The Clouds and the Lake

What: I've now paddled the Salmon Hole to downtown Burlington loop about 7 times, this last time with my sister, Meryl, and our friend Carlos. It's amazing that I can walk my boat three quarters of a mile, paddle, 16 miles, and then walk 2 miles home. With all the rain we had the other night the river level was considerably higher and I had a blast running the rapids at Salmon Hole. The wind was also much stronger. The following day (Wednesday) we had fair weather, with a nice blanket of cumulus clouds settled over Vermont and New York. With a different perspective of being on the lake I was struck by the noticeable absence of clouds over the water.

Panorama showing absence of clouds over Lake Champlain

Ecological notes: My theory is that we had lots of rain on Monday, followed by warm temperatures. Already when the rain was falling it was evaporating and there was a beautiful mist carpeting the understory of Centennial Woods. As the warm moist air rises it reaches cooler air. When enough water vapor cools enough degrees (the birds and bees of making a cloud) it can reach what's called the dew point. Dew point is the point just beyond 100% relative humidity where water vapor condenses out onto a solid substrate, like dust or grass or your tent. An easy example is a cold glass of water on a warm humid day. As the air comes in contact with the glass it cools rapidly. Cold air can "hold" less water vapor, so the air in contact with the glass reaches the dew point and little water droplets form on the glass (but not on your much warmer skin). 

In the atmosphere, as that warm air rises, the water vapor can condense and will appear to us as a cloud. So the greater the difference in temperature between the ground and the sky, the lower the elevation at which clouds should form, because they'll reach that dew point much sooner.

We started paddling on the lake around 9:45am and I guessed the clouds were around 3000'. Once we rounded Apple Tree Point we had a great view of Camel's Hump and a little more than the summit (4081') was covered, so the clouds were probably closer to about 3500'. About an hour later it was considerably warmer outside, and more warm air had already risen into the atmosphere, thus, the air around Camel's Hump had warmed as well. This should have raised the dew point and the elevation at which clouds were forming. Sure enough, by about 11:15am, the top of Camel's Hump was exposed, indicating that the clouds were at about 4100'.

So why no clouds over the widest parts of the lake? The temperature of the lake is more stable and cooler, so the temperature gradient between water and air is far less. Because there is a lower temperature gradient, the air rises at a much slower rate, allowing for water vapor to reach equilibrium rather than condensing out.

Where: Lake Champlain & the mighty Winooski River

Other notes: The sunlight on Tuesday was stunning - those soft sunset golds. The winds were kicking up the leaves of the silver maples that line the Winooski River. I could never understand why they were called silver maples until I saw this a few years ago. The undersides have a much paler color and when the winds dance them around exposing their bellies the whole tree takes on this ethereal silvery sheen. Someone must have named it in the sunset after a good summer storm.

Bees and gender in Insects

What: I've been thinking more about my last post and the importance of words in relation to our understanding of the world around us. I was telling a friend about the woodchuck that's growing fat off our kale, and how he had gotten the broccoli too. My friend asked how I knew it was a "he" and then pointed out how it was weird that animals automatically and unconsciously becomes "he" when the gender is unknown (I'm always conscious of when someone uses the pronoun "she" in a gender neutral situation). The pronoun "it" lacks so much emotion and humanity, like describing an automaton, so, because we like to anthropomorphize animals (e.g. Bambi), we assign gender to them. I even hear people refer to my bees and egg laying chickens as male.


As a naturalist my first questions are often around identification, particularly with insects. I posted an ID request to the bugguide.net community. John Carr sent a response "It's a female dolichopodidae." Well female is awfully specific, but animal scientific classifications ending in -idae (-aceae for plants) are family groupings, which are pretty general (Curculionidae, the weevil family, contains over 40,000 species). This is from a guy who specializes in IDing midges and their relatives, and he could get gender but only ID down to family. So what was he cuing into that said female and not male? Turns out the answer is more about what makes a male a male.

