Sunday, June 24, 2012

A Rare Butterfly Becomes a Meal



While conducting a survey of bumblebees in East Montpelier last week, on the hottest day of the year (so far), I found myself walking along a seemingly ordinary roadside, scanning the flowers as I went.  Bumblebees seemed sparse in this location, so as my eyes passed over the hundreds of blossoms of purple and pink, my attention was drawn to other creatures.  A pair of Monarchs danced together near a patch of milkweed, and Tiger Swallowtails floated on the distant breeze, but one butterfly in particular seemed to stick out.

A pair of wings, orange and black, were splayed out awkwardly across the top of a flower.  I hopped off the road and into the brush to get a closer look, with my net clenched in my hands ready to be swung.  But the butterfly didn’t budge.  As I approached closely, within reaching distance, I noticed something was different.  This butterfly wasn’t about to fly away, because its abdomen was clenched in the jaws of a crab spider! 

Over 100 species of crab spiders can be found in the US.  Unlike many of the most familiar spiders, which build webs to catch their food, crab spiders rely on stealth to ambush their prey.  Some crab spiders have discovered, through the millennia,  that if they can blend into a location that is visited frequently by other insects, they can simply wait for a meal to land right in front of them.


The Goldenrod Crab Spider (Misumena vatia) is common in Vermont, and can be found sitting atop flowers, waiting for an unsuspecting insect to be lured by the sweet nectar underfoot.  The butterfly I found had fallen victim to a vatia.  I was in disbelief to find that its latest catch was an American Snout (Libytheana carinenta), an exceptionally rare butterfly in Vermont and a first for Washington County.  

American Snouts have earned their name because they have a large nose-like protuberance that extends from the front of their head, and is thought to be an adaptation to mimic the petiole of a leaf and aide with camouflage.  In the southern part of their range, Snouts can be very common.  During some years, populations in the southwest can explode, causing swarms that are said to “darken the sky and halt traffic.”  But on the northern periphery of its range, the Snout can be quite rare, and had never been documented in Vermont before 2002.


As with other winged creatures, butterflies can stray extremely far from where they would be expected to be seen.  Some wander hundreds of miles from their typical haunts and are discovered in unexpected places.  Who knows where this Snout could have ended up, had its journey not been ended by a crab spider in East Montpelier.  And who knows how many other Snouts are flying around in Vermont, just waiting to be discovered.

Monday, June 18, 2012

Summer Birding can be a "Mouth-Full"


The official start of summer is just days away, but it feels like spring ended long ago.  The tree canopy is thick with leaves, the clap of thunder echoes through warm, humid nights, and birds are settled into their summer territories.  With the end of the spring bird migration, some birders hang up their binoculars, where they gather dust until next spring.  To the contrary, there is still plenty of good birding to be done!  While the buzzing mosquitoes and biting black flies may make birding more challenging, they are the exact reason why birding in summer can be such a joy: food is plentiful.



Many of the birds that arrived to Vermont in April and May have found a mate, built nests, laid eggs, and many of those eggs have already hatched.  And a nest full of hungry, baby birds can keep attentive parents extremely busy.  When not in nesting-mode, birds will immediately eat most of their food, or cache it somewhere for consumption later.  Now, however, they are busy gathering food for their hungry offspring.  In fact, this behavior of carrying food is a strong indicator that somewhere nearby, there is a nest full of fledglings.  Some birds will fill their beaks with multiple insects before returning to the nest.



Seeing this behavior is a special gift for any summer birdwatcher.  A bird with a mouth-full is a sure sign that the circle of life is completing itself once again.  When you see a bird carrying food, try to observe it and watch where it goes.  If it detects your presence, it may well wait for you to depart before returning to its nest… after all, no parent wants to lead a predator to its helpless young.  But, if you are lucky, you just might get to witness that devoted parent caring for its brood.

So dust off those binoculars and head out to see who may be nesting in your backyard.  There is still plenty of great birding to be done!


All photos were taken in the greater-Burlington area on June 17, 2012

Wednesday, June 6, 2012

Venus and the 7th Inning Stretch

I've learned never to go anywhere without my binoculars or my spotting scope - including to  my son's baseball games. You never know - you may see something you'll never again see in your lifetime! Such was the case yesterday evening, when the clouds parted to allow a rare glimpse of the transit of Venus.

You probably heard about the transit on the news and how the last transit of Venus across the face of the sun occurred in 2004 (they occur in pairs), with the next one calculated to be in 2117. I had heard all about it, but I didn't dream I would actually get to witness it for myself - especially with this week's weather forecast.

The photo here shows Venus as a small, black, round circle in the lower right hand part of the larger bright circle, which is a projection of the sun. I took the photo at approximately 7:08 p.m. (was that the 5th inning?) in Calais. In the center of the sun, if you look carefully, you can see sunspots as well.

Viewing the transit was surprisingly easy, although my attempt to use my binoculars to project the image failed. Instead, I retrieved my spotting scope (usually used for birding) from my car, set it up to point directly at the sun, and projected the image onto a notebook. With a few turns of the focus knob and some fine tuning of the zoom lens, we managed a descent image of the celestial duo.

Very quickly word spread among the families present (who were probably watching the game more closely than I was) and the baseball players as well. Kids who were not on deck to bat, or not out in the field, took turns coming over to marvel over the image of Venus. Perhaps even rarer than this astronomical event, was to see a baseball game interrupted by a natural phenomena!