Tuesday, August 26, 2014

Dogbane beetle

What: The end of summer is the time of the insects! I've been watching the dogbane sprout up new shoots, flower, and finally go to seed over the past three months. Because they're a particularly noxious plant (toxic to almost all vertebrates and many vertebrates - they're related to milkweed which is infamous for its implications for monarch caterpillars), they have insects specialized to feeding on them. Similarly, koalas, which exclusively eat the poisonous leaves of eucalyptus, is specialized to eat one and only one thing. The koala's evolutionary trick was to find a way around the defenses of something so toxic that doesn't have any other predators and then exploit that weakness. So too with the dogbane beetle (Chrysochus auratus). Dogbane is a notorious weed in the midwest, largely because it doesn't have any natural pests that control its population.

On the photo at the bottom, I had actually moved it to a milkweed leaf right next to the dogbane where I found it. There were a number of milkweed aphids on the underside. Once the beetle had crawled to the underside of the leaf it kept stomping its feet and then would fly a few inches to a new spot. It seemed really perturbed by the significantly smaller beetles. After about 30 seconds of "torment" it flew to another leaf.

Sunday, August 3, 2014


Extensive patch of shining club-moss

What: While out on the Long Trail this week with the Crow's Path Adventurers camp (photos here), I was able to return to a patch of shining club-moss (Huperzia lucidula) I had noticed last weekend while scouting with Sam. The patch is located at the turn off to Silent Cliff, just north of Middlebury Gap. It's been about 5 years since I looked more intimately at the club-mosses (family Lycopodiaceae), and I was struck by the strong patchiness of the plant - some of the patches were a dense carpet of up to about a half acre, and it was a rare site along the trail to see any growing by themselves. I have in my head images of little cones sprouting from the tips of clubmosses, and was delighted that, upon closer inspection, there were no cones at all, but a new mysterious type of leaf.

Flattened gemmae, or vegetative propagules, that act in the same way as leaves on jade plants

Ecological notes: Turns out members of the Lycopodiaceae genus Huperzia lack the cones, or strobili. Plants with this strong of a predilection for patchiness typically have vegetative reproduction (e.g. spread by underground roots like staghorn sumacs), really heavy seeds that don't disperse terribly far, seeds that get dispersed by non-volant insects (like trilliums and ants), or extremely narrow and extreme habitat requirements (like cattails in marshes or Green Mountain maidenhair fern in serpentine outcrops).

Each band of spores = 1 yr of growth
Shining club-mosses lack creeping rhizomes/underground stems, which other clubmosses (e.g. Lycopodium spp.) spread laterally out along or just beneath the surface of the soil, so they need to accomplish this in another way. In this case, the gemmae, those flat, paddle-like leaves (they almost look like elm seeds) are vegetative propagules that fall off the parent plant. They don't have far to fall and so aren't carried more than a few centimeters at most from the parent plant. The new plant is a genetic clone of the parent and in time will create its own gemmae (always at the tips of new growth).

Also, unlike similar relatives in the genus Lycopodium, whose sporangia (spore clusters) are borne on cones that reach up into the air waiting to be whisked away by wind, Huperzia have sporangia borne on leaf axils (the little notch where the leaf sprouts off the stem). In the photo to the right, these are the clusters of yellowish bean-shaped things running short segments up the stem. Each band of spores represents a single year of growth, giving some sense of maturity.

There is scant literature around the lifespan of shining clubmoss. A related species, Huperzia sa, can reportedly take 15-20 years just to reach maturity. So it appeared from my brief look into their world that wind dispersal doesn't play much of a role and their presence in large, thick patches indicates that they've been around for a long enough time for their vegetative parts to create dense mats. Maybe it's even an indicator of at least secondary growth.

Where: Unlike the other Huperzia sp. that we have in our state which grow on rocks, H. lucidulum grows on soils. Its preference for rich - yet acidic - moist soils under a hardwood or coniferous canopy make it a common denizen of higher elevation woodlands.

Wednesday, July 23, 2014

Robber flies

Robber fly eating a small white moth
I've had the fortune of seeing quite a few robber flies this year (I first discovered these guys two summers ago). Though seemingly nondescript, they're among the most gruesome of all predators. Relying on surprise, robber - or assassin - flies, lay in wait for an unsuspecting prey to come along and then ambush them, taking the insect out of midair.

