The la plata dolphin is a small dolphin that can be found swimming in the coastal waters of southeastern South America.
These dolphins are identified by their large beak and brownish gray skin tone.
Due to their small size and environment these dolphins are known to be hunted by sharks and killer whale.
They are also known to move slowly through the water and avoid bringing attention to themselves, probably as an attempt to remain hidden from predators and as part of their natural social structure.
Physical Characteristics and Appearance
The la plata dolphin is known for its extremely long beak which is believed to be the largest of any known dolphin species.
On average these dolphins grow between 5 – 6 ft. long when fully matured and weigh around 100 lbs.
They have a pair of large flippers to assist with swimming and the dorsal fin is triangular in shape and tapered back with a rounded edge.
In terms of color these dolphins are a grayish brown skin tone with a lighter colored under-body.
As a marine mammal the la plata dolphin is a warm-blooded animal that breathes air, gives birth to live young and produces milk to feed its babies.
Diet and Hunting Methods
These dolphins are known to eat a diet consisting of various fish, squid, shrimp and octopus.
When hunting in areas that are absent of light it is likely that the la plata dolphin will use echolocation to locate food and find its way around the ocean.
These marine mammals are known as bottom feeders as they frequently consume prey near or at the bottom of the ocean.
Observations suggests that cooperative feeding does take place suggesting that some dolphins may hunt together when searching for food.
Habitat and Migration
The la plata dolphin can be found traveling in the coastal waters of the Atlantic in southeastern South America.
Some of the most common areas that they can be located in include the coastal waters of Argentina, Brazil and Uruguay.
As a river dolphin the la plata dolphin is one of the only known river dolphins to inhibit, hunt and live in saltwater environments.
Because of their small stature and location these dolphins are commonly hunted by sharks and killer whales which may influence their quite nature and desire to inhibit shallow coastal waters.
No significant studies have been confirmed regarding migration patterns, however their shallow range strongly suggests that migration does not take place outside of their coastal area.
Social Structure and Communication
During certain times of aggregation these dolphins may be seen in groups of up to 15, however they generally prefer to travel alone or in small pods where they can remain fairly undetected.
Unlike other species these dolphins are not known for performing acrobatic feats or approaching ships and boats, but may choose to on rare occasions.
Most of the time they are known to move, rise and descend at a slow pace in order to remain hidden from predators and other potential threats.
In active waters it can be almost impossible to spot these marine mammals as they travel and hunt for food.
As with other dolphin species these dolphins communicate vocally through various high-pitched clicks and whistles.
Breeding and Reproduction
The average gestation period for the la plata dolphin (pregnancy period) is around 11 months and sexual maturity is believed to be reached between the ages of 3 – 6, however numerous reports claim sexual maturity can occur as early as 2 – 3 years after birth.
In some locations mating may occur fairly stable throughout the year while other areas experience seasonal fluctuations.
Post birth the female dolphins nurture their young with milk in order to provide them with essential nutrients until they can hunt for their own food.
Healthy mature dolphins are known have a lifespan of around 20 years.
Threats and Predators
The la plata dolphin is known to face a number of human and predatory threats within its region.
Some of these threats may include:
- Predators
- Bycatch
- Habitat degradation
- Pollution
As stated earlier the la plata dolphin is known to face threats from sharks and killer whales.
These dolphins are also known to face threats from being caught in fishing nets and other types of fishing gear as they unknowingly swim into the nets while searching for easy prey.
Commercialized areas that create agricultural runoffs and/or industrialized zones can have an impact on the health of the la plata dolphin, especially in regards to their contributions of waste and pollution, which can lead to habitat degradation and poisoned food among other concerns.
Due to their population size, commercialized habitat and frequent catches with fishing nets these marine mammals are currently listed as “vulnerable”.