Ecological notes: So even with the vast evolutionary divergence of insects into every ecosystem around the world, some morphological adaptations are still conserved or at least have converged. One of those things is a male's ability to detect a female, and they do this in a variety of ways, like hearing, smelling, or seeing females from a great distance. Male mosquitoes, for example, have enlarged antennae to pick up that horrendous and penetrating bzzzzzz sound the females make as they look for that perfect patch of skin. What I'll call foot moths (and cover in a future post) have huge antennae for "smelling" the sex pheromones from females.

Male honeybees, aka drones, have enlarged eyes to spot a queen before other males do. The first picture in the post is a drone; note how the eyes are so big that they actually touch in the middle of the head. The next picture shows a bunch of females at the entrance to the hive, their eyes considerably smaller and not touching on the tops of their heads. Drones are pretty much useless to the colony other than for reproduction. They hanging around feeding on honey, begging for food, and grooming themselves. When the timing is right they'll start going for exploratory flights to breeding sites. These change frequently, so a male needs to be able to spot one from a distance. The story is far more complicated than this, but it's a neat start and I"m tired, maybe more later...

Where: My backyard

Other notes: Ryan Morra and I noticed a whole bunch of female worker bees crawling around on the ground near the hive. I went back with my camera after he left and spotted one a worker dragging another, much lighter colored worker out of the hive. At one point the lighter one started to fly and the other one held on and pulled it back down. Once it got to the edge of the platform the darker one left the lighter one to die on her own. In the middle of summer, this generation of worker bees have the shortest lifespan of just a few weeks (c.f. winter life span can be several months). Kicking out unproductive bees is essential, I guess, to maintaining efficiency.

A gaggle of nouns

A deer stopping for water in the 90 degree heat

Where: Winooski River (still). Zac and I just got back from another paddling adventure to complete my last trip from Bolton to Salmon Hole, this week from Salmon to Skinny Pancake. Another perfect day of paddling!

An outburst of water striders

Other notes: This time of year has the most overlap across life stages for animals. You may have noticed not just one crow perusing the lawn for food, but a mini-flock of 4 or 5, or a sudden flush of 30 robins sweeping through a honey suckle thicket. As nesting season winds its way down (com on goldfinches, hurry up and finish nesting already), lots of family groups are out and about feeding, the males are less territorial trading the stress of land disputes for the comfort of extra sets of eyes to be vigilant. It was hard enough on the trip to identify the many different species of birds, flowers, and trees I was passing by. Throw into the mix the different names for males, females, juveniles, and even collective nouns, and I was a bit over my head trying to keep it all straight. I got curious about what the different names for groups of different animals might be (and is there a term for a herd of cottonwoods? a "stand" is so boring, "grove" gets better, but there's a whole world of opportunity here).

  

A scuttling of mergansers

A motoring of ducklings

  

A ring of ring-bills

A dastardly of F-16s

I've long been fascinated by names and the naming of things. I was first introduced to the quirks of latin names by my love of gray squirrels, and indeed Sciurus carolinensis was the first scientific name I learned. Turns out Sciurus derives from the Greek words skia (shade) and uros (tail). The Greeks must have thought that squirrels their tails much like one might find respite from summer heat under the cover of a parasol. They were wrong, but thanks to the convention of naming things, their error is preserved in our scientific lexicon.

A flapping of kingfishers

Contemporary naturalists seem to have a certain fondness for collective nouns used to describe groups of animals. Being able to call a flock of crows a murder, starlings a murmuration, or vultures a committee is a sure sign of esoteric adeptness when it comes to being naturalist. It's like the painfully obvious difference (to those in the know) between a tourist ("Bar" for Barre, "Shar-let" for Charlotte) from a Vermonter ("Bare-ee", "Shar-lot"). There is delight, beyond proving ones worth in the often ridiculous and colorful phrases. Some are probably grounded in some sense of the animal's natural history, while others, it appears, are from the fanciful imagination of the 15th century British author Dame Juliana Berners, or at least were first recorded by her. She was the prioress of a nunnery, where she kept up her passion and dedication to fishing, hunting, and other outdoor pursuits. Her book, The Boke of St Albans, is damn near impossible to read (much like Canterbury Tales). It includes three sections - on falconry, hunting, and heraldry. In her section on hunting she publishes a lengthy list (3 pages worth!!) of collective nouns. The most famous to make it from her pen to our vernacular is murder of crows, but the rest are just as inventive.

