Digital Nature Walk - The Sand Plains of Glacial Lake Hitchcock
During the last Ice Age, New England, like much of the northern hemisphere, was covered by a massive glacier up to a mile thick. When the Ice Age ended and temperatures started to rise again around 18,000 years ago, this glacier began to melt and the resulting flood waters slowly filled the Connecticut Valley, forming a massive, but skinny glacial lake (Meszaros 2019). This lake, named Glacial Lake Hitchcock by the geologists who first discovered evidence of it, stretched at its height from what is today St. Johnsbury in Vermont all the way down to Rocky Hill, Connecticut, where a large sediment dam blocked the water from flowing into Long Island Sound. Much like the glacial lakes that we still see today in the far north, Lake Hitchcock would have been a dynamic place, with large chunks of ice regularly breaking off from the glacier in the warmer months and floating away through cloudy, turquoise waters. Along with its stores of frozen water, the glacier would also have released tons of sediment that it picked up back when it was still expanding across the landscape into the lake, where it would have formed large, shallow deltas or been deposited as dunes along the shore (Motzkin et al. 1999).
Around 11,500 years ago, the waters of Glacial Lake Hitchcock broke through the sediment dam, flowing down along the path of what is today the Connecticut River and into Long Island Sound, slowly draining the lake over a few thousand years (Meszaros 2019). While Lake Hitchcock itself is now gone, its memory is still preserved in the significant impacts it had on the geology of central New England, including the formation of the Connecticut River. In some places, it also left behind large sand plains, formed from the sediment that had dropped out of the melting glacier. Over time, these sand plains were colonized by various plants that could tolerate their dry, nutrient-poor soils and, eventually, sprouted open forests of pitch pine and scrub oak. Interspersed among the pines were buzzing meadows and patches of bare sand created by frequent natural and human -made fires that served as crucial habitat for a diverse community of burrowing invertebrates.
When Europeans colonized New England, they cut down many of the pitch pine groves and converted the sand plains to farmland. Some of the groves grew back in diminished form during the mass farmland abandonment of the late nineteenth and early twentieth centuries, but most of the plains were developed in the 1900s, resulting in severe declines in these unique habitats (Motzkin et al. 1999; Gluck 2015). Today, there are only a few places left in the state where the pitch pine forests and sand barrens of former Lake Hitchcock, along with the rare, sensitive ecological communities that they support, can still be found. For today's digital nature walk, we are going to explore one of these places.
The Pitch Pine Grove:
The trailhead doesn’t look like it would lead to one of the rarest ecosystems in the northeast - indeed, as somebody who already knows that it does, its normality is striking. As I walk along the edge of the small patch of forest that acts as a buffer between the sand plains and the matrix of bustling strip malls, highways, and suburban neighborhoods beyond, I note the familiarity of the ravenous green wall of sun-loving plants - oaks, cherries, locusts, catalpas, tree of heaven, and a tangle of vines - that block my access with a phalanx of vegetative matter and windblown garbage. When I reach the overgrown dirt path that leads through the wall and continue deeper into the preserve, I find more familiarity in the trees of the forest, which include all the usual suspects, from stately oaks to red maples already blushing in anticipation of fall. The vernal pools that stretch-out on the forest floor are full of water from a recent day of thunderstorms and the humid air is thick with mosquitos and the calls of frogs.
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| Pitch pine (Pinus rigida) crown |
The first sign that this place is any different from the many other swampy, suburban forests that I have eagerly explored in my time comes a little less than a quarter of a mile from the trailhead. In addition to the deciduous hardwoods that make up most of this forest, I have seen a few scattered conifers, including mostly white pines and a few eastern hemlocks - typical, again, for a forest like this one. As I reach this point, however, I notice a stand of trees that clearly do not belong to either of these species. The bunches of long, thin needles on these trees make it clear that they are a type of pine, but the bark appears almost scaly in comparison to the deep furrows of the white pines, and in a few individuals, there are toughs of needles growing out the gaps between the scales. This latter feature in particular pretty much gives away the identity of these mystery trees - there is only one species that I know of that does this - but I take a closer look at the needles anyways, just to confirm. After some brief confusion over a few bundles that have lost a needle, I finally confirm the identity of the tree with a full bundle of three - a pitch pine!
