Question

Which one or more of the following is/are developmental feature(s) of hatchlings of an altricial bird species?

• A. Eyes open
• B. Eyes closed
• C. Down feathers present
• D. Down feathers absent

Hint:

When a condition is stated (e.g., “\emph{if it is blue}”), restrict your denominator to that condition first; then count the favorable cases within that subset.

Answer 1

The Correct Option is B, D

In the context of altricial bird species, the developmental features of hatchlings can be identified as follows:

• Altricial birds are those whose hatchlings are born in a relatively undeveloped state. They typically cannot fend for themselves immediately upon hatching and rely heavily on parental care.
• The hatchlings of altricial birds are generally born with their eyes closed. This means that their eyes will not open until several days after hatching, as they continue to develop outside the egg.
• Furthermore, altricial hatchlings usually lack down feathers at birth. Down feathers are responsible for insulating the body, and their absence makes the hatchlings more reliant on their parents for warmth.

Therefore, the correct developmental features of an altricial bird species' hatchlings are:

• Eyes closed
• Down feathers absent