One of the many fascinating relationships that exist between the birds that inhabit our backyards is one that exists between the gray catbird and the brown thrasher.
During the spring and summer, these secretive birds often share backyards that feature an abundance of dense shrubs, vines, and small trees. Both of their birds feed and nesting with this labyrinth of vegetation. Often the birds compete with one another for the same nesting habitat. They are also known for their fearless assaults on any human or animal that appears to be a threat a nest containing eggs or young.
However, the gray catbird exhibits a behavior during the nesting season that baffles ornithologists. It seems occasionally gray catbirds will visit thrasher nests and actually break, and eat eggs. Several theories have been developed to explain this activity. Some experts are of the opinion catbirds are trying to discourage much larger brown thrashers from nesting in that location. Others suggest that catbirds consider thrasher eggs to be a source of food. Who knows?
Meanwhile this is just one more example how little we know about the fascinating lives of our backyard neighbors.