RESIDENTS AND MIGRANTS ON LAKE ONALASKA

     I watched wildlife on Lake Onalaska, a large, shallow backwater off the Mississippi River in Wisconsin from late April into mid-June.  I did that through the Raptor Resource's live camera and our computer.

     Lake Onalaska has many large mud flats, tall-grass and willow islands and other islands covered by tall, deciduous trees.  That diversity of habitats, including the shallows, make Onalaska a good wildlife refuge, especially during spring and summer.

     Spring and summer wildlife at Onalaska can be categorized into residents, migrants and summer nesters.  Some nesters were migrants earlier.  And all the wildlife make Onalaska intriguing and exciting to experience, in person or on line.

     Some stalwart-looking bald eagles are permanent residents at Onalaska, including when raising young in tall trees on islands from February into June.  The eagles feed on fish, ducks, coots and other creatures they catch.  But they also scavenge dead animals through the year.   

     American white pelicans and double-crested cormorants are majestic, fish-catching migrants that spend some time at Onalaska before pushing farther north to nest.  The pelicans arrive early in March and the cormorants do so in mid-April.  

     Pelicans work together in a line in shallow water to herd and catch small fish in their large bills.  Cormorants dive singularly into deeper water from the surface to snare their finny prey.  

     Though most pelicans push north to rear offspring around Canada's many lakes, many non-breeding, young birds stay at Onalaska through summer.  And some young cormorants are also there all summer.

     The flights of pelicans and cormorants are inspiring to see.  Pelicans alternately flap and soar in line on high, while the cormorants usually fly in  line low to the water.  

     Several each of Canada geese and sandhill cranes arrive here in March when the ice breaks up.  Many of each species continues on their migrations after feeding and resting awhile.  But at least one or two pairs of each elegant kind of birds stay at Onalaska to raise offspring among the marshy islands.  The cranes feed on a variety of small critters, while the Canadas consume grass and other vegetation.  No competition for food between those species.

     Flocks of migrant northern pintails, American wigeons, mallards, gadwalls, shovelers green-winged teal, blue-winged teal and wood ducks, which are all species of attractive, surface-feeding ducks, stop on the shallows of Onalaska in March and April to rest, and feed on plant material.  But only some mallards, wood ducks shovelers and blue-winged teal stay there to nest.  The other species flew farther north or west to their breeding territories on the prairies.

     By late-May, observers see mixed bachelor groups of pretty drake mallards, woodies, teal and shovelers in the marshy shallows of the lake.  Their mates are rearing ducklings in the sheltering marshes.  However, some ducklings will be caught and eaten by mink, raccoons, bald eagles, great blue herons and other predators.   

     Common mergansers, common goldeneyes and buffleheads are all handsome river ducks that prefer to be on large rivers and lakes.  Some birds of each of these interesting species are on Lake Onalaska during March and April, diving underwater from the surface to get food.  The mergansers catch fish, but the related goldeneyes and buffleheads ingest aquatic mollucs, crustaceans and insect larvae among stones on the river bottoms.  These migrating ducks were entertaining on Onalaska, but I don't know that any stayed to nest there.         

     I saw, and heard, many striking red-winged blackbirds, and male each of yellow warblers and common yellowthroat warblers, on the islands of tall grass and willow trees.  I also saw a sora rail on the marshy ground under the tall plants.  All those bird species consume invertebrates, but in different niches, which reduces competition for food among them.  

     I saw, and heard, leopard frogs in the marshes, and saw false map turtles basking on trees that fell into the lake.  A few stately, summering/nesting great blue herons will eat some of the frogs, as well as a variety of fish.  

     A pair of magnificent peregrine falcons annually raise young on a cliff overlooking Lake Onalaska.  These speedy falcons take some of the birds around the lake to feed their young in their nursery. 

     A variety of other migrating birds I've seen on line, including Caspian terns, Bonaparte's gulls, barn swallows, tree swallows, northern harriers, pied-billed grebes and American coots, help make Lake Onalaska interesting in spring and early summer.  I don't know if any of those species nest by the lake.

     A variety of attractive, migrating shorebirds, including least sandpipers, short-billed dowitchers, avocets, stilts, willets, dunlin and two species of yellowlegs, scour Onalaska's large mud flats and shallows during April and May for invertebrates that will fatten them for the last part of their migrations farther north to raise young.  These birds sometimes cover the flats with their numbers.  And those same birds are fascinating to watch careening through the air as a flock, quickly turning this way and that, then landing on the flats again to feed on invertebrates.  But none of those migrating shorebirds stayed to nest on the flats.  However, killdeer plovers, a shorebird relative, do hatch youngsters on Onalaska's flats.     

     Watching Lake Onalaska's birds during spring and early summer this year has been enjoyable and inspiring.  Onalaska's variety of niches offers food and shelter to many kinds of wildlife, making that lake, and its islands, a wonderful wildlife habitat, full of life.