A feline partiality for kiwifruit

Press, 12 September 1987, Page 26

A feline partiality for kiwifruit

Country Diary

Derrick Rooney

i More about kiwifruit — and • cats.

i Dr Warwick Harris, of the - D.5.1.R., reports that while tidying his garden at Lincoln recently he accidentally cut the ;roots of a young kiwifruit plant. ,< "This immediately attracted -our aged cat, who rubbed the 'vine, and picked up and tried to chew the roots. A little while ' later she went a short distance started to convulse violently, and retched, much as cats S»do after they have eaten grass as jjan emetic. I took some photographs to record these observa-*-tions,” says Dr Harris. £ Dr Harris is one of a number &of gardeners who have noticed £ similar reactions by felines to x; kiwifruit plants, and as he res'marks in a note, the responses t>have been documented in China r’and elsewhere. The cause is a J group of volatile compounds found in plants belonging to the genus Actinidia. i& There seem to have been no r systematic studies of the Actini'dia response done in New Zea- " land, but a search of the scientific literature by Dr Jay Mann, a biochemist ■at Lincoln, has revealed that, in Japan researchers have studied an ornamental species “d sevfrom Jt. Onevj called -phenethji. is a ■V r

rose-scented alcohol which is also a constituent of roses and many other essential aromatic oils derived from plants. Another, named matatabi-lactone by the Japanese, has been the subject of some confusion but is now known to be a mixture of five materials, including one related to those contained in the catnip plant, that well-known opiate of felines. The Japanese scientist re-

ported that the aromatic compounds were found in both the leaves and fruit of Actinidia plants, and that they attracted, not only cats but also dogs, lions, tigers, leopards and black leopards. Dogs have subsequently been eliminated from the list and according to Dr Mann some other results of the Japanese studies are questionable. Some of the laboratory work, he says, involved putting drops of the extracts on the tongues of animats. “This is meaningless because the attraction is the smell, not the taste,” says Dr Mann. Nevertheless, there remains Dlentv of evidence that plants of the Actinidia family have a strong attraction for cats, though possibly only when they are cut or bruised, thus releasing the scent There might be a practical use for this. Dr Harris mentioned, for example, the possibility of using a kiwifruit attractant to lure feral cats out of areas where they threaten native birds. I asked Mr Ron Nelson, of th£

Department of Conservation, about this. "Certainly we’re interested in the possibility,” he said. Unfortunately, however, in these days of user pays the possible exploitation of kiwifruit extracts —or similar attractants — against feral cats counts as pure research, and is well down the priority list when projects are being funded. So wild cats are safe enough for the present, An item of secondary information from the Japanese study widens the possible use of kiwifruit compounds, and prompts biological speculation. Apparently one of the compounds was found to attract lacewings, which are predatore of aphids. The inference is that this is a natural defence mechanism of the plant against damage by insect pests. These compounds may therefore have potential for use in horticulture. Does this mean that the pruntags from New Zealand’s millions of kiwifruit vines will one day be rendered down into a safe, nontoxic, and non-polluting aid to

natural biological control of insect pests in other crops? Only if someone puts up the money. And probably not even then. As Dr Mann points out, it would probably be as easy, and cheaper, to synthesise the compounds in a laboratory. New Zealand, incidentally, is not the only country where mere gardeners have noticed the attraction that cultivated kiwifruit vines have for cats. The “Sunset Garden Book,” published in California, lists several Actinidia species for ornamental planting, with a note that all must be protected against cats. Intriguing possibilities for cooperation between New Zealand and southern South America — two regions with similarly ruralbased economies and a common geological origin — are raised by a visiting Argentinian academic, Assistant Professor Stephan Halloy, who has spent two years based at the University of Otago as a senior research fellow. Dr Halloy has been comparing the life-forms and climate of New Zealand’s Alps with those of

the Andes of South America, and also investigating possible “areas of co-operation” between his own country and New Zealand. His stay in New Zealand has been jointly funded by his own university, the National University of Tecuman, the Hellaby Grasslands Research Trust, and the D.S.LR. Botany Division. In a note in the Botany Division newsletter, Dr Halloy says that New Zealand (“Kiwi-land”) and what he calls “Nandu-land” (Argentina plus Chile) are closely related, with numerous bird and plant species and genera in common, and in some areas with similar parent rocks, geomorphology and climate which create analogous landscapes. Because these links are ignored by most of the populations and politicians, he says, they are worth exploring. The two regions are faced by many similar management issues, grow similar crops and livestock in similar climates, and have similar problems in exporting their products. And enough differ-

ences to make exchanges mutually profitable — e.g. llama for kiwifruit, subtropical fruits for stonefruit. For all that, life in Kiwi-land has held a few surprises for Dr Halloy. The results of his main study — comparison of the plant forms and climates of the Alps and Andes — provided one of these. It is clear, he writes, that the closest similarity of New Zealand’s tussock-shrubland communities is with those of the equatorial Andes rather than those of the southern Andes. “This is surprising in view of the wide difference in latitudes, and the lesser biogeographic similarities with this area.” The fellfield and cushion-field communities of higher altitudes in New Zealand, he says, seem similar to communities of the subtropical Pampean mountains. “My second task,” he writes, “is to investigate possible areas of co-operation between Kiwiland and Certainly

the possibilities are great. “Just think that the closest inhabited continent to New Zealand after Australia is South America. History has obscured this closeness and the similarity in several ways. “Basically, most external contacts for both areas have been restricted to a north-south relationship to their colonial parents much further away. This, together with language barriers, fostered a mutual ignorance of each other. And of course you cannot trust or co-operate with someone you do not know.” Happily, he says, there are some signs; of change. Recently an air link with South America was inaugurated — “Once a week, it is true, but it is better than nothing.” People in both countries, he says, seem to have more interest in each other, especially since, Argentina took off its military hat and embarked on a decidedly pacifist and anti-nuclear foreign policy. “Chile, of course, is still unfortunately in the hands of a general.” , = / As interest ; and grow, says Dr people will realise the great potential for technological, and cultural exchange, and for trade and tourer--—