Butterflies, moths, and many other nectar-loving insects have long, spindly and bendy proboscises. Not so the robber fly, whose short and hard proboscis is thrust into the body of their prey. It's hard to make out in the photo, but they have a bristly mustache on their face that is potentially a face mask that protects them as their prey flails about.

Then like a shrew, they inject the unfortunate insect with a neurotoxin that paralyzes it and, like a sea star or spider, follows up with an enzyme that liquefies the prey's innards. From there, they make an easy job of slurping up the slurry of guts.

Friday, July 18, 2014

Peregrines at Rock Point

On April 6, I wrote an email to the Vermont Bird Listserv:
I was out at Rock Point yesterday afternoon when I heard a peregrine falcon! This was exciting enough, but it got even better. I watched it fly out over Apple Tree Bay a couple of times before returning to the cliffs below where we were perched. We then watched it swoop out and hover low and fast over the ice about a half mile out to the fracture line in the ice. Along the fracture (which runs from Lone Rock Point out to Appletree Point) there are a few gaps that have open water.
When the falcon got out to the fracture line it landed and we realized that there was already another peregrine out there. They seemed to be watching the open water, maybe for fish in search of higher oxygen concentration? After a few minutes the same falcon took off and flew back directly towards us, it got to the cliff where we were sitting and started to land before it noticed us. It turned and flew back to the ice, mounted the other bird, mated awkwardly while she slipped on the ice, then flew back about 4 seconds later, as is the economy of mating in birds, before landing at the thrust fault. It continued to shriek, and make return visits to the icy (though never mounted the other bird) for about an hour.

Over the past few months we've been able to watch from a distance the peregrines nest building, hunting off the cliffs, carrying food back to the nest, and now successfully fledging two young falcons! The young are easily distinguished by their incessant screeching and begging. I was able to photograph the dramatic playing of the young as they half-heartedly swooped down at a family of mallards at Mink Bay. 

Wednesday, May 21, 2014

Planties in a bunch

One of the things I relish most are my memories of seeing animals being fallible - like squirrels falling out of trees or beavers tripping. Maybe it's a bit odd (or worse, sadistic), but my enjoyment is in watching the animals suffer, but the reminder that they are animals just like us, prone to error, confusion, mistakes, emotions, and the drive to struggle on.

My powers of empathy extend first to mammals, next on to other vertebrates, and then invertebrates. I can connect with insects, but my connection is not as immediate and often includes a slight sense of awkward self-awareness around empathizing with this clade. My chain of empathy often forgets the plant kingdom (John Berger wrote that we like to look at animals because, unlike them, when we look at them we are aware that they are looking at us in the same way. But the other day while taking photos with one of the kids at Crow's Path, we spotted a most peculiar plant that reminded me that the struggles of life extend to all living creatures.

Unlike most trilliums (trillia?) that push their way through the duff by pushing leaves out of the way, this unfortunate soul got stuck trying to rend its way through a sugar maple leaf. It got all twisted and couldn't quite make it to the unfurling stage. I often see this pattern with Canada mayflower. The plant presses on with development, flowering in this instance, despite the jumble of leaves. Trillium are perennial so potentially the hindrance to photosynthesis will not matter much this year - perhaps next year it may suffer slightly, leaf out later, grow a weaker/shorter stem, etc. Only time will tell.

Sunday, May 18, 2014

The littlest of leaves...

White ash
I've so enjoyed watching all the buds leaf out this year. Each species has its own way of opening up to the warm spring weather - they unfurl, burst, surreptitiously emerge, bolt, elongate, crack, pop, and slither open. What a joy to watch.

Common buckthorn
Speckled alder

Sugar maple


Maple-leaf viburnum
Striped maple

Green ash

White pine

Bitternut hickory

Staghorn sumac

Glossy buckthorn

Wednesday, May 14, 2014


Woodchucklings are on their way. Unfortunately. Despite being obnoxiously adorable, woodchucks are the three-year running champs of destroying our garden. We spotted these little critters on April 17 mating. It doesn't bode well or our veggies this year.

