Post by nomad on Feb 2, 2013 2:43:59 GMT -8
Most Birdwing collectors will agree that today obtaining a pair of the nominate O. meridionalis from Papua is like trying to find the holy grail and if they did, the cost would be out of this world. The closure of IFTA has meant that specimens coming from Papua are non-existent. The principle dangers to the nominate O. meridionalis was not collectors, who obtained their bred specimens through Butterfly Farmers, who now sadly have no outlet, but the wholesale industrial logging of the New Guinea rainforest, which is increasing at a ever greater rate. Good O. meridionalis populations have been lost including those observed by Jan Pasternak at Brown River. Jan Pasternak encounters with this butterfly are one of the great delights of his book. Larry Orsak [1999] has wrote a very interesting article for the New Guinea Digest on his observations of the nominate O. meridionalis in the vast Kikori Basin of the Southern Province of New Guinea. Even Matsuka [2001] seemed unaware of these new populations and in his 'Natural History of Birdwing Butterflies' the Orsak localities are not shown on his location map for this species and they are not mentioned by him. Matsuka did show a isolated low montane population at Lake Kutubu which lies to the north of the lowland rainforest populations occurring in the Kikori. I believe the Orsak article to be a important one and it is certainly worth quoting here in full. I hope those with a interest in Birdwings and O. meridionalis will find as I did, it worth reading. It must be remembered that the Orsak article is now over a decade old, and that the loggers have reached the Kikori Basin. I have seen some disturbing images on the web showing clearing of the forest there. Hopefully the local tribes who own the land, will protect some of their forest, which will ensure the survival of the O. meridionalis occurring in the Kikori.
A Rare Butterfly Common in the Kikori Basin by Larry Orsak.
" The tailed Ornithoptera meridionalis is considered a rare butterfly indeed, an opinion reinforced by its placement, a couple of years back on the U.S. Fish & Wildlife service's Endangered Species List. Yet, in the Kikori Basin of PNG, we are getting a different picture.
The Basin is characterised by its huge expanse of nearly impenetrable limestone karst country. PNG's only known oil fields have created a few intrusions, and there are scattered villagers. We've found O. meridionalis in nearly all these places from sea level to at least 600 meters elevation. However, it is also found off the karst, on clay soils on the lower slopes of the giant extinct volcano Mt Bosavi, where the butterfly's caterpillars utilise a distinctive, apparently undescribed Aristolochia foodplant species.
The butterfly is never common, but it is repeatedly, almost regularly picked up at these sites. Why so widespread here?. The answer probably lies in the microhabit typically preferred by Asistolochia foodplants of the rarer birdwings. They're found in relatively undisturbed forest, where the canopy tends to high. But the foodplant vines grow in well-drained spots in otherwise wet country [ on top, or slightly downslope from razorback ridges are especially favoured ]. The particular foodplant individuals favoured by egg-laying females are invariably the shorter ones growing in recently formed gaps. In essence shorter foodplant vines produce more prolific growth in a given period than taller ones, and growth is most prolific when the vines's head is in the sun, and its feet are wet. Tree gaps are ideal for fitting the sun requirements- not big holes in the forest [ because then the microhabitat starts becoming too sunny and open for these birdwings, and sometimes for the foodplants too]. In other worlds, these rare butterflies breed on disturbed sites situated in the midst of undisturbed forest sounds like a rare combination? That's the source of birdwing rarity!
The karst country of the Kikori basin is dramactic terrain from the air. Innumerable hillocks rise from the landscape almost in checkerboard fashion, punctuated by steep drop offs and sinkholes. In short, its the kind of natural habitat where you're likely to find a myriad tree gaps and well drained slopes perfect for prolifically growing Aristolochia vines.
Most of the Kikori Basin is covered by forests undisturbed by human inhabitance. But O. meridionalis has been found most commonly around Mt Bosavi in areas occupied by higher-than-normal human populations. People have gravitated to these slopes because of the more fertile soil. You can see the dramatic changes in gardening activities from the air as the soils change. Yet, the gardens even tend to be patchy and small, this possibly increasing, rather than reducing, microhabitats ideal for Aristolochia growth and rare birdwing breeding.
Let me offer a statement that sounds like heresy from a conservationist lepidopterist: logging-small scale, community based wokabaut somilling- might actually favour these birdwings. The critical factor, of course, would be the size of tree gaps. It is virtually guaranteed that you'll see O. meridionalis at many sites in the Kikori Basin. But try and collect a specimen, and you'll be lucky indeed to net even a low-flying female. Hence specimens in museum collections are scarce, which in turn, leads to assessments of extreme scarcity Toss in a awareness that industrial logging is rampant in PNG lowlands, and O.meridionalis easily looks like a species headed for extinction.
