The mother may be off hunting or feeding. If in doubt, observe the baby animal from a distance to see if the mother returns within a couple of hours. If you need to capture the animal, use caution. Being held in human hands is extremely stressful for wildlife. Keep the animal's surroundings quiet and warm, but not hot.
Timing is critical.
Severe wounds and fractures need immediate care by a veterinarian. As little as one hour delay can lower the potential of a successful outcome for a critical wild patient.