Category: Kenya

Indo-pacific bottlenose dolphin

Indo-Pacific Bottlenose dolphin

The Indo-Pacific bottlenose dolphin is a species of Bottlenose dolphin. This dolphin grows to 2.6 m long, and weighs up to 230 kg . It lives in the waters around northern Australia , South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its underside is lighter grey or nearly white with grey spots. The Indo-Pacific bottlenose dolphin is usually smaller than the Common bottlenose dolphin, has a proportionately longer Rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as “near threatened” in their Red List of endangered species.

Until 1998, all bottlenose dolphins were considered members of the single species Tursiops truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. Both species are thought to have split during the mid-Pleistocene, about 1 million years ago. Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the Delphinus (genus), especially the “Atlantic spotted dolphin”, than it is to the common bottlenose dolphin. However, more recent studies indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella and ancestral Tursiops and incomplete lineage sorting, and thus support truncatus and T. aduncus belonging to the same genus. Burrunan dolphin T. (aduncus) australis has been alternately considered its own species, a subspecies of T. truncatus, or a subspecies of T. aduncus. Following the results of a 2020 study, the American Society of Mammologists presently classifies it as a subspecies of T. aduncus. The same study delineated 3 distinct lineages within T. aduncus which could each be their own subspecies: an Indian Ocean lineage, an Australasian lineage, and the Burrunan dolphin. The Society for Marine Mammalogy does not recognize the Burrunan dolphin as a distinct species or subspecies, citing the need for further research. Indo-Pacific bottlenose dolphins are very similar to common bottlenose dolphins in appearance. Common bottlenose dolphins have a reasonably strong body, moderate-length beak, and tall, curved dorsal fins; whereas Indo-Pacific bottlenose dolphins have a more slender body build and their beak is longer and more slender. 

Indo-Pacific bottlenose dolphins feed on a wide variety of fish Cephalopod, Squid, researchers looked at the feeding ecology of Indo-Pacific bottlenose dolphins by analysing the stomach contents of ones that got caught in the gillnet fisheries off Zanzibar, Tanzania.  Indo-Pacific bottlenose dolphins live in groups that can number in the hundreds, but groups of five to 15 dolphins are most common. 

In some parts of their range, they spend time with the common bottlenose dolphin and other dolphin species, such as the humpback dolphin. The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions. Gestation period is about 12 months. Calves are between 0.84 and 1.5 Meters, and weigh between 9 and 21kg. The calves are weaned between 1.5 and 2.0 years, but can remain with their mothers for up to 5 years, some mothers will give birth again, shortly before the 5 years are up. 

In some parts of its range, this dolphin is subject to predation by sharks. 

Its lifespan is more than 40 years. Indo-Pacific bottlenose dolphins located in Shark Bay, Australia, have been observed using sponges as tools in a practice called “sponging”. A dolphin breaks a marine sponge off the sea floor and wears it over its rostrum, apparently to probe substrates for fish, possibly as a tool. Spontaneous ejaculation in an aquatic mammal was recorded in a wild Indo-Pacific bottlenose dolphin near Mikura Island, Japan, in 2012. Indo-Pacific bottlenose dolphins have been observed to swim near and rub themselves against specific types of corals and sponges. A team of scientists followed up on this behaviour and discovered metabolites with antibacterial, antioxidative, and hormonal activities in the corals and sponges, suggesting that they might be used by the dolphins to treat skin infections. its near-shore distribution, though, makes it vulnerable to environmental degradation, direct exploitation, and problems associated with local fisheries. 

The major predators of this species are typically sharks, and may include humans, killer whales, and sting rays. In the early 1980s, many were deliberately killed in a Taiwanese driftnet fishery in the Arafura Sea, off north western Australia. Large-mesh nets set to protect bathers from sharks in South Africa and Australia have also resulted in a substantial number of deaths. Gillnets are also having an impact, and are a problem throughout most of the species’ range.

These small cetaceans are commonly found in captivity, causing conservation concerns, including the effects of removing the animals from their wild populations, survival of cetaceans during capture and transport and while in captivity, and the risks to wild populations and ecosystems of accidentally introducing alien species and spreading epizootic diseases, especially when animals have been transported over long distances and are held in sea pens.

Bottlenose dolphins are the most common captive cetaceans on a global scale. Prior to 1980, more than 1,500 bottlenose dolphins were collected from the United States, Mexico, and the Bahamas, and more than 550 common and 60 Indo-Pacific bottlenose dolphins were brought into captivity in Japan. By the late 1980s, the United States stopped collecting bottlenose dolphins and the number of captive-born animals in North American aquaria has increased from only 6% in 1976 to about 44% in 1996. South Korea, in the 2010s, environmental groups and animal protection groups led a campaign ko:2013 to release southern bottlenose dolphins illegally captured by fishermen and trapped in Jeju Island.

