Naturespeak A naturalist's view of the world

April 28, 2009

A Load of Loud Toads

Filed under: Uncategorized — wykes @ 9:30 pm

I would not have known when the first toads started calling in my neck of the woods if it weren’t for that drunk taking out a neighborhood mailbox. My wife and I were awakened at 5 am by the sound of a careening truck in the process of obliterating my neighbor’s mailbox and it’s supporting post.  The catastrophic sound sent us both jumping for the ceiling. The vehicle, unfazed by the obstruction through which it had just passed, came to a rolling stop in the middle of their yard. By the time I pulled on a pair of shoes and ran out to investigate, the culprit was long gone. Only the poor decapitated box, centered within a pair of tire tracks, remained as evidence of the deed.

It was there, while standing in the pre-dawn darkness, that I slowly came to hear the distinctive sound of calling toads drifting in on the warm breeze from the adjacent farm field. Since there was nothing more that could be done about the vehicular posticide, I was able to pause and enjoy the sweet sound of distant toads. As it turns out, I heard a whole lot of toad music over the next few days, but I can thank that inebriated fool for providing me the opportunity to hear the very first trilling notes of the season.

The breeding call of the American Toad (see a non-calling toad below) is a peculiar mid-spring sound. From a great distance away, it rides the air like a soothing background chime (listen here). From 500 feet away, the quality begins to take on a mass alien invasion feel (listen here). When performed within a few feet, the call is downright deafening…I said…d.e.a.f…..what? (listen here). Any way you hear it, however, the sound is not one you’d expect from something as earthy and serious looking as the American  Toad.

These bumply amphibians begin the migration to their ancestral ponds in mid- to late April. The males stake out singing territories in the shallow waters of a marsh, semi-permanent pool, or a pond. There they proceed to blow each others ears out in an attempt to lure in the females. A few hours following  the “bottle meets box” incident, I came upon a host of breeding toads gathering in a Lake Erie marsh. During the peak calling period, toads will call day and night until the job is done. Fortunately, these day-time callers provided an opportunity to both see and hear the big event.

Like all frogs, toads amplify their call via an inflated throat sac (see below). The throat is distended by a few breaths just before the sound is issued and the trilling noise is produced by multiple passes of air over the vocal chords (watch the video here). During the actual calling sequence, which can last up to 20 seconds, the critter appears to be motionless – the throat sac and sides quivering only slightly.

The collective effect produced by a load of loud male toads increases the overall impact of the effort. Individually, the toads are able to signal their sexual readiness, position, size, and – of course – their species identity by subtle variations in their calls. The females, which are mute in this affair, answer these advertisement calls by seductively approaching the callers and allowing them to “prove their prowess.” The end result of all this will be a string of eggs several dozen feet long containing up to 15,000 eggs.

I was giving a nature presentation to a family group on the day after my rude awakening (which was probably about the time the guilty mailbox killer was getting over his headache) when I brought up the subject of spring amphibians. During the ensuing question period, one gal posed a question. “I just started hearing a loud noise a few nights ago,” she stated, “I think is might be a bunch of  insects -’cause somebody told me that there was some kinda new insect out there that is really loud. Do you know what it could be?” After a short give and take, I was able to tell her that she was hearing the sonorous voice talents of the lowly toad. 

It seems that these creatures were really painting the town this past weekend, along with at least one errant human.

April 25, 2009

Living Tiddly Winks

Filed under: Uncategorized — wykes @ 12:54 pm

Nature does not exist soley for our entertainment, but this component should not be overlooked. I’m pretty sure that animals get their chuckles out of watching us. As an example of this, I offer the Red Squirrel that keeps stuffing walnuts into our car’s blower fan. He perches in the maple tree just outside the door and waits for us start the thing up and produce the horrible whining sound resulting from this treatment. The squirrel laughs and then runs away.  I believe that the walnut trees are in on this gag as well, but they aren’t speaking.

