Authors Posts by Matt Pelikan

Matt Pelikan

Matt Pelikan
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A northern gannet carries a bit of nest-building material. As big as geese, gannets make a tremendous splash when they hit the water pursuing fish. —Photo courtesy of Andreas Trepte

It’s not just your magic carpet to the Land of Cheaper Gasoline! If you’re a naturalist without a boat, a Steamship Authority ferry is also…well, a boat.

To be sure, there are limitations. With a fixed schedule and a fixed route, the Great White Fleet never visits the vast majority of our region’s waters. The boat will not slow down or circle to provide a better look at something interesting. And of course you can count on sharing the ferry with several hundred of your closest friends.

But a boat of any kind is better than no boat at all. Oceans are always interesting, and it’s a rare trip between Woods Hole and Vineyard Haven that doesn’t produce at least some viewable wildlife. Sometimes one even gets lucky and happens onto a rarity or a noteworthy spectacle.

It’s primarily bird life that naturalists look for from the ferry. Though herring gulls are dirt common on the Vineyard, they are imposing, graceful birds, and it is rare SSA run that doesn’t attract couple of gulls begging for handouts (or snatching an unattended snack from the weather deck). And for the photographically inclined, a ferry ride presents an unbeatable opportunity for capturing the nuances of a gull in flight.

Similarly, pigeons and house sparrows are common birds, but their habit of scavenging out the ferries sometimes offers an exceptional chance to view or even interact with these birds. (One of my own surprisingly intimate encounters with a pigeon was recorded in a previous Wild Side column, published Nov. 20, 2012, “A common pigeon asks for help on a Martha’s Vineyard ferry boat”). But less mundane avian life is also possible. Perhaps the best bird I’ve seen from a Steamship Authority ferry was a Manx shearwater, slicing the air near the red No. 2 buoy in the Vineyard Haven outer harbor on an unnaturally warm March day in 1998. True pelagic species such as shearwaters are always rare in the enclosed waters of Vineyard and Nantucket Sounds, but some other seabirds can be downright common.

From late fall through early spring, seeing a northern gannet is always possible, and sometimes, scores or even hundreds can be viewed. Goose-sized birds with long wings and pointed beaks, gannets typically feed by plunging into the water after fish or squid. Dropping as much as 100 feet in their dive, gannets hit the water like cannonballs, and the spectacle of a flock feeding close to the ferry is worth the price of admission — even if you’re paying off-Island car rates!

Almost as much fun to watch are common and roseate terns, which arrive in late April or early May, often forming huge feeding flocks near the ferry route before the birds disperse to their breeding colonies. Roseate terns in particular are a treat — graceful, snow-white birds and a relatively rare regional specialty. I know of many birders who have tallied their “life” roseate tern from the weather deck of a Vineyard ferry.

In winter, sea ducks and loons are a given on any ferry ride: scoters (we have three species, all hefty, dark seabirds), common eiders (massive ducks, with brown females and black-and-white males), or tiny buffleheads. Look for ducks especially at the Woods Hole end; loons, in contrast, can appear anywhere along the route, and often allow close views, since they often grow accustomed to the passing of the large ferry boats.

Less regularly seen birds sometimes reward on-deck vigilance. Green herons are sometimes visible shuttling between Naushon and the mainland; a pair of ospreys nests nearly every year right next to the Woods Hole ferry terminal; razorbills (small black-and-white auks) are fairly regular in winter; and if you get really lucky, you might spot a peregrine falcon, bald eagle, or other raptor crossing the water in search of fertile hunting grounds.

On the non-avian front, one wants to stay alert for insects during the warmer months. Once or twice, I’ve spotted a monarch butterfly from the ferry. And one day, a long dash skipper (a tiny butterfly) flew aboard just before an Oak Bluffs departure, perched in a sunny spot, and patiently rested and groomed until the approach to Woods Hole, when it took flight toward the mainland. The experience taught me that fare-evading insects sometimes use the ferry as a link to leave or travel to the Vineyard.

If there is one disappointment inherent in ferry naturalizing, it’s the relative paucity of marine life that’s visible. I’ve never seen any whale, dolphin, or porpoise from the boat; cetaceans rarely enter the shallow, restricted waters along the ferry route. However, harbor and occasionally gray seals are visible on the rocks at Woods Hole. Tremendous flotillas of jellyfish are sometimes visible. And when conditions are right, it’s sometimes possible to see massive blooms of plankton, rendering the ocean milky with a host of tiny plants and animals.

It’s not like having your own tuna boat ready for a “canyon run” whenever you feel the urge. But an SSA ferry provides a stable viewing platform, a warm interior if you get chilled, and — best of all — an easy way to get on the water.

