The Riverine Rabbit

IUCN Red List status: Critically endangered

This little nocturnal rabbit can only be found in the Karoo regions and is currently the most endangered mammal in South Africa. It only lives in the deep silt flood plains of seasonal Karoo rivers and can’t be found anywhere else in the world, making it incredibly vulnerable to habitat loss.

Commonly known as the vleihaas, boshaas, doekvoetjie or pondhaas, the riverine rabbit is found only in the riverine scrub of the central Karoo. The first two names arose from its occurrence in the relatively moist and dense habitat along the seasonal rivers of the area. "Doekvoetjie" refers to the broad hind paws which are furred underfoot. During the 1940s the curator of the Kaffrarian Museum offered a pound for each riverine rabbit brought to him, hence the name "pondhaas".

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IDENTIFICATION

The attractive riverine rabbit is easily identified by the black stripe running from the corner of its mouth over its cheek, a brown woolly tail, creamy fur on its belly and throat, and a broad, club-like hind foot. In the field hares can be distinguished from rabbits by their black and white tails. The tails of rabbits are usually uniformly coloured. Male riverine rabbits weigh approximately 1,5 kg and females 1,8 kg.

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HABITS AND FEEDING

Riverine rabbits feed on their favourite foods, the boegoe bush and ink bush at night, and rest up in forms during the day. A form is a shallow scrape made in the soil under a bush. Two types of droppings are produced. At night, when the rabbit is active, hard pellets are deposited. During the day droppings are soft, taken directly from the anus, and swallowed. In this way the riverine rabbit obtains vitamin B, produced by bacteria in the hind gut, and minerals such as calcium and phosphorus are recycled.

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WHY ENDANGERED?

The riverine rabbit is an endangered species, i.e. it is in danger of extinction and its survival is unlikely if the factors causing the decline remain in effect. The most devastating threat to the riverine rabbit is the loss of its habitat. This habitat is limited to the alluvial floodplains of seasonal rivers in the central Karoo. These flood plains, only 100 - 200 m wide, are formed when the rivers overflow during floods, and deposit silt on their banks. This soil is very good for cultivation compared with other soils found in the dry Karoo. Over the past 50 years over two-thirds of the riverine rabbit's habitat has been ploughed over for this purpose. Other threats to the riverine rabbit's survival include overgrazing and hunting. Overgrazing of riverine habitat opens up cover that the rabbit needs for shelter and to escape predation.

The only way to secure the long term survival of a species is to protect its natural habitat. Some Karoo farmers have declared their farms Natural Heritage Sites to protect the riverine habitat and rabbit. The Dept. of Environment and Cultural Affairs (previously Cape Nature Conservation) encourages farmers to form conservancies for the same purpose (a conservancy is a number of adjacent farms on which landowners cooperate with each other to conserve nature).

Leaving the riverine habitat intact has advantages for both the farmers and the riverine rabbit. The Karoo experiences frequent droughts. Enough rain for cultivation falls during only a few years every decade. It would be more productive in the long-term to use the riverine habitat for grazing rather than to reap the short-lived benefit of ploughing it for cultivation.

Riverine vegetation also binds the soil, preventing it from being washed away in floods and promotes filtration of rainwater to groundwater - another benefit for the farmer who uses windmills to draw up water for his livestock.

A captive breeding colony is run at the De Wildt Cheetah Research Station, outside Pretoria. Plans are afoot to reintroduce rabbits bred in this colony to suitable habitat where they no longer occur.

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DID YOU KNOW?

* The riverine rabbit is found only in the central Karoo and nowhere else in the entire world! This means that the rabbit is endemic to this area.

* South Africa has two hare species, the Cape hare and the scrub hare, and four rabbit species. These are the Natal rabbit, Smith's rabbit, Jameson's red rock rabbit, and the riverine rabbit.

* South African rabbits and hares produce 1 - 3 young per litter. The further away from the equator rabbit and hare species occur, the larger their litter sizes. For example, Alaskan snowshoe hares have seven young per litter.

* A male rabbit is called a buck and a female a doe. 

Current conservation efforts
The Endangered Wildlife Trust runs a very active riverine rabbit conservation programme that aims to conserve the biodiversity of the Karoo region. They also encourage private landowners to participate in conservation stewardship.
How you can help
Contact the EWT if you live in the Karoo and you spot riverine rabbits. The more knowledge they have about their population and distribution, the easier it gets to protect them.
Make a donation toward the Riverine Conservation Programme.
Buy a Lindt Easter bunny next year. Lindt donates a certain percentage of each bunny purchased to conserving the riverine rabbit

The BLUE CRANE

The Blue Crane (Anthropoides paradiseus) belongs to the family Gruidae and is South Africa’s national bird.
The blue crane is currently listed as vunerable in the Eskom Red Data Book of South Africa, Lesotho and Swaziland and the 2010 International Union for the Conservation of Nature and Natural Resources (IUCN) Red List.  There are many threats facing the blue crane such as poisoning, illegal trade, habitat destruction, power line collisions, active persecution by landowners and many more.
Although the blue crane faces many threats, many conservation measures have been put in place to protect the species by various conservation bodies like the South African Crane Conservation Programme of the Endangered Wildlife Trust and the Overberg Crane Group. These groups have managed to form wonderful working relationships with landowners whose property the cranes live on, their staff, as well as the general public, in an effort to protect the blue crane.

