Nebraska Ornithologists' Union

 

Notes- Nebraska Bird Review

Copyright 1983, Nebraska Ornithologists' Union. Used by permission.

Abstract

CATTLE VS. WATERFOWL. After three years of comparatively dry weather that kept our rainwater basins dry most of the time, in 1982 we had lots of rain and lots of water in our basins. The rains started the latter part of April and the waterfowl and shorebirds came in great numbers. Although the water levels raised with each rain, the vegetation grew fast enough to keep most of the water covered. This is where the nesting population of Coots, Pied-billed Grebes, etc., hide their nests, and it is hard to guess how many birds are nesting or where the nests are located.

One of these large basins lies between two of our farms, and I usually drive by it twice a day or so. It is divided into two parts that are fenced and both are used for pasture. Most of the water area is located on a neighbor's land. As usual, several cows and calves were placed in each pasture around 1 May. This is the procedure, and it works well in a normal year, but this was not a normal year, and as more and more rain fell it created a very unusual set of circumstances. The water level kept rising until in June the neighbor's pasture was all underwater except one small corner that was slightly higher ground, and this was where the cattle spent most of their time, except when foraging out into the water. By this time the water had covered most of the vegetation that hadn't already been grazed off. Daily I watched as the water level kept rising and the vegetation got thinner and thinner and it was easier to see the birds on their nests. Also, by this time the cattle were very hungry and were foraging in water more than belly deep, with their calves swimming to follow, even though supplemental feed was being provided for them.

Finally there was practically no vegetation to hide the Coot and Pied-billed Grebe nest&. The birds still stayed oh their nests and tried to defend them from the cattle that were all around them. Each day it seemed that there were fewer nests, and one morning, while I was watching, I saw a bull actually eating a Coot nest while two Coots were attacking it with flailing wings, but to no avail. It continued eating as if the birds weren't even there. Of course, these nests are made of reeds and basin weeds and the cattle were very hungry. The nests continued to disappear until all were gone. The water kept rising, and the cattle kept almost every spear of vegetation eaten, except for the roadside ditches and the pasture I use, which were protected by fences. These areas no doubt produced successful nests, as many birds were observed all summer in these areas.

When the water was at its peak in June it covered the roadway that I used, and it was like being in a boat when I crossed it daily. We had an unusually large number of Soras spend the summer this year, and they would forage in the shallow water on the roadway. Several times I almost had to stop to avoid running over them. I'm sure they were nesting in the roadside ditches. By July this area really looked like a shallow lake, since most all of the vegetation was gone. This attracted several different species of birds which don't normally frequent our basins. In the latter part of July about 30 American White Pelicans arrived, and for the ext six weeks we had Pelicans numbering sometimes more than 200. I have no idea how 50, many could find enough food for such a long stay. Also several Double-crested Cormorants have been staying in this basin lately, and seven White-faced Ibis and seven Cattle Egrets were here for some time in September. In the same month a female Ruddy Duck and six newly-hatched young were seen daily, swimming away from the roadside ditches as I crossed. It was a very late hatch, probably caused by earlier nesting failure, and no doubt caused by the cattle.