In Bloom Now: American Cow-Parsnip

Milestone & Turner Rd Cow parsnip, J Lentowski

American cow-parsnip (Heracleum maximum) growing in disturbed soil around a paper birch near the intersection of Milestone and Turner Roads.

If you’re out and about on Nantucket this month and see super-sized umbels of white flowers that resemble Queen Anne’s lace but are the size of dinner plates, topping plants with beefy stems and large coarse leaves, it’s likely you have come across American cow-parsnip (Heracleum maximum). Typically found at the edges of wetlands and salt marshes, this native wildflower can also pop up unexpectedly in clearings where the soil has been disturbed and the soil is fairly rich and damp.

American cow parsnip Leaf, Williams Ln, Ellen Phelan

A compound leaf of American cow-parsnip.

American cow-parsnip flies under the radar its first season, producing only a bunch of leaves, but in the second spring it makes a grand entrance by sending up flower stalks usually 3-6′ tall, and producing umbels that are around 8″ in diameter. While a plant of this size is sure to make a splash no matter what, American cow-parsnip produces an added frisson of fear in a lot of people, because it is a close relative to giant hogweed (Heracleum mantegazzianum), which is a serious invasive weed introduced from Eurasia. Giant hogweed was introduced as an ornamental by Victorian gardeners, who also brought us such delights as Japanese knotweed (Fallopia japonica) and black swallow-wort, also known as dog-strangling vine (Cynanchum louiseae). The Victorians loved novelty in the form of oversized plants, particularly ones with a sinister twist, apparently. Giant hogweed (also called giant cow-parsnip by some) causes a severe blistering skin reaction that leaves permanent scarring, so it has made the blacklist of “Most Dangerous Weeds” in a lot of places.

Amer Cow Parsnip portrait, KAO

American cow-parsnip showing off its compound umbels and compound leaves.

So, if you stumble across an enormous white-umbeled plant that looks like a Queen Anne’s lace from the Little Shop of Horrors, how can you tell whether it’s giant hogweed or American Cow-parsnip? And why should you care?

First off, it’s wise not to handle ANY plants in the Apiaceae (Carrot & Parsley Family) casually, so take a look rather than wading right in. Did you know that even home garden plants like parsley, carrots, and parsnip all produce harmful furanocoumarins in their vegetation? These are chemicals that when rubbed on your skin followed by sun exposure, can cause blistering burns, a condition called phytophotodermatitis. Handling carrots or parsley is not always a problem, but if the plants are wet, or if you get the oils on sensitive skin, or in large quantities, you can wind up with fluid filled blisters like poison ivy, only less itchy. The oils quickly bond to your skin, and spending even a short time in the sun afterwards can cause blisters to form. The giant hogweed reaction is much, much more serious and debilitating.

So, take a look at your Apiaceae carefully, and hands-off. Assuming your plant has the characteristic large coarse-lobed leaves and big white umbels, the next step is to assess the number of branches in the inflorescence. An American cow-parsnip will have up to 45 primary branches in its umbels, while the invasive and much more hazardous giant hogweed will have 50 or more branches. You can figure out the number of primary branches by looking at the top of the flower head, and counting the round bunches or clumps of flowers. Each bunch of flowers in an umbel equals one primary branch.

Cow parsnip branch bundles and umbel

If your plant has umbels with 45 or less branches, you have a native American cow-parsnip, and the only thing you need to do is avoid handling or weed whacking the plants to prevent possible skin reactions, the same sort of precautions you would take with poison ivy or poison sumac. American cow-parsnip is a great pollinator plant feeding many species of native bees, flies, and wasps, and greatly enhances the biodiversity of its surroundings. Biodiversity goes way beyond pollinators, and this plant offers habitat for many other invertebrate species that feed on the leaves, and spiders that lie in wait for prey.

If on the other hand you’ve discovered a plant with 50 or more primary branches on an inflorescence, you may have found giant hogweed. This species has never been recorded as occurring on Nantucket, and we would love to keep it from ever becoming established. Please get in touch with one of the co-chairs of the NBI Invasive Plant Species Committee: either Kelly Omand at Nantucket Conservation Foundation (komand@ nantucketconservation .org) or Sarah Bois of the Linda Loring Nature Foundation (stbois@ llnf. org) to let them know about your find. Pictures and an exact location will help us determine if your plant is a concern.

