Spider

A nocturnal wolf spider hunting on the snow in the northern Blue Mountains.

October 2019 came to us in a continuum of warm pleasant days and cooler, comfortable nights — that is until Saturday, the 26th when an Arctic cold front started seeping into our region.

Only that morning, while leading a birding tour for friends from Seattle, we had observed six species of butterflies at Ayer Boat Basin.

This was unexpected due to the late date.

By 2 p.m., the first wall of cold air blew in over us and all the butterflies vanished.

The weather deteriorated into a freezing Arctic air mass that blanketed all of southeast Washington, and was still hanging on as of Halloween evening.

So, the question is how wild animals adapt to sudden cold snaps that are many weeks early and not expected.

Most insects that have survived the first few mild frosts simply lose the struggle to survive and they perish.

Most tardy migrant birds that have failed to migrate south pick up and start flying south.

For some individuals within a species, the chance to escape the cold grip of an early winter also spells doom, as most of these birds are insectivores and after the arrival of an early cold snap, most insects are gone. These insect-dependent species of birds all have very high metabolisms that must be fueled with large amounts of living bugs.

If these birds are caught in an Arctic air mass and all the living insects freeze, they simply run out of fuel and go to sleep as they, too, freeze up.

Most small song birds weigh less than an ounce and therefore lack the body mass to withstand an Arctic cold snap.

Since 2008, we have witnessed a major weather shift that has brought longer, warm, dryer falls that have lasted well into December.

This last year, winter did not arrive until the second of February, and then it lasted all of six weeks.

Though it was of short duration, last winter was intense with lots of ice, cold and snow.

By the third week of March it was over. The year before, we lived through a nine-week winter which seemed very short by comparison to the winters of the late 1970s and into the 1980s.

This fall flipped to winter quickly, with the natural world sensing something was amiss with the coming weather.

The Swainson’s hawks left three weeks early this year — all were gone by the third of September, when this raptor normally does not flock up for their long flight south to the Pampas of Argentina until the 22nd of September while weather here is still warm, and grasshoppers, crickets and mice are plentiful.

We noticed this fall that many neo-tropic migrant birds moved out early in large numbers.

So, you must ask yourself how did these migratory species know that winter was rolling in early?

This column I would like to share a story about an amazing natural event that starts in September and continues well into October. This is about the dispersal of an animal that most people fear and despise — in some instances with reason.

I am talking about spiders.

There are dozens of species of both native and non-native spiders here in Walla Walla County.

These animals are not insects, but rather arachnids that have eight legs instead of six legs, as all insects do.

Spiders have been divided up into many families, where some are web spinners and others are ambush, non-web-spinner hunters.

All are predators and feed on everything from small mice and birds to tiny insects, fish and amphibians.

Spiders have superb eye sight, along with many eyes — all the better to see you with.

So, we will focus on how most web-spinning spiders disperse.

Shortly after these creatures hatch from their eggs, which are carefully protected by their mother, in most instances, these tiny young leave the site where they hatched and on a warm fall afternoon they climb to the top of a tall stem of grass or other structure — including man-made homes and even cars and TV antennas.

They then sit and calculate wind velocity and direction, ambient air temps, and then, with their abdomen pointing high in the air, their spinnerets start pouring out a thin line of silk that hardens rapidly and gets picked up by the breeze.

These minute spiders peal off many yards of this narrow silk thread in just a few seconds. Off it soars into the wind.

With just the right amount of silk released to carry its slight weight, the spiderling tucks its legs to its body, and up-and-away it floats connected to the long thread of silk as it is pulled and pushed by the moving air.

Often these spiderlings are pulled high into the sky as the warm air rises in late afternoon. Some go so high as to get caught in streams or currents of air and may travel thousands of miles until the air cools and the great gossamer threads which tow them start to sink back to earth.

Many of you have seen highline wires coated with gossamer, or fields in a late fall afternoon covered with these threads.

Millions of spiders starting out in life take this ride on long strands of gossamer silk never knowing where they will land.

Mossy young spiders never reach maturity, though enough do to continue the species. Spiders are super-important as insect population controllers and as prey base themselves for birds, insects, mammals, amphibians and fish.

So, remember that not all spiders deserve to meet the sole of your shoe, though some are poisonous and must be removed from homes.

More on those pesky species later.

Remember, life is good!