Category Archives: Wildlife

Interpretive Blogs about Wildlife and Plants

Mallards (Anas platyrhynchos)

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Mallard ducks tolerate humans… maybe a little too well.

Mallard ducks are the most abundant and widespread waterfowl in the Northern Hemisphere. They are found from Arctic tundra to subtropical regions on every continent.

Mallard female and male (green head). Photo ODFW.

In Oregon, Mallards are found near coastal and inland marshes, fresh or salt water wetlands and estuaries; lakes, ponds, and rivers; and golf courses and agriculture fields. They are particularly attracted to shallow water with aquatic vegetation.

Flexible Omnivore

Mallards are flexible omnivorous eaters and will vary their diet based on breeding cycle, availability, and migration. As a general rule they primarily eat, or dabble, plant materials. They will also dabble gastropods (slugs, snails, etc.), invertebrates (flies, beetles), crustaceans (crab, shrimp, barnacles, etc.), worms, and frogs. They have also been observed hunting as a flock other small birds and larger animals.

Oregon Department of Fish and Wildlife urge people to not feed geese and ducks. Feeding can create a concentration problem and invites disease outbreaks.

One Eye Open

Not only will they eat many different animals, but many different animals will eat them. Predators could include raptors (like eagles, falcons, harriers, owls, etc.), mammals (such as snakes, raccoons, skunks, cats, dogs, etc.) and others who target eggs and nestlings.

The ability to sleep with one eye open was first demonstrated in mallards, but is not believed to be widespread among birds. This ability allows one brain hemisphere to sleep, while the other is aware.

And Humans…

Ducks were domesticated at least 4,000 years ago in many areas for their meat and eggs. Pure bred Mallards are sometimes domesticated today for their meat and eggs. 

Almost all domestic duck breeds can be traced back to Mallards. Domestic ducks and Mallards are the same species, with some of the same genes. Mallards have the ability to cross breed with 63 other duck species and create fertile hybrid offspring. This ability can dilute a duck breed population and cause severe ‘genetic pollution’ leading to the extinction of wild, indigenous waterfowl. They are considered an invasive species in some areas.  

Mallards are the most common variety of ducks hunted for sport due to high population volumes. They are also considered to be quite tasty. Be sure to check with local regulations before hunting or taking any bird.

Caution

Mallards can become aggressive during the breeding season as they compete and work out territorial disputes. Aggressive behavior can include charging and chases, ripping out feathers and skin, and noise making. Males are generally more aggressive and will repeatedly attack each other. Domestic ducks are significantly less aggressive than mallards.

STATS: Color: breeding males have a solid, dark green head, reddish-brown breast, and pale body; males and females have bright blue patch on trailing edge of wings. Size will vary: overall length, 147 cm (23 inches); wingspan, 89 cm (35 inches). May migrate. Feathers: Special oils let feathers easily shed water. Mallards are adapted for swimming and floating, and some are even talented divers.

REFERENCES
–Oregon Dept. of Fish and Wildlife pages: Swans, Ducks, and Geese (https://myodfw.com/wildlife-viewing/species/swans-ducks-and-geese) and Game Birds, Mallard (https://myodfw.com/game-bird-hunting/species/mallard, and pamphlet Living with Birds (https://www.dfw.state.or.us/wildlife/living_with/birds.asp)
–Wikipedia, Mallard (https://en.wikipedia.org/wiki/Mallard)

Common Garter Snake (Thamnophis sirtalis)

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Things that will eat slugs are a welcome sight in any garden. The Common Garter Snake, along with most snakes in Oregon, is considered ‘beneficial’ because of their diet. The Common Garter Snake will eat slugs, grubs, mice, voles, earthworms, rats, frogs and tadpoles, and generally anything they can overwhelm.

Species in Oregon

There are four species of Garter snakes in Oregon: The Common Garter and Western Terrestrial Garter are abundant throughout Oregon, except the mountains. The Northwestern Garter resides in western Oregon. The Aquatic Garter resides in southwestern Oregon. Snakes are usually black, dark brown or green with a light-colored or red stripe and can reach 48-inches in length.

Where to look

You can find Garter snakes in a variety of habitats such as urban lawns, forests, woodlands, fields, and grasslands. Look for Garters near water, such as a wetland, stream, or pond. Water provides a place to hunt amphibians and as a potential escape strategy.

When disturbed, a garter snake may coil and strike. Typically, the Garter will hide its head and flail its tail. It may also discharge a malodorous, musky-scented secretion or slither into the water to escape a predator. Garters do not have the capacity to seriously injure humans, even though they have small amounts of a mild venom.

Predation

Garter snakes give birth to live and independent young. Gestation lasts a couple of months with birth rates reaching nearly 100. Juvenile snakes are often killed by predators, cars, and lawnmowers! Predators include birds of prey, crows, egrets, herons, cranes, raccoons, otters, bull frogs, shrews, and other snake species (such as the coral and king snakes).

Communication

Garter snakes use a complex communication system using pheromones. The pheromones cues are communicated through tongue-flicking behavior. This system helps them find other snakes through pheromone-scented trails and making it key to breeding.

Learn how to invite these beneficial predators into your garden by reading the Oregon State Extension publications Common Garter Snake and Attract Reptiles and Amphibians to Your Yard.

REFERENCES:
Snakes slither through the garden eating slugs, grubs and other pests (https://extension.oregonstate.edu/news/snakes-slither-through-garden-eating-slugs-grubs-other-pests)
Garter Snakes, Wikipedia (https://en.wikipedia.org/wiki/Garter_snake)
Oregon Department of Fish & Wildlife (https://myodfw.com/wildlife-viewing/species/snakes)

California sea lion (Zalophus californianus)

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California sea lion (Zalophus californianus)

California sea lions are members of the “eared seal” family Otariidae. These pinnipeds live along the rocky Pacific Ocean coastlines of western North America.

They are very social animals and form groups of several hundred individuals onshore. In many areas they have become quite invasive and obnoxious. 

California sea lions are the most recognized pinniped species because they are commonly seen doing acrobatic tricks in shows at zoos and aquariums. While they are known for their intelligence and playfulness, these animals also quite athletic.

In the wild, the California sea lion swims up to 25 miles per hour, which is faster than any other sea lion or seal. This superb speed is related to how they use their front flippers.

Quick Diver

This animal is also an avid diver. When diving deep, California sea lions slow their heart rates to allow them to remain underwater for nearly 10 minutes before surfacing to breathe. This ability gives them an edge in the pursuit of the fish, squid, and shellfish that make up their primary diet.

California sea lions have color vision. They don’t see all colors, however, but are limited to blue-greens of the color spectrum.

REFERENCE:
–Wikipedia, California Sea Lions (www.wikipedia.org/wiki/California_sea_lion)