 

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Meet our Ecological Field Assistants!

Each year, the Nantucket Conservation Foundation’s Science and Stewardship staff hires 2 Seasonal Ecology Field Assistants to help completely all of our many research and management related objectives over the summer and early fall season. Each year we look for people with strong experience in plant research, wildlife monitoring, invasive species management and an overall love and drive for conservation and ecology. We have had some amazing field assistants over the years and 2018 is no exception. Laurel Martinez and James “Mack” McGraw are this year’s Field Assistants. Read a little more about them below and if you see them out on our properties working hard this summer, feel free to say Hi!

Laurel Martinez

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Laurel Martinez holding a ring neck snake at Squam!

After spending several months in the dry mountains of New Mexico, the lush greenery and ocean views of Nantucket are a welcome sight. I am originally from Rockville, Maryland and I attended the University of Vermont where I received a B.S. in Environmental Science and a minor in Plant Biology. Over the course of my time at UVM, I was an intern at the Smithsonian Environmental Research Center where I designed an experiment examining the effect of low dissolved oxygen and pH on oyster growth. I also studied abroad in Botswana with Round River Conservation Studies where I did a project on elephant demography. However, I discovered a love of botany and began to pursue a minor in plant biology.

Soon after graduation, I got a job at the Joseph W. Jones Ecological Research Center where I conducted vegetation surveys under a canopy of longleaf pines. I was thrilled to be able to learn how to identify the plants of the Southeast and put a name to the amazing flora of the longleaf-wiregrass ecosystem. Nantucket offers an entirely new suite of plants to identify, and I am looking forward to the challenge of familiarizing myself with these new species and understanding their role in the sandplain-grassland community. When I’m not avidly searching for plants in the wilderness, I enjoy drawing and baking!

With only two weeks gone by, I have already experienced so many parts of the incredible natural world of Nantucket. During my first week I was surveying horseshoe crabs under the light of the full moon as they emerged from the ocean to the shore, ready to ensure their prehistoric legacy. I also got to wade through the wetlands of Squam Farm, searching for spotted turtles under waist-high ferns and a bed of Sphagnum moss. On a clear, windless night we set up mist nets to catch endangered long-eared bats. Carefully, we examined delicate membranous wings for tears and swabbed a tiny nose for disease as the bat squeaked his protests. Traveling to Coatue was another highlight, where outside the ranger house, rare geraniums brighten the front walkway with magenta petals, seals bask on the beach, and (if you know where to look) lady’s slippers dot the landscape. I am so grateful to be on this beautiful island for the field season and look forward to the new experiences and excitement I am sure to encounter!

 

Mack McGraw

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Mack McGraw and a spotted turtle at Squam Farm

Born and raised on the North Shore of Massachusetts, I’ve been nurturing a love for the outdoors since I could walk. I loved picking up rocks and boards to see what critters might be hiding under them, or catching frogs and snakes in ponds nearby with friends. I always had a million different questions about the natural world, and when given the answers, they only made me think of a million more. Little did I know, my endless curiosity would be gas to the fire for my interest in ecology, and I was lucky enough to attend a vocational high school where I could major in environmental science. I took classes such as forest ecology, marine biology, wetland and soil science, and so much more. I went on many trips including an eight day canoe trip down the Merrimack River and a five day stay at a field station on the Bay of Fundy in Canada. It allowed me to not only observe the ecosystems I had been studying, but employ the surveying and experimental skills I was being taught and synthesize everything I was learning.

This program fine-tuned my love of nature to focus on wildlife sciences, and led me to attend the University of Maine to study wildlife ecology. There I was introduced to the true rigors and wonders of field research, of wildlife and habitat management, and of the ever growing conservation problems that challenge our biologists every day. Seeing more of the natural world from Maine to Peru through my studies, I felt a calling even stronger to try and save it all. That’s when I took to field research, starting with bird surveys in the forests, then saltmarshes. Then I took on a job conducting forest inventories in southern Indiana that afforded me the chance to also work with banding ornithologists, bat biologists, and botanists to help build my skills as a well-rounded wildlife biologist. Now working with NCF, I have this amazing opportunity to work with an array of plants and animals in a suite of different ecosystems, all with the goal of conservation and management in mind.

