Wetlands and waterfowl = a natural fit
NORTHERN SHOVELER DUCKS (Spatula clypeata) kicks off this weeks adventure into natural history topics. It is always interesting to observe the behavior of wildlife as they go about their daily routines in life. And so it was recently at Hendrickson Marsh, the state wetland and upland complex located west of Rhodes Iowa along the Story/Marshall County line. Lots of waterfowl species were plying the water as they fed. I was fortunate to have my long lens camera at the ready to try to obtain images of value. And when this pair of shovelers came into view, I tracked them and fired off many shutter releases in the hope I would get at least one acceptable image. Luck was on my side this time. And now you get to see all the various colors of feathers on this dabbling duck.
Shovelers received their name because of the shape of their bill. It is wide like a spoon or a shovel, an obvious identification marker. Inside the edges of the bill are 110 very fine but tiny projections called lamellae that are used to filter out small food sources when they sweep their bill from side to side in the water. What they gather includes crustaceans, seeds and aquatic invertebrates.
The nest of a shoveler pair is a shallow depression in the ground that the female lines with dry grasses and some downy feathers. The nest site will be on uplands about 150 feet away from the waters edge. Eight to twelve eggs, each about 2 inches long and 1.5 inches wide, will be incubated for 22 to 25 days. Young shoveler ducklings are covered with down and able to walk and swim. Mom leads her brood to the water where those little ducklings instinctively know how to peck at food types and use their tiny shoveler beak to strain the water for foods.
Each fall, just prior to the big migration southward, many dabbling ducks go through a molting process to loose old feathers and grow new ones. This leaves the bird in a brief condition of not being able to fly. Once the new flight feathers have grown, the timing is just right to begin thinking about the soon to come journey to southerly habitats before the coming winter locks up northern lakes.
MORE BIRD INFORMATION ITEMS to share include these observations and reports. At least one Bald Eagle eaglet was seen in its nest along the Iowa River between Marshalltown and Albion. In this remote setting far from people, the eagle pair are going about the business of raising a next generation. There may be more eaglets in that nest than just one. However just one was seen on that particular day. There is another eagle nest east of Marietta, again far from any well traveled roadway. An active eagle nest is located south of Mormon Ridge on the east-west road called 160th Street. Observing from the roadway is doable using binoculars or spotting scope. There are probably about one dozen active eagle nests in Marshall County this year, a good sign indeed.
I continue to hear periodically the trilling raspy call of Sandhill Cranes in and around the small wetland area that one can readily view from highway 330 on the south side of Albion. The nest site or sites for the Sandhills is located further south on private land in another wetland complex. Sandhill Cranes may also be observed in the Otter Creek wetland complex east of Tama, IA or in the close adjacent farm fields to Otter Creek.
This week my own bird feeder station was host to Rose-breasted Grosbeaks, male and female, and American Orioles and Ruby-throated Hummingbirds. There will be more species arriving as May continues to unfold.
Check out warbler arrivals at Grammer Grove park. Walk those pathways that are open and listen carefully. Speaking of pathways and trails at Grammer, last summer’s wind storm did a lot of damage to mature trees. Cleanup will take time as the Marshall County Conservation Board staff chips away at similar damages in almost every park area.
WILD TURKEY HUNTERS in Marshall County as of midweek have reported 55 tom birds. Statewide hunter reports show 10,447, a typical take when compared to past years. Here are some additional wild turkey biology facts: Their eyes have monocular periscopic vision, which means their eyes function independently of each other to transmit information to the brain. With eyes on the sides of their heads, turkeys have the ability to almost see a 360 degree field of view.
Turkey ears are excellent an pin-pointing direction and distance of the sounds of other turkeys, or a hunter trying to make enticing calls. The ears are slightly behind and below the eyes. There is not external ear flap, just an opening. Sounds picked up by turkey ears can register the differences between the right and left sides of their heads, and then use that information to accurately pinpoint the source/location of the sounds.
A wild turkey tom has a head full of blue, white and red skin patches. If the tom’s mood changes, blood flow to those tissues can change the external color patterns to a brighter condition. Those color shifts is a critical signal to other turkeys not so well understood by people.
Turkeys have between 5,000 and 6,000 feathers, of all sizes and purposes. It serves as insulation, waterproofing and ornamentation. A iridescence to those feathers makes them shine with color. Tail feathers are capable of being fanned out. Body feathers can be fluffed up or let down. And of course wing feathers allow this bird to fly. Once up to speed, it will make 55 mph. One of the specialized feathers grows out of the chest of toms….it is called the beard. It is short on young of the year birds or yearlings, but longer on mature toms.
IOWA RIVER FLOW is low. How low? According the US Army Corps of Engineers gauge stations, at Marshalltown mid-week the water was at a snail pace of only 389 cubic feet per second. And the river stage was 9.69 feet. This is a relative number reflective only of the markings on an elevation staff, not at all indicative of actual river water depth. The river is telling us that ground water table levels are lower than “normal” for this time of year. Other rivers in the state are also showing signs of low infiltration rates. Iowa could use more periodic rain in moderate amounts.
This scribe recalls the summers of 1977 and 1988. These were classic drought years when dryness and lack of rain turned lawns brown and wilted crop fields to the point of total loss. Maybe Mother Nature has set us up for a repeat of a big drought. No one really knows at this point what the rest of the year has in store for us. We have all seen the give and take, highs and lows of weather events. Between those drought years noted above were overly wet and flooding cycles that were also damaging to crops, roadways and flooded basements. We can only adapt.
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