Woodcocks 'sky dancing' in the PreserveOn Monday, March 30, from the edge of the Eagle Heights Community Gardens, Roma Lenehan heard at least three American Woodcock giving their peent call from around Biocore Prairie. At least two of them were “sky dancing” over the open area (prairie and gardens). According to Aldo Leopold (A Sand County Almanac) “the show begins the first warm evening in April at exactly 6:50” (7:50" now) and begins one minute later each day. According to Leopold, the display begins at a light intensity of 0.05 foot candles. During the day, Glenda Denniston has flushed a Woodcock at least twice in the last two weeks of March at the edge of Frautschi Point, near the second oak and the gully.
Although the display at the Arboretum continues for weeks, in the Preserve the Woodcock display has only been observed a few times a year. Are these migrant birds only here for a short time, or are there not enough people looking for them? Please let us know if you continue to observe the Woodcock displaying in the Preserve.
0 Comments
Roma Lenehan reported on March 12 that Sandhill Cranes have been seen in the Community Garden, and on March 13, Glenda Denniston heard the first Red-Winged Blackbirds of the season calling at in the Class of 1918 Marsh. A few of them were singing. Please send us your photos of the birds you observe in the Preserve.
Birders are catching the spring fever and are out in droves to watch every new arrival. In preparation for the coming season, our Bluebird crew was last Friday to do some spring cleaning. They had removed in fall all empty nests from the boxes along the Bluebird Trail in the Preserve, but now was the time to repair any damage, remove unwanted freeloaders, and check for weather tightness. Residential housing for Bluebirds, Tree Swallows, and Wrens is all ready for occupancy. Thank you Paul Noeldner, Patricia Becker and Will Waller. Galen Hasler also joined the crew.
![]() The Friends have begun featuring the Preserve on the air, on the "Insurgent Radio Kiosk" of WORT. Doris Dubielzig has recorded a two-minute commentary and calendar of events for the Preserve, to be aired on Thursday, February 12th, at 5am, 6:30am, 9am, and 2pm. She will continue to work with WORT to inform listeners about the Preserve, as well as volunteer opportunities and the Friends field trips. if you miss the radio announcements, you can listen to Doris on the WORT website. Thank you Doris!
If we assume a two-mile-long slab of ice, that slab is about 10,000 feet in length; and 0.05% of 10,000 feet is 5 feet. So with a 10°C drop in temperature the ice will pull 5 feet apart, somewhere, a good-sized crack. Similarly, a 10°C rise in temperature will produce 5 feet of additional ice — and that expanded ice slab has to go somewhere – pushed up into a ridge offshore, or pushed down and under another slab (perhaps along the location of the earlier crack), or pressed against the shoreline.
There is some evidence that local contraction/expansion can begin in shallow areas– perhaps the temperature changes are most pronounced in these shallow areas, or perhaps the ice tends to be thinner there. But for whatever reason, there is observational evidence, accumulated from watching the lake for many years, that cracks and ridges often spread from Picnic Point or from other shallow areas. • One frequent crack/ridge system extends from Picnic Point towards Maple Bluff. • Another extends from Picnic Point toward the shallow areas near the Edgewater (this is the one you observed yesterday). • Still another extends from Picnic Point past Frautschi Point and then on to the north towards Fox Bluff. • Governors Island may be another relatively shallow area that might favor expansion/contraction joints. In 1956, two Wisconsin scientists, Bunge and Bryson, wrote a series of papers about ice on Wisconsin lakes, including Lake Mendota. They discuss the physical processes of crack/ridge formations. They don’t reach firm conclusions about preferred locations, although they note that these features often extend outward from Picnic Point. You ask ‘why is the crack not a straight line’? That is a very tough question. Nature doesn’t seem to like straight lines (the twisted branches of oak trees, the meandering of rivers, the outlines of cumulus clouds, curving coastlines, etc). These cracks and ridges are subject to many other forces besides contraction/expansion– shearing force and wind forces, for example. So it seems complicated. On January 15, 1948, there was a very powerful crack of the Lake Mendota ice that was felt throughout the campus and city. A description of this “ice quake” event was published by Prof. Charles Bradley (husband of Nina Leopold Bradley) in the American Journal of Science, vol. 246, no. 6, page 390. It measured 3.8 on the Richter scale of a local campus seismograph. There is also a news release about a much smaller ice quake in 2008 (http://www.news.wisc.edu/14680). If one walks or skates on Lake Mendota, one frequently hears the sharp sound of the ice cracking. Gisela and I have heard it. Even to the ‘informed ear' these sounds seem mysterious and powerful, and it is not hard to believe the accounts that in medieval times people gave all kinds of interpretations to these sounds (lake gods or devils or omens of various kinds). A word of caution! A pressure ridge is a small zone of complex topography: some ice slabs are pushed up, others may be pushed down. A downward-pushed slab may be covered by water (it's easy to see) or by a thin layer of newly formed ice (it's not so easy to judge the thickness). Enjoy viewing the power of nature at work, but always be cautious when near a pressure ridge. John Kutzbach, Jan 19, 2015 ![]() Eagle Heights Woods beckon for a silent walk in winter - with sunshine, fresh air, tracks in the snow, and an Indian mound on the highest point with views across the lake. We search for history and our place in this history. ![]() Madeleine Young, beloved 4K teacher at Eagle's Wing Pre-School, enjoys the Preserve during her lunch breaks. This week she dared the cold and walked the short distance from the Eagle Heights Community Center to Raymer's Cove. What a view – the cliff decorated with thick ice stalactites and the snow on the lake swirled in fatastic patterns. Check it out and send us your photos. ![]() The eagles have joined the hundreds of waterfowl at University Bay. Roma Lenehan and others sent many of us on the lookout. Arlene Koziol captured a beautiful Bald Eagle in flight. The juvenile eagle below is trying out his skills, sitting along the edge of thin ice - now covering a third of the Bay - and hoping for fish swimming by.
Photos Kutzbach
Have you walked up to the Point lately? Come and see. It looks like Preserve staff and volunteers have removed most of the buckthorn, old growth and re-sprouts. This was an amazing effort in a short time. The views are absolutely gorgeous now, all the way to the Point. When standing at the highest cone mound just before the Narrows, you can now see all the way to the lake beaches beyond the pond marsh and to Frautschi Point. When walking or jogging past the water pump, you know you are on a promontory - water on both sides of the cliffs. The next step will be to maintain control of invasive shrubs and to plant native shrubs that provide habitat for the many birds on Picnic Point. Photos G. Kutzbach - click to enlarge.
|
AuthorGisela Kutzbach and contributors Archives
May 2022
|