Zoo InternQuest is a seven-week career exploration program for San Diego County high school juniors and seniors. Students have the unique opportunity to meet professionals working for the San Diego Zoo, Safari Park, and Institute for Conservation Research, learn about jobs, and then blog about their experience online. Follow their adventure here!
This week we met Dr. Tom Jensen, a Scientist in the Reproductive Physiology Division at the San Diego Zoo Institute for Conservation Research. I learned that Dr. Jensen and I share a passion for the kiwi. The kiwi has long been a favorite bird species of mine. I was fascinated with all of the ways that Dr. Jensen and his team are utilizing “cutting edge” technologies to help kiwi reproduction.
Dr. Jensen’s current project is a process to use testicular stem cells of a deceased male bird to manufacture male kiwi sperm for artificial insemination. There are many potential good outcomes from this project: it would increase the reproductive life of a male beyond death, limit transportation problems of moving endangered species, and remove many of the problems captive breeding programs experience. Birds in captivity have trouble in adjusting to their new environments, mating problems due to seasonal differences in the Northern and Southern hemispheres, and compatibility between some males and females.
The kiwi has been around for about 25 million years and until the late 1800’s was a successful species. Populations have been affected and are decreasing since human settlers arrived in New Zealand. The reasons for the decline in the kiwi are: human introduction of non-native mammals (cats, dogs, stoats), cars hitting them, and habitat loss. The kiwi evolved in a mammal free environment; therefore it never developed avoidance behaviors for predatory mammals like cats. The kiwi’s only natural predators (most of which are extinct) were aerial, therefore its instincts are to freeze when it senses a threat. The behavior of freezing in place makes the kiwi a prime target for predatory mammals.
The kiwi is a flightless bird, about the size of chicken that is native to New Zealand. The kiwi’s home is a burrow, on forest floors and grasslands habitats. It forges for its food in the leaf litter, eating: worms, grubs, fruit, and seeds. The kiwi’s nostrils are at the tip of its unique beak, which it uses as a tool in during foraging. It has a well-developed sense of smell and hearing. Kiwis are also nocturnal.
Kiwis are found primarily on the two main islands of New Zealand, but also have a presence on some of the smaller islands. The conservation status of the four to five sub species varies from: near threatened, vulnerable, endangered and critically endangered. The IUCN (International Union for the Conservation of Nature) recognizes four species; whereas the country of New Zealand has five classified. The brown kiwi has a population of about 20,000, with signs of a decrease. The South Island brown kiwi numbers only about 20,000 – 30,000 (also decreasing). The little spotted kiwi has a stable but small population of about 1500 – 2000 birds. The population is stable because they live on about five islands that are mammal free. There are about 10,000 in the population of the great spotted kiwi and its numbers are decreasing as well. The fifth species is the rowi, currently the rowi numbers are combined with the South Island brown kiwi by IUCN. The belief is that, as soon as the paper work is complete, the rowi will be a separate species numbering about 250, and considered critically endangered.
With populations of the kiwi declining and a survival rate of only 5% of the chicks each year, it is encouraging to know that the kiwi population is getting help. I hope Dr. Jensen is successful with his new process; it is a fantastic way to work on increasing the kiwi population without taking individuals from the wild.
Colton, Wildlife Conservancy Corner
Fall 2012, week six