Therefore, I think it’s o.k. to get a little entertainment at the expense of another creature – as long as the creature isn’t harmed in the process. So, when I discovered a cluster of Click Beetles in my woodpile (see above and here) I immediately put one of them to work. Click Beetles aren’t called that for nothin’. These entertaining little insects have the ability to explosively flip themselves over when placed on their backs. There are hundreds of species, members of a group known as the Elater beetles, and all have this ability.  Before I go any further, take a peek at this video (flipp’n clicker ) and be entertained. No beetles were harmed in the making this video – at least physically!

There is more to this ability than meets the eye or the ear for that matter (they make an audible click when performing this manuever). These beetles possess a peg that extends out from the the first section of their thorax(located between the first two legs as seen here). Normally, this peg is held safely within a furrow in the adjacent thoracic section. When desired, the beetle arches back, pulls the peg out and catches it’s tip on a knob at the head of the furrow pit. Muscles pulling down on this peg create tremendous tension and causes it to suddenly snap downward. The force of this action propels the beetle 8-10 inches into the air like a living tiddly wink. It flies through the atmosphere and, more often than not, lands right side up.

This skill is not just for flipping over, however. When you grab onto Click Beetles they begin to click like small maniacs. Because the creatures are very smooth and seed-shaped, they are able to snap their way out in short order. Each percussive snap vibrates through the hard shelled body and loosens the attackers grip. They are very difficult for predators to pin down.

Predator, or irritating human, avoidance is probably the primary reason for this clicking ability. They can actually flip over without launching themselves, but this is not always reported. One web site commentary even goes so far as to say that a click beetle literally “cannot right itself by rolling on it’s short legs.” While I was putting my beetle through the moves, it managed to turn itself over several times by simply rolling over.

In retrospect, I guess I can be justly accused of promoting this “click or die” idea, however. The simple roll-over portions of the movie clip were, of course, edited out because they weren’t that entertaining. Like all entertainers my beetle simply refused to perform at one point. After a half dozen click and flip sequences, it played possum. Antennas folded and legs tucked, the beast remained comfortably on it’s back as if to remind me that it was not a tiddly wink toy. The ploy worked. I became bored and released it from it’s contractual commitments.

April 22, 2009

Big Rusty Birds

Filed under: Uncategorized — wykes @ 9:27 pm

Standing 4-5 feet tall, and weighing in at 9 1/2- 12 pounds, Sandhill Cranes are Michigan’s largest bird. They are hard to ignore even when viewed from a great distance. They simply command attention when seen in close vicinity.  I was so commanded when I came across a pair of these stately birds at Kensington Metropark last week.  High atop a grassy knoll by the park office, the cranes were preening as I pulled up. Neither my presence nor the scattered downpours disturbed their concentration.

Sandhills, like all birds, spend a lot of time preening their feathers. Wild birds don’t usually engage in such behavior, however,  until they feel comfortable with their present surroundings – after all, bending over backwards and picking away at armpit dingleberries tends to detract from predator alertness. Perceiving that I was not a threat, my two Kensington birds went about their daily duty with a zen-like determination.  You can pick up on a few rules of feather care as you watch their antics (see here a movie of a preener in action ) .

Preening is all about keeping feathers tidy and oiled. A long beak and neck certainly makes things easier, but all birds are endowed with the proper anatomy to get the job done. The length of each feather is individually pulled through the open beak in order to literally zip it together – insuring that the barbels remain interlocked. You can see this “zipping” especially well when the long flight feathers are given the treatment.  Another regular part of the routine involves reaching back to tweak the oil gland located on the rump (see here). In this case, the bird drops his wings to expose the gland and pinches it between the tips of the bill. The exuded waterproofing fluid is then spread over the body feathers.

In a normal sequence, the procedure begins with the back – between the scapulars or shoulder feathers – then to the wing coverts, lower neck and breast.  The wings are extended to get at the “pit” feathers. When two preening birds stand side by side, each at a different stage of the process, the sight offers the appearance of a modern dance statue (see above).

A Tai Chi stretching session (see below) marked the end of the procedure and insured the prospect of proper balance and inner avian peace. Each bird eventually leaned forward, while balancing on one leg and holding both wings out at full spread, and proceeded to hold its other leg straight out. This ultimate stretch-out ended the whole affair. In all, the preening lasted about 15 minutes.