When I am not working, I enjoy bird watching, mountain biking, kayaking, or any number of other outdoor activities. I try to be outside as much as I can and here on Nantucket there is nothing holding me back!

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Tiny insects may save island’s black oaks

Masquetuck oak with damage

Over the last few years, homeowners and land managers have been watching the increasing insect damage to the island’s black oak trees. Last year, the Nantucket Conservation Foundation and the Nantucket Land Council teamed up to fund a student research project to study the oak gall wasp and parasitoids – tiny beneficial insects that prey on the gall wasp – to learn whether they may be mitigating the gall wasp’s impact on island black oaks ( Quercus velutina).

Many of the largest and oldest trees growing wild on Nantucket are black oaks, and this species is a key part of our island forests.Previous research by Monica Davis, then a Ph.D. student at the University of Massachusetts-Amherst’s Elkinton Entomology lab, led to the description and naming of the insect as Zapatella davisiae, and contributed information on the insect’s life cycle and possible origin (likely eastern North America).

The theory is that rapid population booms of beneficial parasitoid insects have brought the numbers of infesting gall wasps in Long Island – the earliest known infestation – to very low levels. The same pattern was observed in recent years on Martha’s Vineyard and then on Cape Cod as the gall wasp and its predators continued to spread throughout coastal forests.

Joe and Cameron Spring 2018

But was this also occurring on Nantucket? Working in Joseph Elkinton’s UMass-Amherst lab, Cameron Smith-Freedman embarked on his senior-thesis research project in the fall of 2017, and this work has already yielded some interesting results.

By comparing densities of the harmful gall wasps in Nantucket branch samples to those collected on the Vineyard and the Cape, the status of the Nantucket infestation has become clearer. Each branch sample consists of this year’s growth at the tip, with prior years’ nodes (points of branching and growth) serving as a time series, offering a glimpse into the last several years as the gall wasp arrived and increased in numbers.

Oak twigs with galls

The branch nodes also contain a record over time of any beneficial parasitoids that may have been present and preying on the gall wasps. Elkinton suggests that the ramping up of beneficial parasitoids is likely what ultimately caused the decline of the pest elsewhere in the region, an ecological process known as “top-down regulation.”

It’s the same sort of situation as when gardeners introduce ladybugs or lacewings as beneficial insects to control aphids, but it’s something the ecosystem is doing on its own, without human intervention.

Due to the island’s isolation, the gall wasp infestation arrived later than in the surrounding region. Smith-Freedman now estimates arrival in 2011, with the first damage not becoming visible to observers until 2014, a typical scenario. At that time, Davis was still working to identify the insect and pinpoint its ecology, origin, and life history. That information is critical in deciding what, if anything, may be done to minimize damage from a newly-arrived insect pest.

Since then, gall wasps and their damage have increased on Nantucket, in home landscapes and in forests such as Masquetuck Reservation and Squam Swamp.

Over the space of just a few years, the insect was assigned a species name and it was confirmed that it was indeed the same insect that was causing infestations on black oak in Cape Cod, Martha’s Vineyard and on Nantucket.

Fortunately, Smith-Freedman’s latest data from Nantucket shows that we do have established populations of the beneficial parasitoid wasps. Using extracted DNA, the researchers worked to compare it to samples stored in a database called GenBank.

This method allows researchers to quickly and accurately identify insects to species compared to traditional methods. The DNA fragment works just like a barcode and is used to determine how a mystery organism is related to other creatures, or to identify it to species if it matches one already in the database.

At this point, Smith-Freedman’s data suggests that in 2017, beneficial parasitoids remained much lower on Nantucket than on Cape Cod or Martha’s Vineyard. But the pattern over time suggests that this year may mark the turning point, when the parasitoids will skyrocket in numbers and initiate a population crash in the harmful gall wasps.

The good news is that two species found to be important predators on the gall wasp are already here on-island and increasing in numbers, ready to lay eggs on the next generation of gall-wasp larvae – and hopefully bring the damage to our oaks down to a minimal level in the near future.

So what does this mean for our Nantucket black oaks? Some land owners have been treating their trees with injected herbicides, and it seems that another year or two of treatment may be enough to see them through.

