On yesterday’s (05/06/2015) 1:00pm Whale, Dolphin and Bird Watch we were able to witness at least two newborn dolphin calves! The Cape May population of Atlantic Bottlenose Dolphins will return to Cape May, New Jersey every year to feed, mate and give birth to their calves. The dolphin’s gestation period is about 12 months, so if a female were to become pregnant in Cape May one year, she will return the next year, 12 months later to give birth to her calf.
When the dolphin calf is initially born, it will be jet black in color and have fetal folds (both are seen in the above photo). Fetal folds may resemble light colored “tiger stripes” on the sides of the dolphin calf that are only visible within the first few days of birth. They will also be covered in a thin layer of lanugo. Lanugo is a type of hair that will help insulate the dolphin calf and keep it warm in our colder Atlantic Ocean and Delaware Bay waters, especially now when the water is only about 50 degrees.
We were even lucky enough to witness this calf breach by itself! This photo is the calf falling back into the water. Although I was not able to capture the individual’s face, this photo is a great example of the fetal folds on the calf’s body and also the calf’s dorsal fin, which will change over time.
Our main project onboard the American Star is compiling an Atlantic Bottlenose Dolphin Catalog for the individuals that return to Cape May, New Jersey each year. In addition to photographing the newborn calf, it was also important that we photograph the mother it was traveling with. Calves will often surface at the same time, and also right next to their mother. The jet propulsion that is created from the mother dolphin will help the dolphin calf keep up with the rest of the pod and save energy.
Using this photo, our naturalists and interns will examine the mother dolphin’s dorsal fin to see if it is an individual that we have seen previously in Cape May. If we are able to match it to an individual already in our catalog, we can make a note that she gave birth this summer and track her calf as it ages in the years to come, or create a new individual in our catalog.
If we zoom in on the previous image, we get another really great look at the dolphin calf’s fetal folds! The calves obtain the fetal folds because of the way they are shaped while still developing inside the mother.
This nursery pod of about 8-12 individuals within the Delaware Bay had two newborn calves and one juvenile dolphin. They were lunging sporadically out of the water, chasing down fish that we were able to see jumping out of the water!
Definitely an excellent sighting of our Atlantic Bottlenose Dolphins! Can’t wait to see the other newborn calves that will be joining the Cape May population this year!
-Melissa Laurino, Naturalist at Cape May Whale Watch and Research Center