The pitch pine (Pinus rigida) gets its common name from its importance in colonial New England's ship building industry. While its towering cousin, the white pine (Pinus strobus), was prized for constructing masts, the wood of the pitch pine's resin-heavy wood was used to produce pitch, a tar-like substance for sealing seams in ship hulls and waterproofing wooden containers. The species was also commonly referred to as the candlewood because the resin-heavy knots in its wood burned easily and were often used for torches (Little et al. 1980). Today, in Connecticut, it is a fairly rare tree, at least in a classic, southern New England hardwood forest like this one, where you'll maybe see one or two, if that, in a whole afternoon of exploring. This is in large part because the pitch pine is an early successional species. In ecology, succession is what we call the semi-predicable process, driven by environmental conditions, species characteristics, and a fair amount of random chance, in which a plant community grows back after a disturbance, such as a storm or fire. An early successional species is one which specializes in growing and reproducing quickly under relatively competition-free conditions following a disturbance. Once other plants start to catch up, the early successional species are often outcompeted. Pitch pines, for example, require lots of sunlight, so when other, slower growing trees start to become established around them, they are typically either shaded out themselves or prevented from reproducing as their seedlings are denied adequate light (Little and Gerret; Gluck 2015).
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| Pitch pines can be identified by their scaled bark, as well as their needles which come in bundles of three and sometimes grow out of the trunk. |
There are two environmental factors which, when combined, can disrupt this successional pattern enough for you to get a forest dominated by pitch pines - sandy soils and frequent wildfires. In general, sand is a very tough medium for plants to grow in because it is made of comparatively large particles with lots of spaces between them, allowing water to drain out very quickly. Sand particles also don't carry any electrical charge (unlike smaller, negatively charged clay or silt particles) and so struggle to hold onto the positively charged nutrient ions required by plants. Among Connecticut's native trees, pitch pines seem to be especially well-adapted to growing in dry, nutrient-poor, and sandy soils, at least in part do their deep root systems, which can reach up to nine feet down into the soil under these conditions (Little and Gerret)! Such deep roots allow the pitch pine to go after isolated pockets of water or nutrients that other plants wouldn't be able to reach. In the Northeast, pitch pine-dominated forests are restricted almost entirely regions with sandy soils, including coastal areas such as Cape Cod and Long Island Sound and certain interior regions such the sand plains deposited by Glacial Lake Hitchcock (Little and Gerret; Gluck 2015). The species can also be found in relatively high numbers on the tops of rocky ridge lines, where similarly dry, nutrient poor soils limit competition, and around nutrient poor wetlands and bogs.
In addition to their impressive ability to grow in sandy soils, pitch pines are also remarkably resistant to fire damage (Little et al. 1980; Little and Gerret). Like many pines, they have very thick bark that acts as a shield against injury from flames, especially for larger, old-growth individuals. In cases where its branches and needles are seriously damaged by fire, a pitch pine can rapidly grow back from special buds in its trunk and crown that are protected by its thick bark or from buds around its base and roots that are protected by the soil. In certain populations that are exposed to high rates of wildfires, pitch pines have even evolved special, serotinous cones that allow them to take advantage of the sunny conditions and lack of competition that occur in the wake of large fires to reproduce. These special cones remain on the tree instead of falling to the ground and are sealed with a waxy substance that melts away in the heat of a fire, allowing the seeds to drop out.
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| Bushes in the heath family (Ericaceae), such as blueberries and huckleberries, are common in poor-nutrient, sandy soils such as those found in many pitch pine groves. |
While rare compared to other New England habitats, the combination of sandy soil and frequent wildfires necessary for a pitch pine forest to form was historically common enough that a distinct, open forest community was able to develop around it. In addition to the pitch pines, sandy soils and frequent fires support various drought and fire adapted oaks, such as the scrub oak (Quercus ilicifolia), as well as members of the heath family (Ericaceae), including blueberry, huckleberry, and bearberry (Kricher and Morrison 1998). A number of birds, including pine warblers (Setophaga pinus), pine grossbeaks (Pinicola enucleator), and black-capped chickadees (Poecile atricapillus), feed on the seeds of the pitch pine (Little and Gerret), while insects such as the buck moth (Hemileuca maia) and Gerhard's underwing (Catocala herodias) rely on scrub oak as a nearly exclusive larval food source (Gluck 2015).
