Day 10

An old friend is sick
Madbob has been sighted each year in the Key West population since 1999. She is a female and has had multiple calves across this time period. Today we saw her for the first time this season. And while she was moving without issue with other members of her group, we noted the presence of bumps or lesions across her body. 

Madbob, a female bottlenose dolphin with cyst like lesions on her skin.

We do not know how old Madbob is. The only way to determine age of a dolphin is to either be aware of the approximate birth year (by following it over time) or by looking at the layers in a tooth (laid down yearly like a tree). 

We will be sending out photos of her to see if other researchers are aware of what this may be. We are hopeful that this does not indicate severe disease and a negative outcome for her.

Male pairs
Hook and Emily (both males, Emily named prior to gender determination) have also been sighted in the Key West community of dolphins since 1999. In fact, Hook was the second dolphin noted in the area on the first day of surveys in February 1999.

What is interesting about this pair is that they are a relatively new male pair. Male bottlenose dolphins in many populations will form pairs that associate fairly regularly. Pairing may be to help one another get access to females for reproduction. Emily for many years was seen almost always with another male (Corona). But a shift occurred about 3 years ago, and Emily began to associate more often with Hook and another local male. Now Emily and Hook are found together most of the time. 

We have no way of knowing what happened in the previous relationship between Emily and Corona. But documenting the change is interesting and important. This information provided more detail about male relationships, and that they are not necessarily permanent.

Fish Tossing
In our last group sighting of the day, one of the dolphins was “fish tossing”. 

Dolphin "fish tossing"

This involves taking the fish in the mouth, usually turning upside down (the dolphin), bringing the head above the surface and then tossing the fish. Dolphins that do this, then will go and pick the fish back up, and many times will repeatedly toss the fish. We see this type of behavior most often in young animals, usually calves, but it can also occur in adults. Some hypotheses for why this may occur, include 1) possibly a need to break apart the tissue of the fish prior to consumption, 2) play and learning for younger animals and 3) teaching of older animals to younger animals.