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Wednesday, August 28, 2013

Back to (Forest) School

Being a teacher, the end of the summer usually means sprucing up your classroom for the coming year.  At Forest School and Forest Preschool, we use the outdoor surroundings as our classroom.  Like here:

and here...

and on this rainy day, here...

So needless to say, "classroom prep" takes on a whole new meaning for Forest Preschool and School without the walls and windows of a traditional classroom.  Here are some of the school preparations that the NBNC staff accomplished today!

A puppet show space, and a pretty window to look through.

Our new fire pit!

The boundary for the building area or a bunch of logs to bound between, depending on how you approach it.

Working hard to prepare the ground for a covered hoop walkway for our wild grapes to grow over.  Stay tuned to see how the hoop walkway develops and how the rest of "Deer Camp" shapes up!

Tuesday, August 27, 2013

Fall Shorebird Migration Underway

It started in July and it will continue into September.  At first it was just adult birds, but now this year's young have joined in the epic journey from the arctic to the equator.  Being a land-locked state, many shorebirds that enter Vermont's airspace likely fly straight through without pause.  But where lake and river levels drop or fields flood, exposing open mud, shorebirds can touch down to refuel.  Now is the time to look for shorebirds in Vermont!

Shorebirds can show up pretty much anywhere in the state that their preferred open, wet habitat exists.  As with most migrants, shorebirds are funneled into the Lake Champlain and Connecticut River valleys, making them hard to find in central Vermont.  Any birder wanting to experience Vermont shorebirding at its best should visit these regions, where some "hotspots" exist that tend to harbor larger numbers and greater diversity.  One such location is Delta Park in Colchester, where the Winooski River empties into Lake Champlain.

Below is a gallery of just a few of more than 20 shorebird species that have been observed at Delta Park over the past few years:

Semipalmated Plover
Pectoral Sandpiper
Baird's Sandpiper
Merlin, after an unsuccessful attempt to hunt shorebirds

Wednesday, August 21, 2013

Caterpillars in the Classroom

Spotted Tussock Moth

There are many rituals that teachers perform as they prepare to return to the classroom, and this year, one of those rituals is going to be especially challenging: searching the local milkweed patch for Monarch caterpillars.  For decades, teachers have raised Monarchs in the classroom with their students, but with declines of over 90% this year, Monarchs are currently absent from much of Vermont.  So what is a teacher to do?

The good news is that Monarchs are one species out of hundreds of native caterpillars that can easily be raised in the classroom.  Unlike Monarchs, most other caterpillars won’t emerge as moths or butterflies in the fall, but hold on to the cocoons and your caterpillar will eclose (emerge from its cocoon) in the spring, reinvigorating students months after they’ve forgotten about their caterpillar friends.  Many of the same lessons that we learn from the Monarch can apply to other species: life, death, adaptation and transformation.  This short tutorial will give teachers some of the tools they need to raise caterpillars in the classroom this fall.

Finding Caterpillars

Beautiful Wood-nymph caterpillar
Caterpillars spend their lives doing two things: eating and trying not to be eaten.  This can make finding caterpillars challenging.  But fear not!  If you spend time outdoors doing some targeted searching, you are likely to stumble upon a caterpillar sooner than later.  Here are a few methods for finding caterpillars:

  • Examine foliage for signs of caterpillar feeding, including damaged leaves and frass (caterpillar poop).  The fresher the damage to foliage, the more likely a caterpillar is still nearby. 
  • Use a beating sheet.  Place a white bed sheet beneath vegetation, and then shake the vegetation to dislodge any caterpillars.  If all goes well, a caterpillar will fall onto the bed sheet and be easy to spot against the white background. 
  • Look for caterpillars at night. Many species of caterpillars hide by day and become active after dark, when fewer predators are out hunting for them. 
  • Search with your students.  Having a few dozen eyes helping you search will increase your chances of success, and your students will enjoy the hunt! 
Caution: Some caterpillars, especially those with hair and spikes can sting or cause skin irritation

Raising Caterpillars

Our Promethea caterpillar doesn't even have a tank!
We feed it lilac, white ash, and black cherry.
Before bringing a caterpillar back to the classroom to raise, it is essential to know what that caterpillar eats.  Many species will feed on just one or a handful of host plants (such as the Monarch, which feeds only on milkweeds).  If you find the caterpillar on a plant, it is likely that that plant is a host.  You can collect some branches of the host plant along with the caterpillar, so it has something to feed on.  If you find the caterpillar away from plants, you must identify it in order to determine what it eats.  Keeping a steady supply of host plant available to your caterpillars may be the most challenging part of raising them.