Like most rare habitat types, pitch pine forests are especially susceptible to disturbance by human activates. Both coastal and central Connecticut - the two regions of the state with the most expansive areas of sandy soils - have been heavily developed since European colonization, drastically reducing the already limited area available for pitch pine forests to grow in. Forests which were converted to farmland and then allowed to grow back after the mass abandonment of agricultural land in the late nineteenth and early twentieth centuries have done so in a somewhat degraded form, often lacking scrub oaks and other important species (Motzkin et al. 1999). Meanwhile, urbanization has resulted in both the development of the sand plains and the fragmentation of remaining habitat. In surviving, intact pitch pine forests, disruption of natural fire regimes by European settlers over the past few centuries has allowed organic matter to accumulate on the forest floor and exposed them to the possibility of being taken over by the white pines and various hardwoods that typically outcompete pitch pines in other habitats (Little et al 1980; Motzkin et al.1999). As a result of both development and fire suppression, an estimated 95% of Connecticut's pitch pine forests have been destroyed or seriously degraded, and the invertebrate community associated with it has become the state's most endangered (Connecticut Department of Environmental Protection 2005). In response, the state's Forestry Division has focused on trying to hold back the tides of succession in the remaining forests, both through controlled burns and selective cutting combined with intentional scaring of the ground, which creates similar growth conditions to those found after natural disturbances (Gluck 2015).
The Meadow:
As I continue farther down the trail, I see more and more pitch pines, though they never dominate to same extent as other groves I've seen nearer to the coast. The property that we are on has a history of development, including use as a fairground, so it seems likely that the area was cleared at some point and that the pitch pine forest that has grown back is somewhat diminished. Indeed, it seems possible that succession is proceeding in such a way that this particular stand could one day disappear. Still, the pitch pines' increasing presence is a good sign that the soils below our feet are getting sandier and, sure enough, in another few hundred yards, I turn a corner and arrive at a clearing, where the forest suddenly gives way to an open, dry meadow, interspersed by large patches of loose, almost totally bare sand.
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| Great Plains flatsedge (Cyperus lupulinus) |
In addition to preventing the pitch pine forests from being outcompeted by the hardwoods and white pines of your typical Connecticut forest, the fire regimes of precolonial New England would have opened up clearings much like this one, as well as maintained patches of loose, bare sand (Gluck 2015). Because of their dry, nutrient-poor conditions, these patches can only be colonized by a small subset of plants that are highly tolerant of sandy soils, such as the Great Plains flatsedge (Cyperus lupulinus) pictured above. Given enough time, the dead organic matter produced over multiple generations of these first colonizer plants would be able to support a wider diversity of sand-adapted species, forming an open, sandy meadow habitat and, eventually, a forest of pitch pine and scrub oak. Before European colonization, this path of succession from open sand to sandy meadow to pitch pine forest would have been halted at different stages in different areas by the occurrence of natural and human-made fires across the landscape - in one place, perhaps, the fires would be frequent enough to keep the ground relatively free of vegetation and leaf litter, preserving those patches of loose, bare sand long-term, while in another spot, it would be rare enough that old growth pitch pine forests were able to form, but not so rare that they were outcompeted by hardwoods. The result would have been a matrix of different successional stages that provided habitat for a diverse community of animals.
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| A sand wasp in the genus Microbembex pollinating a butterfly weed plant (Asclepias tuberosa). |
After European colonization, the fire regime that maintained this diverse matrix of habitats in the Connecticut Valley was heavily suppressed, but at this particular site, Connecticut's State Wildlife and Forestry Divisions regularly perform controlled burns that turn back the successional clock each year to maintain a nice of mix of meadow and bare sand habitat. As I emerge out of the forest and into the clearing, I find myself standing in the middle of the former habitat type which, on this particular day in early July, is decorated with the bright orange flowers of several blooming butterfly weeds (Asclepias tuberosa). A member of the milkweed family, this lovely plant typically grows in dry, gravelly or sandy areas and, like some of the sidewalk plants that we discussed last month, has a deep taproot that helps it to access water in well-drained soils. Its name comes from its attractiveness to butterflies, both as a source of nectar for adults and as a host plant for monarch and grey hairstreak butterfly caterpillars. Like all milkweeds, the foliage of butterfly weed contains high concentrations of cardiac glycoside, a noxious compound that makes the plant unpalatable to would-be browsers and which is transferred into monarch butterfly caterpillars when they feed on it, making them unappetizing to their predators as well (USDA NRCS National Plant Data Center 2006).
