Date & Recher, H. (1990) NATIVE PIGEON/Camphor Laurel RESEARCHes



The publication of Recher 8; Date, as well as Recher, Date et al., all arising from the data collection and analysis by Date under Recher's supervision from UNE - Armidale, commencing in the late 1980s, all overlook the review of existing international scientific literature, some published in German (since 1898) (Overton 1901), clearly proving that a number of Active Constituents of Camphor Laurel trees are both narcotic compounds -including the most common compound in all the Camphor Laurel trees: CAMPHOR; nor included is any reference, available since 1963 in English (Beyer-Brandwijk) clearly indicating that mammals/humans can and have died from eating Camphor Laurel berries/fruit; let alone Martindale (since 1990) Pharmaceutic evidence - copies in most Chemist Shops - clearly stating that CAMPHOR has killed young humans on at least two continents in the past century; CAMPHOR is a NARCOTIC, cumulative toxin, moderately powerful poison, and which existing literature available (before 1990) clearly states to be "present in all the tree parts".

Nor, thirdly, did any of the above Authors or Supervisor attempt to assess whether or not the Chemistry of Camphor Laurel trees should have been reviewed, listed or extracted from any available European or U.S. literature.


Date merely states in her Thesis that research and observations on the numbers of Native Pigeons studied in or around the Nimbin district was the only (two species) Pigeon abundance information collected, including details of what each Pigeon was consuming: Camphor Laurel and other species.

On the basis of the data-set presented in the Thesis and one other paper by Date & Recher, it would normally be appropriate to only generalise about Native Rainforest Pigeons of two species in that sub-section of North East NSW Rainforest/s chosen by Date (Recher) to be the 'working area' of her study (NO MAP PROVIDED).


3.1 It is not at all clear to this day why Supervisor Harry Recher appears to have secured 'no direction' himself, in relation to the choice of the "two most common" Native Pigeon species still common at 1990/1989; for example, one would expect that if the NSW National Parks and Wildlife Service had been consulted, Professor Recher could by then have been advised to try and determine why the less-common/rare/threatened species of birds, e.g. Wompoo or Wonga Pigeons or (for Recher's expertise) Coxen's Fig Parrot - a small bird species, even by 1990 becoming thought of, though not then listed as, 'Presumed Extinct' in NSW, were diminishing in population numbers .....

3.2 No retired Ornithologists were interviewed or cited as to their (then, 1990) knowledge of 'average flock numbers' of the many different species of Rainforest Pigeons daily/weekly known to have been visiting/searching for food in the suburbs of Lismore and Nimbin.

3.3 Notable Regional Botanist, then working at Coffs Harbour Arboretum, Dr Alee Floyd, or his available 'environmental statement' in the (then) Big Scrub Environment Centre Library, concerning 'mass Native Pigeon deaths' since 1955 at Bangalow, due to consuming/over-consumption of Camphor Laurel fruits, were/was not cited/overlooked.

3.4 Domestic ('Rock') Pigeon species Breeders and Pigeon Racers were in no way consulted to determine what has been known in Lismore for over 50 years: northern hemisphere originating Pigeon breeds 'know' not to go into Camphor Laurel trees, and they only eat Camphor Laurel seed after months of bleaching and toxin leaching by rain and sun under the trees, after berry pulp has rotted on the ground.


4.1 Seed / Fruit Vomiting - Not Observed, Not Investigated, - Date & Recher Both Omitted to Mention or Detail Key informant interviews with longstanding historical timber cutters and weed-tree eradicators of the Mullumbimby District, NSW, reveal that observations of Native Birds, especially Pigeon species, vomiting in flight and shortly after take-off were consistently 100% ignored by Ecologists and Journalists working in the NSW Northern Rivers during the period 1985 to 2000. The 'problem' of Native Birds consuming Camphor laurel was not only overlooked because the 'Camphor trees' looked 'OK' and provided shade (after dairying had cut down most of the Region's hill and flatland forests), but also because all amateur birdwatchers stated words to the effect that: "The birds are consuming the fruit (including seed), so there appears to be 'no problem'." To date no one, and no scientific researcher, appears to have mentioned the commonly observed recurrence (C. Morrow, Mullumbimby, 1980-2000) of Pigeon-vomiting of fruit and seeds, including whole seeds, both in flight and from 'perch trees', as well as individual Native Pigeons 'falling dead' from flocks, crop-laden with fruit of Camphor laurel. Finally, both Date & Recher, throughout various publications, clearly ignore/d the presence of at-hand 'community knowledge' to the effect that Native Birds do not like the more toxic types of Camphor laurel fruit/seeds and commonly vomit up the seeds while on fence-posts, watering troughs, etc.