Next, you should try to identify your caterpillar.  There are some great resources on the web to help identify mystery insects, such as the Vermont Atlas of Life.  You can also email a picture to NBNC and we’ll do our best to help with identification.  Knowing what kind of caterpillar you have will shed light on its life history, what special adaptations it has, and what moth or butterfly it will become. 

Our Variable Oakleaf caterpillars have
almost doubled in size since we
found them a week ago
Terrariums that hold caterpillars should be kept clean and well-ventilated.  Provide a constant supply of fresh food to the growing caterpillar.  Research your caterpillar, as there may be tips specific to each species that help ensure successful rearing.  For example, some caterpillars burrow underground to create cocoons and will need a substrate of soil in their terrarium.  NBNC can help, so don’t be shy about letting us know what caterpillars you are raising. 

If you have questions about raising caterpillars, please see the resources below or get in touch and we’ll see if we can help!

Involve Your Students

Be sure to involve your students every step of the way.  Caterpillars grow fast and your students will be excited to see their caterpillars change from day-to-day.  Countless lessons on adaptation, evolution, growth, and change can spur from the raising of caterpillars.  Their progress can be documented with students through art or writing.  Their growth can be measured and graphed, as can the quantity of leaves they consume or frass they excrete.  Our migratory species can even offer opportunities to learn about geography or to find pen pals in other states/countries who share our experience with these delicate creatures.

In Conclusion

This tutorial just scratches the surface of what can be done with caterpillars in the classroom.  The resources listed below provide more tips on identifying and raising caterpillars.  Since much of the school year takes place during the winter months, the window for working with insects is narrow.  The start of the school year offers the best opportunity to raise your “class pet” caterpillars and we look forward to hearing about your experiences in the classroom!

Silver-spotted Skipper caterpillar flaunting its
impressive fake orange eyes
Additional Resources

Champagne, C. 2012. Finding Slug Caterpillars. Retrieved from http://bugguide.net/node/view/668155

Jaffe, S. 2013. The Caterpillar Lab. https://www.facebook.com/TheCaterpillarLab

Wagner, D. 2005. Caterpillars of Eastern North America. Princeton, N.J. : Princeton University Press

Wagner, D. 2011. Owlet caterpillars of eastern North America. Princeton, N.J. : Princeton University Press

Wagner, David L., Valerie Giles, Richard C. Reardon, and Michael L. McManus.  1997.  Caterpillars of Eastern Forests.  U.S. Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team, Morgantown, West Virginia.  FHTET-96-34.  113 pp.  Jamestown, ND: Northern Prairie Wildlife Research Center Online.  http://www.npwrc.usgs.gov/resource/insects/cateast/index.htm  (Version 11APR2001).

Caterpillars of NBNC (part 3)

Missed parts 2 and 1?

This summer has been FULL of caterpillars!  We've had a handful growing up in the critter room all summer, received an awesome visit from The Caterpillar Lab in July, and have been finding new, beautiful caterpillars almost every day.  Here are a few that were found crawling around in Montpelier over the past few weeks...

The Modest Sphinx was found crawling around on a signpost in North Branch River Park.  It was likely about to venture into the soil, where it will build a cocoon just beneath the ground to spend the winter.  

This Fingered Dagger Moth was also found in North Branch River Park, just over the bridge from NBNC.  It ate birch leaves for a few days after we found it before spinning a cocoon.

The Luna Moth may be one of the most beautiful of all Vermont's moths.  This caterpillar was found wandering on the lawn.  It's color changed to pink within an hour, and it had spun a cocoon by the next morning.

This Brown-hooded Owlet was found on goldenrod in the butterfly garden.  The caterpillars are stunning, with their intricate pattern of black, yellow and red.  It is no wonder that this species is on the cover of Caterpillars of Eastern North America.

Two giant Cecropia Moth caterpillars were found by one of our summer campers in the apple tree right next to the Nature Center.  The small white ovals on the caterpillar's back are fly eggs and will parasitize the caterpillar.

