Also known as franciscana or toninha, this is a river dolphin, found in the coastal waters of southeastern South America. Being a member of the Inioidea family, it is only capapable of living in saltwater, so is found in the ocean and saltwater estuaries. This has an unfortunate effect of being around the mouth of rivers, and therefore being effected by all the pollutants picked up the whole route of the river.
It is also regularly noted, that this run-off kills off the fish which this dolphin species requires for survival. It was first described in 1844.
It is thought that fewer than 30,000 of these animals remain in the wild.
There is some tourism around this species. As we get links they will appear beneath the news section below.
Hector’s dolphin is one of four dolphin species belonging to the genus Cephalorhynchus. Hector’s dolphin is the only cetacean endemic to New Zealand, and comprises two subspecies: C. h. hectori, the more numerous subspecies, also referred to as South Island Hector’s dolphin; and the critically endangered Māui dolphin (C. h. maui), found off the West Coast of the North Island.
It is the smallest dolphin species with adults length between 1.2 and 1.6m. The species’ range includes murky coastal waters out to 100 m (330 ft) depth, though almost all sightings are in waters shallower than 50 m (160 ft). Hector’s dolphins display a seasonal inshore-offshore movement; favouring shallow coastal waters during spring and summer, and moving offshore into deeper waters during autumn and winter. They have also been shown to return to the same location during consecutive summers, displaying high foraging site fidelity. The inshore-offshore movement of Hector’s dolphins are thought to relate to seasonal patterns of turbidity and the inshore movements of prey species during spring and summer.
There are 2 subspecies,
South Island Hectors dolphin – Threatened, and with a decreasing population, currently thought to number around 10,000
Maui dolphin – critically endangered, population under 50.
These diverged 50,000-60,000
Below, you will see a list of articles on this subject, and below that, you will see a video on this species
Below both of these, we will add links and information (as we get it) so that you can see these dolphins if you are in the area.
Heaviside’s dolphin is one of four dolphins in the genus Cephalorhynchus. The small cetacean is endemic to the Benguela ecosystem along the southwest coast of Africa. Heaviside’s are small and stocky with adults reaching a maximum length of 1.7m and weight of75 kg. The dolphin has a distinct black, grey and white body pattern, making it hard for it to be confused with any other dolphin found in the same waters. The head is cone shaped with a blunt beak. The dorsal fin is triangular in shape and centred in the middle of the back. The head and thorax are coloured light grey with darker patches around the eye. The dorsal fin,& fluke and dorsal cape are a dark grey to almost black with a band that extends forward from the dorsal fin to the blowhole. The underbelly is white, with bands that extend onto the lower rear of the body. Small white patches are located just behind the pectoral fins and a single white patch extends between these fins on the chest. Sexual dimorphism is minimal, however variation in the shape of the white patch covering the genital slit is distinct between genders. In males, the patch ends in a point, but in females widens out to cover the mammary slits.
Information on reproduction is limited for Heaviside’s dolphins, however they are thought to be comparable to Hector’s and Commerson’s dolphins. Females and males reach sexual maturity approximately between 5–9 years. Mating is thought to occur year-round, however individual females may only produce calves every 2–4 years. Gestation time is unknown. Maximum known lifespan is based on the oldest recorded individual at 26 years old. Levels of predation are unknown, however killer whales(Orcinus orca) are known predators and there is evidence of shark attack from body scars. Heaviside’s have small home ranges of 50–80km as measured using satellite telemetry over 2–3 months and photographic resighting over up to 3 years.
Some individuals have been resighted at the same location for up to 10 years. Prior to 2018, the “International Union for Conservation of Nature” International Union for Conservation of Nature (IUCN) listed the Heaviside’s as ‘Data Deficient’ however, as of 2017 the status was changed to ‘Near Threatened’, owing to improved knowledge on the species from multiple studies. Despite this, the overall population trend remains unknown, and there are many aspects of the species biology that remain to be studied. Heaviside’s dolphin is listed on Appendix II of the “Convention on the Conservation of Migratory Species of Wild Animals” Convention on the Conservation of Migratory Species of Wild Animals Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. The Memorandum of Understanding was established in 2008 and aims to protect these species at a national, regional and global level.
Below here is a video of some of these dolphins, and below that is our usual list of articles on this species (we hope this number will increase in the near future).
Below this, we will add links for you to go and see these dolphins for yourself
The Irrawaddy dolphin is a euryhaline species of oceanic dolphin found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia. It closely resembles the Australian snubfin dolphin, which was not described as a separate species until 2005. It has a slate blue to a slate grey colour. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in Chilika Lake in Odisha, India and Songkhla Lake in southern Thailand.
One of the earliest recorded descriptions of the Irrawaddy dolphin was by Sir Richard Owen. in 1866 based on a specimen found in 1852, in the harbour of Visakhapatnam on the east coast of India.
These dolphins are thought to reach sexual maturity at seven to nine years. In the Northern Hemisphere, mating is reported from December to June. Its gestation period is 14 months; cows give birth to a single calf every two to three years. Length is about 1 m (3.3 ft) at birth. Birth weight is about 10 kg (22 lb). Weaning is after two years. Lifespan is about 30 years.
There are plenty of food items that this dolphin feeds upon. They include fish, crustaceans, and cephalopods. During foraging periods, herds of about 7 dolphins will circle around prey and trap their victim. These prey entrapments occur slightly below the water surface level.
Although sometimes called the Irrawaddy river dolphin, it is not a true river dolphin, but an oceanic dolphin that lives in brackish water near coasts, river mouths, and estuaries. It has established subpopulations in freshwater rivers, including the Ganges and the Mekong, as well as the Irrawaddy River from which it takes its name. Its range extends from the Bay of Bengal to New Guinea and the Philippines, although it does not appear to venture off shore. It is often seen in estuaries and bays in Borneo Island, with sightings from Sandakan in Sabah, Malaysia, to most parts of Brunei and Sarawak, Malaysia. A specimen was collected at Mahakam River in East Kalimantan the local name comes from it.
Presence of the species in Chinese, Taiwanese, and Hong Kong’s waters has been questioned as the reported sightings have been considered unreliable, and the easternmost of ranges along Eurasian continent is in Vietnam.
No range-wide survey has been conducted for this vulnerable species; however, the worldwide population appears to be over 7,000. In India, Irawaddy dolphins are mostly found in Chilika Lake. Known subpopulations of Irrawaddy dolphins are found in eight places, listed here in order of population, including conservation status. It is found in coastal waters of the Bay of Bengal, Sundarbans mangrove forest in the brackish-water Chilika Lake.
Conservation is hard, as this species is found in waters alongside developing nations. As such, they are working hard to food their population and give them a better life – which is generally a place where conservation is a low priority.
Of course, this can help – tourism is an increasingly large worldwide industry. As such a tourism industry, built around seeing this species could create a whole large number of extra jobs. Given the large ecotourism industry of India, it seems an easy extension to add this area.
Below this is a video of the species for your interest. Below that, is an amalgamation of any articles written on this species (we hope to add many in the future). Below that, I will add any links I make to help with you seeing the species in the wild. If you work in tourism and ever see this species, do get in touch, we would love to help people find you.