Affected Oak at Masquetuck, 2017

Many of the trees have been weakened by several years of gall-wasp activity and some may not survive. But Nantucket trees often have unusual responses to disease or insect impacts, as seen with the beech bark disease which appears to have been present on Nantucket for decades without causing significant mortality in our gnarled old American beech trees.

Although injected (systemic) pesticide kills the beneficial parasitoids along with the gall wasps, there should be enough beneficial parasitoids in surrounding natural areas to regulate the gall wasps in the future. Homeowners who have been treating their most valued trees should stay the course for another year or two in hopes that the system is naturally “balancing” itself out as the beneficial insects increase and lower the numbers of the pests.

It should be noted that although infestations in home landscapes and particularly prized specimen trees can be managed with injected herbicide, large-scale treatment in natural areas is not economically feasible, and actually could slow the buildup of the beneficial wasps. This is definitely a case of “the enemy of my enemy is my friend,” as Smith-Freedman and Elkinton emphasize.

Also important to recall is the fact that oaks are ecological powerhouses, and their role is much greater than just producing acorns for wildlife. In entomologist Doug Tallamy’s study of native trees and shrubs, Mid-Atlantic oaks were found to support by far the highest number of Lepidoptera (butterflies and moths) of any tree genus studied. Systemic treatment with pesticides on a large scale would impact all of these species, which form the base of the food chain for many species of island birds.

Smith-Freedman presented his preliminary results at a talk in the Atheneum’s Great Hall April 23, and will return to collect more samples this summer to continue to study Nantucket’s ongoing oak gall wasp/parasitoid battle. Another snapshot in time will help answer the question of when we may see the end of the gall wasp boom.

NCFPostGraphicPreserving

The Nantucket Conservation Foundation is a private, non-profit land trust that depends on contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us! 

http://www.nantucketconservation.org

 

*Note: this article was originally written in April 2018 and printed in the  May 17, 2018 issue of the Nantucket Inquirer and Mirror.

Posted in Forests, Habitat Management, Insects, Research by Collaborators, Trees, Uncategorized | Tagged , , , | 1 Comment

What’s going on with all the brushcutting in the Tom Nevers Area? Wildfire Risk Reduction and Restoring Habitat for Rare Plants and Animals

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Recent brushcutting near the Milestone and Tom Nevers Road intersections.

Take a walk or bike ride along the Milestone Bike Path near the Tom Nevers Road intersection or in the South Pastures area of the island (between the airport and Tom Nevers) and you will notice some dramatic clearing of vegetation and new open areas. Nantucket Conservation Foundation staff have been working on brushcutting management this past fall and winter as part of our Wildland Fire Risk Management Program. This project has two mutually-compatible goals: 1) to reduce the risk of wildfire occurring on Nantucket and 2) conduct management to benefit rare species and plant communities, including sandplain grasslands, heathlands and scrub oak barrens. The Foundation’s Wildland Fire Risk Management Program was first adopted in 2011 by our Board of Trustees and our staff has been implementing management in key areas around the island such as the Middle Moors, Trots Hills, Head of the Plains and now South Pastures.

The unique landscapes of Nantucket’s conservation properties, ranging in size from 10 acres to over 3,000 acres, are surrounded by homes, roads, power lines, and other public infrastructure. People living adjacent to protected lands are lucky to enjoy these beautiful properties just outside their back door, but these areas can also be at risk in a landscape adapted to fire. Many of the plants here on Nantucket contain high levels of oils and resins in their stems, twigs and leaves, which ignite easily, burn intensely and can spread fire rapidly. The vast majority of these species not only exhibit such fire adaptations, but actually require fire or some other type of disturbance for their continued existence. Although these habitats are regionally rare and host numerous rare species, it is problematic when this type of vegetation occurs in close proximity to people and buildings. Fire ecologists consider places where structures and other human development intermingle with undeveloped land containing dense, flammable vegetation to be high risk “Wildland-Urban Interface” zones. Management of vegetation around these zones is key for both preventing wildfires and controlling wildfires if they do occur.

