An Amazon River Dolphin, sometimes called Pink River Dolphin. Their body color changes with age and some adults turn pink as a result of repeated abrasion of their skin surface. Unfortunately, these Pink Amazon river dolphins are endangered for concerned reasons like water pollution and loss of habitat due to expanded development. Amazon river dolphin jumps off water - pink dolphin stock pictures, royalty-free photos & images View of an Amazon pink dolphin at the Amana Lake at Amana Sustainable Development Reserve in Amazonas state, Brazil, on June 29, 2018.
Amazon river dolphin facts, pictures and information. Not all of the Amazon rainforest’s animals live in or among the trees. The Amazon River itself provides a huge and varied habitat for a vast number of animals. One of the most amazing animals of the region makes its home in the river and its many tributaries. Let’s meet the Amazon river dolphin…
Amazon River Dolphin Facts At A Glance
- Other Name(s): Boto, bufeo, pink river dolphin
- Scientific name: Inia geoffrensis
- Type of Animal: Mammal, member of the order Artiodactyla (the even-toed ungulates)
- Animal Family: Iniidae
- Where Found: Amazon River system, South America
- Average Length: 3 m (7.6 ft.), male; 2 m (6.6 ft.), female
- Average Weight: 154 kg (340 lb.), male; 100 kg (220 lb.), female
- Conservation Status:Data Deficient(previously Vulnerable)
- Other interesting Amazon river dolphin facts: It’s a fairly slow swimmer with an average speed of between 1.5 and 3.2 km/h (0.93 and 1.99 mph).
Meet The Amazon River Dolphin: Introduction
Dolphins are a group of aquatic mammals. (Aquatic mammals are mammals that have adapted to live in water). Most dolphins live in the sea.
Dolphins are members of a group of marine mammals known as the ‘toothed whales’. Also in this group are orcas and sperm whales.
River dolphins are a subgroup of dolphins that live in freshwater and brackish environments. (Brackish water is a mixture of fresh water and sea water.)
The Amazon river dolphin is the largest of the four living river dolphin species. It is one of two river dolphins found in South America, both of which are in the family Iniidae. (The other South American river dolphin is the Araguaian river dolphin (Inia araguaiaensis).
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What Does The Amazon River Dolphin Look Like?
The Amazon river dolphin has a robust build. Unlike saltwater dolphins, whose vertebrae are fused (joined together), the bones of an Amazon river dolphin’s neck are separate. This provides the species with excellent flexibility.
The color of the Amazon river dolphin ranges from grey to bright pink. The top side of the body is usually a darker shade.
Adult males are the most likely to be the distinctive pink color that give the species its name. Scientists are unsure as to what causes the pink coloration. Suggestions include diet, water temperature and injuries from fighting. Newly born Amazon river dolphins are dark grey.
The flippers and the flukes (the tail fins) of the dolphin are triangular and have ragged hind edges. The dorsal fin is rounded and not very prominent.
The long, thin snout curls slightly downwards. Utc time zone philippines. The eyes are small but functional (unlike those of the South Asian river dolphin, a virtually blind river dolphin found in Asia).
Like all toothed whales, the Amazon river dolphin has a melon – an oil-filled sensory organ that appears as a bulge on the animal’s forehead. The melon is used for echolocation, the process by which the dolphin uses sound to find its way around in the murky water.
The Amazon river dolphin has three subspecies:
- Inia geoffrensis geoffrensis is found in the Amazon River, and many of its tributaries.
- Inia geoffrensis boliviensis is found in the Madeira River, a tributary of the Amazon, in Bolivia.
- Inia geoffrensis humboldtiana is found in the Orinoco River basin
Amazon River Dolphin Video
You can see some amazing footage of Amazon river dolphins in the wild in the video below:
The Amazon river dolphin has the widest distribution of any river dolphin. Its range covers an estimated 7 million km2 (2,700,000 mi2). The species is endemic* to South America. It has been recorded in 6 countries: Bolivia, Brazil, Colombia, Ecuador, Peru and Venezuela. The dolphin is present in both the Amazon and Orinoco river systems.