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Though it shows a species that doesn't occur on the Vineyard, this photo of a winter crane fly perched on snow illustrates the hardiness and delicate structure of these insects, which look like mosquitoes. —Photo courtesy of James K. Lindsey

The first hard frost of the season — and the Island, by this point, has experienced several — marks a major change in the natural world. Wildlife unequipped to deal with sub-freezing temperatures has departed, gone dormant, or died. This means that the plants and animals still active here are members of a select club — organisms that have evolved specialized physiology or behavior that make cold temperatures tolerable.

Indeed, in the case of certain insects that are active in winter, temperatures around freezing aren’t just tolerable, they’re actively preferred. For these species, it’s warm weather, with its associated risk of overheating and desiccation, that is the danger.

If you keep a close eye on your porch light during the coming weeks, you may be able to spot a sterling example of this unusual lifestyle. December is peak season on the Vineyard for winter crane flies, a small, highly specialized group adapted to life in cold climates. Long-legged and seemingly fragile, adult winter crane are often attracted to lights, which makes them easy to find and observe.

Crane flies in general resemble oversized mosquitoes, which in fact are fairly close relatives of this group. But winter crane flies are in a different family — Trichoceridae — than our more familiar warm-weather crane flies. In addition to their penchant for cold, winter crane flies are distinguished from their summertime relatives by small size (about a half-inch long), the arrangement of the veins in their wing, and the presence of tiny light-sensing organs, called “ocelli,” on top of their heads (other crane flies lack these).

Trichoceridae is a small family, little studied even by entomologists. World-wide, about 160 species exist (next to nothing for a fly family); fewer than 30 species inhabit North America, most of them in a single genus, Trichocera. I don’t know how many species occur on the Vineyard; quite possibly there’s only one. Identification of this group, when it’s possible, depends on dissecting their genitalia under a microscope, and it’s not even clear that an adequate identification key exists for our region.

Whatever their precise identity, winter crane fly adults begin turning up at lights in mid-November and can be found in moderate weather through the winter. They never seem to be numerous, if the numbers turning up my lights are any indication, but they don’t seem fussy about habitat and are probably possible at any porch light on the Island. Despite the low temperatures, males and females manage to find each other to mate (some species reportedly concentrate into mating swarms, though I’ve never observed this).

Little else is known about their reproductive lives: eggs hatch in late winter or spring, larvae are scavengers that feed on decaying vegetation, and after a brief period of pupation, adults emerge again in fall. The small amount of research available on these insects suggests that winter crane flies are very flexible in the timing of their life cycle: larvae and pupae can speed up or slow down their development in response to changing conditions, and presumably do so in order to emerge as adults when conditions are most favorable for mating.

One area of study that has been pursued with these insects is their ability to function in the cold, which is truly remarkable. Some species have survived temperatures well below zero, and many are fully active and capable of flying in temperatures several degrees below the freezing point of water. Ours seem happiest in temperatures from the 30s to the upper 40s; when temperatures approach 60, adults risk overheating and are unlikely to be active.

The muscle tissues in these insects have probably evolved to contract well at low temperatures. And winter crane flies, like most other low-temperature insects, produce natural antifreeze: proteins that lower the freezing point of water and help prevent ice crystals from forming. The real risk to an insect in freezing conditions comes not so much from the cold itself, which a bug can often just sleep through, but from the formation of ice crystals within body tissues. These pointed crystals can pierce cell walls or damage cell organelles, and if you can keep the crystals from forming, cold weather survival becomes much easier.

As with other crane flies, adult winter crane flies have rudimentary mouth parts and eat little or nothing. Indeed, while they may have lively times when they’re out of sight, the ones I’ve seen appear to do little more than perch on a wall or window screen, waiting for a potential mate to arrive.

Given their quiet habits, obscurity, and seasonality, I don’t foresee a Trichoceridae fan club forming. These are not charismatic insects, and their roles in the ecosystem, as scavengers and not doubt sometimes as prey, are ordinary and probably easily filled by other species. But to my mind, there’s something elegant about an insect designed to flourish when all the world is frozen.

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A ring-necked duck in Mill Pond, 2010. —Photo by Sarah Mayhew

Telling someone where they can find a particular kind of bird is always risky. Birds move around a lot, and even if they’re where you say they should be, they often don’t cooperate by being visible or audible. So I really appreciate a reliable critter like the ring-necked duck, which allows a pronouncement like this one: if you bring your binoculars to the pond at Cranberry Acres, the exquisite little Vineyard Open Land Foundation preserve off Lambert’s Cove Road, any day over the next few weeks, it’s virtually certain that you can get a good look at a ring-necked duck. (But approach quietly, or that look will likely be of airborne birds, rapidly receding.)

