Camphor Laurel Fact Files Wildlife poisonings and sterility induced by Camphor laurel, Cinnamomum camphora, Nees et Eberm.in Eastern Australia By Joe A. Friend Research Director, Camphor Research Centre PO Box 105, The Channon.2480

 

An as yet unknown total number of distinctly different chemotypes of Camphor laurel tree exist throughout most of NSW's Northern Rivers Region; some chemotypes are now shown to be extremely toxic, especially during a hot and late summer season. At least one toxic chemotype, or 'Safrole type', is distinctive in its outward appearance, whilst others, including 'Cineole' type (Firth 1979), need further research so landowners can prioritise removal of the more toxic types first. Evidence is presented to reveal that a wide range of native bird species, koalas, possums, and long nose bandicoots, are being slowly poisoned, or turning sterile, due to over-consumption of Camphor laurel fruit, bark, and roots, in areas of 'faunal territory' that are now hyper-dominated by Camphor trees - such that indigenous food selection/s are highly delimited, minimal or zero - as in extreme Camphor-infested land units. Based on the preliminary collections and observations, and combined with recently accumulated knowledge of domestic animal deaths (goats, horses) and induced sterility (fowl, game fowl, geese), more research and toxicological examination of all available chemotypes is now urgently needed.

INTRODUCTION An inspection of NSW Royal Botanic Gardens' records clearly shows that by 1833, Gardens' staff were running the equivalent of what we now understand a 'wholesale nursery' to be, distributing 'Evergreens and other ornamental shrubs" throughout the expanding colony, and up-the-coast by sailing boats and steamships.

Since Camphor laurel had been sent out to Sydney in 1828 from Kew Botanic Gardens, London (as a cutting from a grown tree), if can be reasonably assumed that Camphor laurels in the Sydney Domain were bearing fruit by 1838, and were being distributed through Sydney suburbs and beyond by the 1840's. The first official record of Royal Botanical Gardens history books proves that Camphor laurel propagation was in full swing by the 1860's, when a first detailed entry confirms that "a few" Laurus camphora (syn. Cinnamomum camphora) trees were sent to landscape the "Court House at Maitland" on the Hunter River, north of Sydney. In 1867, a second batch of Camphors were sent to Singleton Court House for shade/landscape plantings. From this evidence, it is suggested that Camphor laurels made their way to Lismore and Grafton, then most other NSW towns of the North Coast by 1880- 1885, either by steamer from Sydney direct, or via Newcastle. 'Ornamental trees' of all or any species, including both species of Privets (Ligustrum vulgarum and Ligustrum augustifolium) were distributed from the Sydney (Domain) Gardens 'Nursery' either as potted specimens or by a "case full" of seeds and/or cuttings, so long as a/ny private landholder or Government staffer requested same. This then sets the scene for the more widespread dissemination of Camphor laurels, which was sped along by the second Camphor subspecies' introduction from Japan in 1880 (Royal Botanic Gardens Record Book of Introductions).

SURVEY METHODS Observation methodologies in use for data collection and assessment of damage- impacts due to camphor laurel on flora, fauna, and humans ...

Significant Surveys Performed To Date

An estimated 10,000 Camphor laurel trees have been inspected from Atherton to Perth, Melbourne, Adelaide and Alice Springs; in no location, esp.>7,500 mature (>10 y.o.) in NSW's Northern Rivers, over the past 5 years (1960-2001) has a bird's nest been sighted within the tree canopy! Not an active or a defunct nest.

1. Frogs in "Wet' Roadside Survey. Over the past three (3) years, driving with windows down in or shortly after at least 40 mm of rainfall, and knowing frogs to be about due largely to warmer weather arriving, I have stopped at known and audible frog-rich sites on either roadside (E/W) of the main road from Rous to The Channon, and return, and looked for any sign of Camphor laurel trees within the visible catchment of the roadside site; no site/s were found, or seen to have any Camphor tress within 50 ms of any abundant 'happy' (remnant) frog community.