After all this preening stuff, you’d think that these Sandhill Cranes would be cleaner but they were, in fact, dirtier!  When cranes feed, they probe the ground with their bills (see here). They are omnivores which feed on small mammals and  invertebrates, but they spend most of their time pulling up plants. While doing so, they get quite a bit of mud on their bills and they make no effort to clean it off.  Sandhills deliberately rub this iron-rich mud into their feathers when preening and thus turn their normally gray plumage into a rich cinnamon brown shade. Since they can’t reach their own face or neck, these parts of the plumage remain pristinely gray and white.

The secondary purpose of preening, therefore,  is to stain their feathers with rusty soil. Some believe this behavior imparts a bit of camophlage which protects these birds when attending their nests and young, but this is not at all certain. Hey, maybe they like to get dirty!

Sandhill Cranes are known for their loud raucous calling and dancing – which, considering this discussion could be called dirty dancing. Their distinctive rattling “gar-oo -oo” carries a long way over the landscape. I was privy, however, to a lesser known species call as the pair ambled close to the car and crossed the road (see here). Cranes emit a low rolling purr in order to keep in contact with each other. I was able to pick up a short burst of that intimate purring, although it is audible only in the first few seconds of the recording (purring cranes).

So, I guess it’s safe to say that up close and personal these birds are simultaneously cuddly, artful, and somewhat filthy.

April 19, 2009

A Silent Explosion of Fleas

Filed under: Uncategorized — wykes @ 9:00 pm

Exploding buds and erupting flowers are natural spring “sounds.”  They are silent sounds, to be sure, but crucial to understanding the season. I suppose an opening tree bud would literally sound like an explosion to a microbe, but for the sake of this discussion it really doesn’t matter. No human explanation of the season is complete without the use of these descriptive pseudo sounds. Spring doesn’t just “show up”, it “arrives!”  I would like to add one more non-auditory spring sound to this slightly meaningless thought string.  A booming population of Water Fleas heralds in Spring just as “loudly” as the buds and blooms.

Water Fleas (see above) are mini aquatic crustaceans cursed with an unfortunate name. Because they are tiny and happen to swim around in a jerky style reminiscent of hopping fleas, they are commonly called “fleas.” They are actually members of a group known as the Cladocerans and are more related to crayfish and shrimp than to cat parasites. 

Populations of these creatures literally – or is it figuratively – explode in the springtime. Dormant winter eggs are called into action as the days lengthen and the temperatures warmen (I know that’s not a word, but it should be). Nearly every body of water, from stagnant pools to the open waters of the Great Lakes, suddenly harbor trillions of these eruptive little life forms. The boom subsides to a rumble by summer, but while it lasts their collective mass probably outweighs the collective weight of every other creature in the water – including the fish!  Water fleas are exceedingly important in their role as zooplankton in the aquatic food chain – so important, that without them the aquatic food chain would cease to work. Talk about a mouse that roars, eh?

One of our local species of cladoceran (sounds like one of the Star Trek aliens, doesn’t it?) is the Daphnia.  Looking at a Daphnia means looking at a little glass seed with an eyeball (see below). Relatively huge by micro standards, this type can be over 3 mm in length.  The head end is evident by the presence of a single eye which, in reality, is a collection of eyeballs compacted into a cluster. When viewed from above (see here) the solitary eye really stands out. Two specialized antennae stick out from just behind the head and they are employed  as swimmerets. The whole body is encased within a clear two part shell which opens along one edge.

Internally they have nothing to hide since they live in glass houses (and therefore don’t throw stones). A dark green central intestine is evident along with a set of flapping gill feet. The gills keep water circulating toward the mouth for a constant diet of one-celled plants. A powerful “jumping foot,” called a post abdominal claw, helps the creature move along underwater surfaces and to deliver winning goals during their occasional planktonic soccer games.  All of these features are visible in this short video clip (see here).

Perhaps the most obvious feature are the eggs carried in a brood patch along the back (see in this view and a detail view here). Every single individual has them because every single individual is a pregnant female. There are no males at this time of year. The eggs are parthenogenically produced – which is a fancy way to say that they develop without the benefit of male fertilization. I’m not quite sure how to say this, but the spring explosion of daphnia consists entirely of amazons. The eggs develop within the body and become fully fledged cladoceranets before they are released onto the world.