They’re worth seeing, though. The males especially, now that they’re emerging from their brief post-breeding “eclipse” plumage, are singularly handsome ducks, with white flanks, dark backs, and iridescent purple heads. The duller females are also attractive in an understated way, brownish overall but echoing the two-toned body pattern of the males. Delicate white “spectacle” markings and a pale area around the base of the bill help distinguish female ring-necked ducks from other female waterfowl.

The overall effect is much like a scaup, or “bluebill.” But the solidly black back of a ring-necked duck is clearly darker than that of a scaup, and scaup (around the Island at least) prefer the sea or the great ponds to the shallow, interior ponds preferred by the ring-neck, which have boldly patterned bills, with a white ring adjacent to a dark tip.

But don’t get your hopes for seeing the eponymous neck ring: for reasons lost in ornithological history, like the ludicrously misnamed red-bellied woodpecker, this duck is named for a mark that is generally invisible in the field, a dull golden band at the base of the male’s neck. But both sexes feature a noticeable peak or crest on the head, and even in bad light, this structural feature will help identify a ring-necked duck.

For reasons best known to the ducks themselves, the pond at Cranberry Acres is a favorite location for these waterfowl as they move south on fall migration. They turn up in other ponds, too, and occasionally even on saltwater around the Island. But some historical accounts of this species note a tendency to favor some ponds over others, seemingly similar ones nearby, and this is definitely the case on the Vineyard. Cranberry Acres almost always has a flock at the appropriate season, and these flocks can be large: I’ve seen more than 30 individuals here. The first fall migrants may turn up as early as September; they’ll likely remain until the pond freezes and forces them farther south.

Ring-necked ducks have never struck me as especially wary. But their fondness for small ponds often means that you can’t see them until you’re quite close. So the first glimpse you get is often of a small flock taking wing in response to your presence. Capable fliers equipped for long migration, ring-necked ducks leap into the air without the running take-off of a scaup. The whistling sound of their wings as they take flight is a sound that I associate strongly with late autumn (and — a useful field mark — the wings lack the extensive white on the top side that characterize the two species of scaup).

The genus to which the ring-necked duck belongs contains some prodigious divers, like the canvasback and the two scaup species. And, to be sure, a ring-necked duck can dive perfectly well. But whether on its breeding grounds, during migration, or in its winter range in the southern United States, coastal Mexico, or the Caribbean, ring-necked ducks generally frequent shallow, weedy bodies of water where diving isn’t an especially useful talent. Ring-necks often feed by tipping their tails up like mallards, or even just picking up food or prey items from the water surface as they swim.

As with many kinds of waterfowl, their diets depend mainly on what’s readily available: aquatic vegetation, seeds, insects and insect larvae, and even occasionally frogs or salamanders. Cranberry Acres is a prolific breeding area for dragonflies, and it may be that an abundance of overwintering dragonfly larvae on the pond bottom is part of what brings these ducks to this pond so reliably.

A fairly numerous species that breeds in a wide swath across Canada and the northern tier of the United States, ring-necked ducks are generally in Massachusetts only during fall migration, and for an ever briefer visit in early spring. There are a few breeding records for the Bay State, though, and it wouldn’t surprise me too much if a pair of this species lingered to breed some spring, at Cranberry Acres or perhaps in a swampy cove head on a great pond. They’re versatile birds, clearly more focused on finding the resources they need than on playing by particular rules.

Ring-necked ducks are regular in small numbers on the Vineyard Christmas Bird Count, and as our winters grow progressively milder, these ducks are likely to grow more regular and more numerous in the winter months. I won’t complain; they’re lovely birds, and even having them here just for the autumn is a fine thing.

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Leaf miners left their lacy trails on this columbine leaf. —Photo by Danielle Zerbonne

The great outdoors can produce baffling mysteries. MVTimes Wild Side columnist Matt Pelikan tries his best to solve them. Got a question for the Wild Side? Send it to onisland@mvtimes.com.

Dear Matt:

What did this to my columbine plant?

– D.Z.

Dear D.Z.:

These damaged leaves most probably show the work of a columbine leaf miner, the larva of a tiny fly in the genus Phytomyza. This pest (if you want to view it that way) appears to be quite widespread and common, and it’s hard to grow columbine (Aquilegia) without attracting at least a few of these insects. Severe infestations can weaken or, conceivably, even kill a columbine plant, but in most cases no permanent damage is done and the only negative impact is seen on the leaves, such this one, which might have pale, winding tracks on them. Depending on how bad the infestation is, and your tolerance for partially eaten leaves, you can remove leaves that you see affected by leaf miners, or you can do nothing, taking some satisfaction in the fact that your garden is supporting an interesting insect. Because they are enclosed within the leaf, using chemicals to control leaf miners is hard to do (and I recommend against using insecticides at all unless you have a really compelling reason).

