Question

Cowbirds lay their eggs in the nests of smaller birds. The fast-developing cowbird chicks hatch first, then push the other baby chicks out of the nest as they hatch. The cowbird is classified as

• A. Pathogen
• B. Parasite
• C. Mutualist
• D. Commensal

Answer 1

The correct option is B Parasite

A parasite is an organism that lives on or in a host organism and gets its food and nutrition from or at the expense of its host.
Since the parasitic mode of life ensures free lodging and meals, the cowbird chick is fast developing in the nest of the smaller bird and also pushes smaller bird’s chicks, it is a parasite for the smaller bird chicks. It is an example of brood parasitism. In this, the parasitic bird lays its eggs in the nest of its host and lets the host incubate them.
A pathogen is a microorganism that causes, or can cause, a disease in a host organism.
Mutualist is the one which is in mutual interaction, an interaction which confers benefits to both the interacting species.
Commensal is the organism which is in a commensalism interaction with another organism. In commensalism, one species benefits and the other is neither harmed nor benefitted except to a negligible extent.