Naturespeak A naturalist's view of the world

February 24, 2013

Black Ducks on Thin Ice

Filed under: Uncategorized — wykes @ 8:12 pm

The wintery Detroit River flowing around Grosse Ile on a late February day was a mixed bag of scenery. A rim of shelf ice clung to the shoreline of empty docks and boathouses. Out in the channel the river moved along at a leisurely pace – open steely blue-gray water with occasional lazy cakes of ice floating by. On the Canadian side, especially in the vicinity of tree covered Stony Island, the river was full of waterfowl.

  

Hundreds of birds rode the small waves generated by the cold northern wind. Most were divers out in the deeper water of the main channel. Because they all fed in a similar style, Canvasbacks, Red-heads and a few Ring-necked Ducks formed the largest clusters (rafts). They bobbed up and down as they dove to seek water celery tubers, pill clams, and the like. Smaller congregations of dabblers hugged the near ice side of the current. Most of them were roosting on the thin ice. All were big-rumped dark birds profiled against a white background and all had the same profile when viewed from the road (this is the only way one can view ducks on Grosse Ile if one is not a resident).

Most of the birds were Mallards, but a few were not.  As a big-rumped island visitor myself, I did notice a number of darker birds in the ice flock.  These birds, appropriately called Black Ducks, stood out from a distance.  One pair remained on the ice long enough for me to capture their images and unwittingly allowed me to ponder the subject of Black Ducks. This ultimately permitted me to inflict my ponderings upon you, dear reader. Black Ducks are not rare but they are uncommon enough to warrant a second look. First of all there is the issue of identification.

The male and female are nearly identical in appearance. Both sexes are very similar to female Mallards. Unlike female mallards, however, they have a chocolate brown body with a contrasting pale (coffee-with-cream color) neck and head. The colored portion of their wing, the speculum, is iridescent purple with a black border as opposed to the same feature on a female mallard which is iridescent blue with a white border. The bill on Black Ducks tends to be olive green while Mallards sport a yellowish bill. Finally, Black Ducks have distinctive deep red-orange feet (the species name rubripes means “ruddy-footed”). I would say that this is a dead give-away except that it is very noticeable on live birds as well (note joke here).

You can’t help but notice that my Grosse Ile fowl were pretty hefty (and lazy – note the pile of droppings deposited were they rested). They were extra diligent, however, and were immediately alerted by my distant presence. Both stood up, waddled away to the open water, and swam away with their escort of Mallards.

This was a definite “pair” of birds. Black Ducks form their pair bonds during the fall and winter migration. “Hey baby, want to take a trip with me?” is the apparent pick-up line in such situations. The willing females, thinking about a romantic tryst along the sunny Gulf States quickly agrees.  One can only imagine what a female who ends up wintering on the Detroit River might say to “Hey baby, let’s sit on the Detroit River ice and look fat.” That at least some of them say “yes” to this proposition is obvious in my Grosse Ile pair.

Since the early 1960’s, this species has declined in numbers. So you could say that my pictures are allegorical in that the species is on some thin ice. Part of the blame goes to habitat destruction and harvest related concerns, but there is more going on. Mallards are being blamed by some. Because the two species freely interbreed, there has been some air time given to the idea that Mallards are slowly diluting the gene pool and that is presented as a bad – or preventable – thing. Those nasty green-heads are mucking up the picture. I’m not sure that perception is entirely correct.

On an evolutionary scale, Black Ducks and Mallards are called “sibling species.” This means that they are very closely related to each other. Genetically there is very little difference between them and, in fact, they may not quite be totally separated from each other.  One well-informed study estimates, based on the mitochondrial DNA, that they separated only 430,000 years ago (sometime during the last Ice Age). That is a drop in the time bucket when considering species formation.

Mallards have a world-wide distribution where-as the Black Ducks are exclusively North American. The Blacks are out-numbered. There are a few traits, such as a slightly later nesting season, that serve to separate the two but behaviorally they are so similar that it is fairly easy for dark-headed drake Mallards to woo unsuspecting Black Duck females into parenthood.

As is true of so many events, we find ourselves in the current age observing what may be a totally natural process. Am I saying that Black Ducks may not survive the whole species independence thing and eventually find themselves back into the world Mallard fold? Am I saying that Black Ducks are still experimental? Yes, I am. So, take your time when looking at Black Ducks because they may not be here ten thousand years from now. Perhaps I am on thin ice in making this prediction, but none of you will be around to call me on it will you?

