American Robin

The American robin is an indicative sign of spring and the official state bird of Michigan.

American robins are a migratory species that breeds from April through July. Typical nesting habitats include residential areas and transition areas between forest and grassland areas; American robins can be found throughout the floodplain.

The goal of the American robin study is to assess the health and abundance of the robin population of the Tittabawassee River that may be exposed to site-specific contaminants, specifically dioxins and furans.

Prey items, including earthworms, beetles, and other terrestrial invertebrates are collected from various sites throughout the floodplain and analyzed for contaminant concentrations. These analyses provide an estimate of the amount of contaminants the robins are exposed to through their diet.

Egg, nestling, and adult tissues are also analyzed to verify that their exposure has been characterized correctly.

Reproductive variables are also measured to characterize the health of the American robin population. These variables include the number of eggs in each nest, hatching success, and fledging success.

American robin data were collected from reference areas in Sanford, Michigan, and the Pine and Chippewa rivers at and around the Chippewa Nature Center to downstream of Midland, Michigan, to the Shiawassee National Wildlife Refuge.

Understanding dietary exposure, tissue concentration analysis, and reproductive variable analysis will reveal the information necessary to estimate the possible risk to American robins in the Tittabawassee River area.