More generally, leaf mining is an interesting strategy used by an astonishing array of insects. The majority of leaf mining insects are probably flies (there is one whole family of flies that specializes in leaf mining). But certain types of moths, beetles, and wasps have developed the same lifestyle for their larvae. If you know what you’re doing (and unfortunately, I don’t) you can often identify a leaf miner by the shape of its tunnels. Also, there is a very close association between a particular leaf-mining insect and a particular species of plant. So identifying the plant that is being mined is a good way to start on identifying the leaf miner itself.

The advantages of being a leaf miner are clear: you’re totally immersed in your food supply, as you crawl your way between the top and bottom cuticles of the leaf. And the tough, outermost layer of cells on the leaf offer some protection against predators, desiccation, and pathogens. The adult form of a leaf miner, though, is as vulnerable as any other free-living insect, and naturally occurring predators and parasites generally keep leaf miner populations controlled to a reasonable level.

Southern New England is lucky to have an entomologist who is one of the most knowledgeable people in the world about leaf miners. Charlie Eiseman, though based in western Massachusetts, has done extensive work on leaf miners and other obscure insects on Nantucket. Charlie has written a book, Tracks and Signs of Insects and Other Invertebrates, that touches on leaf miners, and he’s working on a book entirely devoted to these highly specialized insects. His website, charlieeiseman.com, is worth checking out if you have an interest in the more bizarre branches of the insect world.

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Sonograms of about a half-second of two insect calls, one unknown from my yard and the other a known Carolina ground cricket from the Singing Insects of North America website. —Photo by Matt Pelikan

For many kinds of animals, hearing may be more important than vision, especially for governing social interactions. Birds, for example, have excellent eyesight, generally much better than ours, but the social world of many birds is more a world of sound than of vision. Their call notes maintain contact with associates, convey alarm, or express levels of arousal; their songs attract mates and mark the limits of territory.

Birders long ago realized that knowing the sounds made by different species was a powerful identification method, and accomplished birders can reliably identify hundreds of species by their songs and call. After all, it’s how the birds sort themselves out!

A basic insect recording rig. —Photo by Matt Pelikan
A basic insect recording rig. —Photo by Matt Pelikan

In the insect world, likewise, vision may be crucial for avoiding danger, locating food, or dodging obstacles while in flight. But some groups of insects have evolved complex anatomical structures aimed at producing sound for social purposes. The cricket calling in your yard is a male, advertising his presence to rivals and potential mates alike. If the weather is warm enough, the cricket may call nearly continuously for days on end, investing a high percentage of his energy into making noise.

The structures involved in insect sound production vary from group to group, but for crickets and katydids, the mechanism is a simple one. These insects rub rough areas at the bases of their wings together. The resulting scratches resonate across the leathery forewings of the insect, gaining volume, and some species also position themselves on leaves (sometimes dry, dead ones) so as to broadcast still more loudly.

But unlike the sound-producing mechanisms of a songbird or human, the so-called stridulatory apparatus of a cricket allows for very little variation. These insects have about as much flexibility in their sound-making as you do when you run your fingers along the teeth of comb. You can move your finger faster or slower, but you have almost no control over the pitch or tone of the teeth as you pluck them. The noise an insect produces, in other words, is largely determined by the configuration of its stridulatory structure. And since those structures vary from species to species, the sound you hear is in a sense a representation of certain details of the insect’s anatomy.

As a birder who has branched out into insect observation, I inevitably began trying to learn the songs of bugs. Some calls I’ve learned the hard way, tracing them to their source and then visually identifying the singer. But it’s also possible to learn songs from recordings, which are available on websites such as Singing Insects of North America (entnemdept.ufl.edu/walker/buzz) and Cornell University’s Macaulay Library (macaulaylibrary.org/), or on CDs that accompany some insect field guides.

Simply listening to recordings of known identity is one good way to learn insect calls; the human ear, as any musician will tell you, is a sensitive and discriminating instrument. But I’m also interested in using recording insect songs to produce physical documentation of the presence of different species. Moreover, because the production of sound is so central to the biology of crickets and katydids, I believe that analysis of their calls can help us understand the relationships among insect populations. Differences in the anatomy of insects will translate to differences in the sounds they produce, and careful enough examination of enough songs may lead to discoveries that other methods of observation have overlooked.