Huckleberry Burning

Native shrubs like huckleberry and scrub oak are fire-adapted and burn intensely

Nantucket experienced two severe wildfire events in the 1900’s: in July 1949, approximately 1,300 acres burned adjacent to the Nantucket Memorial Airport and the State Forest; in August 1929, a fire engulfed an area exceeding 6,000 acres stretching from Madequecham to Quaise. Prior to this time, historic sheep grazing helped maintain open, less wildfire prone landscapes. More recent fire suppression and lack of management has lead the vegetation in many areas of the island to steadily growing taller and denser. Also, the number of homes built adjacent to undeveloped conservation lands has been steadily increasing. Because of these factors and the predominance of traditional wooden building materials used on the island, Nantucket has been designated a “Community at Risk” by the National Fire Plan. Further increasing our risk is Nantucket’s 2 ½ hour car ferry travel time, which limits the ability of off-island fire departments to promptly provide mutual aid to our local department in the event of a wildfire.

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Brushcutting done several years ago along the Madaket Bike Path near the landfill entrance.

Nantucket’s fire-dependent habitats are designated as uncommon and exemplary “Priority Natural Communities” by the Massachusetts Natural Heritage & Endangered Species Program because of the high concentrations of rare species that they contain. Restoring, maintaining, and conserving these ecologically-significant areas are high-priority goals for the Foundation. The challenge we face as land managers is to figure out how to best reduce “fuel loads” (the amount of flammable material present within a defined space) to increase public safety within the Wildland-Urban Interface adjacent to our conservation lands, while also complementing our ecological goals. Fortunately, this is not as challenging as it sounds. Brushcutting, tree removal, and/or prescribed burning are all management practices that reduce fire hazard and also promote habitat conditions for rare species associated with our grasslands, heathlands and shrublands.

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The Foundation’s Fecon mulching tractor

The brushcutting work that the Foundation is undertaking requires a heavy duty, specialized piece of equipment called a Fecon mulching tractor. Through the generous support of an anonymous donor, the Foundation purchased its first Fecon tractor in 2012, which was used extensively over the past 6 years and has just been augmented by a second similar unit. During this time, we have systematically widened out existing roadways or cut strategic firebreaks through dense brush where no roads or trails on our Head of the Plains, Trots Hills and Middle Moors properties. This past winter, we began what will be a multi-year fire break establishment and road widening effort within the Tom Nevers area, just south of Milestone Road and west of Tom Nevers Road. The Foundation owns over 1,770 contiguous acres of tall, dense scrub oak immediately downwind of dense residential development along the western side of Tom Nevers Road, making these homes at high risk in the event of a wildfire.

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Recent brushcutting bordering the Milestone Road near Tom Nevers.

These breaks are designed to provide large gaps in the vegetation that will slow the progress of wildfire and provide our fire department with a safe location from which to do fire suppression work. In order to avoid disturbing nesting birds and other wildlife, we limit our brushcutting efforts to the late fall, winter and early spring months. During these seasons, the lack of leaves on dense shrubs also affords increased visibility to the tractor operator so that large rocks and other natural obstructions can be avoided.

North Pasture Firebreak June 5 2017 2

This firebreak in the Middle Moors was first cut several years ago.

Once established, these breaks will be regularly maintained by periodic mowing. Although the initial cut creates a large amount of shredded woody material that gets deposited on the ground as a thick layer of mulch, these newly-opened landscapes look beautiful once the vegetation has greened up in the summer and follow-up treatments will reduce this debris over time. The results of road edge mowing that has been taking place within the Middle Moors area for many years demonstrates that these areas will eventually be colonized by native grass and wildflower species. In fact, some of the largest populations of our state-listed rare plant species, including New England blazing star (Liatris scariosa var. novae-angliae), eastern silvery aster (Symphyotrichum concolor) and sandplain blue-eyed grass (Sisyrinchium fuscatum) occur along open, sunny maintained road edge habitats.

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Just a few of the rare plant species that tend to be found along sunny road edges: sandplain flax, New England blazing star, sandplain blue-eyed grass, eastern silvery aster, and bushy rockrose (left to right)

We invite you to get out and enjoy our properties and see some of these treated areas first-hand, right after they have been cut……and then come back this summer to see how beautiful these newly-opened landscapes look once the vegetation has greened up! If you like what you see, please consider making a contribution to our dedicated fund that supports this important work.

For more information, please visit the Foundation’s website at: https://www.nantucketconservation.org/land-management-2/wildfire-program/

NCFPostGraphicPreserving

The Nantucket Conservation Foundation is a private, non-profit land trust that depends on contributions from our members to support our science projects, conservation property acquisitions, and land management efforts. If you are not already a member, please join us! www.nantucketconservation.org

Posted in Habitat Management, Land Use History, Native Plants, Restoration, Sandplain Grasslands, Scrub Oak Barrens | Leave a comment

Bat Hibernation on Nantucket?

