Thursday, November 28, 2013

Happy Thanksgiving!

Have a Happy Thanksgiving...

An eastern chipmunk (Tamias striatus) nibbling on an unidentified something.
 ... and enjoy your feast (whatever it is)!

Rose hips partially eaten by a chipmunk.

Monday, November 25, 2013

Gotta find them all! continued

My brief field guide for the park continues with the lizards, which means skipping both the fish and frogs.  Fish are easy enough to see in some of the larger ponds, but not so easy to photograph.  Meanwhile, the frogs were simply too fast for me.  Each time I walked up to a pond, I heard them plop into the water before I spotted them.  I will also be skipping the rabbit at the end for the same reason; the only rabbit that I have seen so far darted off into the bushes before I could get my camera ready.

Lizard: Anoles are the most abundant vertebrates I have seen in the park.  In particular, I find Carolina (a.k.a. green) anoles perched on many of the herbaceous plants and bushes.

A juvenile Carolina anole (Anolis carolinensis) shortly before it disappeared into the vegetation.
However, anoles are not the only lizards in the park.  I recently, and very briefly, saw a skink as it buried itself under the leaf litter.

Butterflies: Butterflies of quite a few different species are also very common in the park.  The most striking butterfly I have seen is the common buckeye, which I have now spent quite a bit of time chasing back and forth across the meadow.

This common buckeye (Junonia coenia) kept fluttering a few more feet away each time I approached it.
Follow the links if you are interested in seeing three more of the butterflies I have identified in the park: a tawny emperor (Asterocampa clyton), a gray hairstreak (Strymon melinus), and a dusky-blue groundstreak (Calycopis isobeon).

Heron: The ponds and the bayou -- or rather, the fish and other prey in the ponds and the bayou -- attract a number of heron and egret species.  Especially along the bayou, all I have to do is look up and down the embankment, and I can usually spot one standing in wait near the edge of the water.

A juvenile yellow-crowned night-heron (Nyctanassa violacea) out in the rain.
Lastly, why did I skip over the beetle?  I considered the generic "beetle" on the sign to be somewhat redundant, since ladybugs (featured last week) are beetles -- not bugs.  For contrast, you can see some true bugs (again) by clicking here.  There are other beetles in the park besides ladybugs, but they will have to wait until another post.

Friday, November 22, 2013

Gotta find them all!

The park across the street has a sign advertising some of the organisms that are likely to be found by visitors to the park. (Note that the sign does not include the organisms most likely to find visitors to the park, namely the mosquitoes and chiggers).

Which one of these doesn't quite belong?
I have already made considerable progress in documenting each of the organisms on the sign (and have either seen or heard all but one of them).  Here is a quick guide to each organism, starting from the top left of the sign:

Ladybug: I have found at least three species of ladybugs (a.k.a. lady beetles) in the park.  However, since the drawing was specifically of a seven-spotted lady beetle, I will show that species too.  This species was an interesting choice for the sign, given that it is not native to North America.

Two seven-spotted lady beetles (Coccinella septempunctata).
Dragonfly: I was absorbed in watching a bee (notably omitted from the sign) when I was startled by the sound of the dragonflies pictured below.  They were making a violent clattering as they beat their wings against the vegetation in their struggle.

A male (left) attempting to mate with a female (right) variegated meadowhawk (Sympetrum corruptum).
Turtle: I didn't even have to cross the street to find a turtle.  The one pictured below was on the grass along the sidewalk outside my apartment.

Probably a red-eared slider (Trachemys scripta elegans), but it was hiding its "ears" along with much of the rest of its head.
Squirrel: You may have noticed that I skipped over the acorn.  I don't remember seeing any in the park, but they may have been there (I was not looking specifically for them) or they may have all been hidden by the many squirrels, most of which appear quite well fed.

A fox squirrel (Sciurus niger), but still no acorn.
To be continued...

Friday, November 15, 2013

Looking for a new backyard

One of the challenges of moving to an apartment was that I would no longer have my own backyard.  Although I could observe the animals and plants in the apartment complex's landscaped areas, it might cause some misunderstandings if I started photographing and videotaping directly outside the ground floor residents' patio doors!  After some thought, I came to the conclusion that if I couldn't have my own backyard, I would find something even better -- and now my new "backyard" (just across the street) is a park complete with woods, meadows, a bayou, and a chain of ponds. 

A view of part of my new "backyard".
When first exploring this new backyard, I was quickly tempted off the trail and into the tall grass to chase a butterfly that turned out to be quite adept at eluding me.

