Nature Watch: Fall’s Dilemma – Flee or Fight?
About the author: Steve Ellis is a naturalist and Land Trust member who enjoys sharing his love of the natural world. His blog series, “Nature Watch,” will appear each month in “Habitchat,” chronicling native plants and wildlife you can expect to see during that particular time of year. We thank Steve for sharing his passion, illustrating the importance of island conservation.
Autumn’s colder weather joins with shorter daylight to create a conundrum for local fauna. Do they stay and fight it out or flee south to a warmer place? Either decision carries risks and rewards.
Staying put means the possibility of being confronted with fewer resources. For example, countless insects and other invertebrates perish with the first frost. Small birds have to search harder for a meal just as the need for calories rises dramatically due to inclement weather.
Remaining in place can have advantages. Familiarity with food sources and knowledge of sheltering places means the difference between life and death. Staying also means being able to snap up the best breeding territories before migrants appear in the spring.
Migration is an arduous task. Calories are burned quickly and exposure to predators is increased. Finding safe havens enroute can be difficult. There’s also competition for food with resident birds on the wintering grounds.
The rewards of migration can be well worth the risks. Many of our summering bird species – warblers, flycatchers, swallows and tanagers – spend the winter in western Mexico or south through Central America. Here they find warm, stable weather and adequate food.
Mammals, too, face the same challenges and choices. Most fight it out, but gray whales and some bat species elect to migrate. Other bats and Townsend’s chipmunks enter hibernation, a flight of a different sort.
Plants can only “flee” into dormancy. Annuals live on as seeds, while perennials retreat into their root systems. Deciduous trees and shrubs shed their leaves, while evergreens shut down and prepare for freezing weather.
It’s not a given that all birds of a species make the same choice. Individual Townsend’s and Yellow-rumped Warblers, for example, may elect to stay. Even Barn Swallows have been noted on Christmas Bird Counts.
The decision to flee or fight is fraught with irrevocable consequences. Whether the choice made by an individual is correct won’t be known until the advent of spring.
Flora: Puget Sound Gumplant (Gumweed), Grindelia integrifolia
While most local flora species shut down in the fall, this hardy wildflower bravely blooms into early winter.
Gumplant is a perennial that can grow to a height of 2.5 feet. The leaves at the base can be quite long, but those growing from the stem only reach 3 inches in length. Flowers of this semi-woody plant are yellow and have a disc shape. The bracts surrounding the petals are covered in a sticky, white latex substance which gives the plant its common name.
Gumplants begin blooming in July and last into December, making them the wildflower with the longest flowering season in our area. Several bee and butterfly species pollinate the flowers while gathering nectar. By December, only the hardiest of bumblebees can be found on the blooms.
The seeds are attached to fluff, which helps as they are scattered by the wind. Finches, sparrows and mice eat the seeds.
Gumplants grow in a variety of habitats that offer full to mostly sunny conditions. They’re often found along beaches, and may grow in nutrient-poor soils and gravel.
Look for gumplants above the high tide line on local beaches and along roads in open areas.
Fauna: Ensatina, Ensatina escholtzii
The ensatina is a creature that attempts to have it both ways in fall and winter. This small salamander will be active through the cool, wet weather of autumn. Freezing temperatures send them into the safety of burrows, as does summer heat.
Ensatinas grow to a length of 4.5 inches, which includes a 2-inch tail. They are brownish overall in color and lack a colored back stripe present in some other local salamander species. The head and eyes are large in relation to the body.
This amazing little salamander is fully terrestrial; it never visits ponds or lakes. This allows them to be the most widely distributed on these islands. Females lay a cluster of white eggs in a rodent burrow, or under woody debris, or in a rotted log. The female watches over the eggs until hatching. The young come out as fully-formed – but tiny – salamanders.
Ensatinas prey on a wide range of invertebrates, such as beetles, termites, centipedes, sowbugs, and snails. In turn, they’re preyed upon by garter snakes, owls and raccoons.
Look for this charming little amphibian on forest floors that have abundant moss and fallen wood. They also inhabit backyards and fields. You’ll need a headlamp for your search, as they tend to be nocturnal.