Sunday, November 19, 2017

Hibernating Bald-faced Hornets


I found two Bald-faced Hornets (Dolichovespula maculata) under a piece of rotting wood earlier this week.  Only new queens hibernate, the rest of the colony dies when temperatures drop below freezing.  These queen have already mated and will start new colonies next spring.  Assuming they survive the winter, which doesn't at all seem guaranteed given the scant protection afforded to them by their shelter.
Cold is the most obvious danger.  I didn't find anything that specifically referred to hibernating Bald-faced Hornets, but insects as a group have a wide variety of behavioral and biochemical strategies for preventing and/ or controlling ice formation in their bodies.  But many of these strategies partially rely on an insulating blanket of snow; which helps moderate the temperature of the hibernating insect's immediate surroundings; our Minnesota winters seem to be trending towards a less consistent snow cover.
Bald-faced Hornets have a bad reputation for being nasty insects that sting with little provocation.  I believe this is largely an exaggeration.  I've often watched them up close as they chew on the wood of an old bench, raw material for their paper nests.  Of course coming into contact with their large, ovoid paper nests can result in many, many painful stings.  But often their nests are high up in trees.

I'm sometimes asked something along the lines "What are they good for?"   The quick answer is they prey on other insects,  some of which are pests.  But I think the best answer is why do they have to be "good" for anything; they are living creatures in their own right and that should be enough.


Thursday, October 19, 2017

An Illustrated Life List: European Starlings

This is a re-work of a picture I did in 2014.  I liked the original concept I had of merging a sonogram with starlings calling from utility lines, but I was never satisfied with how I executed it. 

The scenery of the picture is the sonogram graph.  I wanted to highlight the starling's ability to imitate other birds, so the data points of the sonogram are shown as abstractions of birds I've heard starlings imitate.

Sonograms aren't usually depicted in field guides.   But the Golden Guide "Birds of North America" does include sonograms for many birds.  When I first started birding I found these sonograms to be more helpful in describing bird calls than the textual descriptions offered in most field guides.  I could glean a sense of a call's timing, pitch range and variation from the sonogram's blotchy plots and roughly compare this to what I heard in the field.  This though, was before recordings of bird songs were readily available online or mobile devices (cause they didn't exist!).

From the 2014 post
Don't take this as a defense of starlings; I do understand their negative impact on other cavity nesting birds (but really, who's to blame for this), but I enjoy watching starlings.  I especially enjoy listening to them for other bird sounds that they are imitating.  I frequently see them in my neighborhood on the mess of utility lines that run through the alleys and along the streets.  I envisioned these lines as the lines on a sonogram graph, with the starling's call taking the shape of the bird they are imitating; the blips on the sonogram.

Robbins, Chandler S, Bruun, Bertel, Zim, Herbert S and illustrated by Singer, Arthur. A Guide to Field Identification Birds of North America.  New York; Golden Press, 1966.

Monday, October 9, 2017

Insect Notes

A few noteworthy observations of select insect populations since May 2017

Chestnut-marked Pondweed Moth - Parapoynx badiusalis
Perhaps my favorite obscure, little moth.  The Chestnut-marked Pondweed Moth has aquatic caterpillars and is often quite abundant at Westwood Hills Nature Center in the middle of the summer.  This summer I didn't see any.  I've observed occasional population lows over the 18 summers I've been at Westwood, but never a complete absence.

Common Baskettail - Epitheca cynosura
This dragonfly usually emerges en masse in late May at Westwood over the course of one or two days.  This year not a single one appeared.

Giant Swallowtail - Papilio cresphontes
Each year a few of these more southern butterflies stray up into Minnesota.  This was the first year to my knowledge that this species has been observed at Westwood.  One individual was observed laying eggs on Prickly Ash in September.

Painted Lady - Vanessa cardui
This migratory butterfly was abundant in parts of Minnesota this fall and elsewhere in the US. 

Wednesday, August 30, 2017

Mushroom Log - Late August 2017

Laccaria ochropurpurea
Though this mushroom does show some variation in color, the differences in coloration in these photos is probably more due to differences in the lighting.

Mycena semivestipes
 Bleach-like odor, growing on a well decayed log.

Marasmius siccus
This small mushroom decomposes hardwood debris.

Suillus americanus
 Growing under white pines.  Note the brown coloration that occurs when the mushroom is "bruised".
 
Amanita sp.
A. vaginata or one of it's many look a likes.


Thursday, August 24, 2017

Mushroom Log - Late August 2017

All the mushrooms featured in this post were found in white pine stands at Afton State Park.

Lactarius indigo
I think all mushrooms are pretty cool, even LBMs.  But a big blue mushrooms is really cool!

Laccaria sp.
 Possibly L. laccata or similar species, of which there are a few.

Inocybe sp.

Possibly I. geophylla.

The two species pictured just above were everywhere in one patch of white pines.  I think it's interesting how both species are so highly variable in appearance, especially as they dry out and more or less blend together to the casual observer.

Trichloma sp.
 Possibly T. myomyces based on it's overall appearance, small size, and habitat.