LEUCISM is the name biologists have given to the unusual condition for bird's plumage being white or mostly white. When birding folks identify birds, it is primarily by body size, shape and plumage coloration that are the first clues to solving the riddle. When a bird is all white, but looks in form and function as its normal flock members, it will gain extra attention. So it is with this hawk in the Marshalltown area. It is white. But it is not an albino.
This scribe observed what may be the same white hawk last year near Riverview Cemetery. When it eventually flew, its tail top had a very faint or faded reddish tint. Thus my identification was Red-tailed Hawk. Since then, others have seen it too. Then in late December 2011, it was seen again but this time the call went out to a photographer, Mark George, to grab a big lens and report to duty on Sixth Avenue. The result is today's feature critter photo for all of you to enjoy.
Leucism can be partial or total. In some cases, there may be patches of white among normal feathers. Sometimes the white is in patterns or as in this case, all white everywhere. Take note that there is a big difference between leucism and albinism, the former affects just the feathers. The latter affects all pigments of true albinos including skin and eyes. It is usually expressed as pink or reddish eye color, legs and feet.
CONTRIBUTED PHOTO BY MARK GEORGE
An all white (not albino) Red-tailed Hawk posed for Marshalltown photographer Mark George recently. The photo was made near Sixth Avenue in Marshalltown.The trees within Riverview Cemetery are places where it has also been observed. White plumage is called leucism, and is an abnormal genetic mutation that prevents pigment, particularly melanin, from being properly deposited during feather growth.
Red-Tailed Hawks are one of our most common birds of prey. They are year round residents but we will get this raptor in the winter from parts of its breeding range in southern Canada. Once spring breaks, these birds will disperse again to the northlands. So it is not a true migration in one sense, just a temporary move to avoid deep snow and low food supplies.
Concerning snow, a white red-tail might have an advantage in catching prey if the ground was covered with snow. A big white body is less visible when all of its surroundings are white. Snowy owls are normally white and this trait allows them to approach lemmings with great stealth. If snow is on the ground, area fox or coyote hunters wear white for the same purpose, to blend into the background environment.
The opposite of all white is all black. This biological condition is seen from time to time in white-tailed deer, raccoons, or even wild turkeys. Case in point was a story in the June 2010 issue of Turkey Country magazine, and again in the February 2012 issue, where a short story on Black Beauties is told. According to biologists with the National Wild Turkey Federation, melanistic wild turkeys happen in about 1 for each 5,000 birds.
Wildlife biology always has an interesting twist to it. We observe the usual normal coloration in mammals, reptiles and avian critters. Then Mother Nature periodically throws a wrinkle into the mix, perhaps to check on us humans to see if we are paying attention. May we always pay attention to biology. May we never give up our human inquisitive nature to observe, learn, share and find out what the facts are as myths and rumors are squelched.
Winter conferences and outdoor related shows will soon be in full swing. In fact, the Iowa statewide PHEASANTS FOREVER state convention takes place this weekend in Des Moines. Some local PF members will attend to learn what's new. The National Pheasant Fest rotates among several Midwest cities each year. For 2012, Kansas City is the host from February 17-19. Many outdoor related conventions use the off-time of winter to rally forces about long term habitat issues that affects wildlife. Stay tuned for details as their respective times draw closer.
The final antlerless deer season of Iowa begins Jan. 11 primarily in the southern two tiers of Iowa counties. This season was established to help address population aspects of the herd where under-harvest was allowing too many deer to make it through to next year. Southern Iowa terrain is more hilly, timbered and very conducive for the adaptable whitetail. To draw hunters in, weapon choices are open to center fire rifles caliber .24 or larger, shotguns, handguns, muzzleloaders or bow/arrow. Statewide deer take to date is nearing 108,000 animals. The antlerless season ends Jan. 29. A new hunting license and habitat fee is required after January 10th. And as always, deer taken must be reported using the harvest reporting system. Accurate reporting is an important part of Iowa's deer management program.
The Marshall County Conservation Board invites the public to an afternoon of cross-country skiing (if there is at least 1 inch of snow on the ground) to be held Jan. 14 from 1 to 3 p.m. at the Grimes Farm, 2359 233rd Street, just west of Marshalltown. A limited number of skis will be available for checkout at no cost during the event hours and basic instruction will also be provided. Five new pairs of smaller skis are now available for children ages 9-12 thanks to a S.T.E.P. grant, a youth philanthropy program co-sponsored by the Community Foundation of Marshall County through the Martha-Ellen Tye Foundation.
MCCB naturalist Diane Hall states "If you've never tried cross-country skiing now is your opportunity to experience a great winter activity and burn off some holiday calories!" After enjoying the winter woodland scene by ski or snowshoe, participants can warm up with hot chocolate in the Conservation Center.
While there is no charge for use of the skis and snowshoes during a MCCB recreation event, this equipment is available for rental outside MCCB events. The cost for either skis or snowshoes is $5/day with a $50 deposit per set. For a complete copy of the rental policy or for more information on the free ski day on Jan. 14, contact the MCCB at 752-5490.
The Marshall County Conservation Board and Marshall County Izaak Walton League invite first through fifth grade students and their family members to the 28th year of the award-winning Uncle Ike Nature Program. "Woodland Wanderers" is the 2011 -2012 theme which continues on Jan. 14 from 9 to 11 a.m. at the Grimes Farm & Conservation Center (2359 233rd Street).
The Jan. 14 session entitled "Wild & Woodsy" will take participants on an adventure to discover what animals live in the forest. Participants will also craft a forest animal to take home.
The Uncle Ike Nature Program was originally developed in Marshall County and has spread to other counties and states during the past 28 years. The program has received the Chris Holt Youth Environmental Education Award. The purpose of the program is to give children the opportunity to learn about Iowa's natural resources, environment, and outdoor sports. It is hoped the Uncle Ike children will: 1) gain an increased awareness about the earth on which they live and 2) learn to make responsible decisions concerning the environment.
Izaak Walton League membership is not required and there is no charge for the program. If anyone would like more information about Uncle Ikes, contact Diane Hall at the Marshall County Conservation Board at 752-5490.
The Marshall County Conservation Board invites the public to attend its Brown Bag Bunch program entitled "Kauai Adventures" to be held Jan. 18 from 11:30 a.m. to 1 p.m. at the Grimes Farm & Conservation Center (2359 233rd St.). After lunch Marshall County Conservation Board Administrative Assistant, Emily Herring will take participants on a photographic exploration of the Hawaiian island of Kauai, known as the Garden Isle. Come escape to the oldest of Hawaiian Islands, with its dramatic landscapes and rich biological diversity. Learn about history of this unique island and what adventures it has to offer.
Participants should bring their own lunch. Naturalist Diane Hall said, "If the cold Iowa winter has you feeling down, we invite you to cone and enjoy a taste of the tropics."
Garry Brandenburg is a graduate of Iowa State University with BS degree in Fish & Wildlife Biology. He is the retired director of the Marshall County Conservation Board. Contact him at PO Box 96, Albion, IA 50005.