I’m currently experimenting with a field recording rig consisting of a basic “shotgun” microphone (designed to focus on sound coming from a very small area), a small digital audio recorder, and a set of cheap headphones to monitor the recording process. Good results are not easy to achieve: even with the shotgun mic, you need quiet, windless conditions and a close-range “listen” to get good recordings. But with care and patience, you can generally capture a few seconds of clean sound.

I use a free program called Audacity, a basic sound file editor, to snip out the best five or six seconds of a recording. Then I process the resulting file in another program, Raven Lite, to produce a graphical representation, called a sonogram, of the sound. (Raven Lite is available for free from the above-mentioned Macaulay Library website.) Sonograms have been used for years to visually portray bird songs, and more recently to illustrate the calls of bats. But the advent of digital sound formats, approachable processing software, and inexpensive recording equipment has made sonogram analysis available to amateur observers like me.

With the graphical representation of a song in front of you, you can see the timing of individual pulses of sound, examine their shape, determine what the primary frequency of the song is, and discern whether there are overtones or undertones. By comparing an unknown song to sonograms made from identified songs, you can find a good match and put a name to your anonymous singer. In effect, this technology allows you to eavesdrop on insects, capturing their conversations in a form that makes sense to a human mind.

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Even when they’re out of sight and out of mind, ants carry on with their important work.

Solenopsis molesta, a tiny, common species sometimes called the thief ant, magnified 30 times, shot through a microscope ocular. —Photo by Matt Pelikan

Suddenly, swarms of mysterious flying insects! First, I received a report of robust swarm of airborne bugs in Chilmark. Then another report came from an Aquinnah beach, and finally ace bird photographer Lanny McDowell posted a photo in a Vineyard birding Facebook group of a mockingbird inundated in a small but dense swarm of insects. Though that’s only three such reports, that’s three more than I’ve ever received in one season, and I surmise that this has been a good fall for this phenomenon. Perhaps the recent weather pattern — an extended dry spell followed by several heavy rains — prompted a burst of this activity.

First, it should be noted that lots of types of insects congregate into flying swarms, and they do it for several reasons. In particular, many types of midges (a group within the very large order of flies) often emerge from their larval state at once, in massive hatches. Such swarms are essentially insect singles bars — aggregations of individuals seeking to mate. Or sometimes, intent on feeding rather than flirtation, you may find a swarm of hundreds of dragonflies, convened where air currents concentrate prey.

The recent reports, though, didn’t sound to me like midges, nor yet like dragonflies. Happily, the observer in Chilmark managed to snag a few individuals out of the swarm she observed, and ran them by my office for examination under a dissecting microscope. And Lanny’s photograph showed enough detail of the insects for me to recognize them, in a general kind of way. In both cases, the flying insects were ants.

The idea of ants airborne on their own wings — especially in vast numbers — seems to surprise people, and reasonably so. We think of ants as being in or on the ground, or maybe inside a rotting log. We may admire their numbers or their industrious behavior, but there is nothing about routine ant behavior that would make one expect to see them take flight. And yet period swarming flights are a central part of the biology of most ants.

Here’s the deal. Virtually all of the ants you notice — the ones building ant-hills, scuttling across the pavement, or hauling food back to their colony — are females, though they lack a full set of reproductive apparatus. Inside an ant colony, often deep underground, there will be one or more special females (the number varies depending on species). These are queens, larger than their sister workers and basically optimized for laying eggs to populate the colony. You might say that the whole point of being an ant is to protect your queen, bring her food, tend her offspring, and allow her to reproduce.

But nothing lives for ever, and any species needs to have a way to disperse to new locations. Ants address these challenges by means of mass flights. First, seasonal cues prompt the queen (or queens) to begin producing different kinds of eggs, some hatching into winged males (the only time males are produced), others into queens, large-bodied like their mother but not yet quite ready to begin laying their own eggs.

These new queens also start their lives with wings, and in conjunction with the winged males, launch from the colony into a mass courtship flight. Each queen will mate with one or more lucky male (again, different ant species follow their own rules). The males, created to do nothing more than fly briefly and try to mate, die quickly. The now-fertile queens disperse, find a site for a new colony, and produce their own work force of sterile female workers. Voila! The species is perpetuated.

With a specimen queen from Chilmark adequately magnified, I was able to identify the ant species in that swarm as Solenopsis molesta, a tiny, common, and widespread species sometimes called the thief ant. Typical workers are only a couple of millimeters long; the queen, which I photographed, was about four millimeters long. The species is capable of colonizing a wide range of sites, from in the ground to inside the walls of a house. While Solensopsis often scavenges in natural settings, it can also turn up in homes and kitchens as a “grease ant.”