2. Birds 'in' and Under/Feeding Survey. For three years, detailed observations have been made of which bird species feed on Camphor Laurel fruit, and at what stage of fruit ripening any such birds begin to eat (eg Domestic Pigeons only eat old, fallen seeds) across an even-age planting of some Camphor Laurels in central Lismore; no Native Pigeons species have been sighted eating Camphor fruit off this range of differing chemotype trees.

3. Survey of Community Attitudes and Thinking about Camphor Laurel. Commencing with a small survey (N-100) of Terania and Tuntable Valleys, in that community it was found that no-one was/is in favour of keeping any Camphor laurel trees, local attitudes were confirmed by mailing out three 'camphor newsletters' to every residence, and on site landholder interviews. The survey was extended to the residents of Lismore CBD, many of whom live adjacent to large/mature camphor laurel specimen-shade roadside trees, and to over 100 residents along a 21 km roadway from Lismore to The Channon (a 'representative transect'); not one person has been found who wants to keep or protect Camphor-laurel, or have the 'Noxious' declaration of that species revoked in Lismore Shire (as occurred in Byron, Ballina and Tweed Shires in 1999.)

Ongoing Seasonal Surveys - Lismore and environs. A known 250 Camphor laurel trees (mostly mature) have been surveyed regularly and consistently by transect-visual assessment (of roadsides) of canopy/ies, growing between Lismore and The Channon, over the part 4.5 years; in which no wildlife have been detected at any time (excepting occasional visits by night time bats). Within the City of Lismore, a known, plotted 100 Camphor street trees have been actively surveyed for the last three (3) years, for the purposes of asssessing whether the avenues and individual trees support locally rare/abundant wildlife species; no nests have been found in any trees; no insects, including Blue Triangle Butterflies, have been observed by day; nil possums or bandicoots have been observed in or under these trees by night; only native Mistletoe (sp./l species only) has been observed able to tolerate the treeis chemistry, but then only in approximately 1 in 5 of the local tree chemotypes (ex-same parent trees).

4. A cluster of 40 even aged camphor laurel trees grows by roadsides surrounding two central parks in central Lismore, all believed planted from a single 'mother tree' and in the same season; they appear to be approximately 50 years of age. Variation between trees is being recorded, including:

  • 4.1 Presence or absence of epiphytic species, including mistletoe that dies out on certain camphor laurel individuals.
  • 4.2 Leaf chemistry definition, to assess theis species heritability trait for toxic leaf products, eg camphor.
  • 4.3 Other distinctive morphological traits, eg bark type, butt or original trunk.

5. A regular seasonal appraisal of what fruit or age of fallen camphor laurel seed the remnant small population of domesticated pigeon (Columba livia) is consuming in wet/dry and whether any birds have learnt not to eat certain camphor chemotypes.

6. Soil and water Analyses. To assess the cause of milkiness-opaque waters due to camphor impacted soils and clay and name the orange precipitate continuing interseasonal observations are being recorded on all or for most of the above chemical and its natural origins.

Annual Observations At flowering and pre-flowering, in order to discern the different chemotypes of the tree, sampling individuals showing the greatest morphological differences. After flowering, to attempt to find what larvae of which species of butterfly or moth (2/3 species) still live on the trees, or what types of the tree species still support insect attack. All substantive surveys and methods in use to date to be fully summarised in any foreshadowed thesis. It is believed that only short-term testing, and further laboratory analysis within one year would be sufficient to conclusively prove that most camphor laurel is indeed a weed 'worse type'/including more toxic chemotypes than mere 'Noxiousness'.