February 17, 2013

The Fascinating Mr. Fox

Filed under: Uncategorized — wykes @ 11:15 am

I carefully cradled the shriveled fish in my fingertips and held it so I could read the label secured to the specimen with a small loop of string through the lower lip. The handwriting was executed in old-style ink and at one time would have been bold and easy to read. Now it was faded and the nature of the inscription made it even harder to read because it was in the form of a collection number, binomial Latin designation and a place name. It read “1507”, “Trachidermus alvordii” and “Grosse Isle.” I should probably mention at this point that the specimen was a Mottled Sculpin barely two inches long and that it was also over 160 years old. To misquote a famous philosopher: “When 160 years old you reach, look as good you will not.”

The thing that led me to this particular specimen, and a few others like it, was my current “research” on the history of the Detroit River. In searching for offbeat, yet interesting, facets of the river’s history I was drawn to the story of a few relatively obscure fish that were originally described by a Philadelphia scientist with the impressive name of Edward Drinker Cope. The Mimic Shiner, Sand Shiner, Fathead Minnow, and Brook Silversides were first published as legitimate species in a paper about Michigan vertebrates in1865.

You may have noticed (or not) that whenever you see a scientific name, apart from being a genus name followed by a species name, that there is a name and a date in parenthesis following the heady Latin/Greek terminology. These post names stand out because they are familiar looking – you know, like the name of a neighbor (unless you live next to Constantine Rafinesque). In the case of the Mimic Shiner, for instance, the fancy name is Notropis volucellus (Cope 1865). This means that Mr. Edward Cope came up with the official description in 1865. The specimens used for such descriptions are preserved as so-called type specimens – the first of their kind, you could say. In other words, they are important regardless of how common the species itself is.

  Edward Drinker Cope

Now, please don’t go away yet. I don’t mean to bore you with the kind of thing that only science geeks get inflated about. There were several interesting things going on here. First of all, Cope himself is best known as a dinosaur hunter. He was part of the famous “Bone Wars” of the late 1800’s in which there was a flurry of fossil dino discoveries out west. That a dinosaur hunter would have concerned himself with fish is a fascinating thing within itself. But, there is another point of interest for a Michigander. In all cases the specimens used for these actual fish descriptions came from the Detroit River in the vicinity of Grosse Ile – my backdoor.

 

Cope did not venture to Michigan to collect these fish; instead he relied on collections made by other folks. This is where a Professor Manly Miles comes in. A Flint native – originally hailing from New York State – Miles became a professor of zoology and animal physiology at the State Agricultural College in Lansing (Michigan State University). He assembled a great collection of preserved animals at that institution and shared them with most of the prominent naturalists of the day- including E. D. Cope.

Rev. Charles Fox

Miles got his specimens from other people as well. This is where the Rev. Charles Fox came in. Originating from England, Fox moved to Grosse Ile in 1843 and officiated as an Episcopal Minister of the church in Trenton and St. John’s on Grosse Ile. He was an avid natural history collector and apparently sent many specimens to various institutions such as the Flint Scientific Inst. and the University of Michigan. Unfortunately he died young on July 24, 1854 after serving only two years on the staff at the University of Michigan as a lecturer in agricultural practices. This was after a series of unfortunate instances in which he lost a son and had his house burn down. Mr. Fox no doubt took some small solace in the collecting of his little fishes.

Douglas Nelson

Thus we are at the point where I contacted Douglas Nelson, the curator of the fisheries collection at the U of M with an interest in seeing if any of Prof. Fox’s specimens remained. In short they did and in long, I was allowed to examine them. Nelson was exceedingly helpful in this regard and even took the specimens out of their jars for handling etc.

Unfortunately, I was not able to see the type specimens for the shiners, minnows, and Brook Silversides mentioned earlier because they are carefully guarded (for the reasons I previously mentioned).  There is little doubt that these fish were also collected by Prof. Fox and ended up in the Manly Miles collection. But, the free access to the ancient Sculpin and a cluster of 13 Three-spined Sticklebacks were satisfactory for my intentions.