I have no idea what type of ants were involved in the other swarms; they could have been Solenopsis, too, but about 75 species of ant have been found on the Vineyard, with at least a few more surely not yet detected. Like ants most anywhere, ours are abundant and diverse, and mating swarms are a widespread habit among ants.

The sheer ant-power of their highly cooperative colonies makes them major players as scavengers, predators, and prey. But the main importance of ants may be their engineering prowess — the sheer volume of food they can collect and soil they can move.

Ants are agents for dispersing plant seeds; they break down debris and recycle nutrients; they aerate soil; their colonies host a wide range of parasites or partners, ranging from other ant species to beetles and bees. Mating swarms are an especially obvious sign of these humble insects. But even when they’re out of sight and out of mind, ants carry on with their important work.

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What’s this snake?

The garter snake that Laura Bamford found was a darker, less fancy version than this off-Island fellow. Garters on Martha's Vineyard, Matt Pelikan proposes, may have evolved so that their markings help them hide among plentiful oak leaves. – Photo by Matt Pelikan

The great outdoors can produce baffling mysteries. MVTimes Wild Side columnist Matt Pelikan tries his best to solve them. Got a question for the Wild Side? Send it to onisland@mvtimes.com.

Dear Matt,

We spotted this snake near the Farm Neck golf course in Hart Haven. Do you know what it is? We pushed it off the road so it would not get run over.

Laura Bamford

Laura Bamford spotted this snake near the Farm Neck Golf Club in Harthaven.
Laura Bamford spotted this snake near the Farm Neck Golf Club in Harthaven.

The snake Laura photographed is a garter snake, the most common (or at least the most commonly encountered) snake on Martha’s Vineyard. (Garter snake taxonomy is a frightful mess, and depending on what biologist you’re talking to, our garter snakes can be called either Eastern garter snakes common garter snakes. There are a variety of other garter snakes found across North America, with the relationships among them not well understood.) A medium-sized snake, rarely exceeding three feet in length in my experience, this species is widespread on the Vineyard; in particular, it seems to tolerate human activity fairly well, and as far as I know is the only one of our snakes likely to turn up in densely settled residential areas.

Garter snakes have a preference for damp habitats, but are quite flexible in their ecological requirements; likewise, they are versatile hunters, taking anything from earthworms to frogs to mice. Like all of the Island’s snakes, they are considered non-venomous, thought their saliva contains chemicals that may be toxic to some of their prey species and, according to some accounts, slows the clotting of blood. Given their role in regulating small rodent populations, the garter snake is a beneficial animal that should be welcomed wherever you find it. Like all of our snakes, garter snakes have suffered from road kill and predation by skunks, raccoons, and cats.

This is generally a docile species which often doesn’t try to bite even when you handle it (though they do have teeth — and a large one, if sufficiently annoyed, is capable of giving a pretty good nip). A more likely response when garter snakes are disturbed is release of a burst of foul-smelling musk from glands near the anus, and/or defecation on whoever is disturbing them.

Garter snakes may live for a decade or more if they escape being eating or getting mashed by an automobile. They overwinter, often in groups, by hibernating in dens, which are generally rocky sites such as old foundation, stone piles, or pits of debris. In warm weather, this snake is active day and night, and it is generally not hard to find one on the Vineyard.

The one Laura photographed, largely brown with a sort of checkerboard pattern, is typical of the garter snakes one finds on the Vineyard. But over its wide geographic range, our garter snake (whether one calls it Eastern or common) is a surprisingly variable animal. In some populations, these snakes are marked with yellow and black bands, resembling the closely related ribbon snake, which is also quite common on the Vineyard. This striped pattern is evident on typical Vineyard examples like Laura’s, if you look carefully, but the yellow strips are muted almost to invisibility by brown markings.

The distinctive appearance of our garter snakes may reflect the geographic isolation of our population during the five thousand years or so that the Vineyard has been an island. My own hypothesis, which is probably all wrong, is that the dominance on the Vineyard of oak trees, which shed brown leaves which are very slow to decay, may have led our garter snakes to evolve markings that help the snakes hide among fallen oak leaves.

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A handsome trig or red-headed bush cricket. It is commonly heard but rarely seen.

You may think you know what a cricket is. But “cricket” is a generic term, referring to a large and varied group of species. With grasshoppers and katydids, crickets make up the insect order Orthoptera; crickets are distinguished by having long antennae (unlike grasshoppers) and being generally less grasshopper-like than katydids. It’s a fascinating group, and a musical one: Crickets (along with katydids and some grasshoppers) produce “songs” by rubbing specially modified body parts together — a process known as stridulation. In the case of crickets, it’s generally roughened veins along a tough, leathery forewing that rub, and because the vibration resonates across the entire wing, cricket songs can be impressively loud for the work of such small animals.