Monday, August 12, 2013

Summer of the Silkmoth

There are few caterpillars more exiting to find than the giant silkmoths.  Their enormous size, unique appearance, and amazing life history make them fascinating creatures to study and observe.  Their numbers can fluctuate from year-to-year, and 2013 has been incredible for silkmoths.  Last week’s discovery of two Cecropia Moth caterpillars in the apple tree in the backyard at NBNC was definitely a highlight.

Cecropia Moth caterpillar as it was found!

 The Cecropia is probably Vermont’s largest moth, and the mature caterpillars are as long and wide as an index finger.  They have an electric-lime body, covered in colorful, spiky protuberances of orange, yellow, and blue.  Despite their vivid appearance, they can blend quite well into a leafy canopy.  There are, however, countless other creatures searching for these caterpillars with the intent to cause them harm.

The two giant caterpillars feed in the apple tree
Close-up of fly eggs
When we think of caterpillar predators, we often picture birds carrying a beak-full of caterpillars to hungry nestlings.  It is other insects, however, which pose a much more substantial threat to caterpillars.  The Cecropias we found at NBNC were both host to dozens of tachinid fly eggs (the small, white ovals on the caterpillar’s back).  The fly larvae will ultimately kill and consume their caterpillar hosts.  

We caught this tachinid fly
laying eggs on the Cecropias
The threat of six-legged predators has been compounded by the introduction of a fly, Compsilura concinnata, to the northeast in order to control the invasive gypsy moth.  This introduced fly has developed a taste for more than just gypsy moths, and is thought to be playing a role in the decline of the Cecropia and other giant silkmoths.  Whatever the reason, silkmoths numbers have been dropping for decades and the effects of this decline on other species are just beginning to be understood.

While the adult giant silkmoths won’t fly again until next spring, look for their giant caterpillars this summer and fall and share with us what you find!

This Luna Moth caterpillar was also found last week at NBNC

Tuesday, August 6, 2013

The Queen's Visitors

In a small meadow in Burlington, Queen Anne's Lace is in full bloom.  The tall, flat cluster of tiny white flowers are attracting a wide variety of different creatures.  Here is just a sample of the diverse array of pollinators:

Flower Beetles such as Judolia cordifera are feasting away without much fear of my camera lens.  Ironically, the wasps seem to be more skidish around the camera.

This ichneumon wasp (Exetastes suaveolens) was very shy, but persistence paid off with an identifiable picture.  This is a very specialized species.  As an adult, it feeds at a variety of flowers, but as a larva it must consume the caterpillar of the Goldenrod Hooded Owlet caterpillar (Cucullia asteroides).  These wasps are parasites.

Another parasitic wasp feeding a few flowers down is a spider wasp (Anoplius carolinus).  When not foraging at flowers, this wasp hunts down spiders, paralyzes them, carries them to an underground chamber, and buries them alive so they can be consumed by the wasp larva. 

This wasp won't be visiting any more flowers after being captured and killed by a mating pair of Ambush Bugs.  The Ambush Bugs are masters of camouflage and catch prey many times their own size.  The wasp is easy to see in this photo, but can you see the Ambush Bugs feeding on it?

These wasps (Ancistrocerus gazella) consider the flowers of "the queen" to be a perfect place to mate.  The female will later build a nest out of mud and provision it with caterpillars for its young.

This aerial yellow jacket (Dolichovespula arenaria) also stopped in for a meal at "the queen's" waystation. 

Other non-wasps were visiting the flowers, including the Oriental Beetle (Anomala orientalis)

A sawfly (Arge sp.) made an appearance at a flower near the edge of the meadow and the forest.  As a larva, this sawfly feeds on plants.

Adding a fly into the mix, Toxomerus geminatus was one of several gorgeous Diptera species seen.  

This next visitor to "the queen" spends its larval life under the bark of a tree, feeding on other insects.  As an adult, this beetle-that-looks-like-a-moth (Calopteron sp.) can be predatory, or, feed on nectar at flowers.

This is just a small sample of more than 20 species of pollinators that were observed at Queen Anne's Lace in this small meadow in the heart of Burlington.  While they act similar as they feed on nectar and pollen, they each have their own unique appearance and life history.

Watch for goldenrod, just starting to bloom across the state.  As Queen Anne's Lace fades away, the goldenrod pollinator show is just beginning!

Thanks to the many contributors to bugguide.net for their help with identifications.