  Stickleback Specimens

 

  Stickleback Specimen

I here present a few images of these fish which, because they could not have been collected later than 1854, are at least 160 years old. Their white pupils betray the fact that they were originally preserved in pure alcohol (formaldehyde is a much later invention). The presence of half a dozen labels in each specimen jar betrays the fact that these specimens are not ignored or left abandoned. They have been part of research over the years. In fact, the original name on the attached label for the Mottled Sculpin (the Trachidermus thing) has since been changed to Cottus bairdii (Girard 1850).

  Mottled Sculpin Specimens

Yes, someone named Girard (Charles Frederick to be exact) had described this particular species in 1850. The original designation tag for the U of M specimen, probably written by Manly Miles (?) in the 1860’s possibly reflected that it was collected before 1850. Wow this is one old fish – a fleshy artifact from well before the Civil War.

February 10, 2013

Out Mouillee Way, Again

Filed under: Uncategorized — wykes @ 9:41 am

Some could argue that the worst time to be walking the dikes at Pointe Mouillee is mid-winter. The place is totally exposed and without cover for all but the smallest of beasts. Life, as we know it, is out of sight and mind. A casual winter visitor is left with the impression that this is a sterile landscape. This is true enough when bitter northern blows sweep the icy flats clean. At that time, not a creature is stirring, not even a mouse (ho, ho, ho).  But when conditions are on the “milder” side the starkness of Mouillee can be refreshing. While not bustling with activity, there is life on the winter marsh.

My last venture out onto the dikes was in late January. The first obvious evidence of other life forms came in the form of human tracks. The paired marks of a sled framed a set of boot tracks leading down and across the ice. They led toward the dead cat-tail expanse. Above them, the two-track bordering the Long Pond Unit units were also marked with the wobbly linear lines laid down by bike tires. The muskrat trappers were out. Most chose to run their route using bikes because of the long distances they need to traverse.

With the season only days from officially ending and a warm spell due, most of the trappers were making their last run of the season. I bumped into Dave Venier, a long-time acquaintance and veteran ‘rat trapper. He was assisted by his cousin Cliff and a young neophyte by the name of Zack. Cliff bemoaned the fact that the ice would soon be gone. “We water trapped earlier when there was no ice and switched to ice trapping with this latest hard freeze.”  But, he acknowledged, that despite the hardships, the rats were especially fat this year and that brought a satisfied look across his cold-reddened face. He held up a ‘rat for my examination and the creature slipped out of his gloved hands when I snapped his portrait.

Estimating that perhaps 2,000 muskrats were taken out of the marsh this winter by the hardy set of trappers working this place, Venier bemoaned the fact that the “up and down” winter conditions kept the catch way below normal. Fat hairy ‘rats should bring in top prices, however, and the trio rode off down the dike with a sense of success. They paused to exchange a few words with an ice fisherman pedaling his way out to the farthest unit to try his hand at catching a few fat fish.

Two Short-eared Owls dashed out from the rocks on the northward side of the dike as I continued on my way. I hate that. These crepuscular owls are a regular sight on the Mouillee Marshes but there is no way to sneak up on them– especially when you don’t know they are even there. By the time I realized what I was seeing, the birds were gliding in different directions over the distant cattails.  Their hiding place down in the canary grass was betrayed by only a few scuffle marks in the snow and some soft gray down feathers adhering to the stems.

These owls, along with a host of other birds of prey, cruise the marshes seeking mice – those creatures that stir on moonlit nights and windless days.  Winter cattails are perfect cover for these smallest of beasts because they lean over into dense tent-like formations. There are wide open spaces between the clumps, however, and mice must traverse these open danger zones if they want to do anything other than cower in fear all night. The regular tracks of at least one White-footed Mouse (see below) revealed a successful journey.  Another track, revealed a different story.

An x-shaped mark in the snow adjacent to another mouse crossing highlights the ever-present perils faced by Mouillee Mice. These tracks were probably made by a Great Horned Owl where it plunged to earth to nab a rodent meal. No doubt the fearsome fowl had been eying the spot and decided to make its move on one hapless victim but the result, according to these particular tracks, were in the mouse’s favor.

The owl feet struck the snow in open position and together covered an area of about 18 square inches. That they were not drawn together into a killing crush– a move that would have obliterated the track – proves that the attempt was unsuccessful. What we had here was your basic “doggone it” moment in an owl’s life followed by a high-pitched mouse “Alleluia” moment.