* Endemic means ‘only found in’.
The Amazon river dolphin is restricted to freshwater habitats. In addition to the main rivers, it also inhabits smaller tributaries, mouths of rivers, canals, lakes, floodplains and flooded forests.
The dolphin moves between different habitats seasonally. During the dry season, it stays in the main river channels.
During the wet season the water level rises, allowing the Amazon River dolphin to disperse into smaller tributaries. It will also venture into flooded forests and plains, swimming among the roots of trees in search of food. Females and their young tend to spend far more time in flooded areas than males.
Amazon River Dolphin Facts: Behavior
The Amazon river dolphin is mainly active during the day. It is especially active during the early morning and late afternoon.
The Amazon river dolphin is most often observed either singly or in pairs. Small pods of 3 to 5 dolphins may also form. Larger aggregations of up to 30 or more individuals can also be seen where prey is particularly abundant.
Amazon river dolphins use at least 10 distinct calls to communicate with each other. These include various clicks and whistles.
The species has a curious and playful nature. Amazon river dolphins have been observed playing with a range of different objects, including sticks, lumps of clay and small animals.
Although the species isn’t territorial, aggression and fighting is common, especially among males.
Amazon River Dolphin Facts: Lifecycle
Males Amazon river dolphins often bear multiple scars or injuries. This would suggest that they fight aggressively over the females during the mating season.
Object carrying (e.g. branches & other vegetation) by adult males is thought to be a part of their mating behavior. A male will often nibble a female’s fins when making initial contact.
The Amazon river dolphin is a seasonal breeder. Births occur between May and July after a gestation period of about 11 months. The calf measures about 80 cm (31 in) at birth.
The female nurses her young for around 1 year. The strong bond between the mother and calf continues for an additional year or two.
What Do Amazon River Dolphins Eat?
The Amazon river dolphin’s diet is among the most diverse of all the toothed whales. The species feeds on a wide range on prey animals during the wet season. During the dry season it becomes more selective. The dolphins can consume up to 5.5% of their body weight in a single day.
The Amazon river dolphin feeds on up to 53 fish species from 19 different families. Its prey includes catfish, croakers, tetras and piranhas. The dolphin also feeds on freshwater crabs and river turtles. The size of a typical prey animal ranges from 5 to 80 cm (2.0 to 31.5 in).
Typically, the dolphin feeds near the bottom. It uses echolocation to find prey in the often murky water.
The Amazon river dolphin has occasionally been seen hunting cooperatively with other species, including the distantly-related tuxuti (Sotalia fluviatilis) and the giant otter (Pteronura brasiliensis).
Is The Amazon River Dolphin Endangered?
Since 2008 the Amazon river dolphin has been rated as ‘Data Deficient’ by the IUCN. The reason for this is because total population size, population trends, and the exact impact of the various threats faced by the species are not clear. Previously, the species was rated ‘Vulnerable’.
The most significant threats to the species include:
- Hydroelectric dams: The damming of rivers threatens the Amazon river dolphin in several ways. It prevents fish from migrating downstream, which can decrease the amount of food available for the dolphins. It also affects water quality (temperature and oxygen levels) and may split populations (which can reduce their viability by reducing the available gene pool).
- Environmental pollution: Agricultural pesticides and heavy metals (including mercury from gold refining) can accumulate in both the dolphins and their prey species. The overall impact resulting from this has not been adequately studied.
- Fisheries: Amazon river dolphins are sometimes accidentally caught in fishing gear. The species is also hunted by fishermen hoping to reduce competition and to prevent damage to their nets. Fishermen also use dolphin flesh as bait to attract fish.