In a study on three populations of Indo-Pacific bottlenose dolphins in Japan, the characteristics of acoustic signals are believed to be affected by the acoustic environments among habitats, and geographical variation in animal acoustic signals can result from differences in acoustic environments; therefore, the characteristics of the ambient noise in the dolphins’ habitats and the whistles produced were compared. Ambient noise was recorded using a hydrophone located 10 m below the surface and whistles were recorded by using an underwater video system. The results showed dolphins produced whistles at varying frequencies with greater modulations when in habitats with less ambient noise, whereas habitats with greater ambient noise seem to cause dolphins to produce whistles of lower frequencies and fewer frequency modulations. Examination of the results suggest communication signals are adaptive and are selected to avoid the masking of signals and the decrease of higher-frequency signals. They concluded ambient noise has the potential to drive the variation in whistles of Indo-Pacific bottlenose dolphin populations.

Small, motorized vessels have increased as a source of anthropogenic noise due to the rise in popularity of wildlife viewing such as whale watching. Another study showed powerboat approaches within 100 m altered the dolphin surface behaviour from traveling to milling, and changed their direction to travel away from the powerboat. When the powerboat left the area and its noise ceased, the dolphins returned to their preceding behaviour in the original direction.

In Shark Bay, Western Australia, on dolphin behavioural responses showed significant changes in the behaviour of targeted dolphins were found when compared with their behaviour before and after approaches by small watercraft. Dolphins in the low-traffic site showed a stronger and longer-lasting response than dolphins in the high-traffic site. These results are believed to show habituation of the dolphins to the vessels in a region of long-term vessel traffic. However, when compared to other studies in the same area, moderated responses, rather, were suggested to be because those individuals sensitive to vessel disturbance left the region before their study began. Although these studies do show statistical significance for the effects of whale-watching boats on behaviour, what these results mean for long-term population viability is not known. The Shark Bay population has been forecast to be relatively stable with little variation in mortality over time. The Indo-Pacific bottlenose dolphin populations of the Arafura and the Timor Sea are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals “Bonn Convention”. They are listed on Appendix II as they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. The Indo-Pacific bottlenose dolphin is also covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region Adelaide Dolphin Sanctuary “Marine protected area”  in the Australian state of South Australia Gulf St Vincent, which was established in 2005 for the protection of a resident population of Indo-Pacific bottlenose dolphins.

When we have links for viewing these species, they will appear below video and the news section

Common Hippopotamus

Common Hippopotamus

Hippopotamus are a fascinating animal. Large, highly aggressive, and spending most of their days in water. For many people, their memory of a Hippopotamus on safari (or in a zoo) is a pond with a grey bump in the middle. But there is far more to a hippopotamus than meets the eyes. Duromg the night, Hippo leave the safety of the water and go into the bush to graze.

They are incredibly dangerous, and there is a far higher risk for people wandering in the bush to be killed by hippo than anything else. In the past, they were one of the few species that still lived in significant numbers outside reserves. Unfortunately, as the human population of Africa has grown, the majority of these free roaming Hippo have been killed – for an African living on a tiny income, a hippo is a huge pile of meat, which can be sold, and some of its teeth are made of ivory.

A rough estimate suggests that the meat is worth around 8000. When you add in the Ivory teeth, it is possible for a Hippo carcass to be worth a years average salary (and that is the mean salary). 85% of Africans survive on $5.50 per day, which works out at almost exactly $2000 – so for 85% of Africans, a hippo carcass is worth 4 years of salary – assuming that you do not make much money from the ivory, and it would not be surprising if this added significantly.

When you look at these numbers, it is not surprising that people poach Hippos -and it makes it very hard to work out how to save them.

Of course, Hippo can be worth far more in tourism dollars over their lifespan.

Common hippopotamus are possible to see in all the Savannahs that we have listed so far. Visit wild places to see the total list.

Below is links to some of the biggest (though as I say, hippo can often be seen in small reserves and in places outside reserves as well. All our savannah wild places have sizable populations of common hippopotamus.

Limpopo transfrontier
Okavango delta (part of KAZA transfrontier park)
Kenya – Massai mara migration

Black Rhino

Black Rhino

So the black rhino is one of the two rhino species that survive in Africa. Their last common ancestor was around 6 million years ago  (in comparison the Javan and Indian rhino split just 2 million years ago). Being browsers, not grazers, they are far harder to see, as they spend their time deep in the bush, far from the open plains where white rhino are discovered.

Being solitary, they are also generally found at far lower densities than white rhinos. having said this, in many reserves this is as much as a result of poaching as of a low natural density. Having spent some time based around the Kruger, we have encountered White rhino a huge number of times, but black rhino have eluded us, though their dropping have been encountered on a few occasions.

