From the Contact Station November 2023

Fall Spectacles and Foggy Weather

The Cranes are here:  Crane numbers peak in mid-October as the migration brings in our overwintering crowd and those that stop for a bite to eat as they fly farther south into Oregon and California.  We did our count on October 16^th this year.  We drove in to our count assignments about 4 pm behind a tornado warning passing through Vancouver to Battle Ground.  We kept our eyes on the skies for more than cranes that evening.  The count area covers Sauvie Island to the west and Vancouver Lake, all the Refuge and Plas Newydd Farm north of the refuge to the Lewis River on the east side of the Columbia River.  We are stationed at known roosting areas.  As the sun goes down,

we count all the cranes coming to roost.  I was counting on the River S near #11 watching for cranes to come into Big Lake and Rest Lake.  Although I counted 26 cranes moving around the area, most of them were heading out.  Only five stayed or flew in for the evening.  The count for the whole area was 4486 this year.  There were 146 more cranes on the Washington side this year than last, but they were in different places.  Campbell Lake, where we do the crane viewing for BirdFest, had the big number of 881 compared to last year’s 148; Vancouver Lake had a count of 8 compared to 889 last year.  Sauvie Island had the largest drop in numbers of about 800. The last two years we had totals for the whole area over 5100.  The trend since counts started in 2008 has been slightly upward, but it is not unusual to see a difference up or down of 1000 birds between years.  Why? Could be the amount of water in favored roost areas and movement to new areas we aren’t covering.  Could be the weather pattern any given October has advanced or delayed migration.  But it is nice to know we have a nice population coming through and in the last four years we have added at least three individuals to the flocks with our successful nesting.

Enjoying a foggy drive:  If you have avoided coming down to the River S because it was foggy, you are missing out on some of the best days to visit the Refuge.  Come dressed for the chill because when it is completely socked in, you are going to want to stop, roll down your car windows, turn off the heater and listen because you certainly can’t see anything.  The last few weeks have been filled with the calls of Sandhill Cranes, Cackling Geese, Red-winged Blackbird, Killdeer, American Pipits, and an occasional White-fronted Goose among others.  I guess you could go down to the tour on a sunny day and close your eyes, but it is just not the same.  If you take your time, the sun may break through the clouds to reveal a small flock of Sandhills in the mists feeding on the fields right behind the contact station accompanied by a small herd of White-tailed Deer.  Meanwhile, the coyote pups are hopping around in the distance trying to find a

vole breakfast. Then the sun pops through to reveal the lush greens of rain-quenched vegetation bold and bright, with the beginning of fall colors in swaths across the wetlands.  It’s a magical time to visit the Refuge.  The freshness of the air is worth a few deep breaths.

Recently my timing was perfect for a foggy morning and a great surprise from nature.  Slight diversion, but it fits the topic. I once had a roommate back in the day who had a spider phobia.  I could tell by the tone of her voice when a spider intervention was needed. I would move the offending arachnid to the outside and all would be calm again. She would not have liked my foggy day drive.  I was gathering silver threads as I drove the auto tour, they crisscrossed my windshield and hung down across the open

window into the car. I remembered someone telling me it was spider silk. But what made this happen now and was it really spiders?  Fall is an amazing time to see spider webbing throughout the refuge. Random silk threads can be seen between branches at the tops of the trees. They are highways for small spiders to move across spaces. You might see a clump of white webbing with a silk streamer as it floats above the fields.  Northern Harriers fly with silk trailing from their wings. When the conditions are right, the webbing will waft in the breezes. With October’s foggy mornings, the strands of silk are illuminated everywhere, bright white and decorated with water droplets.  Whole sections of wetlands plants can be covered with sheets of lacy webbing.  It’s very beautiful.

So, what’s up?  Turns out spiders, mites and some caterpillars use their silk to disperse across areas in a process called ballooning.   Let’s focus on spiders, or more precisely, spiderlings, the small immature spiders.  Not many heavy adults can balloon, thank goodness. That would keep my friend indoors in the Fall. Yipes “flying spiders”.  Survivability is not a given as movement is at the whim of the winds and exposure to predators, like birds, is increased.  To balloon a spiderling moves up a plant or structure to the highest point possible, stands on raised legs with its abdomen pointed

upwards in a movement called tiptoeing, and then releases silk threads from its spinnerets into the air.  A parachute-type structure is formed which carries the spider on air currents allowing it to disperse.  Most flights end in just a few feet, but if they are caught on strong winds, they can be carried vast distances.  There are reports of spiders caught in the sails of ocean-going vessels and in atmospheric data balloons at almost 16,000 feet.  October to December is a spider-friendly time; they like more moist conditions than summer provides here in Washington.  It’s a good time for the hundreds or thousands of spiderlings to leave the nest.

Interestingly, wind is not always a factor in the spider’s travels.   Electrostatic repulsion will also generate the needed lift. Spider silk is negatively charged, as is the surface of the Earth which is negatively charged by thunderstorms around the world. Since like charges repel, the silk is pushed off the ground and the spider takes flight. Spiders sense these electric fields with the hairs on their legs. And away they go.

Spiders can use their silk to gather water too. Though we know spiders suck juices from their prey, they also will drink from water droplets.  On a foggy morning, you can see droplets condensed on silk strands like beads on a necklace.  Humm, a fluke of nature or are spiders more thoughtful than we think? Scan across the wetlands and you will see blankets of webbing lying across the vegetation.  Some spiders lay out blankets of silk over an appropriate area, then lower themselves below to hang from a silk thread in wait for a meal to become caught in the silk blanket above.

Our recent foggy mornings have provided wonderful viewing of silk threads in the tops of trees, in

the air and over the crowns of plants.  Spiders use their silk-making abilities in so many ways; too many to cover here.  There are dozens of spiders in Western Washington, and over 986 last noted in the state of Washington.  You may not see them as you drive around the auto tour, but you can see where they have been on a foggy day!  I just know I am not telling my friend, when next she visits, about ballooning spiders.

 

Meet Volunteer Dave Lang:     Dave grew up in Minnesota.  He began to see the world with overseas assignments during his enlistment in the Army.  That’s where he picked up some mapping skills with some educational opportunities.  He ended up in Portland where he has lived most of his life and he received a bachelor’s degree at Portland State.  He made his career with the US Forest Service where he was a cartographer.  When he retired from the US Forest Service in 2011, he decided to keep in touch with the outdoors by volunteering at the Refuge.  For the first year or so, he worked around the refuge, looking for and removing invasive plants.  Sometimes the work was done via canoe to get into more remote sections.  He finds being outdoors, especially on the Refuge, very peaceful.  At home, he does nature-scaping with native plants.  He is certainly a good source of botanical information.  He is also a long-time birder.  His international travels didn’t stop when he got out of the service.  He and his wife travel around the states and internationally and are looking forward to a trip later this year to New Zealand where he is sure to add some new species to his life list.  You can meet Dave on Monday mornings at the contact station.  He arrives early and usually does a drive around first thing to see what is out and about.  He enjoys showing visitors where to find wildlife by whipping out a map and marking all the hot spots of the day.  Just like a cartographer!  Visit with Dave on Monday mornings.

–Susan Setterberg, Contact Station Volunteer
images by Susan Setterberg (unless otherwise indicated)