Moms and Calves and More

Moms and calves
Today two of the three groups we encountered had mom/calf pairs. In one was Jpeg and her calf. 

Jpeg and her calf

Previously we discussed what seemed to be an on going trend for Jpeg. Leaving her young calf and moving far away from other group members to feed. Today she was feeding, but the calf remained by her side throughout. Not sure which was responsible for the close proximity between the two of them, Jpeg or the calf.

In our third group was Calusa and her less than one year old calf. 

Calusa and her calf

Calusa has been through a lot in the past, having been struck by a boat once. We noted the presence of fresh propeller scars on her back between her dorsal fin and blowhole during one of our field seasons. She was lucky because the wounds were not deep and they have healed and even re-pigmented. She seems fairly healthy, having raised multiple calves through that time and beyond. Many people are surprised to learn that dolphins can be struck by vessels. Dolphins, while fast swimmers, still do not swim as fast as boats can move. It is not frequent, but other populations near coastal cities also have dolphins with evidence of propeller scars. For this reason, we take great care when moving our boat near dolphin groups. We also make a note of the location and heading of animals when leaving an area, moving slowly in the opposite direction until we are a good distance from the group before we speed away.

Permits required
One thing we have yet to mention, is that in the United States, to directly approach marine mammals, you must work under a permit. Because directly approaching (which we sometimes have to do to collect fin photos) can cause change in behavior, it is considered to potentially be what is called Level B harassment (“potential to disturb”). Prior to the start of our work, we had to first obtain a permit from National Marine Fisheries Service. You will note on our dolphin photographs, we list our permit number. This indicates that the photo was collected legally.

Even though we have a permit that allows us to legally “disturb”, we work very hard to avoid this possibility. This starts with the way we approach and handle our vessel around dolphin groups. For example, when approaching, we work to avoid approaching directly. Instead we point the bow of our boat ahead of the front of the dolphin group and work to move parallel to the group. We also maintain a distance when not working to get dorsal photos. In addition, when collecting behavior data, we monitor the actions of the group members to see if we should back off or even cancel the data collection. Dolphins do attempt to communicate with us at times to let us know they want us to back off. They will either chuf repeatedly (a loud forceful exhalation) or tailslap (slapping the tail on the surface of the water). If dolphins perform these, we back away from them, and if they continue, we terminate the follow.

To learn more about what to do if you encounter marine mammals on the water, please see the following site: http://www.nmfs.noaa.gov/pr/education/southeast/