Naturespeak A naturalist's view of the world

June 28, 2009

Wuz You Ever Stung by a Boy Bee?

Filed under: Uncategorized — wykes @ 9:14 pm

 

The traffic was light and there were only a few couples walking down the sidewalk, but downtown Dundee was swarming with activity last Friday afternoon. Issuing out from a crack between brick buildings, a swarm of honeybees was engaged in a flight of fancy. A large number of bees milled about the corner space where two buildings came together about two stories up (see below). An equivalent number were flying around and their wings were catching the low angled sun peeking over the roof line. It wasn’t immediately apparent what was going on – the action looked very much like that normally seen at the entrance to a hive. It was worth investigating.

 There was a single dead honeybee laying on the shaded sidewalk beneath the hub-bub. It was a worker bee whose time was up. She was probably thrown from the hive after serving her terms of labor. I picked the spent creature up and held her in my palm (see above). Admittedly, the first thought that came to my mind was Walter Brennan’s oft repeated line from the 1944 Bogie and Bacall movie called “To Have and Have Not.” Brennan’s character Eddie would ask “wuz you ever stung by a dead bee?”  He claimed that he was. I probed the lifeless form in my hand to make sure it wuz…er, I mean…was… dead and felt assured that it was no longer in stinging mode. Worker bees are the life force of the colony who gather nectar, tend to the young, and tend to the queen. They are equipped with sacrificial stingers which they employ when defence of the hive is required.  All these functions cease to be functional after death, however.

The next bee I found proved to be much more interesting because it was very much alive. It was a drone – a male bee whose sole purpose in the hive is to mate with the virgin queens. Drones are quite a bit larger and hairier than the workers. They are easily identified by their large black eyes which touch in the middle of the head in the manner of a dragonfly.  This is a bee which can be handled safely because it is sting-less, so placing this one on my finger for a close up was not an act of courage (see below). When closely examined, the drone looks more like a fuzzy fly than a honeybee (see here). 

 The presence of this male bee caused me to re-examine the colony above and I soon realized that most of the swarm actually consisted of drones (see here). This fact, combined with the fact that most of them were flying about, makes me believe that I was witness to a mating swarm. Drones become prevalent in the late spring and early summer when the existing queen lays unfertilized eggs. These eggs develop into the male drones (so, drones have no fathers but do have grandfathers!). A host of newly emerged virgin queens begin to emerge about the same time. 

 The drones begin to fly out every afternoon and congregate into specific aerial locations, usually 10-40 meters high, where they hope to rendezvous and mate with the fresh new queens. In the incredibly precise lingo of bee-keeping terminology these locations are called DCA’s for Drone Congregation Areas. 

Each queen mates multiple times before finally flying off to establish a new colony. What happens to the drones? Well, the lucky ones die soon after mating. The luckless majority return to the hive and bum around. Since they are unable to feed themselves and do not gather nectar or pollen, they have to be fed by the workers. They are all finally kicked out of the hive and are left to starve at the end of the summer.  There are no boys around the hive when it goes into overwintering mode.

My drone appeared confused and made no attempt to re-join his comrades on the launching pad above. I thought about taking the thing around town and asking people “Wuz you ever stung by a boy bee?” but I didn’t. I decided that Dundee wuz not ready for that kind of thing, nor wuz I.

June 25, 2009

A Super Snapper

Filed under: Uncategorized — wykes @ 3:06 pm

 

Many years ago, I recall seeing a huge snapping turtle snared in a fence.  The creature had been caught in the rising flood waters of the rain-swollen Huron River and the flow pinned him up against the wire mesh. After the water receded, the entangled behemoth remained suspended above the ground. It was, to put it mildly, rather upset when it was pulled off. I, on the other hand, was delighted at the opportunity to see the beast. It was the largest one I had ever seen. Unfortunately, I didn’t get the chance to put a tape measure to it or to weight it, but was satisfied that it was at least a 40-50 pounder. The thing that most impressed me was the dimension of it’s paws – fully as large as a grizzly bear’s and equally equipped with similarly massive claws.