In a selected street of Lismore, Magellan Street, a particular sector of mature Camphor trees were identified as 'prime targets' for a survey of native bird behaviour, including Galah, Rainbow Lorrikeet, Rosella, King Parrot, Crested Pigeon, Magpie, and Noisy Mynah. These birds were observed for three evenings per week over the past 12 months, proving that none of them enter the canopies of more toxic chemotypes, but do occasionally sit on dead limbs atop of the canopy of mature less toxic chemotypes. They do not perch here at night.

The Testing Needed 1. A method has been developed, but requires refinement for the purposeful screening of Camphor Laurel tree root bark samples, to assess individual trees for relative toxicity. 2. Assessment of toxic alkaloid concentrations in root tissue or root bark, season by season (individual trees); 3. Inter-seasonal variation in Safrole (carcinogen) and % camphor (human toxin) contents of browse foliage (leaf and twigs) due to the impact on the tree of regular browsing or bark eating e.g. by koalas and possum respectively. 4. To ascertain by laboratory testing with ethically approved species if the three groups of toxins in Camphor laurel roots or berries could be synergistically.

Birds Birds, principally pigeons of a number of native species, were first observed falling dead out of Camphors at Bangalow (Floyd 1950). Notable and arguably most eminent rainforest species botanist, Alee Floyd, was the first to witness the potentially austere problem of Camphor laurel slowly evolving new generations of more toxic chemotypes - no doubt due to genetic hybridisation and sorting of 'new types' created after crossings of earlier Chinese island (1828) introduction/s (Firth 1979) and Japan's Hiroshima type subspecies to Sydney and North Coast after 1880 (Royal Botanic Gardens, Record Books). Although Floyd assumed that the birds had 'been forced' to start eating Camphor laurel after a particularly heavy set of cyclones had blown over most of Bangalow's bangalow palms - the bird's usual major food source - it has never been checked on, whether the area of Camphors that Floyd saw killing pigeons is a particularly toxic chemotype.
Applying hindsight, with our knowledge of at least nine distinct chemotypes growing around the Northern Rivers, it is possible to make an alternative conclusion about what Floyd was witnessing: the first mass death of a native species due to gross feeding on the fruit of more/very toxic Camphor chemotype/s. Certainly, Bangalow is close enough to the centres of presumed hybridisation - where the first Japanese Camphors would have been taken, to cross with earlier Chinese types - near Burringbar/'s heritage home, Avenall. (Personal communication, 2002). According to Lismore identity, Laurence Axtens, trained bush regenerator whose teacher was Ralph Woodford, Woodford taught that the Camphors eaten by Wompoo Pigeon is THE REASON Wompoo's are no longer to be commonly seen. In a rare/unique incident in California, USA, in 1984, an aviary full of Australian budgerigars was completely annihilated (all died!) within 36 hours of Camphor laurel branches, leaves and twigs being placed into the aviary. This mass death was officially registered by a Government vet in one Southern US county. An examination of the available date/observations on 'sick birds' brought as dying/injured specimens to a representative range of Lismore Veterinary Clinics reveals the following: 1. The principal bird species being found sick or dead on Lismore and surrounding roadsides for most of the year over the past two years is rainbow lorrikeet (Trichoglossus haematodus) - these birds feed heavily at times on certain Camphor blooms, blossom, flowers and (probably) petioles; 2. Most other bird species found sick or dead near Lismore roadsides, or that are true 'road hits', may be the result of overconsumption, having too heavy a 'payload', or having their coordination impaired by chemical influences on the brains or eyesight or both of individual birds. Currawong, magpie, pigeons, coucal, rosella, galah, (tawny frogmouth and kookaburra - all these species are known to eat ripe/unripe Camphor berries, etiher directly or indirectly. 3. A clear correlation exists between the species with the highest number of injured/dead and and their known Camphor eating habits.