In 2015, to the great surprise and delight of the conservation community, we were able to add another species to the Island’s list of mammals – we confirmed the presence the Northern long-eared bat on Nantucket! It’s not very often that you can add a new mammal to your list – but this tiny, nocturnal mammal managed to fly under our radar for this long (pun absolutely intended). This species is listed as “Threatened” by the US Fish and Wildlife Service and “Endangered” in Massachusetts. Everywhere else in the northeast, this bat has been nearly completely wiped out by White-Nose Syndrome, a fungus that attacks bats during hibernation in the winter. Here on Nantucket and in a few other coastal locations including Martha’s Vineyard and Long Island, these bats seem to be persisting.

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Northern long-eared bat on Nantucket. Photo credit: Allison Black

Since their discovery, we have learned a great deal about where Northern long-eared bats are found on Nantucket in the summer and what kind of habitats they use. We’ve used radio telemetry to track lactating female bats to maternity roosts and we’ve captured (and released) newly flying juvenile bats in the summer. We’ have been using passive acoustic detectors to “listen” for bats throughout the year. The one big question that remains is are they hibernating on Nantucket? We believe the answer is yes and we are asking the Nantucket community for help in locating hibernation sites on Island!

Elsewhere in the country, these bats generally hibernate in old mines and caves where temperatures are relatively constant and cool, and humidity is high. Of course, we don’t have these types of structures here on Nantucket. What we do have are basements, crawl spaces, attics and lots of old buildings. Last winter, we tracked one bat to a crawl space under a house where it remained for the winter with four of his friends. Despite our best efforts, that is the ONLY spot we have found so far where these bats could be spending the winter. They were tucked up between sistered floor joists in a gap less than 1/2 inch wide.

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Northern long-eared bat in between sistered floor joists in a crawl space under a house on Nantucket, winter 2016/2017. Photo credit: Danielle O’Dell

We are on the lookout for bats on Nantucket in the winter. If you think you might have bats in your attic, basement, crawl space, etc. please give us a call at the Nantucket Conservation Foundation office (508) 228-2884. We would love any reports of bats at any time of year, particularly in the winter. We’re looking for fairly undisturbed, cold spaces that might have high humidity. Old basements or crawlspaces, or capped wells or cisterns would probably be ideal.

Learning more about hibernation on Nantucket is incredibly important. We need to know if our bats are infected with the fungus that causes White-Nose Syndrome. The best way to test for this is by finding them while they are hibernating and collecting a swab of the area. It is possible that our faraway island is providing a refugium for this species!

To learn more about our bat work, please see our previous blog posts here and here.

NCFPostGraphicPreserving

The Nantucket Conservation Foundation is a private, non-profit land trust that depends contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us!  www.nantucketconservation.org

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Showy Insects and Spiders of Autumn

*Note: this article was originally written in September 2017 and printed in the Nantucket Inquirer and Mirror in the November 30, 2017 issue

Fall is finally here. The air is cooling down and drying out, the tupelo trees are turning red and the goldenrods and blazing stars are blooming in all their yellow and purple splendor. With all the fall wildflowers in peak bloom, now is a great time to take a quiet walk in Nantucket’s sandplain grasslands to enjoy the display of color and catch a glimpse of some showy fall insects too.

Of course, the star of the show has to be the Monarch Butterfly. In recent years, we’ve noticed an alarming drop in the abundance of these regal butterflies, but this year, we are encouraged by what seems like quite an uptick in the number of monarchs flitting through the grasslands and shrublands on island. Monarchs arrive on Nantucket by mid-summer and lay their eggs on milkweed plants. Tiny yellow, black and white striped caterpillars emerge and immediately get to work munching on the milkweed. They eventually pupate in to a green chrysalis, and the adult emerges as the familiar orange and black beauty. While the butterflies that arrived here earlier in the summer will die as they only live, on average, 2-5 weeks, their offspring, the adults that we see now, just completed their metamorphosis and will live for up to 9 months. It is these adults that will soon begin their long migration south to wintering grounds in the mountains of central Mexico. Migration on this scale is quite unusual in the insect world and is only known in a few species of beetles, dragonflies, grasshoppers and locusts.

