Earthwatch Resume in Kenya from April 1st 2008
Mothering Sunday comes around once a year, but out there in the animal kingdom, various species, from the meerkat to African elephant, have their own special ways of bringing up baby.
Meerkat (Suricata suricatta)
Status: Lower Risk - Near threatened (IUCN Red List of Threatened Species)
Meerkats are highly social relatives of mongooses, living in groups of up to 30 individuals. In each group, most of the breeding is carried out by a dominant female who produces up to four litters each year.
After a gestation period of 11 weeks, the dominant female gives birth to between one and eight pups in a grass-lined burrow. The pups are born with their eyes and ears sealed closed. They are entirely dependent on their mother during the first few days of life and are unable to defecate or urinate unless the mother licks them to stimulate this behaviour.
Non-breeding adults ‘baby-sit' the young, even if they are not related to them, in the burrow, often for an entire day, during which time the non-breeding adults forego feeding. Female helpers also sometime lactate, and suckle the pups, even though they are not theirs.
On the Meerkats of the Kalahari expedition, Earthwatch volunteers work alongside renowned zoologist Professor Timothy Clutton-Brock from the University of Cambridge and Professor Marta Manser from the University of Zurich, to investigate the causes and consequences of cooperative breeding in these highly charismatic mammals. Volunteers also take part in a range of biodiversity and conservation tasks.
Sea otter (Enhydra lutris)
Status: Endangered (IUCN Red List of Threatened Species)
The sea otter is the smallest marine mammal, coming to shore infrequently and superbly adapted to a marine way of life. It lives, eats, mates and sleeps at sea, typically among kelp beds; individuals have been seen to wrap kelp fronds around themselves to form an anchor when they go to sleep.
Females occasionally give birth on rocks at the shore, but they take their pups out to sea as soon as possible.
Unlike other marine mammals, sea otters do not have blubber to keep warm, but their dense fur keeps them warm. In fact, sea otter fur is the densest of all mammal fur, with up to 150,000 hairs per square centimetre. Regular grooming is essential in distributing the natural oils that keep the fur waterproof and to introduce air into the fur to provide insulating properties. When the sea otter pups are too small to groom themselves, their mother floats around on her back carrying her pup on her belly to keep it as dry as possible. The mother will meticulously groom her pup to ensure it is warm, dry and buoyant. While they are young the mother will leave her offspring on the surface of the water when she goes foraging, but later on the pup follows her and learns to swim and hunt. Pups remain with their mother for up to eight months.
This charismatic species suffered from extensive over-hunting for its pelt and was wiped out from most of its historical range as a result. By 1900 the species was almost extinct. In 1911 an international treaty banned sea otter hunting and although numbers began to increase, populations have never recovered to pre-hunting levels. Today the sea otter remains a highly endangered species and is threatened by oil spills, entanglement in fishing gear, lack of food and an increase in predation.
Join Drs. Daniela Maldini and Thomas Jefferson on the Marine Mammals of Monterey expedition to monitor sea otters and dolphins in the wild in Monterey Bay, California, and help collect valuable information to inform the conservation management of the bay.
Koala (Phascolarctos cinereus)
Status: Lower Risk - Near threatened (IUCN Red List of Threatened Species)
Female koalas usually give birth to just one young, known as a joey, every year after a gestation period of just 25 to 35 days. Like all marsupials, the young are born at an undeveloped stage compared to placental mammals. The tiny baby, which weighs just 0.5 grams, crawls into the mother's pouch and attaches to a nipple. It then remains inside the pouch for about six months as it completes its development. When it outgrows the pouch, the mother carries the joey around on her back. During weaning, the joey starts to feed on special faeces produced by its mother, which introduces the special symbiotic gut bacteria required to digest the eucalyptus leaves which will form most of its adult diet. The young koala remains with its mother until her next baby outgrows the pouch.
Volunteers joining Drs. Alistair Melzer and William Ellis on the Earthwatch expedition Koala Ecology help these koala experts gather data to try to understand why the koalas are faring so well on St Bees Island, when in most parts of their range they are undergoing a serious decline.
Kangaroo-Island echidna (Tachyglossus aculeatus multiaculeatus)
Status: Lower Risk - Near Threatened (IUCN Red List of Threatened Species)
Short-beaked echidnas are one of just three surviving species of monotremes, or egg-laying mammals. Along with their relatives the long-beaked echidna and the platypus, they are the oldest species of mammals.
Short-beaked echidnas are highly secretive and the many volunteers who have taken part in the long-running Earthwatch expedition Echidnas and Goanas of Kangaroo Island have helped to shed light on the reproductive behaviour, ecology and population dynamics of this elusive species. Dr. Peggy Rismiller has been researching the ecology and life histories of individual echidnas on Kangaroo Island with Earthwatch volunteers since 1991.
Eight years of Earthwatch volunteer-gathered data revealed that female echidnas mate and produce one egg every three to five years. It took 14 years of Earthwatch data to discover that females reach sexual maturity at 5-12 years of age. Around three weeks after mating, females lay one leathery egg directly into a temporary pouch, which is incubated inside the pouch for a further 10 days. Female echidnas do not have teats; instead, milk is secreted from pores at the base of ‘mammary hairs' in two milk patches. When a young echidna starts to develop its spine (modified hairs) at around 50 days old, the mother digs a special nursery burrow to put it in and returns every five days to suckle it. The young echidna remains fully dependent on its mother for seven months.
Dr. Rismiller's research also includes the Rosenberg's goanna, a large monitor lizard that shares the echidna's habitat and dines on young echidnas. Her work is continuing to shed light on the fascinating biology of these species and how to help protect the delicate balance of this island ecosystem.
African elephant (Loxodonta africana)
Status: Vulnerable (IUCN Red List of Threatened Species)
Following an exceptionally long gestation period of almost two years, a female gives birth to a well-developed calf. Just a short time after birth the calf is able to see and walk. Young females assist the mother with care of the calf; these ‘allomothers' as they are known, sometimes even suckle calves that are not their own. The young elephant remains dependent on its mother and allomothers for several years.
If threatened, the herd forms a protective circle around the young elephants in the group.
Young female elephants stay within the group they were born into, but males disperse once they reach maturity. A number of Earthwatch expeditions provide volunteers with opportunities to observe and study African elephants in the wild:
For press information please contact Zoe Gamble, + 44 (0) 1865 318852 / zgamble@earthwatch.org.uk
Editors Notes