Out on the far dike, the winter walker is very close to the mouth of the Detroit River. The venerable Detroit River light looms in the frosty distance – a place it has occupied since 1885. Always on duty, the daytime lighthouse droned out a mournful fog signal throughout the morning.

Mouillee is located at the confluence of the Huron River and the Detroit. The Huron mouth was completely frozen over while the big “D” river was open along the main channel on the Canadian side. Piles of ice marked the edge of the main river channel.

There were clusters of Tundra Swans and diving ducks in the open water and at least a dozen Bald Eagles speckled the scene. Most were immature birds with dark heads and tails. All were grouped into small packs clustered around a certain dead fish or duck on the ice.

I would argue (to anyone listening, of course) that this January vista of the lower river, as viewed from the outer dikes of Mouillee is truly a beautiful sight. Even the plumes issuing from the barber pole stacks of the Trenton Power Plant seem fitting. It is a view that makes a winter trip to this “barren” marsh a “w.w.w. experience (well worth while).

February 3, 2013

Squirrel Season

Filed under: Uncategorized — wykes @ 12:15 pm

Fox Squirrels are not terribly social beasts. They will tolerate other squirrels when food is aplenty and have even been known to snuggle in a group nest when winter conditions require it, but they are basically loners. Because they are only mildly successful at road-crossing they have to get together with the opposite sex, from time to time, in order to replace those flattened individuals that don’t make it. I am, of course, talking about mating. The Fox Squirrel calendar is marked for two such mating periods.

You might have noticed that these chunky yellow-brown rodents are very active this time of year and therefore more visible (both alive and in flattened versions). The period from January through early February marks the first mating season of the year – at least for Michigan Fox Squirrels. Yes, it may seem odd that the bitter cold environment of mid-winter provides the setting for the Squirrel Dating Game. Hey, we are talking about squirrels here. The other mating period is in April/May but that event is hard to witness.

Females are only receptive, or in estrus, for one precious day. A male will make every effort to be around any given female when this special day hits and will follow her for days.  More often than not, several males will pursue an individual female. This un-natural congregation leads to an “angry squirrel complex” known among mammalogists as a “mating bout.” True to the name, the males will jockey (bout) for position and actively chase each other away. To them, this is what it’s all ‘bout (squirrel humor). A bout session ends in love and squirrel love only lasts for about 13 seconds.

I’m not sure what kind of bouting preceded the event I witnessed a week or so ago when I saw two squirrels “doing it” in my backyard.  There were only two squirrels present. It was 11:00 am and the ambient temperature was 17 degrees F (that’s  aboot -8 degrees C for you Canadians out there). The two apparently had just attempted to “do it” when I first spotted them. They were grooming themselves as if nothing happened.  But, be warned, that when two consenting squirrels groom themselves in close proximity to each other that means something is in the air.

One, the female as it turns out, was on a horizontal branch and the male was clinging to the main trunk. They were casting glances at each other, however. Winter Fox Squirrels are fuzzy little affairs. This couple looked more like teddy bears than a squirrely pair. Fat and furry, in prime winter condition, these animals showed no signs of any winter stress.

Since I was watching them through a window on my back porch I could not hear any vocalizations but I suspect there were some barks and purrs going on. One text even refers to a peculiar “sucking sound” that accompanies Fox Squirrel courtship (blowing kisses perhaps?).  I could see body language.  Apart from the glances, there were tail flicks and body posturing. When the female turned herself away from the advancing male and lifted her tail over her back, I knew the sparks would soon fly.

The male approached the female slowly and snuggled with her. He groomed her fur for a short while before mounting. The actual event only took a few seconds – as I mentioned earlier, the average timing is only about 13 seconds for this act.  My view of the squirrels was impaired by a diagonal branch and I grew suspicious that this was no accident.  Squirrels usually mate up in the trees but often chose locations that are a hidden somewhat from the prying eyes of voyeuristic photographers.  How they knew the limb was between me and them I will never know.

Soon after the joining was completed, the female ran off and jumped over to the Norway spruce (to spruce up no doubt). The male followed her route, but not in earnest. After a successful mating a copulating plug forms in the female which ends her romantic stage. Males go off looking for other un-plugged prospects and the plugged females begin their 44 day gestation period. Sometime around mid-March she will bear a litter of 3-4 young and hope that at least one of them eventually makes it across the road.

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