Alfafa Sulphurs still out

Yesterday, Truman and I were enjoying a nice late morning walk out at the Yolo Bypass. While walking by a farmer's field of alfalfa, I was surprised to see two alfalfa sulphurs. They were both bright yellow males (?) flying about in a "stop and go" manner. Seems like thngs are flying later into the winter around here.

Dragonflies and butterflies at Sacramento National Wildlife Refuge

On Tuesday, November 18, I visited the beautiful Sacramento National Wildlife Refuge near the Town of Willows in the Central Valley. An amazing diversity and abundance of migratory waterfowl and other birds, like hawks. But I was most surprised to see 22 male green darner dragonflies, 3 variegated meadowhawk dragonflies, 1 pygmy blue butterfly (Brephidium exilis), 1 alfalfa sulphur butterfly, and 3 checkered skippers. The majority of the darners appeared to be searching for females among the grasses and water plants along a small creek near the refuge headquarters. According to my field notes, the latest sighting of darners in the Central Valley I made in 2006 and 2007 was in late October. Two of the meadowhawks were a mating pair laying eggs in a small pool.

Buckeyes and Wildlife in the Foothills of Calaveras County

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Last Thursday, November 13, I was out at a ranch near the Town of San Andres in Calaveras County. It's at an altitude of about 1000 feet and the vegetation consist of grasslands, oak woodland, and chaparral. There are two stockponds and a creek. The rancher is doing a fantastic job of managing his property and there also is an abundance of plants and wildlife.

I saw two buckeyes, both fresh adults. I also saw a couple variegated meadowhawks and about a half dozen damselflies. Birds observed - broadwing hawk, turkey vultures, and western meadowlarks. One of the stockponds was dried and had thousands of dead clam shrimp on the bottom.

The foothills of the Sierra Nevada are quickly being covered with ranchettes - large homes on 5-20 acre lots with vineyards and/or horses. It is good there are responsible ranchers, or soon there would be no habitat left for native wildlife.

Butterflies still out at the Yolo Bypass

This morning Truman and I took a walk out at the Yolo Bypass. Yesterday had been cool (~60 F) and the temperature had dropped even lower last night. So I was surprised to see a relative good number and diversity of butterflies ad dragonflies. We saw three cabbage butterflies, one alfalfa butterfly, about six variegated meadow hawk dragonflies, a mating pair of an undetermined medium sized species if dragonfly (couldn't get close enough to identify it), and surprisingly one buckeye butterfly (Junonia lavinia), and two checkered skippers (Pyrgus communis). The Bypass is begining to fill up with wintering hawks, as we continue to see more of them. Interestingly, Art Shapiro of UC Davis reported that the buckeye can't survive freezing winters, and so most recolonize northern California after we have a winter with freezing temperatures. The buckeye we saw was a nice fresh adult male.

We also heard a male pheasant calling from hs grassy hideout. Walking back to the car, we had a brief discussion with three men clad in orange-colored hats checking out the potential for hunting.

Wildlife at the Yolo Bypass

Today, my dog, Truman, and I took a late afternoon walk at the Yolo Bypass in Yolo County. This is the area where overflow from the Sacramento River is directed so the City of Sacramento doesn't get flooded during winter storms. Part of the Bypass is a State Fish and Game reserve, while other parts are farmed with rice. It was a nice clear, warm day, that made it an enjoyable walk for Mister T.

Even though the Yolo Bypass is located within a few miles of the City of Sacramento, an intensely urbanized area inhabited by a couple of million people, a wide variety and abundance of native wildlife calls it home. You can routinely see Swainson's hawks (Buteo swainsoni), red tailed hawks (Buteo jamaicensis), white-tailed hawks (Elanus leucurus), white faced ibis (Plegadis chihi), and a rare golden eagle (Aquila chrysaetos). During the winter there are literally thousands of ducks, and an occasional flock of tundra swans (Cygnus olor). I have seen large flocks of sandhill cranes (Grus canadensis) flying over the Bypass, as well.

Trials, tracks and scat from river otter (Lutra canadensis) are common at the Yolo Bypass, though I have never been lucky enough to see one here. Beaver (Castor canadensis) are common too. Even though it is widespread and common in the west, I was surprised to see a young black-tailed deer (Odocoileus hemionus) hanging out in one of the groves of willow and cottonwoods a few summers ago.

Today, we saw three individuals of the cabbage butterfly (Pieris rapae), three alfalfa sulphur butterflies (Colias eurytheme), two variegated meadowhawk dragonflies (Sympetrum corruptum), and one large male green darner dragonfly (Anax junius). I thought it was late for these insects, but I checked my field notes and the last day that I saw the first three species last year was November 4, except for the green darner which was last seen on October 28. The first freeze of the year kills these animals off until next spring or summer. Interestingly, my field notes reminded me that I saw a single fresh male cabbage butterfly in flight during the middle of winter on December 11, 2007!

Great Video of a Grizzly Bear

http://nrmsc.usgs.gov/research/video/Kendall_O2005Trailgblick.

Monarchs arrived on the California coast

As they do every Fall, monarch butterflies (Danaus plexippus) continue to arrive on the coastline of California to spend the winter. They have come from throughout western North America, but the majority come from the foothills and lower elevations of the Sierra Nevada. This year, as in years past, I start to see them leisurely migrating as singles through the Central Valley beginning in August. Enroute and especially once they get to the coast, they feed greedily on the nectar from the flowers of Pride of Madeira (Echium candicum) and mule fat (Baccharis salicifolia). I have seen adults whose abdomens are so fat that you wonder how they are able to fly, but the internal food supply will help them survive the winter.

With the shortening day length, the monarchs form Temporary Bivuoacs, sites where the monarchs form clusters of individuals on the branches of the trees. The butterflies continuously stream in and out of the Temporary Bivuoacs and these sites persist because of the constant immigration of animals; Temporary Bivuoacs usually have a good source of nectar. When the air temperature drops, the movement of the monarchs stops, and the sites where they spend the cold months of the year are known as Wintering Colonies. Interestingly, during mild winters or in southern California, Temporary Bivuoacs may persist through the entire winter. The only way to accurately determine if a site is a Temporary Bivuoac or a Wintering Colony is to mark individual butterflies to see if there is any movement of the animals.

In late January into February, the monarchs leave the sites; some stay around the general area, but the majority head into the coast range, especially the areas located in western Kern and San Luis Obispo counties, or into the foothills of the Sierra Nevada.

Another observation - efforts to conserve California monarchs that focus solely on protecting the Temporary Bivuoacs and Wintering Colonies are doomed to failure. The conservation of the spring and summering grounds in the foothills and lower elevation of the Sierra Nevada is critical. In the past twenty years, there has been a burst of ranchettes and development in these areas. Some of the most favored areas for the residential development, and agriculture, especially vineyards, may be best places for milkweed, the foodplant of the monarch.