While I didn't see any monarchs or other butterflies hanging around these particular butterfly weeds, the flowers were still being well serviced by other pollinators, including several sand wasps in the genus Microbembex. As the name implies, these wasps require vegetatively sparse, sandy habitats, like those found in deserts, beaches, and, of course, sand plains like this one, in order to breed. After mating, a female wasp will dig a burrow in the sand, where she will lay a single egg. She then flies off and, in between feeding on nectar from flowers like those of the butterfly weed, hunts for insects to bring back for her more ravenous larva. Unlike many other wasps with a similar breeding strategy, most Microbembex wasps are progressive provisioners, meaning that they continuously bring food for their larva as they grow, rather than stocking the burrow with preserved dead insects at the outset (Lopez et al. 2014). This means that they must remember where their burrows are, a feat which is all the more difficult for species such as the common Microbembex monodonta, which fill their burrows in with sand every time they leave. In a clever series of experiments, biologists Matthew Cormons and Jochen Zell (2023) used various methods to obscure the visual, olfactory, tactile, and vibrational cues that the wasps they studied might use to find their burrows again after a hunting trip. By varying the placement of landmarks around the entrance to the burrow and adding or removing a large barrier that blocked the wasps' panoramic view of more distant landmarks, they were able to determine that Microbembex monodonta primarily use a combination of local and background visual cues to find their burrows. In this, they are very similar to other solitary bees and wasps, which are well known for their impressive visual memories.
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| Deer-tongue grass (Dichanthelium clandestinum) |
Besides the butterfly weed, the meadow didn't really have too many other plants that were flowering. A nearby patch of wrinkle-leaf goldenrod (Solidago rugosa) will surely be a sight to see in the fall, when sickle blades of bright yellow flowers will emerge from their lengthening stalks, but for now, their beauty is concentrated more subtly in the textures of their name-sake leaves. Meanwhile, towards the middle of the meadow is a large swath of deer-tongue grass (Dichanthelium clandestinum), one of my favorite species and an important wildlife food plant commonly found along roadsides and forest edges. Like many grasses, deer-tongue grass produces two kinds of flowers, one of which is produced during the mid-summer and is wind pollinated, and another which is produced in the late summer or fall and is self-pollinated. The self-pollinating flowers are hidden in the hollow sheaths of the grass' stems, such that the resulting seeds often remain in the sheaths until after they die back at the end of the growing season, making them an important fall and early winter food source for birds like the dark-eyed junco, American goldfinch, and wild turkey. For most grasses that use this strategy of producing both cross-pollinated and self-pollinated flowers, it is thought to be an adaptation to growth in early successional, resource-poor, or high herbivory habitats. While the self-pollinated flowers do not produce seeds with as much genetic variation as the cross-pollinated flowers, they do require fewer resources to produce and so can be used to spread quickly or to buy a population time in tough growing conditions. According to Campbell et al. (1983), about 60% of grasses that use this strategy are early successional species and about 2/3s of the remaining species specialize in extreme habitat conditions. In the specific case of deer-tongue grass, there is evidence that they produce more self-pollinating flowers under dryer conditions, though it isn't entirely clear if this is a direct adaptation to dry soils or simply a side effect of plants not being able to grow as large when there isn't adequate access to water (Cheplick 2007).
The Sand Patches:
Moving deeper into the clearing, we arrive at the final habitat type found at this site - a large patch of loose, bare sand, sparsely vegetated with only a few small tufts of flatsedge and switch grass (Panicum virgatum) growing here and there. While it may sound much less exciting than a meadow full of wasps and wildflowers or a rare pitch pine forest, this patch of sand, and a few other similar ones scattered around the clearing, are actually the main reason why I am here today. Keeping these patches relatively free of vegetation is also the main reason why the state burns this clearing each year - there are rare and fascinating organisms which prefer it that way.