 

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Monarch caterpillar

 

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Monarch butterly on milkweed

Another very common insect at this time of year is the larval form of the Flannel Moth. Right now, we are seeing Flannel Moth caterpillars all over black huckleberry leaves in the coastal heathlands and shrublands. These caterpillars are quite conspicuous and easily recognizable. The inch long larvae are covered in long hair-like setae, resembling a Persian cat. Thus, some members of the genus are nicknamed “puss caterpillars.” The caterpillars start out covered in wispy white fluff, but by the end of summer their coloration changes after they shed their skin to grow, and molt to a brownish-tan color. They may look soft and cuddly, but the long soft hairs on these caterpillars conceal hollow spines that contain venom. If you rub against these spines, the resulting sting can cause skin irritations that range from mild itching to painful blisters. So, look but don’t touch these fluffy little caterpillars. Flannel moth caterpillars are usually sparse, but in the summer of 2008, a few areas of the island experienced a major outbreak of these caterpillars as well as a Chaindot Geometers and Io moth caterpillars. That summer, caterpillars completely defoliated huge areas of shrubland. We haven’t seen a caterpillar outbreak quite like that since and all the shrubs recovered from the defoliation with no problem.

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White and brown instars of the flannel moth caterpillar

Another creature that is very easy to observe and common in the grasslands now is the Yellow Garden Spider, or Writing Spider (Argiope aurantia). The large size of this spider is impressive and certainly gives one pause, but it is harmless to humans as they rarely bite and if they do, the venom is mild with little more than a welt as a reaction. They are orb web weavers and tend to build their webs close to the ground in gardens and tall grassy areas. The web itself is distinct as it is large (approximately 2 feet wide) and the spider builds a thick, zigzagged line of silk in the center of the web, called a stabilimentum. You might guess from the name of this structure that it has a stabilizing affect for such a large web, but many biologists dispute its purpose, suggesting that perhaps it actually camouflages the spider sitting in the center of the web, lures prey in to the web, or warns birds of the presence of the web to deter them from flying in to it. Whatever the purpose, the spider takes down this central part of the web on a nightly basis and constructs a new one. Spiders may not be everyone’s cup of tea, but I think most could, from afar, appreciate the beauty of this arachnid.

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Yellow garden spider

 

We highly recommend a walk through the Nantucket Conservation Foundation’s Head of the Plains property or the Nantucket Land Bank’s Smooth Hummocks property in the fall. Both of these properties contain excellent examples of the globally rare sandplain grassland and heathland vegetation communities. Multiple species of goldenrod, New England Blazing Star and many varieties of white and purple asters are all in peak bloom right now and are attracting many species of butterflies and other insects. Now that the island has quieted down, it’s a great time of year to enjoy the peace of these properties and see some of the less appreciated species of wildlife on Nantucket.

NCFPostGraphicPreserving

The Nantucket Conservation Foundation is a private, non-profit land trust that depends contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us!  www.nantucketconservation.org

 

Posted in Caterpillars, Fall Color on Nantucket, Nantucket Wildlife, Sandplain Grasslands | Tagged , , , , , , , | Leave a comment

Nantucket’s Special “Some Bunny”

NE Cottontail Dec 9 2010 by KCB

A live captured New England cottontail (photo by Karen Beattie).

Nantucket’s fauna is very unique – maybe more so for what is not here than for what we have. Numerous species that are common elsewhere in New England are missing from our assemblage of terrestrial wildlife, including chipmunks, possums, raccoons, skunks, fox, woodchucks, and coyotes. What we do have on Nantucket are several species of small mammals and moles, squirrels (which were re-introduced to the island several decades ago by hitching a ride on a lumber truck), several species of bats (including a recently-discovered population of endangered northern long-eared bats) and two very common mammals- white-tailed deer and eastern cottontail rabbits.

Rabbits in particular are one of the most commonly observed wildlife species on the island- they graze on lawns, in gardens, under bird feeders and along road and bike path edges. Anyone who has driven around the island early in the morning has likely noticed the sheer number of road-killed rabbits, which are quickly “recycled” by nature’s undertakers – crows, gulls and vultures. The lack of previously-mentioned predatory mammals is likely a contributing factor to these high population numbers. What is not widely known is that Nantucket is also home to another very rare and elusive species of rabbit- the New England cottontail, our special “some bunny.”

