Q.What is brood parasitism? Explain with the help of an example.

Brood parasitism is a specific type of interspecific interaction where one species (the parasite) lays its eggs in the nest of another species (the host), leaving the host to incubate and raise the parasite's young. The host bears the entire cost of parental care, while the parasite gains all the benefit — the host's own offspring often suffer reduced survival because the parasite's chicks may hatch earlier, grow faster, or even push the host's eggs out of the nest. …

Ecological interactions are the countless ways in which organisms in a community affect one another. Some of these interactions are mutually beneficial, some are harmful to one side, and some are neutral. Among the most fascinating and deceptive of these relationships is brood parasitism. This is not a simple case of one animal eating another or competing for the same food; it is a form of parasitism — a relationship where one species (the parasite) benefits and the other (the host) is harmed — but the "resource" being stolen is not food or shelter in the usual sense. The resource is the host's parental care.

In brood parasitism, the parasitic species has evolved a remarkable strategy to avoid the energy and risk of raising its own young. Instead of building a nest, incubating eggs, and feeding chicks, the parasite lays its eggs in the nest of a different species. The unsuspecting host bird then incubates the foreign egg alongside its own, and after hatching, feeds and protects the parasitic chick as if it were its own offspring. The cost to the host is severe: it wastes its time and energy raising a chick that is not its own, often at the expense of its own biological young, which may be pushed out of the nest or outcompeted for food.

The NCERT textbook provides a clear and classic example of this phenomenon: the cuckoo (Cuculus canorus) and the crow. The cuckoo is a brood parasite. The female cuckoo carefully watches the nest of a potential host, such as a crow or a warbler. When the host bird is away, the cuckoo quickly lays one of her own eggs in the host's nest. To reduce suspicion, she may even remove one of the host's eggs from the nest. The cuckoo's egg often closely resembles the host's eggs in colour and size, a crucial adaptation to avoid detection. …

Name both costs to the host explicitly -- the energy spent raising an unrelated chick, AND the loss of the host's own reproductive output -- naming …