DISTRIBUTION
The blue crane is a near-endemic to South Africa with a small isolated population of about 60-80 birds occurring around the Etosha Pans in Namibia and a few isolated birds in Botswana and Swaziland.  It is the most range restricted of all the cranes in the world and is abundant in limited areas of its range, but is rare in most areas of South Africa.

Within South Africa there are three main strongholds of this population.  The first is in the Overberg/Swartland regions of the Western Cape Province, the second is the central Karoo population of the southeastern region of the Northern Cape province and the western regions of the Eastern Cape province extending into the southern regions of the Free State, while the third is situated along the eastern section of the country and includes the southern parts of Mpumalanga, the northeastern Free State and parts of KwaZulu-Natal.

Historically, blue cranes occurred mainly in the grassland biome along the eastern section of the country.  The loss of the natural grasslands in the Free State, Northern Province, Mpumalanga and KwaZulu-Natal, and the replacement of the natural vegetation with wheat and dryland pastures in the wheat producing regions of the Swartland and Overberg in the Western Cape, changed the distribution and demographics of the blue crane population.
Today the largest numbers of blue cranes can be found in the Western Cape (± 12 000 birds), with a smaller population in the Northern/Eastern Cape (± 5 000 birds) and the rest (± 5 000 birds) occurring in the remainder of its current distribution range.

HABITAT
Blue cranes are mostly independent of wetlands and this allows them to be more widespread than the other crane species within South Africa.  With regards to natural vegetation, within South Africa the species can be found in the open grasslands and the grassland/Karoo ecotone, while in Namibia it occurs in the grasslands and dwarf shrublands fringing the pans.  The species is frequently found in agricultural fields and in the Western Cape it is restricted to cereal crop fields and dryland pastures.

FEEDING HABITS
Evidence suggest that the blue crane is primarily vegetarian and eats small bulbs, seeds and roots.  They do, however, eat a variety of insects (locusts, termites, caterpillars, grasshoppers, beetles, etc.), worms, crabs, fish, frogs, reptiles, and small mammals.  The blue crane is often reported doing damage in various agricultural crops, like wheat, barley and lucern.  In most cases the birds are feeding on spilled grain.  In the Overberg, they regularly feed from feed bins set out for sheep and ostriches.  Birds feed mostly by pecking, but they do dig using their bills.

BREEDING HABITS
Blue cranes only pair with one mate (monogamous), and despite being very social animals are extremely territorial while breeding, driving any other blue cranes from the breeding territory.  They nest in summer and the laying date can be anytime between August and April. Non-breeding birds form non-breeding flocks during this period.  After the chicks have fledged, they together with the adults join the non-breeding flocks to form large over-wintering groups.

Blue cranes nest in wetlands, open grasslands, Karoo and agricultural areas, where all-round visibility is good.  The birds often return to the same area and nest in the vicinity of the previous year’s nest.  Generally the nest is a scrape in the ground with a few stones and sheep dung scraped together.  In wetlands, however, they usually nest on a pad of vegetation.

A pair of blue cranes is said to mate for life and display a wonderful courtship dance which comprises of the two individuals jumping up and down with their wings extended. The birds are mature at about three to five years of age.  They usually lay two eggs with an incubation period of 30 to 33 days and both male and female incubate the eggs. Both chicks are frequently reared with each attempt and are fed on an initial diet of insect larvae and worms. The chicks are able to fly at about three to five months. The parents are very protective of their young and will guard them aggressively.
Mortality of chicks is high during the first year and is caused by a variety of disturbances. The following breeding season, the young juveniles will join the large flocks of non-breeding birds.

MIGRATION
Blue cranes are migratory only within South Africa and only within certain regions.  Little is known about the migratory habits and published statements are often contradictory.  In the Western Cape, evidence from satellite tracking and colour ringing suggest very localised movements within this region.

MOULTING
Blue cranes are known to go through both a partial moult as well as a complete moult, when they become flightless.  On the Agulhas plains, blue cranes go through a synchronised moulting during the second half of summer.  Birds going through flightless moult form large flocks in areas where disturbance is less frequent and close to water bodies into which they can escape when threatened.

 Birds going through a complete moult tend to be skittish and move away at the first sign of disturbance.  The cranes seem to use specific sites for moulting and these sites need to be identified and conserved. The time needed to re-grow flight feathers could take up to two months.