The most accessible example of cricket stridulation comes from field crickets, of which the Vineyard has two, possibly three species. These are the large black crickets you find in your yard (and in your basement); their bodies are close to an inch long, and on females, a long, needle-like organ called an ovipositor protrudes from the tip of the abdomen. It looks dangerous but isn’t – its sole function is laying eggs in soil or leaf litter.

The two field cricket species I’m sure occur here are almost impossible to tell apart by appearance. But happily, the timing of their life cycles differs reliably. The spring field cricket hatches in the late summer, passes the winter as a hibernating nymph, and resumes growth when the weather warms in spring. By about early June, this species is fully grown and singing away in yards, meadows, and pastures. Spending the winter as an egg, the fall field cricket lags behind its cousin in developing, not reaching maturity until late summer. There is a brief period from late July to mid-August when I think both species can be heard; but by September, only the fall field cricket is active, and the difference in seasonality helps keeps these two closely related species from interbreeding.

The field crickets give the quintessential cricket song: a loud, relentless, but rather musical “crick, crick, crick …” The song is so familiar that many people barely notice it. But although these insects are easy to detect, they probably are not the most numerous crickets on the Island. That honor, I’m persuaded, goes to one of the field crickets’ smaller relatives, the so-called ground crickets. These insects resemble their heftier cousins, but as a group, ground crickets top out at about a half-inch in length. Some species barely break the quarter-inch mark.

Ground crickets, which mature and begin singing in mid-summer, produce sound in the same manner as their larger cousins, and the nature of the sound is therefore similar. But being smaller, ground crickets stridulate much faster, producing something more like a twitter than a series of well-spaced “cricks.” (Imagine a quickly rotating pulley with a squeaky pivot.) If you have ears and have ever been outside in the summer, you’ve surely heard several species of ground crickets without knowing it; while they occupy many types of habitat, ground crickets call day and night, and some species thrive in lawns and gardens.

But hearing one and seeing one are two different things. Ground crickets spend most of their lives concealed in leaf litter on the ground. Being both small and the same color as the debris they hide among, ground crickets are very, very hard to get a look at. By tracing the sound of a singing one, I can often narrow the search to a patch of ground a few inches square. But start poking around to find the singer, and your quarry shuts up and scuttles away. If you get a glimpse, you’re lucky, and if you can consistently get good looks at these creatures, well, you’re a better naturalist than I am!

The ground cricket species do differ in appearance, though, and even more so in how they sound; each species has a typical rate of chirping and distinctive tone quality. I’m gradually learning to distinguish them on this basis (at least three species occur widely on the Vineyard). And our other groups of crickets, which are no easier to see than the ground crickets, can similarly be recognized by sound: the tree crickets (a group of odd, ethereal, greenish bugs that sing sustained, musical trills), bush crickets or “trigs” (singers of scratchy songs from the ground and undergrowth), and even the mole cricket (never heard one myself, but I’m told they live here).

Masters of concealment, crickets are part of a vast community of insects that most people never see. But they’re out there, reproducing, eating, and being eaten, part of the huge web of life that surrounds us. And above all, they’re stridulating, millions of individual plucking sounds adding up to the soundtrack that characterizes a summer night. Abundant now, their numbers wane as the autumn progresses. Enjoy them while you can.

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Black racers (Coluber constrictor) are important predators in grasslands, shrublands, and forest edges, which are all part of the Vineyard landscape. —Photo by Patrick Coin

The great outdoors can produce baffling mysteries. MVTimes Wild Side columnist Matt Pelikan tries his best to solve them. Got a question for the Wild Side? Send it to onisland@mvtimes.com.

Dear Matt,

This, from our Tisbury columnist:

“By the way, have you seen a large black snake recently? Black racers (Coluber constrictor) are important predators in grasslands, shrublands, and forest edges, all part of the Vineyard landscape. They are harmless to humans but control rodent populations, including the white-footed mice that host deer ticks (and Lyme disease). The Vineyard Conservation Society is helping to collect data on these snakes.”

So, the question is, do you know any more than this? Should we be rooting for these snakes?

Yes, we should be rooting for them, and it’s been quite a while since I’ve seen a black racer. I wrote a column on what I perceive to be the steady decline in snake numbers about a year ago. I think racers are especially challenged because they move around a great deal, which makes them vulnerable to getting road-killed.

The Vineyard Conservation Society web site asks: If you have a black racer sighting to share, please contact BiodiversityWorks via email with any information, such as the location of the sighting, the date (or month and year), the number of times you saw it in that area, and any photos you may have of the snake. Email biodiversityworksLiz@gmail.com with any info.