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The Amazon River Dolphin is a group of dolphins that primarily dwell in the South Americas waters, especially in the Amazon river. Also known as the ‘Pink River Dolphin’ or the ‘Boto’, they are not to be confused with the marine pink dolphins. This water mammal is the largest of all the other river dolphin species, and cannot survive in salt water. It is a very distant relative to the sea dolphin, and has a pink to pinkish-grey pigmentation on their bodies, which is one of their primary characteristics, giving them a very unique appearance (and hence their name). The Boto is the only river dolphin that is kept in captivity, mostly in the USA, Venezuela and Europe. However, the rate of mortality is high amongst the captive specimens.
Table of Contents
Amazon River Dolphin Scientific Classification
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Table of Contents
Pictures Of Pink River Dolphin
Amazon River Dolphin
Size: Length of the adult dolphins varies between 2 and 3 meters.
Weight: Can weigh up to 160 kilos.
Skin Color: Color is dependent on their age. While the baby Amazon river dolphins have a dark gray dorsal side, the ventral side is lighter gray. With maturity, the flanks and the ventral side begins turning pink. Pink is predominant in the males. Their colors fade gradually with age, having blue-gray and white tinges all over.
Eyes: Small round eyes but with a strong eyesight.
Beaks: The beaks are pretty long with a strong built adapted to capture prey.
Teeth: The jawline is made of a combination of 24-34 conical and molar-like teeth.
Fins: All fins are same like other dolphins except that they don’t have dorsal fins, but instead, has a hump on the back that gets larger with age.
In the wild, the average life expectancy of these animals is only 33 months. However, in captivity, they have been recorded to have lived between 10 and 30 years.
Pink dolphins primarily inhabit the Amazon River in South America, but their range extends to the basins of the Orinoco and the upper Madeira River as well.
Habitat: Where do Pink Amazon River Dolphins live
Botos are generally concentrated below the confluences of the channels. They dwell in the fast flowing, whitewater, clearwater or blackwater rivers of the lowlands. But they are strictly freshwater mammals. They are also found in the lakes, the largest tributaries of the rivers, and seasonally in the flooded rainforests.
Classification of Subspecies
Depending upon their ranges, the dolphins have been classified into the following:
- Inia geoffrensis geoffrensis of the Amazon
- Inia humboldtiana geoffrensis in the Orinoco
- Inia geoffrensis boliviensis from Bolivia
Pink Dolphin Amazon River
The Amazon River Dolphins are social and friendly creatures, living since centuries in the Amazon and its tributaries. Usually seen roaming alone, or in pairs during the mating season, these dolphins would hover in groups of 10 to 15 when there is an abundance of prey. Like most other species, these dolphins sleep with one eye open.
Typically, these creatures are slow swimmers, and are primarily diurnal. They are mostly active early in the morning, until late afternoon. They breathe at a shallow angle, displaying their dorsal fins, the beak and the melon all at a time.
Like many other species, the botos are seldom seen leaping above the water surface. However, the Amazon River dolphins are often seen swimming upside down, though the reason is uncertain. It is thought that, the fleshy cheeks of these dolphins act as an obstruction to their bottom vision, for which they tend to turn upside down to get a vision downwards.
Diet: What Do Amazon River Dolphins Eat
Their diet primarily consists of fish, and they depend on healthy fish populations for their survival, feasting upon over 50 types of fish. They also consume shellfish, crabs, crustaceans, and even small turtles.
Video: Feeding the Boto Dolphins
Sounds and Communication
Apart from emitting the sonar (inaudible to humans), these Amazonian dolphins use whistling tones for communication. Researchers say that, this sound has some connection to food. Research has also revealed that, these vocalizations are different in structure to the typical whistles of other dolphin species.
Before mating, the adult males carry objects like branches, floating vegetation, or hardened clay balls in their mouths to the females to propose for mating. Sexual dimorphism is evident in these creatures, with the males weighing and measuring between 16% and 55% more than females.
Courtship and mating foreplay have also been recorded with the male nibbling the female’s fins. However, if the female is not receptive, the male would react aggressive. The frequency of intercourse in a couple is high, and they have been observed to use at least three different sex positions – lying head to head, lying head to tail, and contacting the womb at right angles.
