Horicon

Horicon Marsh is a 33.000-acre freshwater marsh, which makes it the largest one in the US. 23.000 of this is federal land, with the rest in state property, managed by the Wisconsin DNR. This is relevant because the management techniques are slightly different in the two halves, the latter allowing hunting, for example, while the former prohibits it entirely. Much of the land is closed during nesting season, and available to visitos only during the winter.

Dead trees are bird heaven

Although this is a world famous birding establishment with its abundant wildlife, the marsh is not natural at all, it was subject to continued human manipulation over the years. In the mid 1800's a dam was built to harvest the energy for milss and such, which created a lake here, later they drained the lake and attempted farming in the area. When that failed miserably, the land was converted back to marshland. Vegetation is largely manipulated too, for example, many species which waterfowl like were planted in large amounts. Managers frequently manipulate water levels to try to control invasives in the area, of which we saw many examples: purple loosestrife (Lythrum salicaria), which was originally brought in as a garden ornament from Europe, but it escaped and now threatens wetland ecosystems, reed canary grass (Phalarys arundinacea) and burdock (Arctium spp.)- and probably many others. But not only plant invasives are damaging the wetland, the invasive carp (Cyprinus carpio)) is doing damage to the aquatic communities by stirring up the mud and altering light conditions and other variables.

green frog

northern leopard frog

Moving on to animals, we saw a green frog (Rana clamitans), which has a large tympanum to help him hear, and a leopard frog (Rana pipiens).

Canada goose

Now onto the birds. Thanks to Laurie and Nick's skills we saw many species of birds in the marsh. Horicon is famous for Canada geese (Branta canadensis). The geese that stop here in migration are part of the Mississippi Valley Population (MVP) of Canada geese. In North America, there are several million Canada geese, consisting of 12 distinct subspecies. There are more than 1 million Canada geese in the MVP, with about 100,000 to 200,000 stopping at Horicon Marsh each fall. Another race, or subspecies, nests on the marsh and throughout Wisconsin, called the giant Canada goose. The Canada goose has always been a part of Horicon, although the MVP geese did not stop here historically. The tremendous numbers which the fall migration brings is a more recent event. After the restoration of Horicon Marsh, the first flocks arrived in the late 1940's. Through management and the establishment of food plots, they were attracted to the area. Since then, their numbers have increased dramatically. By the mid-1970's, the success of the program was beyond expectation, and the goose population at the marsh had become a matter of concern. It became apparent that a potential disease epidemic would do tremendous damage to a large proportion of the entire MVP. Canada geese are susceptible to botulism, avian cholera, duck viral enteritis as well as other waterfowl diseases. Therefore, other marshes in east-central Wisconsin have been developed to accommodate Canada geese in fall, thereby spreading out the flock.A census of their numbers is regularly made by counting resting flocks from an airplane. Regulations and quotas are set each year to permit hunters to take about 25% of the population.

belted kingfisher

eastern kingbird

yellow-headed blackbird

Those of us who were lucky and quick saw the yellow-headed blackbirds (Xanthocephalus xanthocephalus), the belted kingfisher (Megaceryle alcyon) with its hilarious hairdo, and the eastern kingbird (Tyrannus tyrannus).

barn swallow

tree swallow

We learned that the way to tell barn swallows (Hirundo rustica) and tree swallows (Tachicyneta bicolor) apart is to examine thair tails - the barn dude has forked tail while the tree dude has a more straight one. Tree swallows also have iridescent blue-green feathers on their backs as adults. The barn swallow builds mud nests, typically under rooftops, while the tree swallow nest consists of multiple layers of grasses and thin twigs, and is lined with large feathers from other species. They both and forage for insects in open areas, and are often found in large flocks.


We also got to know something new about ducks in general: there are divers and dabblers among them. Diving ducks, or "divers," are ducks that propel themselves underwater with large feet attached to short legs situated far back on the body (like loons) . "Dabblers," in contrast, have smaller feet and their legs are situated farther forward (like mallards). While a few dabblers may occasionally dive to feed or to escape predators, typically they skim food from the surface or feed in the shallows by tipping forward to submerge their heads and necks. 

solitary sandpiper (Tringa solitaria)

greater yellowlegs

Among the birds we saw running around were sandpipers (of which Horicon has about 8 species), yellowlegs, which has two subspecies, greater and lesser yellowlegs (Tringa melanoleuca and Tringa flavipes), and they are relatives to killdeers (the bird who fakes injuries to draw away predators, a technique of which apparently some ducks are also capable). The call of the greater one is harsher than that of the lesser yellowlegs. The greater yellowleg is larger than the lesser and has a longer bill. Yellowlegs forage for food in tidal areas. They wade into the water to fish, darting around the shallows and stabbing at the water. Lesser yellowlegs eat aquatic and terrestrial invertebrates, especially flies and beetles. They occasionally feed on small fish and seeds. Unlike other shorebirds with long bills, greater yellowlegs do not probe the sand for invertebrates; rather they use a swaying motion to strain the water with their bill. While feeding, wading birds like great egrets and glossy ibis stir up food in the shallows, and the greater yellowlegs take advantage by excitedly darting around snatching up small fish. They are often described as "frantic feeders." Small invertebrates and berries are also included in their diet.

wood duck pair

green heron

We also saw some green herons (Butorides virescens), wood ducks (Aix sponsa), a great blue heron (Ardea herodias), and American white pelicans (Pelecanus erythrorhynchos )  on our way home. American white pelicans like to come together in groups of a dozen or more birds to feed, as they can thus cooperate and corral fish to one another. When this is not easily possible – for example in deep water, where fish can escape by diving out of reach –, they prefer to forage alone. But the birds also steal food on occasion from other birds, a practice known as kleptoparasitism. 

great blue heron

American white pelican

Their bill is huge and flat on the top, with a large throat sac below, and, in the breeding season, is vivid orange in color as is the iris, the bare skin around the eye and the feet. In the breeding season, there is a laterally flattened "horn" on the upper bill, located about one-third the bill's length behind the tip. This is the only one of the eight species of pelican to have a bill "horn". The horn is shed after the birds have mated and laid their eggs. 


And this is also our goodbye for this semester's blogging. I hope you found this newly invented teaching method fun and useful, or were at least grateful that I took notes for you :). Here are two random pics for goodbye.

Sad umbrella in the marsh

Do we look professional or what :) ??