As the summer approaches, a few of the females will decide to produce a few males, you know, just for the heck of it.  They’ll have their little romantic get-togethers and then lay sexually produced resting eggs for the winter season. For now, however, it’s time for the girls to have a big p-a-a-a-r-t-a-y while making their own kids and eating algae until they get sick. True, most of them will get eaten before the spring fling is over, but such is the way of explosive life.

April 16, 2009

Hey, Hey We’re the Monkeys

Filed under: Uncategorized — wykes @ 9:16 pm

It would be a logical assumption, based on the name alone, to deduce that Fairy Shrimp are extremely delicate in nature. All shrimp (apart from the oxymoronic jumbo type) are little and fairies are gossamer fleeting sprites. Any creature bearing these combined names must have the constitution of frost on a warming day. Right? Not right. In their relative space and time, Fairy Shrimp are titanic and as tough as nails. The very fact that they exist is a testament to this latter fact.

Every spring, when melt and rain water temporarily fills woodland depressions, these vernal pools are instantly populated by a whole fleet of micro-crustaceans. These life forms spring into spontaneous existence as if popping out of the ether itself. When the pools dry up later in the season, the residents vanish as the spots become bone dry. Eastern Fairy Shrimp, crustaceans in a group known as the Branchiopods, are actually among the largest members of this fleet. They are barely over an inch in length, yet are behemoths in relation to the other micro-crustaceans about them.   

True to their name, however, Fairy Shrimp are sporadic (just like Tinkerbell) and you never know whether they’ll put in an appearance from spring to spring. Because they seem to come and go like magic, they are given the Fairy desigantion. There are over 200 species world-wide, but the most common in our neck of the woods is the Eastern variety. I recently encountered some of these facinating spring animals in a vernal pond at Crosswinds Marsh and scooped some up for examination.

I’m really not sure if they were in that pool last year but this year I looked for them and was rewarded for the effort. When free swimming (see title picture) they travel about at an even, but slow, rate of speed and they do so while upside-down. Their slender shape, constantly flapping swimmerets, and bulging red eyes (see here) are their most apparent feature when in this pose. In hand (see below), they appear almost like salmon fry. The pink coloration combined with a definite “tail” and a dark intestinal line running down their back certainly enhances this fishy look.  They are, never-the-less,  crustaceans and so exhibit the segmentation typical of that group. 

The head is made up of two segments where the antennae, eyes and large mandibles originate. The thorax consists of 11 segments each equipped with a pair of multilobed swimmerets and the long segmented “tail” ends in a two pronged appendage (see below). In practice, the swimmerets are responsible for generating a flow of water that brings bacteria, algae, detritus, and protozoans up to the mouth. They eat as they go, so to speak.

You can tell the females from the males since males have larger antennae and the females carry egg cases at the base of their thorax.  Fairy Shrimp are rather fragile as adults, but their eggs are not. The first generation of eggs, those laid over the first month, are thin-shelled. These are produced, laid, and hatched in short order. The second generation, those laid just before the pools dry up, are thick-skinned and drought resistant. After the last drop of water evaporates and the bodies of the adults are rendered into dust, these second generation eggs remain in the soil.

Over a normal cycle of seasons, the eggs will remain dormant for 6-8 months. They hatch out, like magic, when re-immersed in water the following spring. Given a set of abnormal circumstances, these eggs can remain dry and viable for as long as 15 years or more! Now, that’s tough.  Because of this, the eggs – which are actually cysts with fully developed embryos inside – are better considered as sleeping shrimp capsules. Or, better yet, as “instant life crystals” that have the potential to become “Instant Pets.”

As “instant life crystals” Fairy Shrimp eggs are still shipped around the world as Sea Monkey eggs. Yes, you’ve probably seen those ads that used to be on the back of comic books that showed a happy little family of naked pink monkeys swimming happily about their fish bowl kingdom. Some of you may even have ordered the little castle set-up that went with the mail-order set.  All of you were no doubt disappointed when the things that hatched out bore absolutely no resemblance to primates or anything remotely cute. 