We've already gotten a hint about the importance of loose, bare sand from the Microbembex wasps we found feeding in the meadow. Sand is a relatively easy substrate to dig in and, as a result, a lot of insects and other invertebrates have evolved to burrow into it, whether it be to find shelter for themselves or for their offspring. Because roots hold the soil together, sandy areas with fewer plants tend to have soils that are easier to dig into and so many sand-burrowing invertebrates prefer them. Bare sand can also provide good places to bask in the sun, allowing cold-blooded insects to warm-up, as well as open hunting grounds for predatory species to stalk their prey. Tiger beetles in the family Cicindelidae include an especially diverse assortment of species that specialize on bare sand habitats, and, in Connecticut, these species have come under particular threat. The most famous of these threatened tiger beetles (though, really not that famous, unfortunately) is the puritan tiger beetle (Cicindela puritana), one of Connecticut's only federally endangered species. The beetle is a sand bar specialist that has been pushed out of almost all of its habitat along the shores of the Connecticut River and the Chesapeake Bay, leaving only a handful of populations left. Though fairly common elsewhere, the ghost sand tiger beetle (Cicindela lepida), a pale, dainty species that lives on coastal dunes and interior sand plains like this one, is a state-listed endangered species in Connecticut, where only two known populations remain.
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| Big sand tiger beetle (Cicindela formosa) |
Big sand tiger beetles are particularly well adapted to navigating the difficult thermal landscape of their sandy habitat (Bell et al. 2019). Because they are cold-blooded organisms, beetles cannot regulate their own body temperatures like we can; instead, their body temperatures are influenced by the environment around them. In the morning, when temperatures are cooler and a beetle needs to bask in the sun to warm up its body, it is able to take advantage of the fact that sand has a very low specific heat, meaning that sandy soils take relatively little energy input in order to heat up. It is therefore possible for even fairly large beetles like the big sand tiger beetle to raise their body temperatures in a reasonable amount of time when basking on sand. However, in the intense heat of a summer afternoon, the high temperatures of a sandy surface can also create the opposite problem for beetles and cause them to become overheated. On warm days like this one, you will often see tiger beetles engaged in a behavior called "stilting," in which they rear up as high as they can on their long, thin legs, pushing their bodies away from the hot surface of the sand and (hopefully!) into cooling breezes (Dreisig 1990). Subspecies of the big sand tiger beetle that live in hotter regions also tend to have more white on their shells, which reflects sunlight instead of absorbing its heat (Schultz & Hadley 1987). If all that isn't enough, the beetles will take shelter under the sparse vegetation around the edges of the patch or burrow down into the sand. While the surface of sand can be very warm, it often cools down quite a bit just a short distance below the surface because sand does not conduct heat very well, meaning that it does not spread easily down through the soil column. This is why so many desert-dwelling critters live in burrows.
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| Clubbed mydas fly (Mydas clavatus) |
It isn't just habitat specialists like the big sand tiger beetle that appreciate the temperature regulating potential of sand - other, more wide-ranging insects will take advantage of its usefulness as a surface to bask on as well. While I am watching the beetles, a large, buzzing insect that I think at first is some kind of bee or wasp does several close fly-bys. I quickly retreat away from the area that the insect seems to be defending, but later, I see it land on the surface of the sand patch and identify it, not as a stinging bee or wasp, but as a clubbed mydas fly (Mydas clavatus). Named for the golden band on their abdomen, members of this small, little know family of flies are apparently not an uncommon sight on bare sand patches (at least down in Texas), where they bask in the sun to warm up, just like the tiger beetles (Camp 2005). However, unlike the beetles, they do not, as far as I can tell, rely exclusively on sandy soils for reproduction, instead laying their eggs around dead wood, where their larva feed on beetle grubs.
The coolest thing about the clubbed mydas fly (in my opinion) is that it is what biologists call a Batesian mimic, meaning that it visually and/or behaviorally mimics a species with some nasty defensive weapon - in this case, certain stinging spider wasps in the family Pompilidae - despite actually being completely harmless (Missouri Department of Conservation). This allows the mimic to take advantage of the bad experiences that many predators have likely had with trying to eat the critter that they are imitating and, ideally, avoid getting eaten themselves. In the case of the clubbed mydas fly, their similarities to a spider wasp (which are pretty convincing, aside from their namesake clubbed antenna) apparently work well enough that they feel confident using them more aggressively - experiences like mine, where they try to intimidate humans many times their size, are apparently not uncommon.
