Nesting Waterfowl in the Sacramento Valley
By Luke Matthews
Small pockets of migratory ducks such as Northern Pintail, Northern Shovelers, and Green-winged Teal can still be seen hanging around in the Sacramento Valley; however, the vast majority of our 7 to 10 million wintering migrants have left for their norther breeding grounds.
Although the numbers are not as impressive as the wintering numbers, California currently supports roughly 500,000 breeding ducks across 17 different species. However, three species (Mallard, Gadwall and Cinnamon Teal) make up the vast majority of our nesting duck populations. In fact, these three species account for roughly 85 percent of the total breeding duck number in the State. In the Sacramento Valley Region specifically there are currently about 80,000 breeding Mallard, Gadwall, and Cinnamon Teal. Although they are much less numerous in the Sacramento Valley, other common breeding waterfowl species include Canada Geese, Wood Ducks, and Mergansers.
The breeding season is now well underway in the Valley and we expect to see peak nesting activity toward the end of May. Mallard, Gadwall, and Cinnamon Teal are all considered to be upland nesting duck. This means that they nest on the ground in grass or other types of vegetation. Although Cinnamon Teal primarily nest in marsh habitats, all three of these duck species are regularly found nesting on fallow rice acres. Canada Geese also typically nest on the ground in close proximity to water; however, they have been documented nesting in odd places such as building rooftops, trees, and cliff sides.
In contrast with the rest of our local breeding duck species, Mergansers and Wood Ducks are cavity nesters. This means that they build their nests inside old tree cavities or nesting boxes. They typically only nest in cavities in close proximity to water sources such as creeks, sloughs, ponds, or rivers.
Soon ducklings and goslings will be hatching out and if you are lucky you will be able to see some of these cute fuzz balls swimming around at your local pond or up in rice country!
Luke Matthews is the Wildlife Programs Manager for the California Rice Commission