Today, you can still order these little miracles from the official Sea-Monkey web site (no, I’m not kidding) but you really don’t need to pay for the experience. Free Sea-Monkeys are currently reigning over a spring pool near you.

April 13, 2009

Of Beaver Bugs & Woody Notes

Filed under: Uncategorized — wykes @ 8:35 pm

In the last blog entry, “The Master of Castor,” I ended things just as we were staring at the b-hole of a beaver.  This time, I’ll start there because it’s not a bad place to be. You see, apart from affairs of the  fur and that marvelous tail, the castor glands of the beaver are valid subjects in their own right. These paired glands, which produce what is known commercially as castoreum,  exit out of the beaver’s body at this point so the place can’t be avoided.

I won’t show you what the glands look like once they have been taken out, but if you can imagine a pair of prune-sized punching bags linked by a  flat leather strap you will have the basic idea. When a beaver is skinned, the glands are normally taken out and dried.  Most trappers will use the stuff as a lure, but there is another commercial use which brings these structures into the company of some pretty high society.

O.K., if you want to be anal about it, the castor glands are not really glands in the true biological sense of the word, but when hovering over the anus of a beaver one really doesn’t need to be anal does one? We can call them glands and the world will be alright.   In some circles they are called “beaver pods” as a way to make them sound fruity or non-anal, I guess. Whatever you call them, these structures exude a yellowish paste that smells like….well, a smell that is hard to describe.

 A freshly trapped beaver actually smells quite good – the slightly sweet castor oil smell hovering about the creature like an aftershave. In life, the beaver smears it about in order to mark territorial boundaries and consequently it’s fur becomes saturated with it. One German chemist classified the smell as “sharp and burning with a creosote or tar-like note, reminiscent of the glowing odor emanating from birch tar or Russian leather.”  Now, that really clears things up doesn’t it? Personally, I think it smells like bad Cinnamon. There is plenty of room for both of us to be right.

The oil is actually a chemical stew packed with over 24 identifiable compounds.  Most of these chemicals are Phenolic compounds and some “rather exotic nitrogen containing compounds,” but salicylic acid derivatives and cinnamic acid are also part of the brew. Cinnamic acid, as you might suspect, is a major component of Cinnamon! Why, you might ask, is so much known about this stuff? Castoreum has long been a major ingredient used by the perfume industry.

Only the highest quality perfumes use real castoreum oil in their mix, but many carry on the tradition by using a synthetic version. The original beaver castoreum were dried and aged for up to five years before they were used. Such classic perfumes as Emeraude, Coty Chanel, and Lancome Caractere are castor based. In the trade, these perfumes are classified as giving off leathery or woody notes, and I doubt you can get much more earthy than beaver musk.

Just when you think you’ve now heard it all, I have one more thing to throw at you. When examining the beaver which inspired all this enlightenment, I noticed a tiny creature walking all over the front paw (see here). I believed it to be a flea at first, but upon taking a closer look realized that I was in the presence of a Beaver Beetle. This extremely unique little insect (only 2 mm long) can only be found living on beavers. It essentially lives off of beaver dandruff and parasitic mites, so the relationship to it’s giant host is symbiotic and beneficial.

In the form of a simplified beetle without eyes or wings (see top view at beginning and underside view above), this flattened insect is fully adapted to crawling through dense fur. I found two of these creatures on this individual, but most beavers have many more beetles-in-residence. One study revealed 192 living on one animal alone.

So, Beavers have upon their back beaverbugs to ride ’em and upon their butts two beaver pods that smell quite indescribum.

April 10, 2009

The Master of Castor

Filed under: Uncategorized — wykes @ 5:09 pm

Don’t ask me why I ended up with a dead beaver. Let’s just say that I did and that it was legally obtained. I skinned it and processed it, as per fur trade tradition, but I also gave it a good visual once over before doing so.  I’d like to share some of this “once-overing” with you and – according to my own tradition – show you some things you probably didn’t really want to see. You can consider this your indoctrination into the “Beaver Club.” Now, stop snickering, this is a good thing.