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| Velvet ant (Pseudomethoca sp.) |
Speaking of insects that look like something they are not, I also noticed a number these tiny, reddish ants rushing this way and that across the sand patch, carefully exploring any small holes or divots in the soil with their antenna. The last time I was here helping with a controlled burn, a state entomologist pointed these guys out to me and told me that they are female velvet ants, probably (based on my own research) in the genus Pseudomethoca. She also told me, to my surprise, that they are not in fact ants, but wasps! So, we now have a big fly that is imitating a wasp and a bunch of wasps that looks like ants - the sand plains can be a confusing place! Unlike the mydas fly, however, the velvet ant's similarities to actual ants are not a case of one organism evolving to imitate another for defensive purposes, but of two groups of organisms being very closely related. Both wasps and ants, along with bees, are part of the same order - Hymenoptera - and there are actually a lot of cases of visual similarity within the order. We have talked before on this blog, for example, about the nuptial flights of certain ant species, in which members of the winged breeding castes take to the skies en masse to mate. Just as these winged ants look a little like wasps at first glance, so the female velvet ant looks like an ant.
Interestingly, it is only the female velvet ant which is wingless - the male has a full set of wings just like any other wasp and flits around the skies above patches of bare sand, looking for females and feeding on the nectar of flowers. Females, meanwhile, crawl around on the ground, using chemical cues to look for the burrows of ground-nesting bees and wasps, which their young parasitize. Hosts vary quite a bit, with most velvet ants specializing on a particular species or group of solitary wasp or bee, though there are few that specialize on social wasps, bees, or ants. Upon finding a suitable nest, the velvet ant will gain access, a process which can be as simple as walking or digging down into a hole in the ground, but might also be quite challenging if the nest is well-guarded, as is often the case for highly social hosts. In these cases, she will rush the entrance as the guard or guards try to sting her, relying on her thick exoskeleton to deflect their attacks. It may take several attempts for a velvet ant to get inside a nest under these circumstances, but if she does get inside, she will find the chamber or chambers within the nest where the host keeps its own young and find some that are at the right stage of development - meaning, in most cases, that they have entered their cocoons or pupae. If they are at the right stage, she will lay her eggs near the pupae, then use her stinger to paralyze the young bee or wasp within and stop its growth. After the eggs hatch, her young will feed on the paralyzed pupae until they grow big enough to pupate themselves and turn into adults (Brothers et al. 2000).
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| Burrowing wolf spider (Geolycosa sp) turret. Note the hollow chamber in the middle that leads down into the vertical burrow |
In addition to the velvet ants, my entomologist college also pointed out signs of the final critter we will be looking at today, signs that I probably would never have noticed if she hadn't said anything. Here and there around the edges of the sand patches were small clusters of turret-like structures built from small pieces of wood, charcoal, and pebbles. A closer look reveals that the turrets are hollow and lead down into vertical shafts. These are the homes of the aptly named burrowing wolf spiders in the genus Geolycosa. Unlike many wolf spiders, which are active hunters that chase down their prey of small insects and other invertebrates, turret spiders are ambush predators that seize prey that wonder too close to their burrows, which they dig out with their fangs and, in some species, protect from the elements using these turrets. In an interesting paper about the digging process, Suter and their collegues (2011) provide some specific numbers for the general rule that we talked about above, where sandy habitats often support lots of burrowing animals because it is easier to dig in sand. According to their calculations, a typical burrow, which is about 13 cm deep, requires that about 23-29 joules of energy be spent by a spider digging in small-particle, tightly packed clay soils vs. only 8-10 joules in large-particle, loosely packed sandy soils. As with the sand tiger beetles and other sand burrowing species, burrowing wolf spiders also use their burrows to regulate their body temperature, moving up and down along the vertical length of the burrow to warm and cool themselves (Humphreys 1978).
Most species burrowing wolf spiders spend just about all of their lives in the burrows they construct for themselves, with the exception of males that come out upon sexual maturity to look for a mate. When they find one, the male moves into the female's burrow for a while until she molts for the final time before reaching sexual maturity and pushes him out. The male then performs a display of simple body movements and tapping and waving legs before mating. Interestingly, female burrowing wolf spiders are actually quite attentive mothers, who carry their eggs on their backs until they hatch and then continue to carry around their young for a while without risk of being eaten (something that cannot be said about all spiders). When they are still fairly small, the young spiders leave their mother's burrow and start digging their own, usually not too far away, which they continue to renovate and expand as the molt and grow older. Burrowing wolf spiders have a two-year life cycle in which young spiders overwinter twice in their burrows before reaching sexual maturity (Miller and Miller 1987).