Baby Pink Amazon River Dolphin
Reproduction and Life Cycle
The boto dolphins breed seasonally, giving birth to the pups between the summer months of May and June. The season of giving birth to the young ones coincide with the flooding season, providing an advantage to the female and its babies. While they stay in the flooded regions longer than the males, until the water level goes down. These areas have enough sources of food to provide the juveniles with enough nutrition they require for growth.
The gestation period lasts for about 11 months to 1 year, and in captivity, the birth takes around 4 to 5 hours. During birth, the size (length) of the calf is around 31 inches, with the lactation taking about 1 complete year. The females can again develop offspring after 15 to 36 months. It takes almost 2 to 3 years for the baby dolphins to be adult and independent.
The calves are born between July and September. The period of breastfeeding is relatively long in these mammals, which in turn shows a strong bond between the child and the mother. Also, during this time, the babies learn from the parents and are developed by their care and attention. While the male dolphins attain the age of sexual maturity when they attain the length of about 2 meters, the females sexually mature at about 1.7 meters.
- A characteristic that is unique to these dolphins is the presence of stiff hairs on the beak, which are sensory organs aiding them to sense the presence of a prey in the muddy river bottoms.
- These water mammals have conical teeth in the front portion of their mouths, which is ideal for holding their prey. The molar teeth situated in the rear end of their mouths are shaped ideally for grinding food before they swallow. This is known as ‘heterodont’ dentition.
- Unlike other dolphins having a fused vertebra, this species can freely move their neck on all sides.
- Length of the fins allows these mammals to perform a circular movement, and is ideal for exceptional maneuverability during swimming through the flooded forest.
- These animals known for their keen eyesight and hearing, which assist them in defending themselves in the deep river basins.
- They have large flukes and flippers that make it easy for them to maneuver in the shallow depths of river water.
- These dolphins are able to emit audible sonar vibration, which assists in echolocation of their prey.
Pink Amazon River Dolphin Pictures
The petroleum industry in the Amazon and Orinoco basins pose a threat to the dolphins by means of polluting the aquatic ecosystem where the species is found. In Colombia, the oil pipelines have been blown up by armed groups, causing irreparable pollution.
The raise in contaminant levels of mercury have also caused and increased the total number of recorded deaths among these mammals, especially close to the gold mines, where mercury is used in the process for mining gold.
Predators: What eats an Amazon River Dolphin
These dolphins have few natural predators, but at times, they are hunted down by anacondas, jaguars and caimans. They are also attacked by humans for their skin for leather and for their fat for cooking (and also for leather). They are also caught to be kept captive in aquariums.
They have not yet been officially declared as threatened or endangered. Because of insufficient data, the IUCN 3.1 has categorized it under their ‘Data Deficient’ list.
- Like many other dolphins, the Amazon dolphins are not acrobatic, and it is difficult to train them.
- Unfortunately, these dolphins really don’t have a defense.
- The other four river dolphin species (viz., Indus River Dolphin, Chinese River Dolphin, Franciscana River Dolphin, and Ganges River Dolphin), which are functionally extinct or close to extinction, have their females larger. The opposite holds good for the Amazon River Dolphins.
- Historically, these animalshave been spared by humans since the local legends and mythology says that, these creatures have special powers.
- An Amazon river dolphin named Apure lived for forty years at the Duisburg Zoo in Germany.
- The Botos are not afraid of boats, thus they often suffer from wounds by colliding with them, and even get tangled up in fishing nets.
- The Amazon River Dolphin Conservation Foundation is a non-profit organization that works to conserve the population of these dolphins and their environment through education, research, and collaboration.
- Among the five species of river dolphins, the pink dolphins are considered the most intelligent, with the brain capacity being 40% bigger than that of humans.
- The pink dolphins are known to prey upon the piranhas, the legendary terror of the Amazon.
- Homosexual behavior in the form of ‘nasal sex’ has been observed in the Amazon River Dolphins, wherein, these dolphins would enter their penises into other males’ or females’ noses (blowholes). This makes them the only animal performing ‘nasal sex’.
Pink Amazon River Dolphins