Beavers are fascinating creatures that well deserve the centuries long human attention paid them. There is no telling of the history of Canada or of the Northeastern United States without mention of this fur bearer and it’s essential and political role in nation building (and destroying). Once upon a time you were considered a nobody unless you were a member of the Beaver Club.  High profile members of the fur trade such as James McGill or the Mackenzie clan were once members of the esteemed beaver club in Montreal (see medallion below and a club plate here). So, you see, the idea of gaining Beaver knowledge is not all that odd.

Beaver, more properly known as Castor canadensis, are becoming more common in Southeast Michigan – a place that they have not been for the better part of 150 years. Here in the Detroit River region these animals were literally located in the epi-center of the fur trade and were regionally trapped out long ago. Although common elsewhere, their re-appearance here has only slowly advanced over the past ten years or so.

 Getting a good close look at one of these giant rodents is time well spent. While I’ll spare you the whole body shot of the animal, the creature I examined was around 32 inches long and probably weighed in at about 20 pounds. Judged by normal beaver standards, this guy would be considered small. One hundred pound beavers are not unheard of and it is no wonder that they rank as the world’s second largest rodent (behind the Capybara).

The tail is the one single beaver feature that everyone seems to know about. I mean, you can ask the average pre-schooler to draw a beaver, or ask them to describe the beaver’s tail, and they’ll tell you that it is flat with “checker” marks on it. The above average pre-schooler will go on about how the beaver uses this scaly appendage for swimming and spreading mud on it’s darn (they shouldn’t say dam). The obnoxiously brilliant pre-schooler will tell you how the beaver will slap the water with its tail as a danger signal and that the early fur trappers considered this part of the animal as a delicacy.  In order to bring us all up to the level of a pre-schooler, I present to you the tail in question (see below). 

The large paddle-like tail is indeed flat and “checkered.” About 1/2 inch thick (see here), the skin portion of this particular tail was about  8 inches long by 4 inches in breadth. The musculature extends into the body and much of the beaver’s rump beyond the hips is actually fur-covered tail. An irregular set of scales cover the surface (see detail shot in beginning photo) and a few sparse hairs stick out from under the overlapping edges. This is one of nature’s better tails!

 I didn’t want to correct the above-average pre-schooler quoted above, but the beaver’s magnificent tail is actually used more as a rudder than a swimming flap. Huge webbed hind feet (see below) are responsible for propelling the beast through the water when swimming. The small front feet are held tight to the chest while swimming, but the back ones expand out to near human palm size when fully extended (see here). Incredibly, the second toe on each back foot  is modified – the hard part of the nail is split into a flattened upper portion and a perpendicular bottom portion(see here). The purpose for this toenail is for fur combing and spreading water-repellent oils.

 As a cousin of the muskrat, the beaver shares many traits with it’s diminutive relative. A dense woolly underfur, beneath the tawny layer of oily guard hairs (see here), keeps Castor and his little cousin dry and warm in their watery habitat. Both species have stout golden incisors. While the beaver’s massive chisels are meant to chip away at wood and bark, the muskrat’s slender chippers are fit only for “felling” tender cat-tails. The lips on both species can close tightly behind the incisors to create a water tight seal (see here) when chewing underwater. Both water mammals have short ears (see “hear”) and nostrils that can be closed off when diving. A final point of similarity between the two is that both have very active musk glands. The beaver definitely takes this part of his being to the extreme, however.

There are two major scent glands on the beaver – anal glands and castor glands. Both the males and the females have them, and the two are difficult to tell apart unless a female is in nursing condition. Both sets of glands open into the animal’s cloaca (see here). Sorry, I had to show you this, but it was necessary. There are two external “nipples” that connect to the anal glands and two internal Castor gland ducts that open up into the b-hole (yes, you read that correctly). The anal gland fluids are used to mark territory and the castor glands to provide “personal information.”

Sensing that I have probably brought you to the brink of your normal sensibilities, I’ll give you a break from this beaver talk and stop for now. I warn you, however, that I’ll be back in a few days with some serious Castor oil chat and a good close look at an insect that only lives on the backs of beavers! Stay tuned.