The actual mating process seemed rather uneventful, other than a few high pitched chirrups, but there was a rather long process of nuzzling, smelling, and coyly playing with one another that preceded copulation.

Sunday, May 11, 2014

Signs of spring

It's been an exciting couple o weeks here in Burlington. In addition to the dramatic sighting of a moose in our yard!!, we've had a number of other visitors. This morning a catbird was singing. Yesterday, a house wren. And persistent throughout has been the large flock of juncos and white-throated sparrows (some chipping sparrows mixed in as well). 
Female dark-eyed junco (females have more brown on sides than males and are less bicolor)
Chipping sparrow

The aptly named white-throated sparrow. Song is a whistle-y "Oh Sweet Canada Canada Canada"

Saturday, April 5, 2014

Sapsuckers and sap flow

What: Last week, I was out checking the bees with Zac and Sophia and we noticed that the boxelder looked like it had wet its pants. A few days earlier, Clay had spotted an odd ball woodpecker in our backyard and I thought from a quick glimpse it may have been a sapsucker. When we inspected the "wet spots" on the boxelder, sure enough there were all sorts of little drill holes. We licked the bark and it was delicious.

There are a lot of origin stories about the human discovery of maple sugaring. I'll bet almost all of them are false and created many generations after humans were utilizing syrup. I've got three bets for how humans discovered sugaring:
  1. Red Squirrels: I've watched red squirrels chew little notches in branches of sugar and red maples. I've also watched them return and lick off the sap from bark later.
  2. Sapsuckers: Water can be hard to come by in the winter. Curiosity, particulalry when there's a need for something, runs high in humans. My first inclination when I saw the drill holes and wet bark was to wonder what the sapsucker was after. My second inclination was to taste the sap. I was rewarded with a delicious treat.
  3. Broken branches: Silver maples and boxelders both grow along floodplains. Winter can be rough on trees and without the metabolic activity to heal wounds, exposed wound sites will "bleed" once the sap starts flowing. Early in the sugaring season, when temperatures still drop well below freezing at night, any sap that might flow out of a broken branch can freeze into a sapsicle. The water freezes first and the outer coat is extra sweet. Kids love to suck on icicles and I'll be it was a kid that first discovered these sweet treats. 
I've kept an informal list over the years of species that I've seen sapsuckers tapping. The list this year includes: Black walnut, Red oak, Boxelder, Silver maple, Hemlock, Bitternut hickory, White pine, Norway spruce, Black cherry, and Paper birch.
black walnut with drill holes from sapsucker

Monday, March 31, 2014


What: With the winter pretty sloggy and crummy, I thought I'd replace some of my time out wandering with my game cam. Part of the inspiration to put it back up again was a road kill coyote carcass my friend skinned. Yard and I placed the carcass out near Centennial Woods to see if we might get a video of the gray fox I'd been tracking earlier in the winter (haven't seen tracks from it in a few weeks). With the warm weather we were hopeful. While we didn't get the fox, we did get an even better surprise! A few weeks ago, there was some banter on Front Porch Forum about fisher sightings. This is from March 8:
This morning at around 5:45 I saw a cat-sized critter that had a snout and puffy tail run by between the Centennial apartments and cohousing townhouses. It was a little too dark to see color clearly, though I could see that the fur was at least somewhat dark. At first I thought fox, but then thought fisher. Has anyone else seen one lately?
Someone sent a follow up response on March 9:
I too saw a fisher late last week - running through the woods between Latham Court & Thibault Parkway, headed in Colchester Ave. direction. Same time frame - just before dawn. Kitty owners be aware - keep your lovebugs indoors at night! These guys don't fool around. 
While I've seen fishers and tracked them throughout the area, I was skeptical since I hadn't seen any sign this winter of fishers in/around Centennial Woods. I looked for tracks following the second posting and only saw the regular raccoon, possum, house cat, and domestic dogs. Sam spotted a woodchuck out in our yard around the 15th, so it could have been a sleepy whistlepig checking the weather (woodchuck comes from the Cree word, wuchek, which means, you guessed it, fisher; apparently early whites couldn't tell the difference between the two animals and confused the term).

