Predation underfoot

13 06 2008

While pulling garlic mustard in Sapsucker Woods the other day, I was suddenly aware of a keening wail coming from nearby.  It was the sort of sound that makes a person feel a bit uncomfortable, so I stopped for a moment to see if I could figure out what it was…

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Six birds (2 robins, 3 RW blackbirds, and a goldfinch) perched in a small oak about 20m away, looking agitated and peering down at the ground, but not the source of the sound…Now my curiosity was really piqued, so I maneuvered for a better vantage point and was greeted by an uncommonly viewed scene of predation: a long-tailed weasel  was firmly attached to the back of a  cottontail rabbit(!), biting repeatedly at the base of the rabbit’s neck.  The rabbit was the source of the wail, and as I watched the keening soon stopped and the weasel was left with his lunch.  

This weasel was likely a male (males are larger than females and tend to go after larger prey, like rabbits), and was hunting right around the time that weasels have young.  Distinguishing long-tailed weasels from short-tailed weasels can be difficult, as the male short-tails overlap in size with the female long-tails, but given the prey choice of this weasel I am fairly confident that it was a long-tailed weasel.  

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This joins several other predation events I feel lucky to have witnessed here in Sapsucker Woods–several others involved frogs or turtles being carried off by crows (in one instance a chipmunk ate a green frog!), Cooper’s Hawks and Red-tails feeding on birds or small mammals, and the ubiquitous fish/frog foraging of the great blue herons and belted kingfishers.  But this was my first mammal-on-mammal predation in Sapsucker Woods (not counting the trespassing deer-hunters this past winter), and it was pretty spectacular!  Any predation happening in your backyards?





Recently spotted in Sapsucker Woods

10 04 2008

Don’t just take my word for it, spring is beginning to, well, spring into action, and the skunk cabbage are coming up in droves, especially along the Woodleton Boardwalk on the east side of the road.  Skunk cabbage have an amazing ability: they can actually generate heat to melt its way through frozen ground, paving the way to an early arrival on the scene.  And we’re not talking about a few degrees here or there; in some cases, they have been recorded warming up to 35 degrees celsius above the ambient air temperature!  And there are very few plants out there that employ thermogenesis in their arsenal of adaptations.  So next time you see the lowly skunker poking up from a hummock, give it its due: you’re looking at one hot plant!





The many faces of Sapsucker Woods’ pond…

30 03 2008

gooses

As Spring nears and the sunlight increases, let us not forget the beauty of the last few months. Currently Sapsucker Woods pond is crisscrossed with the paths of geese fighting and celebrating their triumphs, a morass of rotten ice and brown murk. Soon the honking of the geese will give way to the spring peepers, the trilling sparrows, and those beautiful gems of the North American landscape, the warblers.

But-as everything gets richer and messier, I find it oddly calming to think of the pond in midwinter. Its solid surface a shining blue, the snow in regularly spaced spindrifts that suggest art, and the frenzied sounds of the chickadees…For all its length and stubborn darkness, winter in Sapsucker Woods is a great time for contemplation and reflection, and for all the hubbub that awaits us in the coming Spring, there is small piece of me that will yearn for the simplicity of winter.

sswpond





Time travel, sapsucker-style

4 02 2008
oblikk

Carpe diem!

Seize the day!

Live in the now!

These exhortations can be heard from time to time, trying to convince someone to pay more attention to what’s happening in the present. Funny thing is, sometimes it takes a look at the past to put the present in context. I am asked many questions about the history of Sapsucker Woods, and I have been perusing the back catalog of old newsletters to Lab of Ornithology members, trying to piece together some of the manmade influences that had helped to shape its current habitat. In doing so I stumbled upon a rich trove of aerial imagery that goes back over 70 years, and decided to do a retrospective photo history of Sapsucker Woods.

Most people who visit the Lab assume that the pond has always been there, and that this small chunk of woodlands has been protected forever.  The truth, however, is much more interesting.  So, if you’re interested in taking a trip on the wayback machine, or perhaps getting a little help from a cardboard box (a la Calvin & Hobbes), click on the Sapsucker Woods Aerial Photos tab below the header and enjoy.





