Category Archives: Wildlife

Interpretive Blogs about Wildlife and Plants

American Beaver (Castor canadensis)

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Why is a rodent on our state flag?

The rodent on the Oregon State flag is an American Beaver. In 1969, the Legislature recognized the American Beaver by naming it Oregon’s state mammal. Beavers enhance habitat for many other fish and wildlife species through dam-building activities. Beaver ponds provide areas for people to fish, hunt and view wildlife.

How did beavers earn this honor?

During the 1800s, beavers and several other fur-bearing animals were trapped and killed for their pelts or fur. Pelts were shipped back east, to Europe, and China to make beaver hats and coats.

Beaver pelts and activities played a significant role in helping to get Oregon’s economy and growth started. Some say that Oregon’s early economy was built on beaver pelts.

Beaver swimming (courtesy ODFW)

Unregulated trapping virtually eliminated beavers from many landscapes. Other animals trapped included mink, otters, muskrats, martins, raccoons, red fox, grey fox, bobcats, and other furs.

Recovery

With proper management the beaver has become re-established. Beavers can be found in many state waters where the habitat needs are met. Beaver habitat almost always include riparian habitats with trees such as cottonwood and aspen, willow, alder and maple.

Small streams with a constant water flow that meander through relatively flat terrain in fertile valleys seem especially productive of beavers. Beavers can also be found near larger bodies of water such as lakes.

Well suited for water

Beavers are well suited for aquatic life with their paddle-shaped tail, webbed hind feet, compact body, and thick coat with coarse guard hairs that are coated with waterproof oils. Beavers also have a special membrane that cover their eyes and nose when swimming. Finally, Beavers are able to extend their time underwater (to at least 15 minutes) by slowing their heart rate.

Telling the difference

Beavers can be mistaken for muskrats or nutria. The tails and sizes of these animal are strikingly different.

Beavers are the largest rodent in North America often weighing in excess of 65 pounds, and may reach nearly four feet in length. The broad, flat paddle-shaped tail of the American beavers is nearly invisible when they are swimming.

Both muskrats and nutria are quite a bit smaller than beavers and very different tails. Muskrats and nutria have thinner tails and are significantly smaller. Nutrias typically range from 9-20 pounds and have a round tail. Muskrats have a thin, slightly flattened tail and can reach up to 4 pounds.

The tail of a Muskrat and Nutria will either sways back and forth like a propeller or are held out of the water as the animal swims. Nutria are considered invasive in many areas.

Clumsy on land

Courtesy Washington Dept. of Fish & Wildlife
photo by Laura Rogers

Beavers are at risk when foraging on shore or when migrating. Because of their size, behavior and habitat, adult beavers have few natural enemies. Predators include humans, bears, coyotes, bobcats, cougars, and dogs.

The beaver’s sharp incisors are used to cut trees and peel bark while eating. These incisors continually grow but are worn down by the grinding, tree cutting, and feeding. As the incisors wear down, the back surface is softer than the front which helps to create the sharp edge.

Beavers eat a variety of vegetation, roots, herbs, etc. Commonly consumed foods include hammer willows, vine and big leaf maples, alder, and cottonwood. In the winter, they depend on woody plants for most of their food.

Not all are dam builders

Beavers build deep water dams which helps deter predators, facilitates an underwater den entrance, and promotes growth of their favorite foods. Dams vary in size from a small accumulation of woody material to structures 10 feet high and 165 feet wide. 

These water areas help provide habitat for many fish and animals, and are critical to juvenile salmon.

But not all beavers build dams. Beavers living on lakes or large rivers that maintain a constant level do not build dams. They may still build lodges and bank dens for resting and rearing their young.

Beavers are also the mascot for Oregon State University.

REFERENCES:
–Oregon Dept. of Fish and Wildlife, Beavers (https://myodfw.com/wildlife-viewing/species/beavers, and Beaver factsheet (https://www.dfw.state.or.us/conservationstrategy/docs/Beaver_factsheet.pdf)
–The Oregon Encyclopedia, Fur Trade in Oregon Country gives a thorough account of the fur trade and economic impacts generated for the state (see https://oregonencyclopedia.org/articles/fur_trade_in_oregon_country/#.XtVBrW5Fycw

Brandt’s Cormorant (Phalacrocorax penicillatus)

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There are three different types of cormorants on the Oregon coast. Brandt’s Cormorants reside year around and are easily recognizable during breeding season by its unique throat patch.

Photo Courtesy of ODFW

How it got is name

German zoologist Johann Friedrich von Brandt identified and named the species in 1838 while working at the Academy of Sciences in St. Petersburg, Russia. His species description was based on a specimen taken by Russians exploring the Pacific Coast at the time.

Territory for the cormorant extends from Alaska south through Mexico along the Baha peninsula. Year around residency is predominately in the U.S. along marine coastlines and estuaries near the ocean.

Favorite haunts include Washington, Oregon, and California which offer rich food sources associated with California water currents. Populations redistribute along the coast then the effect of this current diminish as this resource dissipates.

Recognizing them

In the breeding season males display an intensely blue gulag pouch. They attract mates by pointing their bill skyward and prominantly displaying their pouch.