4.2 Not Setting Up a 'CONTROL' to Test Birds in Flight By the year/s that Date & Recher set up Date's Pigeon data collection and Camphor berry consumption methodology, it was well known 'local knowledge' that most Camphor trees invading Northern Rivers ridgelines were spread by Native Birds - most especially Pigeons (1960-1990) (retired Ornithologist ex-Lismore, interviewed 1998) - yet neither Date nor Recher in any of their published works prove or disprove, nor even attempt to test their apparent 'blind' assumption that the frugivorous Native Pigeons were spreading the Camphor laurel seeds in their excrement. Only subsequent interviews with professional timber-removers having decades of field experience proved this assumption wrong. Widespread (Byron, Tweed and Lismore Shires 2000-2004) and detailed inspection of bird baths plus watering troughs on farms in Autumn reveals significant high percentages of vomited Camphor laurel seed - with nil excrement whatsoever. Circumstantial evidence collected from Native Pigeon species aviary professionals in Tweed Shire (2000-2004) clearly indicates that aviary-kept pigeons fed on one type only of Camphor laurel fruit appear to show 'no sign/s' of individual or flock sterility for up to eight years (to date), but they perform nil long-flight exercise (in aviary), hence (in hot weather) aviary-bred pigeons never suffer the muscular spasms and vomiting due to CAMPHOR volatilisation/vaporisation of "noxious fumes" (Burrows, 2001) with reduced available oxygen for the birds' lungs.


5.1 Given the 'sheer abundance' of Camphor Laurel trees by 1990 in the Nimbin area, as well as most other parts of Lismore Shire, one needs to query why Date, or Recher or any of the co-authoring colleagues never stopped to ask (in the thesis) why with such prolific volumes of fruit every year available to birds through most districts of Lismore and eastern-neighbouring Shires (Byron, Ballina, Tweed) that none of the pigeon species appeared to be in commensurate abundance, why some species were apparently so uncommon, or finally, last but not least, that the (why?) abundant fruits of Camphor Laurel could or would not be toxic;

5.2 Apparently Date did not observe birds vomiting out the fruit or seeds after their (over) consumption, and her recording of bird species and what they were seen eating; when a bird flew off, that was the end of the record/ing by Date and/or co-observers. Apparently most of them including Recher supervising knew (because they failed to interview longstanding landholders, many/any local Naturalists or retired Ornithologists!) that as hotter weather prevails, or after its onset in Spring, on hot days, CAMPHOR volatilises at the internal metabolic temperature of birds ca. 38C, causing vomiting to occur. With higher rates of volatilisation, fuller crops/stomach and various muscle contractions, bird vomiting soon after take-off is a more regular event.

5.3 Timespan Denning a Native Pigeon's Life (Birds Australia and Federal Department of Environment, Canberra 2003). The average lifespan of Native Pigeons recorded by seasonal banding to date is approximately 20-25 years, well in excess of the 2.5 (10%) years taken, and only 18 months of data collection by Date. If sterilisation by cumulative (narcotic) toxin poisoning was occurring when the researchers studied the 'Nimbin Pigeons' they would have been surely unaware of it happening unless incredibly detailed autopsies and blood analysis/es were performed - which they were not! In essence, the research was 'short termist'.


The principal outcome/generalisation in the 'Conclusion' of Date's Thesis is that if two species of Native Rainforest Pigeon are 'O.K.' in terms of (then) numbers consuming Camphor Laurel berries (and seed) every year, then "all species" of NSW Rainforest Pigeon/s are certainly going to be 'O.K.' ('She'll be right, mate,' approach?)

A second generalisation or malassumption of the Thesis, and hence, flowing on to Date & Recher's subsequent scientific publications - none of which questions the alien (Northern Hemisphere) chemistry of Camphor Laurel IN ANY WAY/at any stage, is that Camphor Laurel berries provide winter sustenance for Rainforest Pigeons in the dry time of the year (late winter to late Spring) when Native Rainforest tree species have less or little fruit. However, detailed seven-year observations clearly prove that over 76% of all Camphor Laurel types (chemotypes/genotypes, after Hiraizumi 1949) fruit in the relatively wet autumn period (March - May) with a minority of trees fruiting in the dry period - less common chemotypes (hybrids) now known to be more toxic/have higher narcotic, carcinogen and/or sterilising compound concentrations (see


Last but not least, it needs to be stated emphatically that Professor (now retired) H. Recher is or was a small native bird expert specialist, not a Native Pigeon (medium-sized birds) expert, nor a/ny expert (other than his own nomination) on either Frugivorous Bird species, or any other species of ecologically distinctive North East NSW Rainforests.

Since 2002 H. Recher has failed to respond to all new scientific information provided by email and post to his Professorial position at Edith Cowan University in Perth.

7. SPECIES MANAGEMENT? (Pigeons or Camphor??)

In the dubiously-titled publication of NSW National Parks and Wildlife Service "The Biology and Management of Rainforest Pigeons in N.S.W.' (Recher, Date & Ford, 1986, Species Management Report No. 16), those authors reach vague, unsubstantiated conclusions related to Camphor laurel, AND, as in all their other publications, ignore this tree species' known chemistry and toxicity, e.g. (page 41) "The present abundance of White-headed, Superb Pigeons and Topknot pigeons may depend on the availability of exotic plants, such as Camphor laurel, Privet, Wild Tobacco and Lantana ...." and "Control or eradication of Camphor laurel could adversely affect the abundance of ... Topknot and White-headed Pigeon [species]." Yet, nowhere in any of Date or Recher's publications is any concern shown for the possibility that the Pigeons were/are consuming only certain types (Firth, 1979, also of University of New England) of the Camphor laurel, and hence the need for the tree's management - NOT the management of Pigeons!!

Senior Scientific Director
Camphor Laurel Research Centre
Lismore NSW
Dated: 10 May 2004