A lonesome of bald eagle

It might be easy to chalk the lengthy list up to the poetic musings of one more skilled in writing than shooting, but I think Berners, like other hunters, had stories that got bigger and bigger with time: "I once caught a fish th-------------------------is big." I imagine that sport hunting was a hobby for the finer and fancier of folks, a well-educated bunch that would lounge around the hearth in their parlors recounting hunting tales from days of yore. "If you think today was good, you should've been here yesterday, we caught a suit of mallards, a muster of peacocks, a covey of partridges, and a bevy of girls."

A hawking of kingbirds

Language reflects what's important to the culture that uses it. Thus, the Yup'ik Eskimos, for example, use the word kanevvluk for fine snow particles, natquik for drifting snow, aniu for snow on the ground, and have other distinct lexemes (like a root word) for variations of snow. So if your culture values hunting and the pride that comes with it you might expect a distinct lexicon to accompany it, much like any subculture develops its own language to describe shredding the gnar, sick pow-pow, etc.

An awkwardness of herons

Since her writing, many more collective nouns have sprung up, some useful and serious, others amusing and useless (a clutch of auto mechanics). In the captions for each picture, I've thrown my hat into the ring, vying for a few new collective nouns.

A flotsam of jetsam

As a side note, the publishing of Boke of St Albans made Berner the first published woman in England.

Berner's list of collective nouns in its original format

Storm + Winooski River Paddle Revisited

Bonus post: Just wanted to post a quick video I put together from that epic thunderstorm last night. For a better synopsis of conditions leading up to and during the storm, check out The Weather Rapport.

What: Last Wednesday and Thursday I paddled the Winooski River from Bolton Dam down to Salmon Hole in Burlington (about 30 miles or so). There are a couple of great paddling guides online (1) (2) that give a sense of what to expect from the conditions on the river, but do little to describe the sheer joy of getting lost in the meandering freedom of the Winooski's bends and folds. Only occasionally did the old span bridge or rumble of a semi's engine break remind me of the thin border of silver maples separating me from the faster pace of asphalt and clocks.

Ecological notes: I was particularly fascinated with the enormity and odd grace of the committee of turkey vultures that seemed to defy my cultural expectations of what a vulture should be (on Friday I'll post more about collective nouns, like committee, for animals). Wednesday evening I came to a fork in the river where it split around an island. I saw a turkey vulture circling low on the south stretch of the island and so I set down that direction. As I slowly approached, another turkey vulture landed on a gravel spit about a quarter mile down from me, followed shortly by three more. I tied up my boat and crept slowly along the shore line to get a better view. As I rounded the bend I was treated with a spectacular view of about 25 turkey vultures either sunning themselves on the rocks or perched up in the trees preening themselves.

In that late afternoon heat I wanted nothing more than to spread my own arms out and sun myself on the rocks with them. I couldn't help but wonder if that was the ultimate motivation for the turkey vultures' behavior. When I got back, Callan and I came up with a pretty short list of reason why we thought the vultures (and other birds) might do sun themselves. Here's what we came up with:

1. Kill bacteria by drying them out (they're detritivores, an animal that eats dead stuff, which is probably a source of all kinds of nasty bugs)
2. Kill other parasites, like taking a dust bath
3. Produce Vitamin D
4. Warm themselves up before going to bed
5. Warm themselves up to increase metabolic rate, digest food faster
6. Visual display of power to other turkey vultures
7. Dry off

I've also seen cormorants do this (see photo above), pelicans, and green herons. Some quick research shows that many birds do this, but their posture is different from the vultures and cormorants shown above. Indeed only a few others, like anhingas, storks, and other herons, do this standing up with wings spread. The ring-billed gull colony I encountered the following afternoon had about 300 individuals (plus a small handful of mergansers) all standing facing the sun, but with wings closely tucked in).

