NWA 4/13 - 26, 2012

A Northwoods Almanac for April 13 – 26, 2012 

Sightings

3/24: A first-of-the-year (FOY) Eastern bluebird was reported in a yard near Mercer.

3/26: Hannah (Bonnie) Dana in Arbor Vitae saw a June bug trying to get into her garage. She noted that last year she didn't see June bugs until the middle of May.

3/27: Pete Johnson reported his FOY loon on San Domingo Lake in Mercer, and John Randolph reported seeing his FOY loon on Bolger Lake.

3/29: Joe Mastalski reported his FOY loon on Lower Kaubashine.

3/30: Mary Kaminski saw loons on Upper Springstead Lake on 3/30, and on the Wilson Flowage on 4/1, but still hadn’t see one near her home on Cochran Lake as of 4/5.

3/31: Scott & Kathy Reinhard reported their FOY loon on the Lake Bastine area of the Turtle Flambeau Flowage.

4/1: Janet Alesauskas saw her FOY loon on Sunflower Bay on Tomahawk Lake as did Kit and Ellen Deubler on Elsie Lake in the Township of Lac du Flambeau.

4//1: Mike and Carol Beno in Presque Isle had the most unusual sighting, and he assures me it was no April Fool’s joke: “Passing Horsehead Lake on Cty B, we spotted some bright white birds on the surface along a line of emergent weeds. So large and brilliantly white, they had to be swans - 12-15 individuals. Many tundra swans have been flying around our neighborhood the last few weeks. These birds, however, had entirely black necks. Necks were serpentine in profile, as with all swans, but entirely black all the way to, and including, their heads.   

“Those we saw were at a distance of more than 100 yards . . . White fluffy bodies; solid black necks and heads.”

So, the question is what did Mike see? No such swans exist in North America, so my only thought is that these swans could have been dipping their heads down into black muck to get some delectable underwater tuber, but I really don’t know. Did anyone else see these birds, and does anyone else have a theory on them?  

4/2: Ospreys were seen on the nesting poles along Hwy. 47 near McNaughton. Ospreys usually don’t return until mid-April at the earliest, which is, of course, when ice-off usually occurs.

4/3: Janet Alesauskas reported the FOY pine warbler for our area on Lake Tomahawk.

4/3: Ralph Kerler heard his first beautiful call of a loon on Little Crawling Stone Lake.

4/6: Janet Alesauskas paddled into one of her favorite bays on Lake Tomahawk and watched a FOY solitary sandpiper.

4/6: Mary and I saw our FOY tree swallows on Powell Marsh.

4/6: We watched an adult eagle feeding a chick in the nest across the river from us. While we haven’t kept long-term records on hatch dates for this eagle pair, this is the earliest date of hatching that we can recall. Eagle chicks most typically hatch in the last two weeks of April. Given that fledging occurs on average in 70-90 days, this chick could be flying in late June.

4/7: Kay Streng on Diamond Lake just south of Hwy 70 reported the FOY yellow-rumped warbler for our area.

Trumpeter Swan Info

The trumpeter swans that migrated from our area in the fall have likely all returned, and if you want to learn more about the swans you may see, follow this procedure: If banded/collared trumpeter swans are seen, there are two simple ways to report them. A swan observation report (dnr.wi.gov/org/land/er/forms/swanreport.asp) can be filled out and submitted online. Or the observation report can be submitted over the phone by calling the DNR wildlife management office at 608-588-3432. Please be sure to note the color and any numbers that are written on the band.

Salmonella at Bird Feeders

I’ve received two reports of birds dying at feeders from what sounds very much like salmonella. The disease typically spreads by contact between birds or through their droppings especially where they are concentrated at feeders.

Feeders should be cleaned with a solution of one part bleach to 10 parts water. The entire surface of the feeder should be scrubbed or brushed. Additionally, accumulations of discarded seed and droppings under feeders should be removed.

If people see dead or sick birds, they should keep their cats and dogs indoors, since with certain strains of salmonella the animals could become infected through eating affected birds.

Dead birds should be removed from feeder areas. People can pick the birds up by using a plastic bag to avoid direct contact with the bird; it's important to wash carefully after handling potentially diseased birds.

