire to record it and decided to grant me one little burst (but it was a nice little burst).

  After recording this songster and getting one quick photo, I figured that would be all I’d get. This little guy proved to be more generous than I could imagine, however. In a few minutes it emerged out onto the board walk and immediately dropped into a spread eagle pose (see here). The bird was taking advantage of the hot morning sun and performing a little sun bathing ritual.  My presence made him a bit nervous and he frequently hopped back into the shadows. Fortunately, the lure of the summer sun finally overwhelmed the fear factor and he lost all sense of restraint. He eventually let it all hang out (see here).

  In full solar glory, the bird pointed his hind end toward the sun. Every wing and tail feather was fanned out, the body feathers fluffed, and the head turned up and slightly sideways. All that was missing was a reflective panel held under the chin.

  Take a good close look at the detail picture above and you’ll notice that the body feathers are lifted to the point where they expose the naked skin. It must feel good to air out these nether regions. I can’t help but to point out that the patch of bare skin visible in this shot is directly above the tail.  This is wren butt, ladies and gentlemen- a full moon in the full sun.

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