Franciscana

What do franciscanas look like?

Franciscanas are small dolphins; the females are a bit larger than males. The body is smooth and slender, the beak is very long and skinny and the eyes are small. The triangular-shaped flippers are large with undulating trailing edges.  Franciscanas are light coloured dolphins - brownish to grey on the top and lighter on the sides and belly. The dorsal fin is low and rounded with a broad base and the tail flukes are extremely broad, up to a third of the length of the body.

What’s life like for a franciscana?

The typical group size for franciscanas is small - two to six individuals but higher numbers of up to 15 dolphins have occasionally been seen together. There is evidence for long-term associations between individual dolphins. Franciscanas have been observed cooperatively feeding together.

Franciscanas become sexually mature when they are between 3 and 5 years old.

Franciscana pregnancies last about 11 months and mothers feed their babies with their own milk for 9 months before weaning.

The life expectancy is thought to be shorter for franciscanas than other dolphins; it is estimated to be 15 years for males and 21 years for females.

Franciscanas are not acrobatic at the surface; they move smoothly and slowly and so are generally difficult to see in the wild.

Both sharks and orcas prey on franciscanas but the biggest threat they face by far is from human fishing activities.

What do Franciscanas eat?

Franciscanas hunt shallow-water fish species belonging to several families, mostly on or near the sea floor. They also eat squids, octopus and shrimps. Franciscanas eat locally and seasonally abundant fish and other marine prey depending on the seasonal prey availability.

Where do Franciscanas live?

Franciscanas live in shallow coastal waters including saltwater estuaries such as the Rio de la Plata estuary, along the coastlines of southern Brazil, Uruguay and Argentina. Franciscana distribution is not continuous along this strip of coastline as there are some well-known gaps in their range.

Franciscanas prefer waters beyond the surf zone up to 50m deep in some areas and only up to 35m deep in others. They are generally found in turbid, sediment-rich water, but they also inhabit clear waters and shallow waters close to islands and rocky shores. Some franciscanas do spend their lives within estuaries and do not venture into the open ocean.

Franciscanas do not migrate and tend to stick to a limited home range which has lead to populations becoming genetically distinct from one another.  Scientists trying to figure out the number of distinct populations now recognise at least five populations from north to south making it hugely challenging to comprehensively protect their natural diversity.