Monday, November 2, 2015

November Phenology- 2015

Phenology - the scientific study of periodic biological phenomena

Asian ladybeetle - Wikipedia
You know it is November when the Asian ladybeetles, Harmonia axyridi, form swarms and they head in as unwelcome house guests for the winter.  Unlike the sweet ladybugs of my childhood, this invasive species starts gathering in hordes in October,  planning to survive the winter in any shelter they can find.  They are attracted to light or shiny surfaces, especially on warm afternoons after a cold spell announces the oncoming winter.

They were imported into the US multiple times from the 1960's on because of their appetite for aphids.  They never really thrived until the first large infestations were reported in 1988, possibly as an accidental import through New Orleans.  Since then they have really gotten the hang of coexisting with humans.  Their foul odor and the habit of taking little bites of us makes them the #1 invasive species of fall.

Because of their annoying habit of nipping on our skin, swatting them is a natural reaction.  This leaves a foul odor on your skin from a yellow defensive chemical that they secrete from their legs.  The yellow stain starts appearing as dots around the house even after they have disappeared into the nooks and crannies.

Available in a number of patterns -
Although our invaders are uniform in appearance, this species can be highly variable with a choice of colors and the number and placement of their markings.  The males tend to be smaller and have fewer markings.  Like most invasive species, they have some predictable traits.  They live up to 3 years during which they have multiple broods each year.   They have few natural predators in their new found land, just a few parasites that are rarely lethal.

November Phenological Phenomona  
Click to enlarge- REK
Studying the biological world's timing of natural events can give us hints of what to look for in November.  Squirrels are stashing acorns in competition with turkey, deer and larger mammals.  Today I captured video of this fat ground hog, Marmota monax, porking out on the acorns just a few feet off of our deck.  Although I was filming inside our darkened cabin, it detected a slight movement of the camera and went into a defensive freeze, then took off over the bluff toward home. It has been feasting because it will lose 1/3 to 1/2 its weight during hibernation.

Bear-broken branches litter the ground.
Bear claw marks on white oak
Bears have been climbing our white oak trees, breaking branches as they harvest green acorns.  Female black bears are storing fat to feed the young born during the winter and will be denning soon.  What a great system, delivering their cubs in their den and sleeping through most of the early nursing without having to get up at night!

Other November things to look for:
  • Polistes red wasps are patrolling the house, looking for a crack to nest in for the winter.
  • The  cricket chorus is slowing down.  The last voice to be heard is Jay's jumping bush cricket whose brief buzzing call announces the beginning of winter. 
  • Stick insects are now clinging to the sides of our house.  After spending the summer feeding on the leaves high in the trees, the wind, falling leaves and temperatures are dropping them to the ground where they optimistically start climbing up again.
  • Time to get the bird feeders ready.  The best of the berries are already starting to disappear and available insects are becoming rare so birds need alternate food sources, especially high energy sources like peanut butter/seed wads and suet cakes.  If you have bears around your neighborhood, you may want to wait a few weeks until they den.
  • With the leaves off the trees it is a good time to look for squirrel dreys, bird nests and even a trophy hornet nest to harvest before winter breaks it down.  

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