Sick and dead birds found under Camphor laurels After realising about 1999 that some Camphor chemotypes are in an 'extremely toxic' category compared with most of the early (1828, Chinese) introductions to Sydney the author decided to undertake more detailed observations of level ground with no long grass under all of Lismore's Camphor laurel street trees, ^even when driving along in my car (at reduced speeds!) I was quickly 'rewarded' with dead pigeons from lunder roadside Camphors at South Lismore 9in the early summer of 2000. This was repeated in 2001 with Hunter pigeons dead from under Uralba Street Camphors owned by Lismore City Council, all specimens of which were frozen for future possible autopsy. [NB. NSW NP&WS did not agree to have autopsies conducted - despite their Act's clear regulation - until early 2002]. From the few birds collected to date, notwithstanding that thousands probably die in the 'long grass' of late summer throughout the region when most Camphors ripen their berries, it is possible to generalise that hypothetically, small bodied fruit eating birds are the most likely to be highly impacted by lower levels of consumption of green or ripe Camphor berries, eg most recently, in the case of Lismore CBD Camphors — two dead Lewin's honeyeaters (Meliphaga lewinii), a part time fruit eating species - were found (28/02/02) under a visibly 'obvious' more toxic chemotype of Camphor laurel, a morphologically discrete tree with smaller yellow-green leaves, (not usually dark green), suggesting a higher Safrole content in its tree parts.

'Local knowledge' According to longstanding resident of the Lismore District, Alex Hunter, a direct descendent of Governor Hunter (ca.1810 in the Colony of New South Wales), members of his family and others in his watershed were 'fully aware' of the damaging impact of Camphor laurels on wildlife - vertebrates included - by 1970. Whereas Alex Hunter grew up in a family whose parents accepted the Camphors as 'shade trees for grazing properties' he was one of a new generation wanting answers to certain 'difficult questions'; eg "Why do we have to suffer this Colonially-distributed Northern Hemisphere ornamental?" So the Hunters, as a result, started clearing their land, just leaving the native tree species. Until recent times, NSW Northern Rivers knowledge has been restricted to believing that if certain native birds still ate Camphor laurel prolifically, then it couldn't or wouldn't be bad for those species. However, no studies or academic researches have ever been made into the fecundity or sterility of any bird species commonly consuming Camphor berries. Nor has any researcher or university academic showed any interest whatsoever in the increasing tendency of many species to consume green (unripe) fruit, including very hard green fruit with higher camphor % concentrations (and maybe other toxins).Pursuant to receiving a number of reliable reports (Mallanganee and Mummulgum) of Camphor berry eating causing fowl and game fowl species to become (reversibly) sterile, Alex Hunter conducted a research trial on his own property with geese; sterility was reversed within three months of taking free range geese away from under Camphor trees.

Fish Farmer-landholders with creek or river frontages were the first group of people to try and alert authorities like State Fisheries and the newly established EPA and NPEWS that fish were fast disappearing from the Orara River, west and northwest ofCoffs Harbour (Tom Davidson/Kungala, personal communications, 1999). The 'alert' and concern of landholders was eventually heard by Coffs Harbour City Council, and one limnologist-consultant commenced Karangi Dam investigations about 1990, for that Council. Freshwater ecology expert Bishop, from Bungwahl near Taree, began his experiments in the Orara River around 1991-92, the work proving that native rainbow fish (Melarstaenia duboulayi) are indeed killed by leaf toxins added to Orara River water. This was published in 1993. Bishop, in Mitchell-McCotter and Assoc., Sydney). So, a rather typial species could have been revealed as being representative of greater fish deaths in the Orara River, but this did not occur. Bishop returned to consulting work on the NW Central Coast, and no Government Departments took any notice whatsoever of his work - which included basic statistical analysis, least of all State Flisheries, who have the responsibility of looking after fish stocks and remnant biodiversity in all streams and estuaries. Repeated attempts and part time research by freshwater fish expert, Tom Davidson, of Kungala, including field collections and tank experiments with both native shrimps, Macrobrachium sp,p as well as Firetail Gudgeon, Hypseleotris sp, in the late 1990's. He proved that all the tested fish died when just 50g of Camphor leaves were added to a 10 litre water tank.

