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Grosbeaks light up our spring season

IMAGES BY GARRY BRANDENBURG — Rose-breasted grosbeak birds, a male and female, take up frequent spots at the sunflower feeder to eat. The large heavy beak of this species is adapted to break open wild fruits and seeds. Plants like elderberry, blackberry, raspberry, mulberry, juneberry and seeds of smartweed, pigweed, foxtail, milkweed, sunflower, tree flowers and tree buds will suffice to help feed this bird species. Insects are also on their menu which may include beetles, bees, ants, sawflies, bugs, butterflies and moths.

Rose-breasted grosbeaks (pheucticus ludovicianus) lead off today’s adventure into things wild and free. It is hard to pass up the colorful feather patterns of the male with his bold white chest, with red chevron under a black head. In flight, his color pattern will draw your eye because of his black and white back and wing coverts.

For the female, its brownish coloration and dutiful camouflage helps her stay hidden and inconspicuous while nesting duties are in order. Forest lands, field edges, and backyard settings will do quite nicely for nesting and food finding. For us humans, we get the added bonus of observation when they visit backyard feeding stations.

Winter habitats for this migrating bird are in the forest lands of Cuba and Central America. Summer ranges can be found in northeast portions of the United States, the upper Midwest and southern Canada. The Canada range also extends northwest into the prairie provinces. Average arrival dates in Iowa are May 1, and departure dates are on or about September 21.

The nests of rose-breasted grosbeaks have been described as so flimsy that one can almost see the eggs in the nest by looking up at the nest bottom. A loose open cup of course sticks, twigs and grasses will work, and added elements may have leaves, straw rootlets or hair.

The nest location will likely be in the fork or crotch of a sapling. Males and females help each other build the nest. Each also takes turns sitting in the nest before eggs are laid to test its suitability.

The finished nest can be four to nine inches across and up to five inches high, and the nest cup itself is three to six inches across and one to three inches deep. Into this nest will come one to five eggs, and perhaps two broods will be raised during the nesting season.

Incubation takes 11 to 14 days, and young stay in the nest for nine to 12 days. Both sexes take turns incubating the eggs during the day. At night, the female is the primary egg warmer.

Bird banding and recapture frequencies have determined that this species may live as long as 12 years or more. Two documented cases reveal a capture and banding in 1972 and recapture in 1984 in Vermont.

A Maryland banding from 1976 was recaptured in 1987. This species is a common forest bird. The Partners-in-Flight organization estimates there are 4.1 million rose-breasted grosbeaks at the end of each nesting season.

Enjoy this unique and colorful bird whenever and wherever you see it along hiking paths, trails, or adventurous hikes into county park forest lands.

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Wild turkey harvest data compiled by the Iowa DNR Wildlife Bureau tells the story of how many bearded turkeys were taken during the recently completed spring hunting season. Statewide, that number is 11,927, a number on par with and similar to past spring seasons. Throughout Iowa’s varied landscapes, each county is different in its habitat structures of forests, streams and crop ground layouts.

So it is to be expected that within habitat zones of highly forested acres and intermixed smaller farm sizes, turkey population numbers are larger. That is how Allamakee County in far northeast Iowa can come in with a turkey harvest of 433 birds.

Now just for comparison, a switch to a highly agricultural county with minimal wooded stream sides is Grundy. Turkey hunters reported only two turkeys taken in Grundy, but here in Marshall County, hunters registered 73 birds.

Every county in Iowa had turkey hunters. Every county has its pluses and minuses regarding habitat zones suitable for wild turkeys, but it is safe to say that the adaptable wild turkey has re-established itself into just about every nook and cranny to find a way to prosper and survive.

Hen turkeys now in their nests are following their natural instinct to repopulate their species. Hopefully I will be able to bring you a photograph in the future of young turkey poults exploring their new world as they follow their mother’s meanderings into and along forest edges. I hope that at some point this spring you will be in the right place and right time to see wild turkey young for yourself.

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Our Iowa River in Marshall County has fallen in elevation to a moderate level. From last year’s mini-drought conditions and very low flow rates, it has come back as the result of spring rainfall events.

The river did get nearly to a bank full condition on May 9. On that day at 9 a.m., it crested at a stage reading 15.79 feet. This did create a bit of floodplain overflow adjacent to Highway 14 north of Marshalltown.

That was temporary, and now the river has come back down to a stage reading of about 11.7 feet, a four foot decrease in elevation. So for the moment, or until the next series of large rainfall events happens, the Iowa River is our index into how water within the soil profiles of the watershed have been replenished. As of now, soil moisture levels are excellent for all green growing things and for our farmer friends’ cropland acres.

A lack of timely rains, if over a long enough time frame, can lead scientists to create drought index maps that show relative soil dryness conditions from mild to moderate to severe. For the entire Midwest, or the country for that matter, drought index maps become useful tools to help forecast what we humans may anticipate as our summer season approaches.

Dry conditions will persist in some areas while other areas get too much rain. Us humans cannot dial in any perfect scenario of desired rainfall. That is not within our control and never will be, so we must adapt since that is really our only choice. Nature rules.

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Following is another episode of Earth Notes, or Nature Notes, with advice to us humans about the power of natural systems. Another river to our north, the Red River along portions of South and North Dakota and Minnesota border, is the only region of the United States that drains north toward eventual release in the Arctic Ocean.

The Red River passes through cities with names of Fargo, Grand Forks and Pembina before it eventually gets to Winnipeg, Manitoba, Canada. From Winnipeg, the river must travel into Lake Winnipeg and then other rivers that empty into the Hudson Bay.

What is special about the Red River? First, it is a drainage way for water from a very flat and level landscape. Thanks to past glacial episodes, of which there were many, the floodplain of the Red River is actually the bottom of an ancient glacial lake. Scientists named this landscape feature Lake Agassiz, after a scientist that studied the effects of glaciers on the land.

Second: Behind retreating ice fields of glaciers, and while the glaciers still blocked outlets of glacial melt water, lakes formed at the toe of a glacial. Those waters took in new runoff from the open landscapes further south, and any silts, clay and sand that may have been in those runoff waters settled out over many centuries of time. A flat lake bottom resulted.

Third: the Red River runs north for 394 miles with an elevation change of only 229 feet. This equates to a drop per mile of only seven inches on average. At Fargo, the river drops only five inches per mile. Near Pembina, the river slope is only 1.5 inches per mile, a very flat condition indeed.

This creates the makings for flood events after heavy snowfall melting, after heavy rain events, or a combination of the two. If you were to drive Interstate 29 north from Fargo right now with intentions of going into Canada, there is a good chance the interstate will be closed in places due to flooding. Remember, I-29 is located on the bottom of ancient glacial Lake Agassiz.

You can follow news reports about flooding just as I have that show vast areas of the floodplain of the Red River appearing as a huge lake. Space station photography and other satellite imagery confirms and compares the present status of the Red River from one year ago to today.

For right now, the Red River is a huge lake, a moment of time for nature to remind us that she is in control, we are not, and that rivers will from time to time carry too much water. At other times, the river appears low, tranquil and benign, as in last year, when those portions of the Dakotas and Minnesota were experiencing drought conditions rated as extreme.

I’ll leave you with this reminder about Mother Nature. Our human lifespan is just too short compared with eons of time that has gone before us and will take place long after we are gone. Glacial history, with its multiple comings and goings, is letting us know we are not in charge of climate at any time.

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Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.

Contact him at:

P.O. Box 96

Albion, IA 50005

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