As the years pass, my description of that turtle inevitably grows. Now that I reflect, that fellow was probably “only” 35 pounds and the paws were more like those of a Black Bear and not a “Grizz.” I know it was over 25 pounds for almost certain, I think. Recently, I spotted another monster Snapper at Kensington Metropark which got me to thinking about that earlier individual (see above).  I’d say this monster eclipsed the earlier one – at least in my mind – and likely has a shell length of 18 inches. This time I have photo proof, but it does little good without size reference (if you’ve seen those pictures of Hogzilla, you know what I mean).  You can compare it with the lily pads, which are about 6 inches in diameter if you take a look at this video sequence (see here).

This turtle was prowling the lily pad shallows close to the Great Blue Heron rookery and it probably has bulked up over the past few years by feasting on fallen chicks. He had attained the age where the shell takes on the appearance of a large smooth boulder. The patches of clinging algae give it the ancient look of an ancient moss covered ruin. Because of this camouflage, it vanished into the muddy bottom when ever it stopped moving. Those massive bear claws are about the only part of the creature that was not covered with patchy green growth.  Even the thick neck , which extended out well beyond the leading edge of the shell, was encrusted with hair-like tufts.

I witnessed a brief encounter as this mega turtle came upon another large snapper in the vicinity. The second turtle was “big” (see here) but it was dwarfed by the larger one.  They stared each other down for the better part of five minutes until the smaller one broke for cover when the big one broke the stalemate and inched forward.

This brings me to the question of how big Common Snappers can really get. Often a snapper conversation gets confused with an Alligator Snapper conversation and figures like 300 pounds get bantered about. The Alligator Snapper, however,  is a southern turtle and doesn’t enter into the north country so we need to stick to figures like 8-35 pounds to cover an average Common Snapper. The current record weight for a wild caught turtle is close to 80 pounds ( a captive one one weighted in at 86 pounds!). Normally the shell length of a Common Snapper is recorded as being between 8 inches and 17 inches and the record length is 18.5 inches.

I’m not claiming any thing near record weight or shell length for my turtle. Fortunately, I never got the opportunity to measure it so I can present my case with a hefty dose of “could be”  underneath those ominous surface bubbles. Whatever the actual size, it was an impressive creature worthy of future exaggeration.

June 22, 2009

Mellow Yellow

Filed under: Uncategorized — wykes @ 8:35 pm

Yellow can be an infectious color. No, I don’t mean that in a negative sense.  It is a color that tends to like company and, if it lacks companionship, soon draws it in.  You could say that it spreads and affects the world around it. Take for example one of our yellow Frenchtown township fire hydrants. Given the fact that these structures often suffer the from the effects of dog pee,  it is an appropriate shade for a hydrant – better than red, in fact. I photographed the lonely hydrant (see above and here) along the edge of a field of green winter wheat. A large cluster of yellow plants are collected around it like moths to a porch light.

These plants, called Field Pennycress, are making something like an artistic statement. They are members of the mustard family who reserve their yellowness for their seed pods instead of their flowers.  It almost looks like they are attempting to hide the hydrant from the standard red brush of the traditionalists. Or, is the hydrant hiding from liquid-filled canines?

A lone Spatterdock  flower (see below) calls immediate notice to itself due to it’s yellowness. Better known as the Yellow Water Lily, this waxy plant bloom never fully opens. It exposes just enough of it’s inner sanctum to attract pollinators. As a yellow period in a paragraph of green, the effect is subtle but effective.

Towering above the understated spatterdocks, the cattails reserve early summer for thier yellow expression. The cattail flowering season lasts only for a week or so, but it is a grand yellow event when it occurs in mid-June. As the male flower spikes mature, they begin to shed buckets of powdery pollen to the wind (see below). Each spike looks as if it were dipped in bright powdered tempera paint.  The action of even a gentle breeze will cause the grains to disperse into the wind as puffy clouds of fertility. When thousands of cattails are shedding at the same time, the effect is magical.