The Ethics of Delicate Habitats:
Well, that just about wraps up our tour of the Sand Plains of Glacial Lake Hitchcock! I hope you enjoyed learning about this strange, fascinating habitat as much as I enjoyed exploring it. Before we part ways there is one last important thing that I want to talk about. One of my main purposes in writing this blog generally and in writing series such as Digital Nature Walks and City Flora specifically, is to encourage informed encounters between people and the more-than-human world around them. I am a big believer in the idea that the best way to motivate people to protect threatened places and organisms is to get them first to love and appreciate them; and the best way to get people to love and appreciate things that aren't intuitively interesting or inspiring is by providing them with information that challenges that intuition so that the next time they encounter that place or organism, they see it in a new, deeper way. By giving people a few cool facts about the plants they see on the side of the road during their commute or the birds they hear while hanging out at the local park, you can hopefully encourage them to open their eyes to the diversity of life around them and to start thinking ecologically - why do some organisms live here and others don't? What traits do they share? How do I affect the ecosystem I live in and how does it affect me? That is why I generally give details about the locations of the places I go to for Digital Nature Walks, including the name of the place, the town name, and even trail access locations - if you can, I want you to go and see these things for yourself!
As you may have already noticed, I have not provided much of any detailed information for this particular article on the location of the site I explored, and that's because, if I am being honest, I don't necessarily want you to visit it. While the site is very ecologically interesting and sits on land that is fully open to the public, it also contains a very small example of a rare and delicate ecosystem that is home to some rare and sensitive plants and animals. Many of the organisms that we talked about here, including some state listed species, require the bare, loose sand found in the clearing in order to survive and reproduce, and too many people visiting and trampling these areas could leave them uninhabitable. Given the details that I do give, it would be possible (if perhaps a little difficult) to find where this site is and how to access it, but I would encourage anybody reading who is interested in visiting to first think deeply about why it is that they want to do so. For me, I wanted to visit because I have a particular (if somewhat amateurish) interest in the sand tiger beetles that live there and in organisms that specialize in rare habitats. I also wanted to get some photographs that I could use to share the beauty of this place with people who might not know about it, something which I do think is important for preserving sand plain habitats in the long term. Now that those goals have been completed, however, I have no plans to go back in the near future, except possibly to help out with some of the management work through which I learned about this site in the first place.
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| Eastern coyote (Canis latrans var.) footprints. Other animals that recently passed through the clearing and left their footprints behind included white-tailed deer, wild turkey, and eastern cottontail rabbit. |
For most people reading this, I suspect that just learning that the sand plains exist and being introduced to the plants and animals that call them home will be enough. If you are one of these people and you live in Connecticut, Massachusetts, New Hampshire, or Vermont, I would encourage you to keep an ear open for talk of sand plains and to be ready to raise a stink if they are threatened - there aren't many intact examples left and, unfortunately, not all of them are protected. If you read this and you really want to see the sand plains in person, I would consider taking the trail just to the edge of the clearing and viewing it without actually walking on the sensitive sand patches beyond. If you are really interested in seeing a bunch of specific, sand loving plants and insects with your own eyes, consider looking for them in a less rare ecosystem or, if the uniqueness of seeing them on the sand plains is the whole thing, at least be sure to follow these rules during your visit.
1.) Plan your visit for late July or August - without getting into too much detail, there is an active coyote den that you have to pass pretty close to in order to get to the dunes. By this point in the summer, the pups should be old enough that a small disturbance from you won't be a huge deal and the insects will also still be out.
2.) Watch your step - a lot of the insects here live in burrows, so watch out for these and try not to step on them. There is a loose trail running down the center of the clearing and you should try to stick to it as much as possible. Don't ride a bike, ATV, or any other kind of vehicle anywhere in the property, but especially in the clearing.
3.) Don't pick up or take ANYTHING - that includes, but is not limited to: plants, animals, insects, rocks, sediment, or cultural artifacts. Watch, observe, photograph, but do not capture. Also, don't litter.
4.) Consider only going once - plan to spend a few hours at the site. Enjoy yourself, be respectful, take your time, and then leave the place alone. Don't return frequently or perhaps ever.
I hope that all of this doesn't sound too gate keep-y. The line we are trying to walk here is a genuinely challenging one, running between the real benefits that personal encounters with places and organisms can have for motivating people towards conservation and the risk that too much encounter will cause damage to the more sensitive among them. The last thing I want to do is tamper down on anybody’s enthusiasm and I hope that as we went on this walk together, you found wonder in the existence of this strange place and its unique creatures. As we part ways, I hope that you will now continue down this path towards loving them and that this will lead you to think deeply about the best ways for you to help protect this and other rare habitats wherever you may live.
