Jim Williams has been watching birds and writing about their antics since before "Gilligan's Island" went into reruns. Join him for his unique insights, his everyday adventures and an open conversation about the birds in your back yard and beyond.
Shortly after I was given the Chimney Swift nest last month (see previous post), I found the nest of a Northern Cardinal. Compared to the craftsmanship of the swift’s, cardinals build with less precision. Ragged comes to mind, although in defense of the cardinals their work weathered for several months before I found it. This nest is made of sticks and leaves, grape-vine bark, unidentified vine pieces, and strips of cellophane. I found it in a Buckthorn tree (Buckthorn should never be allowed to grow to tree size). It’s the first nest I’ve seen in Buckthorn, and that put it rather in the open. The other two cardinal nests I’ve seen were tucked in the middle of large and thick bushes, almost impossible to see. Above, the cardinal nest. Below, for comparison, the swift nest. Cardinals twist and weave their materials, while swifts use their saliva for glue.
Snowy owls are being seen along the East Coast as far south as Virginia in what appears to be a significant irruption year for these owls in that part of the country. Dozens if not hundreds of owls have been reported. Birders are delighted with what is a most unusual opportunity for them.
Major airports, large and flat and winter white right now are attractive to snowy owls, resembling the flat tundra habitat they call home. Airports don’t like birds of any species on their property because of possible bird-plane collisions. Fatal accidents have happened.
Minneapolis-St. Paul International Airport is no different in its appeal to this owl species, but perhaps different in that snowy owls are pretty regular there, albeit in low single-digit numbers.
New York”s JFK airport had an owl problem last week. It was solved with shotguns. This made news, stimulating loud outcry from birders and conservation groups. A switch to live-trapping quickly followed.
At our largest airport harassment is the first means used to move owls off the property, according to Patrick Hogan, spokesman for the metropolitan airport commission. Fake coyotes and wolves also are employed, moved from place to place to simulate the presence of predators. If the owls persist, live-trapping is used. This work is done by the animal control division of the Department of Agriculture.
Mr. Hogan assured me that the airport has never used or considered a method of removal that was fatal to the birds.
The owl pictured below was found near Aitkin a few years ago. In the past day or two snowy owls have been reported from that area, along witH great gray owls. The flecks of black on this bird's feathers indicates it is a juvenile, hatched this past spring. Juvenile snowy owls are those most frequently seen south of their usual habitat.
A friend wrote to tell me that she had covered the perches of her bird feeders with material to keep birds’ feet from contact with cold metal. She has a kind heart. Actually, birds have adaptations to foot muscles, nerves, and blood supply that make damage from cold weather unlikely. While looking for information on this in Cornell Lab’s “Handbook of Bird Biology,” I learned that some birds have fingerprints. The feet of birds like raptors and parrots have papillae, small, nipple-like projections that cover the bottom of the foot. They form patterns that vary from individual to individual, allowing birds of similar appearance to be identified one from another. This is said to be handy in particular for identifying birds of significant value, birds stolen for instance. I wonder if you can scan bird eyes for the same pupil differences used to identify humans. Probably. Generally speaking, at this point in human development we can do way more than we need to do.
Migration of birds of all species north and south is very different than it was a decade or two ago. That's well-documented for waterfowl in particular in a story in the most recent edition of the magazine Delta Waterfowl sends to members.
The story reports results of study of hunting statistics for the past 25 years.
“What we found,” said Dr. Frank Rohwer, president of Delta Waterfowl, “was a phenomenal later shift in the harvest of migrating ducks in the mid-latitude and southern states.”
The information indicates that the birds are migrating later, although Dr. Rohwer did not come right out and say so.
He used Kansas as an example. Average harvest date for Mallards in 1961 was Nov. 7. That date shifted to Dec. 5, 28 days later, in 2008-2009. For duck species resident in those southern hunting areas, birds that would not be migrating, harvest-date patterns were unchanged.
Ducks are staying later into the fall and winter seasons in North and South Dakota, which is why harvest dates to the south are becoming later. In January 2012 a record number of ducks and geese were counted in North Dakota. The article said that lack of snow cover was the primary reason the birds had not moved south.
In South Dakota a similar situation was seen. Nearly a million birds were found during a January 2013 survey.
“Those midwinter numbers and the motivation for waterfowl to migrate south are driven by the amount of snow cover, open water, and periods of cold temperatures,” Dr. Rohwer was quoted as saying.
Is it that climate no longer pushes the ducks south at historic dates? Or, for southern hunters, is it that the ducks don’t get down to them, not having to go as far south to find open water and food (which is climate-related).
The question: Is it climate change or habitat change? Biologists believe it is both.
At Sand Lake National Wildlife Refuge in northeastern South Dakota later migration of geese is more obvious than such for ducks. That information comes from refuge biologist William Schultze.
“Since I began working here in 1976,” he wrote in an email, “the average peak of the Snow Goose migration has shifted from late October to near mid-November.
“I see changes in agricultural practices in North Dakota and Canada as the primary reason for that shift,” he said. “One other factor that might be considered is the amount of wetlands available, at least in northern South Dakota, since the mid-1990s. The larger wetlands that remain open longer can hold a lot of ducks and geese,” he said.
Goose movement was heavy after Nov. 21 at Sand Lake, the date refuge lakes froze over. The number of Snow Geese reported on the refuge on Nov. 20 was 130,000, with 125,000 ducks and 5,000 geese estimated. Five days later the number of Snow Geese was 400, Canada Geese 3,500, ducks 18,000, and swans zero.
This photo of Snow Geese was taken at Sand Lake NWR.
The chimney that provided me with a Chimney Swift nest last year has done so again. A friend helped me Wednesday morning take photos of and then remove the nest from the chimney. That involved some gentle pry work with a spatula. These birds have adhered their nests to the brick surface just above the fireplace floor and just below the metal chimney liner. A rough surface is needed for nest placement. The birds’ saliva is the glue that holds the nest in place and together. The nest sat about 10 feet down from the chimney opening and two feet above the fireplace floor. It was easily reachable. The chimney lining is evident in the photo. We’re looking at the nest from the bottom. What appears as the bottom edge of the nest in the photo is actually the front lip of the nest. The nest was surprisingly shallow, and had a slight downhill slant. The nest projected three inches from the brick, and is four inches across. The cup that held the young birds — normally four in number — has a diameter of about two inches. That’s pretty cozy. This nest held some egg shell pieces. There was no evidence on the fireplace floor of birds ever using the chimney. Young swifts produce their waste in fecal sacs that are removed by the adult birds. The birds, their sounds first mistaken for bats, could easily be heard while the nest was active. The swifts have returned to this chimney for several years without a miss.
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