April 6, 2009

Seeing Red Hare and There

Filed under: Uncategorized — wykes @ 4:02 pm

As I am writing this installment, I’m looking out over the computer screen and out through the front window. There is a gentle snowfall descending from the sky. Last night we got a few inches of the heavy white stuff  and it’s not showing any signs of letting up as the day gets older. It is a bit mind-numbing to see that it’s April 6 according to the inside ‘fridge calander but only March 6 according to the real visual record. Although there is nothing truly shocking going on here, the weather talk of the day will be of the “can you believe it” nature. This type of weather is par for the course – it’s just that we are the ones with the short term memories.  In a way this is good, because it creates in us a “newness” of being in a place where every day is different from the next. Dogs think this way, so why can’t we?

I bring this memory stuff up, of course, because I want to try your memory for just a moment. I’d like to cover a few subjects that I’ve touched on before. My intent is not to numb your senses, but simply to get you to “fetch” your senses back.

The picture of the Red-winged Blackbird at the head of this piece is brand new, but the subject is brand old. These stunning black and red dynamos are hard to ignore this time of year. Every time they belt out an “Oaka-leee-a” chorus is cause for me to stop and admire the scene. Now, I haven’t forgotten that I’ve called this to your attention on more than one prior occasion but I do so only because I think it’s worth it.  There is something new here as well.

Male Red-winged Blackbirds have been facing off since mid February. They have been actively staking out wetland territories in anticipation of the day when the females come home (here’s a female from last year). Well, the new “news” is that the girls have finally arrived at the Erie shore! I saw my first one on Saturday and yesterday the marsh world was transformed with the beguiling charms of dozens of females. Needless to say, the male birds are well aware of what’s going on and they are pumped.

All the guys are going about their business with a renewed vigor. Their calling rates have increased along with the intensity of their displays. The male bird pictured above is completing his so-called  “song spread” display in which the Okalee vocalization is accompanied by a flaring of the wings and tail and a raising of those red epaulets. That shade of red, called Phoenician Red by the way,  is so-termed because of it’s resemblance to the red shellfish dyestuff once traded to the Greeks by the Phonys.  In-between these typical displays, however, the males are also doing a lot of strutting. This behaviour is often overlooked because it is performed in silence.

A strutting blackbird exhibits all the pomposity of a third-world general reviewing his troops (see the photos below). Head up and beak pointed skyward, this general is pictured as he patrolled his section of the boardwalk at Lake Erie Metropark. Though his kingdom is but a small piece of wet ground, he guards it as if it were a palace placed upon a lofty mountain (see a movie here). Unlike puppet generals, these birds have the ability to hide their scarlet epaulets if they so choose. Through a series of controlled skin muscle moves – similar to those which create goosebumps in humans – the males actually raise up their epaulets above the covering layer of black feathers so that they are more than obvious. So, even in the strutting pose, the red shoulder is deliberately on exhibit. After the breeding season, these shoulder pads will be covered for the most part.

Red-wing Blackbirds are polygynous, which means they keep a harem of multiple females. The males have to actively defend a territory of 150 to 2,000 meters or more in order to insure proper nesting conditions for thier assembled mates. Average males have 5 females in their families while super males have been known to collect 15 or more! In practise, even though the females are not all true to their mates and will occassionally slip away for some action with the mailman, this behavior provides a pretty good form of gene insurance.

The other old subject that I’d like to bring up again has to do with the frisky behavior of spring Cottontail Rabbits. Not that they really need to, but rabbits perform a sort of pre-mating dance in order to get their hormones going. The routine consists of a series of playful face-offs, dashes, paw slapping, and some vertical jumps. Male rabbits will join in vicious kickboxing routines, but bunnies of the opposite sex become downright giddy with each other.

On the last day of March – the real March – I caught a couple of rabbits so engaged in the back yard (see movie here). While the Red-wing performance has a well choreographed sound track, the bunny dance is a silent routine. I decided to give the short sequence a soundtrack, so be forewarned. Turn the sound all the way down if you want your experience to be a strictly scientific observation session, but keep it up if you want to catch a silly thought and forget this crummy weather for a moment. Fetch!