Cattail pollen is only mildly allergenic, so it’s unlikely to make you sneeze. It is, in fact, often collected as a food source (called pu huang in Asian tongue) and mixed with wheat flour for baking. The grains are fairly heavy, as pollen goes, and most of them drop down to the water after a short ride on the breeze.

As the masses of cattail pollen collect on the wet surface, they begin to adhere to each other and form stringy mats which look like shredded silk (see below and here). Due to their four-parted micro-structure they inherently link together into linear shapes like so many buidling blocks. A cattail pollen mat is a piece of very temporary art. They form due to the gregarious nature of yellow, but the action of the wind & water soon pulls it apart.

The deep greens of mid summer will eventually win out over most of the natural yellows until they return in the autumn. The artificial hue of the hydrant, however, will continue to beckon territorial mutts throughout the summer.

June 19, 2009

The Pear is Everywhere

Filed under: Uncategorized — wykes @ 9:39 am

Quick Michiganders. Think of the last wild plant you would expect to encounter in the S.E. portion of our state. You might say the Rafflesia, the world’s largest flower whose odoriferous bloom smells like a decaying cow or perhaps the ancient Welwitchia which looks like a pile of yard waste. If you came up with either of these plants then chances are you will be very disappointed with my ultimate answer. Actually, I’m thinking something much less dramatic in this case. I’m talking pear here – prickly pear cactus to be exact.

As a natural resident of the western part of the state I am familiar with the prickly pads found in the sandy fields of Newaygo and in the sand dune country of Lake Michigan. As a transplanted resident of S.E. Michigan I am also aware of the cactus population just over the border in N.W. Ohio. As an ignorant traveler to the beaches of North Carolina I was delighted by the sight of numerous clusters of prickly pear scattered among the dune grasses (here’s one), but I was caught off guard by finding one of these plants in southern Wayne County.

In retrospect, I should have realized that the Prickly Pear is not just a desert plant it is an everywhere plant. There are over 50 species and they enjoy the most northerly (and easterly) distribution of any North American cactii. They even spread into eastern Ontario and British Columbia! Imagine that, a Canadian cactus. There are several types in this area, but the particular pincushion pad in question is called the Eastern Prickly Pear aka Opuntia homifusa.

The Eastern Prickly Pear cactus is not a pretty looking thing. It is, as you can see from my Wayne county example above, this one earns the nick-name of “Devil’s tongue.”  Like the devil his-self, they survive by staying low and lean. During the winter, all moisture is drawn from the fleshy pads and they take on the wrinkled appearance of a catcher’s glove. Summer finds them re-hydrating, growing new pads, and flowering with bright yellow blooms. These pads are evenly covered with raised clusters called areoles- each areole armed with a few prominent spines and a tight cluster of reddish brown bristles.  One needn’t worry about the big thorns, it’s those nasty bristle spines that get you. I guess you could say that the devil is in those details.

Even during my brief encounter with this individual plant, I brushed up against it and received a few detached bristle spines as a reward. These tiny spines, called glochids, are nettle-like in persuasion and manage to work their way into your skin in quick order and create a rashy reaction. Interestingly enough, the parasitic young of our native clams are also called glochidia. This name refers to something that attaches on for an irritating ride. To be fair, the plant is only trying to defend itself against an army of herbivores.  At its core it is a succulent treat and is widely eaten by man and beast alike. The pear-like fruits are considered delicacies – once they are exorcised, of course.

We can go on pretending that the prickly pear as an oddity in our realm, but it really is nothing more than a fascinating part of the home team.

June 15, 2009

Craters of the Moon Fish

Filed under: Uncategorized — wykes @ 8:53 pm

Birds do not have the corner on the nest market. As a matter of fact, some fish rank right up there with the feathered tribe as nest makers. Members of the sunfish family, such as bass, bluegills and true sunfish, put quiet a bit of effort into making sure their nests are just right. Their egg-holding structures are at least on par with killdeers, terns, and gulls because both creatures work with a similar sandy substrate. The colorful little Pumpkinseed Sunfish is a prime example of his type – and yes, I did mean to say “his.”

