Category Archives: Wildlife

Interpretive Blogs about Wildlife and Plants

Oregon Swallowtail (Papilio oregonius)

Posted on by

Bees sip honey from flowers and hum their thanks when they leave.
The gaudy butterfly is sure that the flowers owe thanks to him.

Rabindranath Tagore
Courtesy Unsplash Royalty-free

The Oregon coast is very lucky to have a native butterfly species that is both colorful and spectacular.

The Oregon Swallowtail is part of a larger Papilionidae family that includes some of the largest and most beautifully colored butterflies in North America. North America has 40 species.

Territory

The Oregon swallowtail lives only in Oregon, Washington, Idaho, and south-central British Columbia. Swallowtail species can be found in the Arctic Circle south into Mexico. Most sightings in Oregon are along the mainstems and immediate tributaries of the Columbia, Deschutes and Snake Rivers.

There are over 550 butterfly species in this family. Most reside in tropic and subtropic regions. The Oregon Swallowtail may have originated there.

Food

Adults feed on wildflower nectar from thistles, balsamroot, phlox, daisies, asters, rabbitbrush, penstemon, milkweed, and dogbane. The larvae (juveniles) feed on tarragon sagebrush (also called wild tarragon or dragon wormwood, Artemisia dracunculus).

Swallowtail butterfly caterpillars feed on a wide range of plant families, and often depend on one of five families: Aristolochiaceae, Annonaceae, Lauraceae, Umbelliferae (Apiaceae) and Rutaceae.  These plant families include toxic plants. Once eaten, the toxin makes both the caterpillar and butterfly also toxic which helps protects them from predators.

Predation

Oregon Swallowtails have wingspans up to 4-inches that sport a bright yellow with black-lined pattern and a ‘tail’ that extends off the back wing. The yellow wing markings of the Oregon swallowtail are brighter than the common swallowtail.

The tail is not required for flight, and may be sacrificed to escape predation. The hope is that the bird may ‘swallow the tail’ rather than a more critical body part and allow the butterfly to survive.

Several Swallowtails can also change their behaviors to help reduce predation. They will imitate the behaviors of other distasteful species, and several studies show females imitating males as a way to reduce predation.

Predators can include birds, wasps, spiders, and preying mantis, skinks, skunks and human collectors.

When to look

Look for Oregon Swallowtail butterflies in flight between April and September. Those seen early in the year are generally lighter in color than those seen later and blend well with the color of early plants.

Swallowtails are wary and strong fliers. This butterfly was selected as Oregon’s official insect on July 16, 1979, not only because it is a native but also because it has ‘Oregon’ in is common and scientific names. Oregon Swallowtail butterflies are a wonderful aesthetic gift.  

REFERENCES:
–Oregon Dept. of Fish & Wildlife, Oregon Swallowtail Factsheet (https://www.dfw.state.or.us/conservationstrategy/docs/Swallowtail_factsheet.pdf)
–Butterfly Identification, Oregon Swallowtail (https://www.butterflyidentification.com/oregon-swallowtai.htm)
–EReference desk (https://www.ereferencedesk.com/resources/state-insect/oregon.html)
Wikipedia, Papilio machaon oregonius (https://en.wikipedia.org/wiki/Papilio_machaon_oregonius)

American dipper (Cinclus mexicanus)

Posted on by

The American dipper appears as a small nondescript bird found along the west coast from Panama to Alaska. Take another look. Sometimes big surprises come in little packages.

American dipper

What makes this species special? Why is this nondescript, dark brown to gray bird amazing? It doesn’t look amazing, but don’t judge too quickly… several things make them very special.

Indicator Species

Think of the old reference to a ‘Canary in a Gold Mine.’ Canaries were used as an indicator species for the mining industry. Canaries are very sensitive to methane and carbon monoxide. Early mines did not have ventilation systems and could be very dangerous. As long as the canaries were singing, it was safe.

American dippers are very sensitive to pollution and are only found on rushing, unpolluted streams.  They look for streams with rocky bottoms and overhanging banks, and areas with adequate nesting locations.  

If you were thirsty and lost, the sight of an American dipper near or in a stream is a sure indicator of good water quality.

Diver Extraordinaire

American dippers hang out near stream edges, bobbing up and down on long legs, and foraging aquatic insects and larvae, crayfish, and caddisfly larvae. They will also eat fish, tadpoles, mayflies, mosquitos, dragonflies, worms, and midges.

Suddenly, the dipper dives into the cold, rushing stream. The bird bobs up and down searching for prey. American dippers are great swimmers and will wade and move small rock as it hunts.

Diving gear

Moments later the dipper pops up very close to the dive location. How can it do that?

Dipper species have their own built in ‘diving gear.’ They have an extra eyelid membrane that allows the bird to see underwater. In addition, the bird can also close off the nostrils (with special scales) when submerged. Finally, their extra oily feathers may keep them warmer when underwater and help shed water quickly.

Diving makes dippers prey for large trout.

Migration

American Dippers are permanent residents for an area and do not migrate. They will move around an area to take advantage of insect hatches and find unfrozen water. Indicator species typically focus on animals that do not migrate.

Huge Song

Both sexes of this species sing an elaborate song year around. The song includes high whistles and trills that can be heard above the chaotic rushing water.

Nests

The American dipper builds an interesting rounded nest as well. The globe-shaped nest is built by male and female birds. It usually on or near a rock ledge, river bank, under a bridge, or even behind a waterfall.  The nest will usually have a side entrance near the water.

The birds dip grass and other materials into water before adding them to the nest. The outer mossy layer is 8-10 inches in diameter and absorbs moisture. Coarse grass helps keep the inside 2-3 inch in diameter chamber dry. The inside chamber also includes leaves and bark.  The female typically incubates 2-4 white eggs. The male helps to feed the young which fledge in about six weeks. Streamside territories are fiercely defended.

REFERENCES:
–Oregon Department of Fish and Wildlife (https://www.myodfw.com)
–Wikipedia, American dipper (https://en.wikipedia.org/wiki/American_dipper)
–All About Birds, American dipper (https://www.allaboutbirds.org/guide/American_Dipper/)

American crow (Corvus brachyrhynchos)

Posted on by

American crow (Corvus brachyrhynchos)

The American crow, the more you know about them the more interesting they are. Crows are a large, intelligent, all-black bird with a hoarse, cawing voice that is familiar over much the continent.

They are common sights in treetops, fields, and roadsides, and in habitats ranging from open woods and empty beaches to town centers. These birds are inquisitive, somewhat mischievous, and good learners and problem-solvers.

They usually feed on the ground and eat almost anything, including earthworms, insects and other small animals, seeds, and fruit as well as garbage and chicks they rob from nests.

Communal Roosting 

American crows are very social, sometimes forming flocks in the thousands. In the winter, American crows congregate in larger numbers to sleep in communal roosts.

Roosts can consist of a few hundred up to two million crows. Some roosts have been forming in the same general area for well over 100 years. 

Mobbing

American crows will work together as a group to harass or drive off predators, a behavior known as mobbing. This interesting video features a crow solving 8 puzzles in a row in order to reach food.

The crow has also been the subject of Native American legends, including this one: http://nativeamericans.mrdonn.org/stories/raven.html