They also have wispy white plumes along the side of their head and on their back, which show well against the solid black of the rest of their plumage. In bright light, their feathers have a green iridescence. During all seasons Brandt’s Cormorants have buff-colored feathers that outline the gular region. The other two Oregon species do not.

All Cormorants are fish-eating water birds and have four toes joined by webbing.

Where to find them

Always near the water, cormorants rarely fly over land. Nest building activities are one of the few reasons they ever come to shore.

Nests are typically built in colonies on windward slopes of rocky islands, steep cliffs, and sandy beaches. Brandt’s Cormorant tend to live together in large flocks, particularly in California and Oregon.

Nesting territories reflect this high population behavior and are quite tiny. Male Cormorants arrive at the nesting areas before females to claim their space or existing nest. They vigorously defend their nesting area and begin nest construction or refreshing,

The circular nests are typically around 14 inches wide and just over six inches tall. They contain grass, moss, weeds, sticks and driftwood, feathers, and marine algae.

Let’s Go Fishing

Brandt’s Cormorant are strong divers and excellent swimmers. Unlike other cormorant species, they do not spend a lot of time drying their wings. They do like to fish together.

They even forage schools of fish together in groups that includes other seabirds, and sealions. The group appears to work together feeding in concert. As some birds rapidly surface, others are flying to the leading edge of the flock.

Cormorants dive beside or below a school of fish and drive them to the surface. Remarkably Cormorants are able to dive up to 230 feet. During the chase, they grasp prey in their bills, crush it, and swallow it headfirst.

What’s on the menu?

Brandt’s Cormorant will eat at least 93 fish species such as anchovy, perch, herring, seabass, and other animals such as squid.

Population Declines

Even with superior swimming and fishing, the Brandt’s Cormorant populations appear to be in decline. Human activities such as spills and pollution threaten all seabirds and their prey species.

Brandt’s Cormorants may be more sensitive to the impacts than other birds because they only forage in waters where spills often occur or concentrate. Human (and dog) disturbances can cause birds to abandon a colony or leave a population vulnerable to predation.

REFERENCES:
–All About Birds, Brandt’s Cormorant (https://www.allaboutbirds.org/guide/Brandts_Cormorant/overview and life history pages)
–Oregon Dept. of Fish and Wildlife, Pelicans and Cormorants (https://myodfw.com/wildlife-viewing/species/pelicans-and-cormorants)

Lingcod (ophiodon elongatus)

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When a fish smiles…

Lingcod (ophiodon elongatus) are almost primeval looking with large, gaping mouths and 18 large, sharp canine-like teeth. The term “ophiodon” means “snake-toothed.”

Lingcod can sometimes be blue. Photo courtesy of NOAA.

This fish was given the name ‘Lingcod’ because it looked a bit like both a ling and a cod fish. Not because it was either or even related. Lingcods belong to the greenling family (Hexagrammidae).

Description

Lingcod colors can vary. Photo courtesy of NOAA.

This voracious predator can grow to be 5 feet long and weigh up to around 130 pounds. Average size along the Oregon coast is around 2-3 feet (or around 5-10 years old).

The fish has a sinuous body with two successive long fins. They are typically dark gray, brown, or greenish on the back with some copper-colored mottling or spotting along the upper back, and sometimes blue.

Territory

Lingcods are native to the North American west coast from the Gulf of Alaska into Baja California, Mexico. Adults like to be near rocks, inshore up to 230-fathoms deep. Young lingcod prefer sandy or muddy bay bottoms and inshore areas.

As adults Lingcod are fairly sedentary and non-migratory. Males migrate to nearshore spawning grounds in late fall to establish and aggressively defend nest sites. Preferred sites have strong currents and are near rock crevices and ledges.

Spawning occurs in winter. Mature females leave the spawning ground after depositing the eggs.

Male Lingcods guard the nest until hatch (about 8- to 1-weeks later). Successful spawning would not be possible without this protection. Rockfish, sculpins, kelp greenlings, Sea Stars, and other cod will quickly destroy an unguarded nest.

Prey & Predators

Adults are aggressive predators that will eat just about anything they can fit into their large gaping mouths. Prey includes smaller lingcod, squid, octopi, crab, and large rock fish. Predators include sea lions and harbor seals, along with sharks and larger lingcod.

Fishing

Lingcods are prized by ocean sport and spear anglers, and have been an important part of local cultures.

Restrictions to protect habitat can involve seasons, areas, and equipment. Be sure to check Oregon Sport Fishing regulations and seasonal changes, licensing, and limits.

Lingcods harvested nearshore are often larger and tastier. Going out beyond the bay could be well worth the journey.

The smile…

Fish don’t smile. Mind the fingers… 

REFERENCES:
–National Oceanic and Atmospheric Administration (https://www.fisheries.noaa.gov/species/lingcod)
–Oregon Dept. of Fish and Wildlife, Lingcod (https://myodfw.com/fishing/species/lingcod)
–Fishing Booker (https://fishingbooker.com/fish/lingcod/us/OR)
–Wikipedia, Lingcod (https://en.wikipedia.org/wiki/Lingcod)