As soon as the water temperatures creep into the upper 60’s F the male Pumpkinseeds seek out the shallow shoreline waters and begin to construct depressions in the sandy bottom.  They push away the overlaying sediment in order to expose the harder gravel layer beneath. By employing vigorous tail sweeps, a dimple-like crater of 4 – 16 inches  diameter is carefully constructed. Often the nests are built within a field of aquatic vegetation and their work is easy to spot against this verdant background (see here). More commonly, however, multiple male “Punks” get together to create a crater field resembling a lunar surface (see above). O.K., the moon isn’t covered with water, but if that comparison bothers you then you need to go somewhere else for a while.

The lunar reference is a valid one. Pumpkinseeds are technically known as Lepomis gibbosus which means “scaly gilled fish shaped like a full moon.” These decorative little fish are not actually full moons, but they are like one. Their nesting grounds are like lunar surfaces but they are not actually,… well…never mind.  The common name Pumpkinseed is probably more descriptive anyway, because I’ve never seen a full moon with fins! Then again, fish don’t come from pumpkins either. Let’s just stop thinking for a moment, shall we?

In truth, these fish don’t really look like either comparative entity – they are more peacock-like. A male in full breeding wear (see below) is a wonderfully colored fish with spots of orange, sky blue, black, yellow, and red. Distinctive radiating blue lines arc over the gill flaps and call attention to the jet black gill flaps which terminate in bold dashes of reddish orange. These gill decorations are crucial to their masculine duties.

Once the fish finishes with his scooping task, he then patiently waits over his nest (see below) and prepares to intercept passing females. The girls, attracted to the brightly garbed males, spend little time at any given nest site. They arrive out of nowhere, tip up at a 45 degree angle, and start laying eggs. The pair will get together for a second or two as the males release clouds of sperm to fertilize the tumbling eggs. Then, the whole thing is over just like that. The male kicks the female out (girls are from Venus, you know) and switches to bachelor parenting mode. He will accept a few more egg donations if offered, however, but the final buzz off remains the same.

For the next few days, the proud father aggressively guards his precious cargo and fans them until they hatch. Every curious by-passer is investigated and pushed away with a vigorous display involving  an impressive flaring of the gills. You can see a piece of this action in this short video clip (see here). I’ve slowed down the sequence in case you missed it the first time (you might also enjoy the super slow sound effects as well).

As a father, the Pumpkinseed dad is as dedicated as any of his avian counterparts. He’ll watch over his little tribe for as long as 11 days before finally letting them out into the big bad world. If a young fish wanders away, he’ll grab it in his mouth and shuttle it back to the safety of the nest space.

Perhaps the most remarkable thing about this whole male nesting/parenting thing is that the urge to eat small fish is turned off for a while. These finny males, contrary to the accepted norm that guys think with their stomachs, forego their natural instinct to snack. Even when one of the hatchlings is actually in his mouth, a male resists all temptation and eventually spits the potential meal out. You can imagine how embarrassing it would be, not to mention species-stupid, to accidentally eat one of your tiny children. After the breeding season, this restriction is lifted and woe unto the small child fish that returns to thank dad on Father’s Day.

June 12, 2009

Shedd’n to Red

Filed under: Uncategorized — wykes @ 8:53 pm

I have a love/hate relationship with my backyard Red Squirrels. Things were at their lowest point earlier in the year after these diminutive rodents destroyed my car’s air conditioning fan. Upon seeing the new brood of squirrelets this spring, however, my criticism meter shifted toward the positive side. I will never love these squirrels, but have to admit that seeing mom with one of her little ones provided a nice little natural moment (see above). It was at this point that I noticed that this female was still in the process of shedding her old winter coat and was shedd’n to summer red. You could clearly see patches of reddish orange shining through the coarser gray layer – especially on her shoulders.

The spring squirrel molt can begin anytime between late March and early July and it basically progresses from head to tail.  One study revealed that the sequence starts on the feet, then goes to the head, and moves down the body to the rump. The tail fur, oddly enough,  isn’t replaced until the autumn molt comes along in October.