This in effect was the scientific corroboration of Bishop's earlier work with rainbow fish, albeit unpublished. Brunswick, Clarence and Tweed fishermen From interviews conducterd near Brunswick Heads, along the Clarence River, and (especially) near the mouth of the Tweed River, professional fishermen independently corroborate that since about 1990 (on the lower Tweed River) fish size and numbers were reduced significantly or were negligible in proximity to any streamside/overhanging Camphor laurels, especially big ones with exposed roots. As usual, both regional media, and NSW Fisheries, have taken nil notice of this consistently and multiply reported impact of a known highly camphorated 'pesticide tree'. More detailed questioning of commercial fishermen upstream on the Clarence River revealed that not only fish but also crayfish and prawns were "not worth fishing for" within about 50ms upstream of most Camphor infestations, and approximately 80-100 ms downstream (or more in the case of heavy infestations with more toxic chemotypes represented. One needs to ask, why didn't and why hasn't NSW State Fisheries taken notice of this toxicity problem? Perhaps they weren't ever told, or the right people weren't told, or are never educated about weed toxicity - let alone the propensity of a weed's toxin levels to become/evolve to worse levels with every generation arising from new inter-subspecies crossings.

Koalas (Phascolarctos dnereus) According to Dr. Paul Gill, Chief Veterinarian with NSW Agriculture's Wollongbar Research Station - who conducts regular wildlife autopsied, the two most commonly witnessed causes of death of koalas in the Lismore-Northern Rivers region is not chlamydiosis of the rear-end or anywhere else - it is most likely either lymphocarcoma (malignant) or mesophilioma, which is less common (First report published by Canfield Aust. Vet.Jnl 1988). The high frequency of cancers was verified by Friends of Koala, Meerschaum Vale group, on the basis of over 100 autopsies. As with most other collected 'dead wildlife' of collected individuals, most commonly media-reported koala deaths are 'roadkills' by either cars and vehicles or dogs and wild dogs.

However, this 'easy reporting' whilst welcomed by journalists looking for a fast story, in no way commences to investigate the underlying reasons as to why koalas become so chemically or. physically disturbed as to end up resting and not moving off roads and roadsides, instead of getting up tree protection zones. The increasing number of symptomatologies described for dead koalas over the past few years, as viewed by an independent inspection of all NSW Agriculture autopsies, reveals that there appears to be a correlation between the wide variety of distinctly discrete Camphor chemotypes and the wide-ranging variance of symptoms amongst dead koalas for which an autopsy was performed. However, the reality of our current dilemma around Lismore is that volunteer koala spotters confirm that certain koalas are seen consuming Camphor laurel foliage, even by daytime, that two studies confirm that koalas eat significant amounts of Camphor leaves etc. through winter and spring, and that we continue to face a declining koala population. A most profound comparison has recently come to light. A Department of Education herd of mohair goats turned sterile after eating Camphor laurel loppings from Kempsey High School trees, from 1999 to 2001; then, after over 15-18 months of proven sterility, in this young herd of goats, all individual goats slowly died in the next 4 months (2001-2001). Since goats are usually noted for their lack of fussiness in dietary terms, and constitutional 'hardiness' in overall terms, it comes as a shock-surprise that Camphor laurel supplementation may cause goats to die. This situation is I believe indicative, as there is prima facie evidence that not only goats, but many species of domesticated and native birds, appear to turn sterile, then die prematurely from repeatedly sustained consumption of Camphor laurel (leaf/green berries, esp.)

Horses It has been known in the Lismore District for over fifty years, handed on verbally, but never recorded by NSW Agriculture, that if horses are kept in paddocks on acid soil with Camphor shade trees, the trees can consistently kill any horse that chews a significant amount of tree bark. Personal interviews of old landowners and their offspring reveal that it was also well known, 50 years ago or more, that February-March was the most toxic time of the year.

 

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