Arizona Birding Trip

In the last week of March, Mary and I led a Nicolet College adult continuing education class of 10 intrepid birders to southeastern Arizona. We had picture-perfect blue skies and warm weather, and tallied 101 species over 4 ½ days.

Our highlights included 9 species of hummingbirds: broad-billed, broad-tailed, rufous, magnificent, blue-throated, black-chinned, Allen’s, Costa’s, and violet-crowned. We also got close-up night-time views of a pair of elf owls and a whiskered screech owl. Our search for an elegant trogon came up short, but we had great views of gray hawks, Lazuli buntings, Scott’s orioles, a diamondback rattlesnake, and numerous southern Arizona bird specialties.

Most importantly, we enjoyed ourselves immensely and surrounded ourselves in the beauty of Arizona deserts and mountain canyons.

Eagles Swimming

Over the years we’ve had numerous people tell us about watching a bald eagle swim to shore with a fish that was too heavy for it to lift. Now there’s a video of an eagle in Louisiana swimming to shore with a nutria it found dead on the water: http://www.youtube.com/embed/87xNpOYOlQ4?rel=0

           

Aspen Flowers Dropped Two Weeks Ago

Aspen catkins emerge before their leaves appear, their feather-like tufts of hair adorning numerous tiny seeds. We have two species of aspens in the Northwoods – quaking aspen (Populus tremuloides) and big-tooth aspen (P. grandidentata), and each individual tree is either male or female. While both male and female aspens produce catkins, only the male catkin has pollen. When the right breeze comes along in early summer, the pollinated female will release her seeds, which are swept away to some distant place.           

There’s often a significant distance between male and female trees given that aspen groves are clonal, meaning that all the trees in a grove are identical in gender. Hence, if a male sapling happens to give rise to the grove, all the individual trees in the grove will be male.

Because everything is so early this spring, look for aspen seeds blowing in the wind perhaps as early as late April!

Territorial Takeovers

Loons are currently returning to their territorial lakes, but just because they were the occupants of a lake last year, doesn’t mean they have title to the lake this year. In Oneida County, Dr. Walter Piper from Chapman University in California along with Charles Walcott of Cornell University and Jay Mager of Ohio Northern University have studied territoriality of common loons since 1993. Two to five undergraduate students from Chapman, Cornell and other universities join their field team each year.

Dr. Piper has found that one of the most striking aspects of loon social behavior is the frequency of territorial takeovers. He writes, “Takeovers (also termed “evictions”) are in fact the most frequent means by which nonbreeders of both sexes attain breeding status. They occur in a stereotyped way: an intruder enters a defended territory, physically displaces the pair member of its own sex through aggressive behaviors including wing-beating and head-dunking, and then quickly establishes a pair bond with the mate of the displaced bird. If it is strong enough, the displaced individual takes refuge on some undefended lake nearby. Weakened individuals, nearly always males, may be killed after repeated attacks by the usurper. Takeovers are statistically more likely to occur in territories that produced chicks in the previous year than those that failed to do so. This pattern suggests that intruders are targeting territories for takeover that have proven to be of high quality.”

So, returning loons have their work cut out for them if they want to maintain their nesting sites from last year. To learn more about Dr. Piper’s research and observations, visit his website: http://www1.chapman.edu/~wpiper/index.html

Why Lakes Don’t Refreeze after Ice-out

            Ice-out occurred on nearly all of our lakes by 3/20, and with snow forecast for this week of April 8-14, several folks have inquired about the possibility of the lakes refreezing if our weather reverted to its normal April temperatures.

            Well, never say never, but it would be rare indeed if our lakes refroze. The reason? Water flip-flops its density at 39°F. Rather than being more dense as it gets colder, at 39° it becomes lighter as it cools to 32°F.  Thus, water directly beneath the ice is 32°, and the water temperature gradually increases to 39°F toward the bottom of a lake. This is a revelation to most folks, but otherwise lakes would freeze from the bottom up.

So, in spring, as sunlight penetrates the ice, the water just below the ice slowly  warms, becoming more dense, and thus sinking.  Eventually the entire water column of the lake reaches 39°F, and that’s when ice-out normally occurs. Now the water has become much too warm for lakes to refreeze if it gets cold again for a little while. It would take an exceptionally lengthy cold spell to cool lake water enough to refreeze again after ice-out – I don’t know if it’s ever happened.