(winter)berries’ bounty

10 11 2007

The canopy continues to thin here in Sapsucker Woods, leaving the trails adrift in reds and oranges. Oaks and beeches are some of the last holdouts, their leaves providing much of the color in the all-too-soon-to-come winter landscape. However, these leafy slowpokes aren’t the only thing brightening up the grays of late fall; among the most spectacular is an oft-overlooked native shrub that becomes even more beautiful as it drops its leaves. The culprit? Winterberry.

yug

(a thick crop of winterberries)

For most of the year, Common Winterberry (Ilex verticillata) is a nondescript shrub with deep green glossy leaves, but come Fall it sprouts linear clusters of intense red berries that become more prominent as this deciduous holly drops its leaves. It can be found from Nova Scotia to Florida, and west to Missouri, excelling in areas of poor drainage. Around Sapsucker Woods, this is the only native deciduous holly we have, but there is another red-berried plant that it is sometimes confused with: Honeysuckle.

winterbsvhoneysuckvert

(winterberry on left, honeysuckle on right)

Honeysuckle is one of the most invasive shrubs in the area, forming dense thickets of yellowish-gray striated bark along woodland edges. The superficial similarity to winterberry lies in its possession of juicy-looking red berries, and its shrubby nature. You can find honeysuckle just about anywhere you want to look in Sapsucker Woods; much of the understory on the north side of the pond is composed of either honeysuckle or buckthorn (both invasive berry producers), and both were likely brought to Sapsucker Woods by the very creatures we spend so much time studying, namely fruit-eating birds (though each is likely also a favored treat for another woodland nuisance, the white-tailed deer). Honeysuckles also have the ability to spread vegetatively and some research has suggested that they can poison the chances of other plants through allelopathic interactions.

honeysucker

(light-green patch of honeysuckle)

The thing that all three of these berry producers have in common is the production each year of a heavy crop of berries that are characterized by being “low in nutritional content“. Roughly translated, these berries are the equivalent of a can of coke, offering nothing more than a rush of soluble carbohydrates, and this results in them being eaten later in the season as birds (especially migrating birds) target fat-rich foods. While it might not seem intuitive, berries can also be high in fats, and a selection of other berries in the landscape (dogwoods, sassafras, poison ivy) are relatively high in lipids (fats), and offer something closer to a bag of chips to the migrating masses, and most of these berries are gone by the end of Fall.

Given these intrinsic differences in the “value” of a given berry, it’s fun to think about how a fruit eater might choose to exploit these resources, and it is thought that birds try and eat a mix of sugars, proteins, and lipids for nutritional balance. However, by midwinter, all that might be left for a hungry resident is the equivalent of a can of coke…





Cercopidae Sapsuckers

2 06 2007

cercopid

(The bubbly protection of the meadow spittlebug on a goldenrod stem)

Behold the meadow spittlebug (Philaenus spumarius), a homopteran in the family Cercopidae.

What’s that you say? You only see frothy bubbles? Well, my friend, deep within that sputum-y layer is a xylem-sucking fiend, tapping into the nutrient-poor system plants use to transport liquids for food. Technically, those bubbles aren’t spit because they’re not formed using the mouth but rather, erm, the other end. Dig down through the flatulent rear-end madness, and what you will find is a young “froghopper” in its nymph stage.

spittle1spittle2spittle4

Why all the spittle?

Turns out it’s not all that complex. This spittl-y shield works like the “brilliant pebbles” of our vaunted Strategic Defense Initiative were supposed to work (some would say even better), keeping predators at bay through a layer of insulating tiny bubbles that hide the nymphs from a world full of hurt while they grow. Furthermore, these bubbles give the froghopperitos a moist shield to prevent dessication, something the SDI never managed to work into its plan (perhaps they could have partnered with that lotion obsessed guy from Silence of the Lambs?).

In any case, the spittlebugs seem to be having a good year this year, and I’m finding them in nearly every patch of goldenrod around. How ’bout you?

UPDATE: check out the comments for some good revisions from Vasha–looks like the anti-dessication angle might not be all it’s cracked up to be…