Which of the following is a sign of distress in wild animals during rehabilitation?

Lethargy and reduced appetite are indeed clear signs of distress in wild animals during rehabilitation. When an animal is experiencing distress, it often leads to changes in behavior, such as decreased energy levels and a lack of interest in food. Lethargy may manifest as a notable decrease in the animal’s usual activity, making it less responsive to stimuli and interactions that typically elicit a response. A reduced appetite often accompanies lethargy, as stress can interfere with the animal's physiological processes and appetite regulation, resulting in them eating less or refusing food altogether.

In contrast, increased grooming can indicate a variety of behavioral states, such as normal self-maintenance or stress in specific contexts, but it is not a definitive sign of distress on its own. Excessive vocalization can be a response to stress, but it can also occur in typical communication behaviors depending on the species. Normal activity levels would generally suggest that the animal is not experiencing distress, which is why it does not align with the context of signs indicating distress.