All mammals have to go through an an annual molt in order to keep up with the changing seasons. This change normally involves a switchover from a long cold weather coat to a short warm weather covering along with a shift in fur color.  The Red Squirrel is an exception to this pattern. When they molt out of  thier winter grays they do not alter the density or length of their pelt, although they do make a color shift. Being small, the difference in heat retention is probably minimal. Larger mammals – at least the northern ones – have to go light in order to keep from sweating to death during the warm season.

One of those larger molting mammals, with whom I also share a love/hate affair, is the White-tailed Deer. This is an animal that undergoes a rather dramatic summer molt to a orange-red hue . I spotted a velvet buck (see above) earlier in the week that had already undergone his molt. This one was well into his antler growth cycle as well. Later on in the same day I spotted a doe feeding on waterlilies in the marsh shallows (see here). This female was in mid-molt and you could clearly see her old hair sluffing off to reveal a smooth orange layer beneath (see below).

Mammal molts are controlled by hormones which are, in turn, controlled by photo-period. The length of daylight, in other words, acts as a trigger to set off the chemical reactions necessary to start producing a new layer of fur. General health, diet, and temperature do have a slight effect as well. The hormonal cause and effect on White-tailed Deer results in a change from long to short hair. During the winter, the hairs are densely packed (over 2500 hairs per squre inch) and long (15-17 mm).  They are also hollow and underlain with a layer of woolly fur. The summer coat, initiated in May or early June, is actually denser than the winter garb ( 5,000 hairs per square inch) but is significantly shorter. Summer hairs are not hollow, so the body heat is quickly dissipated through the new crew cut.

I trust that the next time I spot this female, she will have attained her sleek red persona and will look, well, almost pretty. As long as she doesn’t make any attempt to store any walnuts in my car’s air conditioning fan, my “deer meter”  will drift away from disapproval for the time being.

June 9, 2009

Welcome to the Spawnorama

Filed under: Uncategorized — wykes @ 10:01 pm

This time of year is a great time to witness just how common the Common Carp can be. They have been quietly gathering into the weedy shallows from the big waters of Lake Erie for the better part of a month now. Huge groups of lusty males have been keeping company with gangs of plump females in anticipation of the “big event” that will take place there.  Although these imported fish are year-round residents, their presence goes largely undetected through most of the year. All it takes is a slight change of spring  temperature to bring this quiet army to the forefront.  Once that critical temperature is reached, nearly every little bay and marshy flat is converted into a boiling cauldron of giant fish.

The biological boiling point of marsh water is about 60 degree F., as it turns out.  The Lake Erie Metropark marsh reached this temperature last weekend and as a result, the normally quiet surface was rent asunder with carp spawning activity. During  the Spawnorama, due to the exertions of hundreds of amorous carp, the marsh literally appeared to boil (see above). 

The  basic spawning activity involves small clusters of 4 or 5 individuals consisting of  a female carp with multiple eager male escorts (see above and here).  Since the males are conspicuously smaller next to the roe-enhanced girth of their chosen females they are easily identified (see here), but they can just as easily be pinpointed by their “catching up” position in the cluster. The female swims about at a fairly brisk  pace and keeps just ahead of her pursuers. It is likely that this racing behaviour is a way for the female to insure the vitality of her suitors. Eventually, the group swims through a patch of submerged water plants and the female begins to shed her load of eggs. Triggered by her body movements, the males are prompted to release clouds of sperm into the water in the hope that they will be the legal fertilizer of at least a few thousand of her eggs. The effort breaks the surface and churns the water (see beginning picture) In the process of  jockeying for position, some over anxious males come entirely out of the water as they roll right over the top of the female (see below).

Perhaps the best way to appreciate the full impact of the carp spawnorama, is to watch this brief video (here). This event is full of sound and motion. The big show will repeat itself over the course of several days before dying down, but smaller groups will continue to spawn through the early summer until the water temperature reaches the upper 70’s or the females run out of eggs.