The New England cottontail (Sylvilagus transitionalis) is the only cottontail rabbit native to the northeastern United States. It prefers dense shrubland habitats where it can effectively hide from predators, and for this reason is rarely seen. The more common eastern cottontail (Sylvilagus floridanus) looks virtually identical to the New England cottontail, but has a different number of chromosomes; therefore, the two species cannot interbreed. Eastern cottontails occur in shrubland habitats as well, but also frequent open grasslands, suburban yards, parks and fields. Because Nantucket was mostly open grassland habitat during colonial times due to extensive sheep grazing, New England cottontails were probably never numerous. Therefore, the eastern cottontail was introduced in the late 1800’s to provide game for hunters (along with snowshoe hares and black-eared jack rabbits, which are no longer common here). The eastern cottontail has since become our predominant local rabbit.

Eastern Cottontail at South Pastures Feb 10 2012 by KCB

A live captured eastern cottontail (photo by Karen Beattie).

The U.S. Fish and Wildlife Service (USFWS) has placed high priority on locating sites where there are still viable populations of New England cottontails due to concerns regarding drastic declines across their range. Habitat loss was likely a major factor in these declines. Nantucket was identified as one of the most likely sites where remnant New England cottontail populations could still exist. This is because they were known to have once occurred here and there are vast expanses of highly suitable, undeveloped habitat currently available – most of which is within the island’s vast, protected conservation properties.

Starting in 2011, the Nantucket Conservation Foundation (NCF) Department of Science and Stewardship undertook an island-wide search for this species by conducting live trapping and tissue sampling combined with collecting fecal pellets (aka bunny poop). The best way to definitively distinguish between the two cottontail species is by DNA, which can be extracted from a pin drop of blood, a small tissue sample taken from the ear, or fresh fecal pellet collected on snow or frozen ground. Out of 216 samples collected over several years from many locations across the island and submitted to the University of Rhode Island for analysis, 11 tested positive as New England cottontails – all of which were collected from the Foundation’s Sanford Farm, Ram Pasture and the Woods property. This is significant information, as it indicates that there is a small but viable remnant population at this site. Prior to this discovery, the only locations within Massachusetts where New England cottontails were known to occur were Cape Cod and a small area in the southwestern Berkshires.

NEC vs EC by Mark McCollough. USFWFgif

Comparison sketch of Eastern and New England Cottontails (by Mark McCollough, US Fish & Wildlife Service).

So why is this important? The New England cottontail has become extremely rare within the last 50 years. It was once found east of the Hudson River in New York, across all of Connecticut, Rhode Island and Massachusetts, north to southern Vermont and New Hampshire, and into southern Maine. This former range is believed to have declined by over 75 percent. This trend is attributed to the introduction of the eastern cottontail as well as the region-wide decline of its preferred dense shrubland habitat. On Nantucket, these dense shrublands are rare priority habitats in and of themselves that support other rare species such as northern harriers, eastern whip-poor-wills and several species of rare shrubland-associated moths. Knowledge of the presence and the locations of population concentrations of New England cottontails within Nantucket’s shrublands will enable better management of these ecologically important habitats.

Want to help? There is one additional way that New England and eastern cottontails can be differentiated: skull suture patterns. Skull sutures are junctions between the major bones of the skull. In New England cottontails, some of the skull suture lines are irregular and jagged, while those of eastern cottontails are smooth. If you happen to be a rabbit hunter and are interested in “donating” the intact head of any rabbits you harvest, the NCF Science and Stewardship Department will gladly accept your contributions – just store each specimen in an individual Ziploc bag (with the name and contact information of the collector, date, and specific location where the rabbit was harvested recorded with permanent marker on the outside) and freeze it while it is still fresh. Call the NCF’s office at 508-228-2884 and ask for any member of the science staff for more information!

*Please note, this blog post was originally published in The Inquirer and Mirror in the article series called Island Ecology. The Foundation’s Science staff regularly contribute to our local newspaper and reprint the articles here the following week.

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The Nantucket Conservation Foundation is a private, non-profit land trust that depends contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us!  www.nantucketconservation.org

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