Camphor laurel and Sterility and Death of Birds

Fledgling Black-faced Cuckoo-shrike(?) unable to fly or walk, right side partially paralysed. Disgorged 5 camphor seeds and one berry.

Current community division and divisiveness over the usefulness v. downside-values of the tree species Camphor laurel has to-date not been publicly debated, let alone featured by journalists. Mainstream environmental thinking has generally relied upon scientific research. However, in the case of Camphor only two theses have ever been written/finalised in Australia:

Firth (Alstonville) 1979, The Ecology of Camphor, University of New England, Armidale.
Date & Recher 1989, Birds - Two Species of Pigeons - in Camphor Laurel, University of New England, Armidale.


Whereas Firth is the official expert on the tree species, and lives in this region, his finding that at least one species of local bird which is now uncommon but was - in the 1970s - a heavy feeder on Camphor, has been commonly ignored; the bird species concerned is the Blue-faced Honeyeater, which is rare to-non-existent in areas (eg The Channon) where toxic chemotypes of Camphor Laurel are predominant.

In the case of Date's thesis, supervised long-distance by small bird expert Dr H. Recher, two fundamental errors or assumptions were made, so far not taken account of by the Information-loving Environmental movement.

The thesis and publications arising from the Thesis generalise about all pigeons species - including rare ones - of NSW's North East region, on the basis of data/Analysis collected for the two most common, Camphor adapted species.

Date & Recher took nil account of the existence of more toxic chemotypes, now becoming increasingly commonplace; especially in drier habitat, on more exposed shallower soils where most toxic type/s appear to have become best adapted.

So that, whereas amateur ornithologists in this region commonly see certain species eating some Camphor berries, this does not mean:
(a) that all pigeon species can or will eat them;
(b) that most or all other pigeon species cannot or do not stay fertile as a result of consuming toxic constituents; and,
(c) that all pigeons or Rainbow Lorikeets also surviving as populations on them are actually in abundance; in fact only one Pigeon Species, of all Northern Rivers birds that eat Camphor berries is in abundance ; in fact only one Pigeon species, of all Northern Rivers birds that eats Camphor berries is in abundance - the White Headed Pigeon.

Critique of Date and Recher paper, click here

Whereas CSIRO surveys pre-1990 confirmed the common presence of Silvereyes in Camphor Laurel, also eating camphor berries, this species (and sparrows) are now defunct entities over most New South Wales Northern Rivers districts.

Under and within serious Camphor infestations, including those where every other plant species is excluded (by most-toxic chemotypes) it is remarkable that none of the common Rainforest ground-feeders can be found to live or nest there: Brown Warbler, Green Catbird, Satin Bowerbird, Paradise Riflebird, Logrunner and Lyrebird. Nor do Owls or Boobook inhabit large Camphor infestations.

Evidence of Invader-bird species agressiveness, Cronin (1989) published limited evidence, supported by widespread birdwatching in NSW and Queensland since 1940, that Currawongs feeling on Camphor laurel become more aggressive individual birds.

Fresh Evidence of Bird Species Comeback after Mature Camphor Tree Removal. In recent work involving 100% removal of all Camphor laurel, large/mature trees, implying a total cutback on Camphor fruit in the diet, landcarers in the Rocky Creek-Dunoon subcatchment have noticed an increase in Australian Brush Turkey (Alectura lathami) numbers, up over 300% in just 3 years of consolidated bush regeneration.

References:
1. Cronin, L. 1989, Concise Flora of Australia, Reed Books, Sydney.
2. Firth, D.J., 1979 Ecology of Cinnamomum camphora (L) Nees et. Eberm in the Richmond Tweed Region of North Eastern NSW, Thesis, Department of Botany, University of New England, Armidale.
3. Date, E.M., Recher, H.F. and Ford, H.A., 1991, Nature Conservation 2: The Role of Corridors, Surrey Beatty and Sons.
4. Date, E.M. et al, 1996, The Conservation and Ecology of Rainforest Pigeons in Northern NSW, Pacific Conservation Biology 2: 299-308
5. Recher, H.F., Date E.M. and Ford, H.A., 1995, The Biology and Management of Rainforest Pigeons in NSW, Special Management Report No.16, NSW National Parks and Wildlife Survey

 

 

Dead birds & sterility - Chronological record

1900 The Northern Star (Lismore) prints news report that Cinnamomum camphora is already an invasive weed to the east of Lismore, toward Bangalow, suggesting outward invasion from 'centre of hybridisation' (Chinese x Japanese subspecies) near Burringbar and/or Wollongbar (oil industry once planned by NSW Agriculture).

1940's First native pigeons and farm horses determined to be dying from consuming Camphor berry and bark respectively Lismore district) as well as commercial bird infertility reported to NSW Agriculture ca. 1948 without response, infertile poultry also found inedible due to 'camphoration of bird flesh; second generation Camphors implicated.