A female can lay from 100,000 to over 2 million tiny yellow eggs depending upon her size and age. It is little wonder that the genus name for the carp, Cyprinus, is a reference to the Cyprus home of Venus, the goddess of fertility. Each egg is about a millimeter in diameter. On it’s brief journey through the water, the sticky egg is fertilized and adheres onto a plant leaf  where it will hatch 4-5 days later.  The chances that any given larval fish will survive to spawning age is slight, but that is, of course, another story for another time.

June 5, 2009

This Ain’t No Bumbling Bee

Filed under: Uncategorized — wykes @ 10:23 pm

Even though the Carpenter Bee and the Bumble Bee look similar, there’s a world of difference between them. Take a good close look next time you see a big bumbling bee probing a flower and you may find yourself looking at a craftsmen. Carpenter Bees are large hairy yellow coated bees that can be identified by their shiny black abdomen (see above). Bumble Bees have fuzz covered black abdomens and therefore don’t give off a glimmer of reflected light. Both bees are common, but the Carpenter rarely gets the recognition it deserves.

You can afford to get a close look at a Carpenter. The females have a functional stinger, but are hesitant to put it to work. The males tend to act aggressively, but because they are sting-less they can’t back up their bravado!  If  the bee is nectaring at a flower and displays a patch of yellow pollen on it’s legs,( like the one shown below), it’s a non-aggressive female.  She will ignore you and allow you to watch as she busily gathers nectar and pollen, but she will not linger at any given flower.  Fine hairs on the hind legs form a pollen basket where the sticky yellow stuff can be collected and carried aloft. Her task is to gather an ample supply and quickly get it into temporary storage. If you have enough time in your day, it might be a rewarding task to follow one of these industrious gals home in order to see one of her spectacular carpentry creations.

Carpenter Bees store this pollen in carefully constructed tunnels for the purpose of raising a brood of young. These tunnels are chewed into solid wood and are easily identified by their perfectly round 1/2 inch entrances (see below). The holes are machine perfect as a matter of fact – the only natural giveaway are the slightly beveled edges. These bees are solitary in nature, but they tend to group together into loose knit “colonies” because of their shared individual preferences for a good piece of wood. This means that you’ll see several holes in a relatively small area on a select piece of wooden real estate. In the view of a Carpenter,  a perfect piece of home wood is an un-painted section of an eave, deck, or picnic table.

Deep inside, the central tunnels branch off  into several side galleries. Each gallery is divided into six or eight apartments (see below and here) which become the brood chambers. Once a female has constructed a gallery section, she begins to provision it with baby food. Balls of pollen are packed together witha dose of nectar glue to form loaves of “bee bread.”  A single egg is laid on the pollen ball and the chamber is then sealed off with a wall of chewed wood. The adjacent chambers are likewise provisioned and sealed with particle board dividers until the entire gallery is full. When the larvae hatch, they will feast on the nutritious mix, pupate and then chew their way to freedom.

The whole cycle of Carpenter Bee life takes one year. The newly emerged bees come out in August and they eventually return to spend the winter back in their old nursery galleries. Emerging the next spring, they feed and mate and come to the end of their B-line in July. Up until now, I’ve only mentioned the females in this scenario but it’s time to give the males their due. It is thier job to mate with the females and they spend an inordinate amount of time patrolling the gallery sites looking for some Bee-hind, if you know what I mean.

Patrolling male Carpenter Bees can be intimidating. Because they go after anything that moves, they frequently buzz human heads and send their owners packing – regardless of their stingless nature. The boys are striving to intercept the females and will investigate anything that remotely resembles one. Rival males are also kept at bay in the process. Because of the fact that they bore into wood and annoy passerbys, these big brash bees are considered pests by some, but their pollinating services more than make up for these percieved faults. 

As a final treat, I bring you a short video clip of a male Carpenter wooing a female.  Take a look here and you’ll see a spirited male hovering about a rather disinterested female. While she preens non-chalantly, he performs some dazzling wing moves in an attempt to get her feminine attentions. Although she walks off and appears to give our suitor the cold shoulder, the two did hook up immediately after this sequence.