Not that my video confirms that my neighbors saw a fisher, but it certainly indicates that this is possible. The fisher in the video is most likely a male (males are significantly larger than females, almost twice as big). Males also have much larger home ranges than females (up to ~7 miles in winter, but in Burlington this could be smaller with the abundance of squirrels, particularly red squirrels in and around Centennial Woods), so their spotty presence may be due to patrolling their territory.

We also captured squirrels interacting with the carcass, which was pretty interesting to watch.

Thursday, March 27, 2014

Marcesence - Photo essay

What: One of my students, Kaleigh Wood, posted about marcescence a couple of years ago. Marcescence, which is common in trees in the oak family, fagaceae (e.g. oaks and beeches), is the process in which the leaves die in the fall before the abscission layer completes the process of releasing the leaf from the tree. I think that these trees just have poor timing and cold weather kills the leave. Others suggest that the dead leaves help protect from the cold, water loss due to wind, or deer browse.

The cost of keeping leaves on is that harsh winter winds could rip the leaves off the tree, exposing the branch to insect predators and pathogens. I suppose another overlooked benefit could be that oak leaves are highly acidic and have high concentrations of tannins. There might be incentive not to drop leaves, where the acids and tannins would leach directly into the soil, making growing conditions for the tree more difficult. By retaining the leaves, the acids and tannins may break down before reaching the soil.

 Whatever the reason may be, the leaf petioles on this red oak (growing along the edge of an open field) had been shredded. Some leaves still barely clung to the branches, but mostly all that remained were the frayed fibers of the petioles.

Sunday, March 23, 2014

Turkey Vultures

What: It's FOY (first-of-year) season, and the skies are abuzz with the wing beats of our first returning migrant birds. Apparently, they didn't hear about our record-setting cold weather. I love the first flocks of vultures returning north. They come with the male red-winged blackbirds, the waterfowl (if only our ponds would thaw!!), and the courtship behavior of our over-wintering birds like chickadees.

I spotted this committee of vultures (see my post on collective nouns) over the St Joseph Cemetery on Archibald St in Burlington on Saturday afternoon. There were at least 15 birds.

Over the next few weeks we'll see more and more birds returning to the state. It's an exciting time of year - I'd love to hear what other folks are starting to see as the days get longer and (hopefully) warmer.

Saturday, February 15, 2014

Plastic snow

Sastrugi - the sharp features of a windswept snow surface bordering fractured plates of ice in middle of photo.

When I was younger, I had one word to refer to all that white stuff in winter: snow. As I got older and had more experiences with it, particularly through snowboarding, I realized that not all snow is created equal. Snow taxonomy has a history much older than winter ecologists, and much of the rich language found in cold climates to describe snow has been adapted by winter ecologists (like the Russian sastrugi - above, or Innuit qali - below).

Snow can be grouped into three categories:
  1. Falling snow
  2. Snow on the ground
  3. Surface-generated ice features (like ice needles being pushed up from the ground on wet trails, hoar frost, icicles seeping out of cracks in bedrock)

Qali describes snow hanging from trees (like in the image above). Because our snow the other night fell in a frenzy of blustery winds, there wasn't a whole lot of qali left on the trees. Sintering is a natural process where snowflake crystals fuse together. Sintering can happen due to pressure (like stepping on the snow pack) or temperature (melt-freeze together). Because the snow crystals actually bond together, qali will act as a liquid moving in slow motion. Snakes, like in the image above, are common features in northern woods after a good snow storm. We observed a spot today where the sintered snow had bent down around the rock, creating a perfect overhang for a weasel to pop in and out of while hunting.

Wednesday, February 12, 2014

Getting closer...

What: Sam and went out to the lake yesterday to check in on the progress of the lake freezing over. Boy oh boy did it look frozen all the way across! With the continued cold weather the lake just might be crossable this winter! This would be the first time since 2007. Lake Champlain won't be the only large lake to freeze across. Looks like Superior is on the same trajectory (news story here)!!!

In the afternoon there were people playing hockey out on the ice (specks in bottom left of above photo). Later that evening Jon and I ran out to the light house and followed snowmobile trails. So at least as fall as the break wall, the ice is solidly frozen.

Monday, February 3, 2014

A photo essay in ice

What: Not to inundate the ecstatic beauty with overanalysis, I wanted to cap the week with a photo essay of the things that caught my eye.