April 3, 2009

Sight Unseen

Filed under: Uncategorized — wykes @ 4:39 pm

Two more spring amphibians have come to my attention recently. Although I knew both where “there” I never really got a chance to see either one, so this discussion involves a pair of sights unseen. The first,  being a cluster of loud-mouthed Wood Frogs, announced themselves with a cacophany of chuckles while the second, a Smallmouth Salamander, left a mute cluster of eggs as evidence.  Both species make use of ephemeral spring woodland pools for breeding purposes and both can be difficult to “see.”

Among the spring heralding frogs, the Wood Frog is among the earliest, although it is usually trumped vocally by the Peepers and Chorus Frogs. As a species, they have the northen most distribution of any amphibian and can be found north of the Arctic Circle. Woodies, as you might expect given their name, are basically woodland creatures that spend most of their life as a silent residents of the leaf litter world. When these secretive frogs approach temporary pools in the spring to breed, they let it all hang out – so to speak. If they were people, you’d say that they let their hair down, but since frog fur is about as fine as you can get, that would not be a good analogy.

In the flesh, these golden brown frogs are about 2 inches long and are endowed with very distinctive face masks – often referred to as a robber’s masks (see here).  In the aural arena, Wood Frogs are champion quackers. Their croaks come out as “chucking” notes sounding more like expresso hyped ducks than a frogs (Listen here – In this sound segment you’ll notice that a gang of creeking Chorus Frogs are also participating in the battle of the bands).

I recorded these calls in a flooded woodlot in Oakland County. The creatures were out in the deeper water and quite out of my reach – being sans hip waders at the time. Had I of waded out to the center stage, where the action was, I would have been able to see the callers themselves and their gelatinous egg masses. All the females tend to lay their eggs into one large communal egg mat with each one contributing over a 1,ooo eggs a piece.

While I can’t show you the Wood Frog eggs, I can show you some Smallmouth Salamander eggs. These precious packets were  laid in a woodlot pool in southern Wayne County (see title picture). The salamanders that laid them were long gone by the time the eggs were collected. Prompted by the first warm rain of late winter, these blue-speckled amphibians (see here) migrate to their ancestral pools to breed – answering the same instinctive call that beckoned the Chorus & Wood Frogs.

Unlike the frogs, however, salamanders are silent breeders. Oh, they get frisky alright, but their manner of breeding consists of a pantomimed dance in which the male lures the female over their sperm packets. Once fertilized, the females drape small clusters of jelly eggs (masses of 3-30 eggs) onto submerged sticks and stems. The whole egg-laying thing is over in a matter of a few nights, after which the adults slink back onto land and vanish into the leaf litter.

The pictured eggs are “well along.” As you can see, the embryos are clearly visible inside their 1/2 inch jelly spheres. When put into the proper light, the multi-layered structure of the eggs becomes evident (see below). There are at least three membranous capsules, with the inner two visible as a set of clear double lines,  encapsulating the developing salamanders inside. The embryos themselves appear to be at least a few weeks into their growth. Each has three pairs of external gills, a pair of so-called “balancers” sticking out from each cheek, a well developed tail fin, and a pair of stubby front legs. Every now and then, they will do a loop-de-loop inside their capsule as if testing out their swimming abilities, but for now they wait for the big moment when they will break out into the big world (any day now based on their stage of development).

We’ll get back to these little smallmouths at a later date in order to track their growth, but there is one more egg feature I’d like to point out  before we call this discussion over. You may have noticed that the eggs, although mostly consisting of clear gelatine, appear to be speckled or greenish.  These spots are actually evidence of a species of algae that grows within the gel. Eventually the entire cluster will take on a bright green hue due to the growth of these tiny plants.  The algae is question, called Oophilia amblystomalis, is only found on amphibian eggs. It is believed that the algae not only removes excess ammonia and nitrogen from the eggs, but also creates an oxygen rich environs for the larval salamanders.

A beneficial algae in symbiosis with a minimally-mouthed salamander? I’ll wager that you never saw that one coming!

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