There is one small detail that I’d like to point out in this video, however.  After the female takes off, the befuddled male is momentarily distracted by a nearby bird dropping and he approaches it as if it were the female! This is probably the closest this type of bee becomes to being a Bumble(ing) Bee. In his defense, he quickly realized his mistake and then took off after his true love, but I can only imagine the conversation that followed when she asked him what took him so long to catch up. “Oh, I temporarily mistook you for a piece of bird crap, honey,” would be the likely reply. Given that response, it is a small miracle that she didn’t sting him to death.

June 2, 2009

The Belly of a Blue-footed Bird

Filed under: Uncategorized — wykes @ 3:47 pm

Unless you are a bird bander, a chicken farmer, or just a farmer with chickens you’ve probably never seen a brood patch. This is the featherless area on a nesting bird’s belly which comes in contact with, and incubates, the eggs. In order to see it, you have to have a breeding bird on it’s back and willing to sit still. Without this crucial  little patch of nakedness there would be no baby birds (well, there would be a few, since not all birds have brood patches, but certainly not as many). So, when I came upon a freshly dead female Baltimore Oriole that had an obvious brood patch I was compelled to share it with you. Here was a breeding bird that was on it’s back and sitting still – very still. A dead bird is never a pretty sight but it is a pretty good opportunity to learn a few things.

Let’s face it, female orioles cannot compete against their dashing orange and black mates for eyeball time. That’s the way it is in the avian world.  The females of this species do have a subtle beauty all their own (see here).  Although possessed with a significant splash of orange against an otherwise greenish yellow body, blue is their color of note . The sky blue beak and perching feet (see above) are not features that show from afar, but do stand out upon close inspection.  Looks definitely take a back seat to talent, however, when one considers how these birds construct their intricately woven basket nests (see here). This spring I saw one of these nests in the process of construction (see here). The female was visible inside the still transluscent bag as she added another strand of plant fiber to the weave.

Keeping to the bird at hand, the delicate female cradled in my palm displayed a raised patch of feathers surrounding a slit-like opening over the belly (see here).  Blowing away these feathers revealed an open patch of brooding skin beneath (see below). This arrangement is very similar to the marsupial “pouch” found on the opossum. In life, the bird can close up the gap by controlling the bordering feathers just as the ‘possum shuts in her young like a coin purse. 

The bird doesn’t carry young in her fold but instead uses the bare skin to incubate her clutch of eggs. She opens the fold, settles onto the eggs,  and makes direct body contact with them – skin to egg. In this way the bird can efficiently transfer her body heat (around 100 degrees F) directly to the developing embryo inside. In the case of the oriole, the eggs are cream colored with splatters of black and they are laid in clutches of four. Constant egg turning by the female insures complete coverage and eventually the circulation of the embryo distributes the nurturing heat. This heat transfer also benefits the hatchlings as the nesting process continues on it’s normal course.

Brood patches – a.k.a. incubation patches -develop from a normally naked portion of the central belly called the apterium. This is one of those million dollar words that simply means “featherless,” and it is good to know that bird feathers grow in tracts and do not cover the entire body. Yes, all birds have narrow naked parts which are visible as the smooth skin between the goosebumps on your chicken meal! As the nesting season approaches, hormones direct the body to shed the feathers around the belly apterium. Some birds, such as ducks, have to pluck these feathers out, but our oriole need only watch as the downy feathers sluff off. Eventually, additional blood vessels begin to engorge the flesh and thicken the skin to the point where it looks like a wrinkled pad. After the season, the process reverses itself and the bird resumes a state of minimal nudity.

In some birds, both the male and the female develop brood patches, but in the oriole world only the females incubate the eggs and develop brood patches.  This brings up the question surrounding this dead female and the fate of her young. Since she is the sole incubator, her passing would mean the end of the line for her clutch. But there are clear indications that she had not yet laid any eggs. In the early stages of brood patch development, before laying and incubation actually begins, the thin skin retains the transluscent look as seen on this bird.  The skin becomes thickened and opaque only when the egg warming begins.  This oriole’s death, therefore, probably resulted only in an empty nest and, of course, a teachable moment.

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