1950-51 Regional Botanist/Conservationist, Alee Floyd, first reads Bangalow reports, locally published (Northern Star?) that hundreds or thousands of Native Pigeons of more than one species, subsequent to these birds' usual food species - Bangalow Palm population having been severely reduced after local, coastal cyclonic storms.

1970 A deceased regional ornithologist in a 1998 interview first noted that Native Pigeon populations were becoming significantly reduced at/in Lismore, as compared to 'thousands of pigeons every evening' visiting the city in separate species - flocks for the decades 1950's - 1960's, over which decades he made detailed observations of the daily flock ingress.

1979 Regional Camphor Expert, Dr. D. Firth, publishes list of birds commonly sighted eating Camphor/or seed of Camphor subsequently implicated in the regional demise of this species.

1980 CSIRO Wildlife Research publishes field evidence from NE NSW Regional Surveys that Silvereye were sighted eating Camphor fruit (green?); alarm not raised.

1986 Flying Foxes first sighted (Lismore South) competing with birds at evening in Winter, consuming Camphor berry at night; population declines commence for some flying fox species.

1987-88 Summer, extended dry conditions - at Bungawalbyn locals witness Straw Neck Ibis, Magpie and Rosella all falling dead from (over-consumption of Camphor berry (and bark?), corroborated by field visit from NSW Agriculture Farm Inspectors who, it is reported, decided to eradicate those trees.

1990 Retired Byron Shire Councillor E. Sigley, and C. Morrow (Camphor laurel control expert of Mullumbimby), both affirm the continuing demise/eventual (2000) disappearance of large flocks of Ibis over, around and in Mullumbimby district.

1997 First observation that Blue Faced Honeyeater is now uncommon in this district (cf. Firth 1979, see above), 18 years after the species was reported to commonly consume Camphor. (Masters Thesis, Camphor Laurel Biology, UNEArmidale, 1979).

1998 First observations that relatively small, remnant flocks of Native Pigeons do not alight in or on hybrid Camphors planted at The Channon on the riverbank, seasonal observations being continuous (1998-2002), fruit of which (more toxic chemotype) is seen consumed by Fruit Bats at night (Winter).

1998 Tweed Valley professional game bird breeder (see attchment) reports that all birds kept 'open range' under Camphor laurel were seen to consume Camphor berry and seed fallen from Camphor trees (Tweed Advocate 10/03/98).

1999 Fifth-generation Corndale (Lismore district) landholder, A. Hunter, reports "over a decade of sterile and inedible eggs" from his free range geese, the birds spending "most of their daytime grazing hours under large fenceline Camphor trees, THEN performs experiment with single female goose, separately penned for three months 'commenced laying fertile eggs after one month and edible eggs after two months, when fed on a Camphor free diet.

2000 Crested Dove and Diamond-Necked Dove found dead under particular types of Lismore Camphor trees; Silvereye noted by astute observers to be defunct in many districts of the Region.

2001 First White Headed Pigeon found sick with only Green Camphor berry in its crop- stomach; nil other contents. Bird died within 24 hours of attempted recovery after found sick, not hit on roadside Terania Creek Landcare (18/08/02).

2001 First authenticated reports that private lessees and landholders have observed Pheasant Coucal (Centropus phasiarinua) and native pigeons 'falling dead' directly out of Camphor trees (Lismore District 1999-2001).

2002 Feb-March, mass bird deaths of only native birds in the Central Parks of Lismore, confirmed by Lismore City Council workers who picked up and took most birds to the Tip for burial; two birds (Lewins Honey Eater found dead adjacent to one more- toxic Camphor Laurel chemotype tree on LCC land fronting Magellan Street.

2002 Second White Headed Pigeon found dead, roadside under shrubs, no sign of hit damage, on opening revealed 25 ripe purple and black hard Camphor berry; adult bird appeared in good health otherwise (10/04/02).

2002 Third White Headed Pigeon found dead, roadside, at Main Arm, so sign of hit damage; crop-stomach revealed approx 50% black hard Camphor berries (03/08/02).

2002 Third White Headed Pigeon found dead, roadside, at Main Arm, no sign of hit damage; crop-stomach revealed approx 50% black hard Camphor berries (03/08/02).

2001-2002 White Headed Pigeon population collapse at and around The Channon appears to be collapsing/having collapsed after over 50 years of locals stating their flocks were 'regular and predictable' for their properties and trees regularly visited.

1999-2002 Once visibly common populations of both Brown Pigeon and a flock of Crested Dove/ Pigeon, in and adjacent to The Channon village, on roadways and in streambank Wild Tobacco, quickly declines to 'non visible' and single bird only sightings respectively.

July 2002 King Parrot paralysed in legs then dies at The Channon; at the end of a mild drought period (June-August) this young bird is found to have only cracked Camphor fruit coats and seed in its stomach contents; independent Veterinarian Sept 2002 Green Winged Pigeon dissected to show one hard Camphor laurel berry in trachea; one cracked berry in stomach.

2001-2002 USA EPA publishes on Internet that (American) native bird species die from 'respiratory failure' after consuming Camphor berry, readily killed.

 

 

Critique of Date and Recher paper