Nature Watch: Autumn Drama Unfolds in October
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.
Changing seasons in nature are generally gradual. The lone exception is autumn, when first frost kills most insects and ends plant growth. Cooler temperatures and lessening daylight halt the bloom of phytoplankton, the tiny algae that form the foundation of life in Puget Sound. Animal life that grazes on the algae perish or migrate. Many fish and invertebrate species retreat from shallow waters to stabler conditions found at greater depths.
Doubtless fall’s most eye-catching feature is the deciduous trees. Willows, maples and others withdraw sugars from leaves and store them in their trunks as photosynthesis winds down. The leaves’ true colors are revealed; yellows and golds where the green of chlorophyll once reigned. October’s dramatic changes serve to remind us that nature has turned off the tap.
Here’s a look at two species you might notice in October.
FLORA: Bitter Cherry, Prunus emarginata
Bitter Cherry is an important member of local forest landscapes. Reaching a height of 50 feet, this species can attain a diameter of up to a foot. The bark is reddish-brown or gray, with horizontal, raised blisters.
Cherry leaves are 1 to 3 inches long, oblong or oval shaped. In spring, they’re joined by clusters of small white or pinkish blossoms, which host more pollinating insects than any other native tree. The blossoms become bright red fruits by summer, a favorite of finches, American Robins and especially Cedar Waxwings. Bitter Cherry trees are easy to spot in autumn; their yellow to reddish-orange leaves contrast with the dark green hues of firs and hemlocks.
FAUNA: Columbian Black-tailed Deer, Odocoileus hemionus columbianus
The local deer are in a rut. For bucks, a set of antlers is a prerequisite for the annual drive to reproduce. Antlers are the fastest growing bone in nature. They erupt in spring, reach maturity in September and by October, the “velvet” skin is gone.
Bucks begin the rutting season by sparring with each other. Often a large buck will select a younger male as a sparring partner. This mismatch benefits both – the dominant male gets back into fighting trim while the younger gains experience. True fights only occur between closely matched mature bucks. These sessions are usually brief, ending in one contestant’s rapid retreat.
This month, bushes and small trees may show signs of violent slashing, evidence of aggression from solo bucks. After raking his antlers through the greenery, a buck will rub his forehead, leaving behind the scent of challenge to nearby males.
During the rut, a buck becomes single-minded in his pursuit of does, leaving them inattentive to traffic, an important factor local drivers should keep in mind. Ruts peak in October and ceases by December. By late January, antlers are shed, until the cycle begins anew in the spring.