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Airborne Cats

Home Thatch-eating caterpillars ruined roofs DDT was the cause of the deaths of cats in Borneo A “cat-drop” occurred to replenish the cat population
Tom Harrisson (left) with local villager.

The earliest reference to the cat story is a two-page description of the events leading to the cat drop written by a person, Tom Harrisson, who claims to have been personally involved with the effort (Harrisson 1965). Harrisson provides a date for the cat drop, 1959, which does not appear in any other rendition of the story. He also suggests that the cats died as an “obvious result” of eating cockroaches that had died from the insecticide sprayed to prevent malaria, although he does not mention which insecticide was used. He praises the positive effect of the anti-malaria effort but laments the consequences of the rat infestation resulting from the loss of the cats, especially in the “Kelabit highlands”, an upland area of Sarawak.

In his explanation of the cat drop, Harrison relates that new cats were collected in coastal towns by the WHO, placed in “parachute-borne containers bulging with cats of every degree of age and rage” and dropped in “the interior uplands” with help from the Royal Air Force (RAF) flying out of Kuching. In another publication of his (Harrison 1959b), which describes conditions in Borneo twelve years after World War II, he mentions that the North Borneo government “pioneered the use of supply drops for out-stations and field parties” and that these drops were used “with effect for the World Health Organization” in Sarawak. An example of this is given in the report by de Zulueta and LaChance (1956) who describe an air-drop to replenish their stock of DDT (of all things) by the RAF in 1954. Further verification of air drops over Borneo is given in an Internet site dedicated to a RAF supply-transport airplane (the “Blackburn Beverley”) used for these efforts (Stubbs 2007). The author of the website mentions the creation of special cages to parachute “live chickens and even cats to alleviate rat problems in jungle forts” from the transport plane.

The longhouse at Bario, Sarawak in 1959 (Harrisson, 1959)

During World War II, Harrisson led a guerilla operation in which he and a squad of commandoes dropped into a remote area near Bario, Sarawak, and convinced the local tribesmen to start killing Japanese soldiers occupying the island (Harrisson 1959a; Heimann 1998). He lived in Borneo after the war as curator of the Museum of Sarawak. However, he was also a bit of a maverick with regards to his scholarly activities and readily alienated others. His obituary (Anonymous 1976) states that “his publications were the petrol-pumps that refueled his ego”, and “that sometimes his intuition tempted him to make dangerous imaginative leaps”. His biography is titled “The Most Offending Soul Alive” (Heimann 1998) which further implies an irascible nature and doubts as to the veracity of his story. However, Harrisson’s version of the cat story is referenced by Gordon Conway (1972) in which Conway relates both aspects of the cat story (moths and cats). Conway also provides an account of the incident involving the geckos in the cat story, which he states occurred in Sabah rather than Sarawak. As Conway states (without reference), “like the cockroaches, they too are frequently eaten by cats and thus can pass on the accumulated DDT”. Conway also states that, in Sabah, cats were collected in towns and transported to upland areas (presumably via roadways), but does not indicate who collected the cats.
A page from the RAF 'Operations Record Book' showing 20 cats dropped by parachute on 13-Mar-1960
The most dramatic proof for a cat drop is provided in the “Operations Record Book” kept by the RAF (Royal Air Force 1960). The report describes that on March 13, 1960, a crew in a Beverley transport plane flew out of Changi, Singapore and “carried out a unique drop to Bario in the Kelabit Highlands in Sarawak”. The items dropped were also mentioned; a total of “7000 pounds of stores” including “over 20 cats to wage war on rats which were threatening crops”. The report goes on to state that a reply was received from a person on the ground who thanked the RAF and the “cat donors and cat basket makers”, and that “all cats safe and much appreciated.” In addition to his association with Bario during World War II, Harrisson (1959b) returned there during the 1950’s to help build an airstrip. Given this location for the cat drop, it is most probable that the insecticide used in this area was DDT since it was not was not in the “First Division” of Sarawak where dieldrin was used (the First Division was in the area near the capital of Sarawak, Kuching).

However, Harrisson’s is not the only version of events in Bario at the time of the cat drop. Harrisson’s biographer, Judith Heimann (1998) states that another person besides Harrisson also came up with the idea of a cat drop in Bario. Heimann had located the transcript of a wireless message to Borneo Airways from Harrisson requesting a plane to carry the collected cats and fly Harrisson out of Bario after their delivery, but a plane was not available for landing in Bario’s short airstrip. Heimann then states that a District Officer, Malcolm McSporran, in Bario rebuilding the airstrip, related to her that he (independently) arranged with the RAF to drop cats along with materials for the airstrip. McSporran explained that that the cats used for the drop were collected in Kuching by members of the fire department which suggests the WHO was never involved in any aspect of the cat drop that occurred in Bario. This version of the story also explains the “7000 pounds of stores” dropped with the cats (Royal Air Force 1960) as those needed for the airstrip. Heimann also brings up another element of the cat story not reported elsewhere – the lack of cockroaches from the insecticide spraying caused a proliferation of bed bugs in the longhouses. McSporran’s account of events in Bario related to the cat drop is also detailed in a book by Alastair Morrison (1993). Interestingly, Morrison does not connect the increase in rats with a loss of cats from insecticide spraying even though he describes the anti-malaria campaign in the region and credits de Zulueta, “a most hard working Columbian” for leading the effort in Sarawak. Furthermore, Morrison claims to have discovered the “true background to the cat drop” – McSporran’s request for cats came as a consequence of a rat having eaten a hole in his pillow while he slept to remove the contents for a nest lining.

A final note: A short article in the Quarterly News of the Association of Former WHO Staff of April-June, 2005 mentions that the WHO library staff receives many queries about the cat story and “library staff wondered whether cats had been really parachuted over Borneo.” If the library staff does not know of a report, then it is very likely the WHO never published a report implicating their involvement in the cat drop.


  • [Anonymous.] 1976. Obituary, Tom Harrisson, O.B.E., D. D.O. Rain 13(2):2-3.
  • Conway GR.1972. Ecological aspects of pest control in Malaysia. In: The Record of the Conference on the Ecological Aspects of International Development, (Farrar MT, Milton JP eds.) Washington University, December 8-11, 1968, The Natural History Press, Garden City.
  • de Zulueta J, LaChance F. 1956. A malaria-control experiment in the interior of Borneo. Bulletin of the World Health Organization. 15:673-693.
  • Harrisson T. 1959a. World Within: A Borneo Story. London: The Cresset Press.
  • Harrisson T. 1959b. Innermost Borneo: Ten Years’ Exploration and Research. The Geographical Journal 125 (3/4):299-311.
  • Harrisson T. 1965. Operation cat drop. Animals 5:512-513.
  • Heimann JM. 1998. The Most Offending Soul Alive: Tom Harrisson and His Remarkable Life. Honolulu, Hawaii: University of Hawaii Press.
  • Morrison A. 1993. Fair Land Sarawak: Some Reflections of an Expatriate Official. Ithaca, New York: Cornell Southeast Asia Program.
  • Royal Air Force. 1960. Operations Record Book. Report of Beverley Flight of 48th Squadron, March 1960, Changi, Singapore. Compiled by Fg. Off. Humphrey.
  • Stubbs PW. 2007. The Beverley Association. Available: http://www.beverley-association.org.uk/despatch/despatch.htm [accessed 2 April 2007].
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