Tuesday October 3, 2006
Too warm for polar bears
Adapted to cold environments, two polar bears were hardly prepared for the ‘warm hospitality’ at Singapore Zoo, HILARY CHIEW reports.
VISITORS to Singapore Zoo might think the polar bears (Ursus maritimus) in the glass-fronted enclosure are luxuriating in the cold pool water but in fact, the Arctic creatures are suffering from overheating.
A four-month investigation by an animal welfare group found sub-standard living environment that provides only a tiny part of a polar bear’s natural home range. The nomadic bear home range in the wild can reach 80,289 sq km but the zoo’s outdoor enclosure is a mere 391sq m.
In the report What’s a polar bear doing in the tropic? released early this month, Animal Concerns Research and Education Society (Acres) found, in its undercover work between September and December last year, mother bear, Sheba and her male offspring Inuka, exhibiting signs of severe heat stress. Both bears constantly pant, in efforts to cool down.
The bears pace and swim aimlessly, behaviour which indicates abnormal animal-environment interaction and a sign of psychological disorder. The bears also displayed high levels of inactivity, which researchers attributed to the environment failing to satisfy their natural inquisitiveness.
Long regarded as the par excellence zoological park in this region, Singapore Zoo acquired Sheba in 1978 from the Cologne Zoo in Germany when it was a two-year-old cub. Born in 1990, Inuka was sired by Nanook, which died in 1995.
The zoo, which attracts an annual 1.3 million visitors, claims in its website that it is successful not just in keeping polar bears but in breeding a male cub, the first in the tropics, because the enclosure has an air-conditioned den, a separate den for rearing cubs and a 3.5m deep pool for the bears to cool off.
Live fish are released into the pool to simulate wild conditions for the bears to go ”fishing” while meat and fruits are hidden in ice blocks for the bears to discover.
The zoo says “as a physiological reaction to the warm climate, our polar bears have a thinner coat and they moult more often than their counterparts in cold countries”.
However, the Acres investigation found the enclosure environment wanting. Report authors Ann Corrigan and Louis Ng say the pool temperature at 17°C is not cold enough as Arctic sea temperature remains around -20°C year round. Any temperature above freezing is warm to a polar bear, which is physiologically built to retain its body heat. In fact, they will experience heat stress at an ambient temperature of 21.1°C. At the outdoor enclosure, Inuka and Sheba spend almost a quarter of the time lying spread-eagle in order to cool down. Acres found the indoor air-conditioned dens to be too small for the bears to rest comfortably.
Although neither bear has experienced Arctic conditions, this does not mean that they have adapted to the warm climate of Singapore. The report says the bears still possess all the physiological adaptations to life in the Arctic, contrary to claims by the zoo.
“Even if they lose some fur and blubber, they will always have black skin that absorbs heat.” In fact, the ”thinner coat” is an exhibition of substantial fur loss and together with massive loss of lean muscle mass, are obvious physical signs of distress.
It also noted the occasional algae growth on the bears’ hair shaft, which gives them an appearance of green fur. This indicates that the pelt is constantly hot and damp.
The outdated concrete substrate and the limited ground space in the enclosure provide minimal stimuli to a species that forages, digs and builds day nest in the wild. The enclosures, the report concludes, do not meet many of the guidelines set by zoo associations and animal welfare organisations.
The report notes that studies have shown polar bears to be poor candidates for captivity even in the best circumstances, because they are extremely wide-ranging, cold weather carnivores that travel up to 80km or more in a day.
Progressive zoos in Britain, Switzerland and Germany are phasing out polar bears on welfare grounds. The polar bear specialist group of the World Conservation Union (IUCN) does not advocate captive breeding of polar bears.
The report also questions the educational benefits of the daily ”token feeding” shows, which it found to promote unnatural animal behaviour and reinforces the outdated idea that zoo animals are for human amusement. Highlights of the show include Sheba ”waving” and Inuka ”belly dancing” and ”clapping” before they are rewarded with food.
Since 2004, Acres has been in discussions with the zoo, calling for improvements to the bears’ living conditions. The majority of the recommendations were not implemented, including providing full air-conditioning (like for the penguins) and soft substrates for the bears to construct day beds, chilling the pool water and modification to feeding methods.
For the long term, Acres recommends relocating the bears since they cannot be released to the wild. However, Sheba is old and may not survive the relocation journey.
Acres suggests that once Sheba passes away, Inuka be relocated to a facility with more appropriate climate like in Canada, to give it a better quality of life. It also urges the zoo to end importation of Arctic animals.
In a press release announcing the launch of the report, Acres says it is pleased that the zoo agreed to the long-term solutions after it was presented with the findings in June.
Singapore Zoo has declined to comment on the Acres report.