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.

Posts about Bird biology

Golden-winged Warblers get a gift

Posted by: Jim Williams Updated: January 16, 2014 - 12:52 PM

A wind that blew strongly through northwestern Wisconsin in the fall of 2011 left behind the 90,000 acres of woodland destruction. Benefits from this would be hard to find.

But, consider the Golden-winged Warbler. 

This tiny brightly colored migrant depends on Minnesota and Wisconsin for 40 percent of its breeding habit. Golden-wings need a young-forest landscape, successional growth. For many reason human-based that type of forest is diminishing.

The Wisconsin storm jumped and bumped its way across the woods. The blowdowns are scattered. The entire situation is ideal for what happened and is happening next. Where possible, the scarred land is being restored as nesting habitat for Golden-winged Warblers.

This is an effort jointly pursued by the Wisconsin Department of Natural Resources, six county governments, private landowners, and the American Bird Conservancy, a non-profit devoted to the welfare of birds.

Golden-wings are in a steep population decline, steepest of any songbird species in the past 45 years. We’re losing about four percent of these birds each year. Interest on your bank account of four percent annually, compounded, could fund your retirement. Lose four percent each year and you go bankrupt. That’s what could happen to the warbler.

The bird seeks nesting habitat in woodland about three to 15 years of age. Of the 90,000 acres touched by the storm about 13,000 have been identified as suitable for restoration to benefit the bird. That work is underway. The first Golden-wings to enjoy the fruits of that storm could be nesting there this coming spring. 

Ruffed Grouse and American Woodcock also should benefit by this landscape change.

This is good news for and good work done by everyone involved.

Below, a Golden-winged Warbler photographed near the area pounded by the storm.


 
 

Snowy Owls east of us, and some here

Posted by: Jim Williams Updated: December 19, 2013 - 7:50 PM


The movement of Snowy Owls south from Canada into New England and states south to Virginia is being called the largest in two decades. Many owls are being seen. More information can be found at http://nyti.ms/1fqeek7

That blog site also has two fascinating videos of Snowy Owls being harassed by Peregrine Falcons defending territory. Pretty cool.

Minnesota is seeing more Snowies that usual, also, although our numbers do not approach those to the east of us. For some reason, reported sightings are clustered in and around Benton County. Either there are more owls there or more people seeing and reporting them.

How bird nests differ

Posted by: Jim Williams Updated: December 16, 2013 - 10:25 AM

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. 

N.Y. airport might shoot snowy owls, but not MSP

Posted by: Jim Williams Updated: December 11, 2013 - 2:14 PM

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.

 

 

Bird fingerprints

Posted by: Jim Williams Updated: December 9, 2013 - 3:00 PM

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.

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