The black rhino is a younger species than the white rhino having evolved from it, 4-5 million years ago.

They both have 2 horns, made of keratin, the same as our fingernails, with the front one being longer than the back one. The front horn has an average length of 50cm, though this is not a set thing. Plenty of black rhino have been measured with a horn 135cm long, and the world record was a horn 150cm long.

Regions of their range have been lost at various times, though in recent times, there has been an effort to turn back time In May 2017, 18 eastern black rhinos were translocated from South Africa to the Akagera National Park in Rwanda. The park had around 50 rhinos in the 1970s but had lost them all by 2007. In September 2017 18 were reintroduced, and 1 has been born since. The park employs a team to protect the rhinos and so far this has worked. In October 2017, This transfer took place in 2018. The governments of Chad and South Africa reached an agreement in October 2017,  to transfer six black rhinos from South Africa to Zakouma National Park in Chad; this was complete by May 2018. Once established, this will be the northernmost population of the species. The species was wiped out from Chad in the 1970s and is under severe pressure from poaching in South Africa. The agreement calls for South African experts to assess the habitat, local management capabilities, security and the infrastructure before the transfer can take place.

Historically there have been a wide range of subspecies suggested for this species: The most accepted position considers seven or eight subspecies, of which three became extinct in historical times and one is on the brink of extinction. I have listed all these below

  • Southern black rhinoceros also known as Cape black rhinoceros (D. b. bicornis) – Extinct. Once abundant from the Cape of Good Hope to Transvaal, South Africa and probably into the south of Namibia, this was the largest subspecies. It became extinct due to excessive hunting and habitat destruction around 1850.
  • North-eastern black rhinoceros (D. b. brucii) – Extinct. Formerly central Sudan, Eritrea, northern and south-eastern Ethiopia, Djibouti and northern and south-eastern Somalia. Relict populations in northern Somalia vanished during the early 20th century.
  • Western black rhinoceros (D. b. longipes) – Extinct. Once lived in South Sudan, northern Central African Republic, southern Chad, northern Cameroon, north-eastern Nigeria and south-eastern Niger. The range possibly stretched west to the Niger River in western Niger, though this is unconfirmed. The evidence from Liberia and Burkina Faso mainly rests upon the existence of indigenous names for the rhinoceros. A far greater former range in West Africa as proposed earlier is doubted by a 2004 study. The last known wild specimens lived in northern Cameroon. In 2006 an intensive survey across its putative range in Cameroon failed to locate any, leading to fears that it was extinct in the wild. On 10 November 2011 the IUCN declared the western black rhinoceros extinct.
  • Chobe black rhinoceros (D. b. chobiensis) – A local subspecies restricted to the Chobe Valley in southeastern Angola, Namibia (Zambezi Region) and northern Botswana. Nearly extinct, possibly only one surviving specimen in Botswana.
  • Uganda black rhinoceros (D. b. ladoensis) – Former distribution from South Sudan, across Uganda into western Kenya and south-westernmost Ethiopia. Black rhinos are considered extinct across most of this area and its conservational status is unclear. Probably surviving in Kenyan reserves.
  • Eastern black rhinoceros (D. b. michaeli) – Had a historical distribution from South Sudan, Uganda, Ethiopia, down through Kenya into north-central Tanzania. Today, its range is limited primarily to Kenya and Tanzania.
  • South-central black rhinoceros (D. b. minor) – Most widely distributed subspecies, characterised by a compact body, proportionally large head and prominent skin-folds. Ranged from north-eastern South Africa (KwaZulu-Natal) to north-eastern Tanzania and south-eastern Kenya. Preserved in reserves throughout most of its former range but probably extinct in eastern Angola, southern Democratic Republic of Congo and possibly Mozambique. Extinct but reintroduced in Malawi, Botswana, and Zambia. It also ranges in parts of Namibia and inhabit national parks in South Africa.
  • South-western black rhinoceros (D. b. occidentalis) – A small subspecies, adapted to survival in desert and semi-desert conditions. Originally distributed in north-western Namibia and southwestern Angola, today restricted to wildlife reserves in Namibia with sporadic sightings in Angola. These populations are often referred to D. b. bicornis or D. b. minor, but some experts consider them a subspecies in their own right.

The most widely adopted alternative scheme only recognizes five subspecies or “eco-types”: D. b. bicornis, D. b. brucii, D. b. longipes, D. b. michaeli, and D. b. minor. This concept is also used by the  IUCN, listing three surviving subspecies and recognizing D. b. brucii and D. b. longipes as extinct. The most important difference to the above scheme is the inclusion of the extant southwestern subspecies from Namibia in D. b. bicornis instead of in its own subspecies, whereupon the nominal subspecies is considered extant.

Note:  to look at the rest of the rhino family click here

Seeing Black rhino is hard, but they are in most African reserves that we list

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