But it's not. Despite the concern of the U.S. Fish & Wildlife Service, here on the ground we know O. meridionalis in PNG flies nearly everywhere polis motu is spoken from Gulf Province to the Southwest, arching over and all the way around the eastern end of the island, then on the north side going at least far west as the Mt Victory area of Collingwood Bay [ Oro Province] but getting specimens to verify its abundance... aye, that's the rub".
It is interesting to note that small selective logging unlike major industrial logging might actually help O. meridionalis and other birdwing butterflies. Also that Orsak unlike Jan Pasternak found the males of O. meridionalis flying high up in the tree canopy. What is desperately needed in papua is another outlet for the native butterfly farmers who will breed these birdwing butterflies and in doing so will earn a living from their forest, which in turn will help protect it.
Below is a lovely photograph by Matsuka of O. meridionalis at Wau, Papua.
A Rare Butterfly Common in the Kikori Basin by Larry Orsak.
" The tailed Ornithoptera meridionalis is considered a rare butterfly indeed, an opinion reinforced by its placement, a couple of years back on the U.S. Fish & Wildlife service's Endangered Species List. Yet, in the Kikori Basin of PNG, we are getting a different picture.
The Basin is characterised by its huge expanse of nearly impenetrable limestone karst country. PNG's only known oil fields have created a few intrusions, and there are scattered villagers. We've found O. meridionalis in nearly all these places from sea level to at least 600 meters elevation. However, it is also found off the karst, on clay soils on the lower slopes of the giant extinct volcano Mt Bosavi, where the butterfly's caterpillars utilise a distinctive, apparently undescribed Aristolochia foodplant species.
The butterfly is never common, but it is repeatedly, almost regularly picked up at these sites. Why so widespread here?. The answer probably lies in the microhabit typically preferred by Asistolochia foodplants of the rarer birdwings. They're found in relatively undisturbed forest, where the canopy tends to high. But the foodplant vines grow in well-drained spots in otherwise wet country [ on top, or slightly downslope from razorback ridges are especially favoured ]. The particular foodplant individuals favoured by egg-laying females are invariably the shorter ones growing in recently formed gaps. In essence shorter foodplant vines produce more prolific growth in a given period than taller ones, and growth is most prolific when the vines's head is in the sun, and its feet are wet. Tree gaps are ideal for fitting the sun requirements- not big holes in the forest [ because then the microhabitat starts becoming too sunny and open for these birdwings, and sometimes for the foodplants too]. In other worlds, these rare butterflies breed on disturbed sites situated in the midst of undisturbed forest sounds like a rare combination? That's the source of birdwing rarity!
The karst country of the Kikori basin is dramactic terrain from the air. Innumerable hillocks rise from the landscape almost in checkerboard fashion, punctuated by steep drop offs and sinkholes. In short, its the kind of natural habitat where you're likely to find a myriad tree gaps and well drained slopes perfect for prolifically growing Aristolochia vines.
Most of the Kikori Basin is covered by forests undisturbed by human inhabitance. But O. meridionalis has been found most commonly around Mt Bosavi in areas occupied by higher-than-normal human populations. People have gravitated to these slopes because of the more fertile soil. You can see the dramatic changes in gardening activities from the air as the soils change. Yet, the gardens even tend to be patchy and small, this possibly increasing, rather than reducing, microhabitats ideal for Aristolochia growth and rare birdwing breeding.
Let me offer a statement that sounds like heresy from a conservationist lepidopterist: logging-small scale, community based wokabaut somilling- might actually favour these birdwings. The critical factor, of course, would be the size of tree gaps. It is virtually guaranteed that you'll see O. meridionalis at many sites in the Kikori Basin. But try and collect a specimen, and you'll be lucky indeed to net even a low-flying female. Hence specimens in museum collections are scarce, which in turn, leads to assessments of extreme scarcity Toss in a awareness that industrial logging is rampant in PNG lowlands, and O.meridionalis easily looks like a species headed for extinction.
But it's not. Despite the concern of the U.S. Fish & Wildlife Service, here on the ground we know O. meridionalis in PNG flies nearly everywhere polis motu is spoken from Gulf Province to the Southwest, arching over and all the way around the eastern end of the island, then on the north side going at least far west as the Mt Victory area of Collingwood Bay [ Oro Province] but getting specimens to verify its abundance... aye, that's the rub".
It is interesting to note that small selective logging unlike major industrial logging might actually help O. meridionalis and other birdwing butterflies. Also that Orsak unlike Jan Pasternak found the males of O. meridionalis flying high up in the tree canopy. What is desperately needed in papua is another outlet for the native butterfly farmers who will breed these birdwing butterflies and in doing so will earn a living from their forest, which in turn will help protect it.
Below is a lovely photograph by Matsuka of O. meridionalis at Wau, Papua.
Attachments:
bartekgoldyn. For that price almost certainly a female of the West Papuan O. meridionalis tarunggarensis from Timika. 