Sources:
Bell, A. J., Calladine, K. S., & Phillips, I. D. (2019). Distribution, abundance, and ecology of the threatened Gibson’s Big Sand Tiger Beetle (Cicindela formosa gibsoni Brown) in the Elbow Sand Hills of Saskatchewan. Journal of Insect Conservation, 23, 957-965.
Brothers, D. J., Tschuch, G., & Burger, F. (2000). Associations of mutillid wasps (Hymenoptera, Mutillidae) with eusocial insects. Insectes sociaux, 47, 201-211.
Camp, D. (2005). Beneficials in the Garden - Mydas fly. Galveston County Master Gardeners. https://aggie-hort.tamu.edu/galveston/beneficials/beneficial-26_mydas_fly_1_(Mydas%20clavata).htm (Or Mydas Fly - Galveston County Master Gardeners)
Campbell, C. S., Quinn, J. A., Cheplick, G. P., & Bell, T. J. (1983). Cleistogamy in grasses. Annual review of ecology and systematics, 14, 411-441.
Cheplick, G. P. (2007). Plasticity of chasmogamous and cleistogamous reproductive allocation in grasses. Aliso: A Journal of Systematic and Floristic Botany, 23(1), 286-294.
Connecticut Department of Environmental Protection (2005). Comprehensive wildlife conservation strategy. Connecticut Department of Environmental Protection
Cormons, M. J., & Zeil, J. (2023). Digger wasps Microbembex monodonta SAY (Hymenoptera, Crabronidae) rely exclusively on visual cues when pinpointing their nest entrances. PloS one, 18(3), e0282144.
Dreisig, H. (1990). Thermoregulatory stilting in tiger beetles, Cicindela hybrida L. Journal of arid environments, 19(3), 297-302.
Gluck, E. (2015). Pitch Pine-Scrub Oak Barrens. Connecticut Woodlands. https://www.business.ct.gov/-/media/deep/forestry/spb/ctwoodlandspitchpine2pdf.pdf
Humphreys, W. F. (1978). The thermal biology of Geolycosa godeffroyi and other burrow inhabiting Lycosidae (Araneae) in Australia. Oecologia, 31, 319-347.
Kricher, J. & Morrison, G. (1998). Peterson Field Guide to Eastern Forests: A Field Guide to Birds, Mammals, Trees, Flowers, and More. Houghton Mifflin.
Little, E.L., Bullaty, S., Lomeo, A., Rayfield, S. and Buehl, O. (1980). National Audubon Society Field Guide to Trees, Eastern Region. Alfred A. Knopf.
Little, S. & Gerret, P.W. (N.A.) Pitch pine. United States Forest Service. https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/pinus/rigida.htm
Lopez, V. A., Reinoso, P. L., Hook, A. W., & Matthews, R. W. (2014). Red Imported Fire Ant Alate Corpses Opportunistically Used as a Major Food Resource by a Scavenging Solitary Wasp (Hymenoptera: Crabronidae). Journal of Entomological Science, 49(4), 337-341.
Miller, G. L., & Miller, P. R. (1987). Life cycle and courtship behavior of the burrowing wolf spider Geolycosa turricola (Treat)(Araneae, Lycosidae). Journal of Arachnology, 385-394.
Missouri Department of Conservation (N.A.). Mydas flies. Discover Nature Field Guide. https://mdc.mo.gov/discover-nature/field-guide/mydas-flies
Motzkin, G., Patterson III, W. A., & Foster, D. R. (1999). A historical perspective on pitch pine–scrub oak communities in the Connecticut Valley of Massachusetts. Ecosystems, 2, 255-273.
Montana Natural Heritage Program (N.A.). Big sand tiger beetle - Cicindela formosa formosa. Montana Field Guide. https://fieldguide.mt.gov/speciesDetail.aspx?elcode=IICOL02046
Schultz, T. D., & Hadley, N. F. (1987). Structural colors of tiger beetles and their role in heat transfer through the integument. Physiological Zoology, 60(6), 737-745.
Suter, R. B., Stratton, G. E., & Miller, P. R. (2011). Mechanics and energetics of excavation by burrowing wolf spiders, Geolycosa spp. Journal of Insect Science, 11(1), 22.
USDA NRCS National Plant Data Center (2006). Butterfly milkweed (Asclepias tuberosa L.). USDA Plant Guides. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/cs_astu.pdf
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