A common buckeye (Junonia coenia) butterfly perched on grass.
Once off the trail, I found that the meadow, which looked quite plain from a distance, was in fact full of wildflowers...

A blanket flower (Gaillardia sp.).
... and insects feeding at those flowers...

A skipper (Hesperiidae) visiting a flower.
... and also a surprising number of insects and mites that preferred to feed on me.  Therefore, in subsequent visits to the park, I made a slight adjustment to my wardrobe.

My new boots are not just for the rain!

Monday, November 11, 2013

Assassins all around, part two

The lone assassin bug that I found in Maine did not seem to have many food options available as winter approached.  In contrast, back here in Houston, the thriving insect community is still supporting a large and diverse population of assassin bugs.  I've found these assassin bugs lurking in the park across the street...

A milkweed assassin bug (Zelus longipes), not on milkweed.

... poising to strike from the flowers along the road...

Another assassin bug on goldenrod (Solidago sp.).
... and even coming in through the hallway window at work.  Since I did not have my camera with me at the time, I captured this last assassin bug and brought it home for further observation.

A leafhopper assassin bug (Zelus renardii) that I caught and brought home.
Just like the nymph that I described previously, this related species of assassin bug keeps its front legs sticky, presumably to aid in capturing prey.  Having sticky legs does come with a significant drawback though, as I noted when I put this assassin bug into a container with some dirt.  Almost immediately, its legs were coated in the dirt.  When given a choice, however, the assassin bug appeared careful to avoid walking directly on dirt -- and by the next morning, it had managed to clean off all the debris.

Friday, November 8, 2013

Assassins all around, part one

In the yard in Maine, the most stunning transformation that occurred during the transition from summer to fall was of the burning bushes.  These small trees went from rather modest plants to the most ostentatious ones in the garden, with vividly pink leaves...

Fall foliage of the burning bush (Euonymus alatus).
... and multitudes of brilliantly red fruits.

Burning bush branches loaded with dehisced fruits.
 As I was admiring the burning bushes, one leaf with a bit more green on it stood out from the others.

A pale green assassin bug (Zelus luridus) nymph on the burning bush.
Hanging on to the leaf was an immature pale green assassin bug (Zelus luridus) waiting to grab prey with its sticky forelegs and then stab the prey with its sharp beak.

The assassin bug nymph raising its sticky forelegs in defense, or maybe in preparation for attack!
Though the assassin bug initially seemed disturbed by my attention, I kept seeing it on the same leaf over the next couple of days.  Then, the leaf fell from the tree and the assassin bug disappeared with it.

Monday, November 4, 2013

Don't try this at home

In the summer, when it is warm and the flowers are plentiful, the vast majority of bumble bees out and about are female workers.  Instead of reproducing themselves, these workers collect nectar and pollen to feed to their mother (the queen) and their many younger siblings.  However, the workers are not all completely sterile.  After the queen dies towards the end of the season, some of the workers may begin laying eggs of their own.  Even though these eggs are unfertilized (since the workers never mated), they are still viable -- and they will all develop into males.

A male orange-belted bumble bee (Bombus ternarius) visiting a flower.
In bumble bees, as well as other Hymenoptera, the females are diploid (having two sets of chromosomes and developing from fertilized eggs) and the males are haploid (having only one set of chromosomes and developing from unfertilized eggs).  A consequence is that as bumble bee colonies begin to decline in the fall, more and more of the bumble bees visible on flowers will be males.

A male common eastern bumble bee (Bombus impatiens) visiting a cosmos inflorescence.
Male bumble bees differ from females in the number of their antennal and abdominal segments, the structure of their hind legs, and, in some species, the size of their eyes and the length and color of their hairs (especially on the head).  For example, notice the yellow fuzz on the face of the male bee below.  In the females of this species, the hairs on the face are black.

A very fuzzy male Bombus ternarius resting on a rock.
An important, and potentially less subtle, difference between male and female bumble bees is that only the females sting.  Bee stingers are modified ovipositors, which bees' ancestors used to lay eggs.  Since only the females had ovipositors, only female bees now have stingers.  Not only are male bumble bees unable to sting, they are also quite docile; many of the male bumble bees I found would tolerate being petted gently without flying away.

The bee was very fuzzy indeed!
Please note that I do not recommend trying this yourself (unless you have also worked extensively with bumble bees and are confident that (a) you can correctly identify the males and (b) you are not allergic to bumble bee stings).  Although less common in the fall, female bumble bees are still present and they may sting -- repeatedly -- with little provocation.

A male (above) and much larger female (below) Bombus impatiens.
Explore some more: Bumble bee identification and see more pictures of male bumble bees at the Natural Current Events Facebook Page.