Dear Matt,

stinkbug-eggs.jpgFound this on my grill cover last month.  It’s disappeared since, so I wasn’t able to observe it for long. It reminded me of something you’d find under the sea. This is a close-up; the entire thing was about a half-inch long. Do you know what deposited this interesting cluster?

It’s a cluster of insect eggs, likely something in the stinkbug branch of the business, but that’s the best I can do.

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Why choose venomous victuals when you could sup on a butterfly?

For this robber fly, supper will be a bumblebee. Sort of a mixed blessing, if one is not careful. (Photo by Matt Pelikan).

Predation of one insect by another is not surprising: entire orders of insects, like the dragonflies, are predatory; and among flies, beetles, and many other orders, some families have turned their back on eating plants and evolved into hunters. What surprises me is that, amid the vast variety available to an insect that eats other insects, some predators court danger by specializing in prey that fights back.

A robber fly preys on an ichneumon wasp. (Matt Pelikan)
A robber fly preys on an ichneumon wasp. (Matt Pelikan)

An example that I’ve been fascinated by lately is a dark gray robber fly called Proctacanthus (like most insects, it isn’t well enough known to have a common name). About an inch and a quarter long, Proctacanthus ranks among the largest robber flies found on the Vineyard, and although it seems to be rather solitary and territorial, it also seems to be fairly common and widespread. And, as far as I can tell, all it eats are bees and wasps.

Like all robber flies, Proctacanthus is harmless to people but bad news for other insects. Robber flies specialize in aerial ambush, picking flying insects out of the air, piercing their bodies with a sharp beak, and injecting the prey with chemicals that paralyze it and break down its tissues. The robber fly then, quite literally, drinks its dinner, using its pointed mouthparts like a straw to slurp up its liquefied prey. When the fly has drawn as much nourishment as it can from its victim’s body, it drops the empty husk and resumes hunting.

Suitable for their predatory habits, robber flies are powerful fliers, and their legs are equipped with long spines that help them capture and hold their victims. While many robber flies are generalists in terms of diet, others specialize. One species of robber fly is a notorious slayer of butterflies; another eats spiders right out of their webs. But none seem quite as wedded to taking dangerous prey as Proctacanthus.

The first Proctacanthus I ever found was clutching a bumblebee. A while later, I found one eating a black-and-white ichneumon wasp in a woodland clearing. Passing the same spot two hours later, I found what I feel sure was the same robber fly eating a different ichneumon wasp, this one bright orange. Almost every Proctacanthus I see is eating something when I find it; and every Proctacanthus I’ve seen with food has been consuming something that stings. When you’re not much larger than a wasp yourself, the possibility of death or serious injury from a sting is very real. So I found myself wondering how and why this fly evolved to live so dangerously.

The “why” is easy. Bees and wasps are a fine choice to specialize in, if you can avoid getting stung. Few other insects are looking to tangle with a wasp, so there is not much competition for prey. Because bees and wasps are abundant and diverse, they represent a plentiful, season-long source of food. And the fondness of bees and wasps for taking pollen or nectar from flowers makes them easy to find: a typical tactic for Proctacanthus seems to be to stake out a flower-rich area, wait for a bee to come close, and nail it.

Surely the size of Proctacanthus helps it successfully vanquish stinging insects. The wealth of spines lining its powerful legs undoubtedly help it keep a firm grip on its prey, and a fine layer of dense hair that covers parts of the fly’s body may offer a little protection against stings. But it was not until I saw Proctacanthus actually hit a prey item that I figured out its secret.

A female Proctacanthus had been hanging around my yard for a day or two; I had disturbed it several times and had seen it eating a tiny, iridescent green bee. Then as I was watching a yellow-jacket taking pollen from a flower, the wasp was suddenly swept out of my field of view by a swooping robber fly. Holding its prey, the fly landed briefly on a twig, quickly adjusted its grip on the yellow-jacket, and flew to another perch in a lilac bush.

I approached carefully, so as not to disturb the fly, but even so, I was enjoying close looks within about 15 seconds of its initial attack on the wasp. And at that point, the wasp already appeared to be totally paralyzed by the fly’s venom! Wrapped in the fly’s spiny arms, the yellow-jacket was utterly inert; the fly, with its beak embedded in the back of the wasp’s thorax, already appeared to be eating.

Perhaps all robber flies are equipped with venom that effective. But for Procatcanthus especially, the ability to quickly paralyze its prey is vital. Tackling wasps may sound dangerous. But with the right tactics and a fast-acting venom, Proctacanthus makes it look safe and easy, paralyzing its victims before they realize they’ve been attacked.