Some patterns in the list of birds that sun themselves standing up with wings out emerge: many are aquatic, they tend to be darker, they're carnivores, they're very large birds, they live longer than most birds, and most are in the stork order, Ciconiiformes. After writing this I looked up the order of pelicans (Pelicaniformes) to see if it used to be included in Ciconiiformes, and sure enough Pelicaniformes is often proposed as part of Ciconiiformes. What's even cooler and more surprising is that new world vultures (as opposed to buzzards and their old world kin) are close cousins of the storks. So if this behavior of standing up and sunbathing is monophyletic (occuring only in one evolutionary branch of birds), then it might be reasonable to assume it originated in a single ancestor of new world vultures, herons, storks, cormorants, and pelicans. The behavior might then serve a unique purpose among these birds.

I didn't find anything conclusive, but it looks like birds will sunbath for all the reasons that Callan and I came up with. A 1957 paper on the topic indicates that birds might also sunbathe socially; if one starts sunbathing then others will join her/him. I'm not sure what the primary purpose of sunbathing is for these birds, but I'll bet spending lots of time in/near stagnant water (for cormorants, herons) and eating carcasses (vultures) makes these birds susceptible to parasites so having a way to kill them would be good (maybe the black of a vulture heats their feathers up to a higher more lethal temperature).

Additionally, vitamin D deficiency can pose skeletal problems, making large body size a critical reason to sunbathe. Ciconiiformes and vultures don't migrate far, so in the winter they're not getting as much vitamin D as say migratory song birds might. Vitamin D deficiency prevents an animal from absorbing calcium from food. Prolonged deficiency (as with people in northern latitudes) can result in weakened bones that bend and curve under the body's weight (like the stereotypical bow-legged Eskimo). Sunning would be an effective way of producing vitamin D.

Another source says that warming up feathers "resets" their curvature, bringing them back to their most efficient shape, an obvious advantage for a turkey vulture, which spends most of its time soaring looking for food. But I couldn't verify this with any reputable sources. 

Where: Winooski River, about 2 miles upstream from Richmond.

Mourning doves

What: We've got a pair of mourning doves (Zenaida macroura) that started to build a nest in a boxelder (Acer negundo) at the end of our street. I watched the male bring supplies to the female all morning. It was a hot and listless day and the female was yawny waiting for the male to return with sticks (for more on how to identify male vs. female, check out: The Secret Life of the Mourning Dove by Michele Patenaude; in short males are larger, have rosier chests, and have more irridescent heads).

As is evident in the video, it appeared as though the male was testing the strength of each twig/pine needle to be added to the nest by banging it against the ground. Flimsy ones were discarded, sturdier ones brought back. It was fun to watch him pick through the bounty of needles and twigs in search of the perfect ones. I was in and out all morning, but I'm pretty sure the male worked on this for about 6 or 7 hours before my sister and I left the house. By the following afternoon it was abandoned for whatever reason.

A finished mourning dove nest is kind of a disaster so it was hard to tell that it had even been abandoned. I found one a few years ago with Ian Worley and I asked if it was old because it looked like it was in awful shape. He said that was par for the course and the active nests I've seen since then look almost like the birds don't really care at all for craftsmanship or aesthetics. But I guess if you're building a nest in a scraggly tree like a boxelder you build a scraggly looking nest to blend in.

Ecological notes: The nest went unfinished and I think they selected a nearby site over the next couple of days after the video. Last Sunday, Brian was outside and watched the doves attacking a red squirrel. I went out and the red squirrel was coming down a white pine with feathers clinging awkwardly to its mouth. At least one of the mourning doves, and I can't really think of a more docile bird, were going crazy. So the video is from July 1st, 7 days before "the attack". I suspect that they rebuilt and soon after laid eggs. I don't know that the eggs had hatched yet, but my guess is that the doves defended their nest from the red squirrel and the red squirrel might have bit back, but not been actively hunting the doves.

Where: Burlington, VT in my backyard.

Other notes: The red squirrels have been extra bellicose the past couple weeks. It's amazing, I hadn't really seen any of them in my back yard for about two months - just an occasional sighting. But now that the fruits on our black walnut (Juglans cinerea) are swelling, they've been fighting off the gray squirrels like that's the last food source on earth. They start wailing at dawn and don't really stop. What's interesting is that the gray squirrels, though they are certainly submissive, have been equally vocal.

Also, there was a robber fly in my backyard today. I couldn't tell what kind it was nor could I tell what it was eating, but it was fun to watch it devour its meal in fits and starts.