CROW Case of the Week: Common Nighthawks #18-2714 & 18-2715

The common nighthawk (Chordeiles minor) is rather uncommon in respects to its name. Since it is known to be active both at dawn and dusk, it is not strictly nocturnal, nor is it related closely to hawks in general. In fact, it is more related to an owl. This medium-sized bird can be well disguised due to its gray, white and black color patterns. This camouflaging can be seen as a blessing, but also a curse since nighthawks tend to nest on open ground.

Interestingly, the common nighthawk feeds entirely by flying directly into a swarm of insects with mouth and throat wide open. No major foraging or seizing food with their feet or bills, this simpler process, which involves diving and swooping, allows dinner to go right down the hatch without much effort. 

The common nighthawk’s dive also works as a courting ritual. Males descend upon females by making a booming sound when air rushes over their wings. They eventually land on the ground before the female to spread and shake their tails, puff out their throats and croak at her. Young common nighthawks make their first flights on average at roughly 21 days. Complete development usually occurs in the 45 to 50 day range.

On July 9, two fledgling common nighthawks were admitted to the hospital from Fort Myers. Upon examination, one of the two birds was found to be overtly healthy, however the other one was found to have severe subcutaneous emphysema – when gas or air is in the layer under the skin – along the right side of its abdomen.

“When we receive sibling animals, they often are together because they are not old enough to fend for themselves. In the case of these nighthawks, they were very close to being independent, but needed a little more time,” said Dr. Kyle Abbott, CROW veterinary intern. “We kept both to help them reach a larger size where they can feed and fend for themselves. It also allowed us to monitor the sibling that appeared healthy and ensure it was fit to survive on its own.” 

Regarding the injured patient, a small vent was made in the air sac to allow the air to escape. The bird was provided with antibiotics and housed with its sibling. “Making the small vent in the skin allowed the trapped air to escape the space under the skin. Once this air was removed, the body could repair whatever underlying injury allowed the air into that space,” said Dr. Abbott. “We could not identify the inciting wound, but these injuries can occur from external wounds or from rupturing air sacs internally. Birds have structures called air sacs throughout their bodies, in addition to lungs, as part of their normal respiratory tract.”

Both nighthawks received flight training and were released on July 28 in an area where other nighthawks were observed. “Once these two learned to eat in our care, they did well,” said Dr. Abbott. “They continued to grow and reached a stage where they were big enough to take care of themselves.”

Finding nighthawks on the ground does not mean they fell from their nests. Nighthawks are known to be ground nesters who do not build nests. They lay their eggs directly on the ground and rely on camouflage for protection from predators. 

“In the case of these siblings, one was found in a screened-in area of a house, which is not normal. When we see something like this, it is likely pets or another predator may be involved, and it is safe to have them seen by a wildlife veterinarian,” added Dr. Abbott. “For most other young animals found on the ground, it may be in their best interest to leave them. We are available to answer any questions about found animals to help decide if they need our help. It is always best to contact a licensed wildlife rehabilitator before attempting to help a wild animal.”

 

CROW Case of the Week stories are written by Bob Petcher and appear weekly in the Island Sun and River Weekly Newspapers.

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