Even rarer than Bhutanitis lidderdalii are the three other species in the genus Bhutanitis. Bhutan claims only one of the four species as its national butterfly, and lidderdalii isn't it. Lidderdalii is found in other countries as well as Bhutan. Bhutanitis ludlowi is found, to the extent that it's found at all, only in Bhutan as a resident. It has been believed extinct. It is still a grear rarity. It's been called the "holy grail" species for butterfly watchers to find.
Photo by LC Goh.
Ir'a been celebrated on a postage stamp.
If not the first, the second living human known to have seen this butterfly alive has a Blogspot blog.
Because ludlowi is so rare, trafficking in its dead bodies is illegal, but that is not stopping trafficking from taking place online--at least in theory. (As collectors pointed out with regard to lidderdalii, people may pay high prices for butterfly carcasses they'll never see.) Search engines are not responsible for people who choose to conduct illegal business online, but did Google really have to sell the carcass traffickers a sponsorship?
Again, some people who are interested in conservation of Swallowtail butterflies think the best strategy is to sell "collectors" on the idea of having perfect specimens that were reared in captivity and killed upon eclosion. In this group we find, for instance, Zhengyang Wang, whose studies of Asian butterflies this web site has cited before.
Others favor the happier and more modern idea of shifting butterfly watchers' interest to seeing living butterflies and, if lucky, collecting good clear pictures that preserve a moment of interaction between living human and living animal. This web site is in the latter group, partly because I remember "collecting" a few moth and butterfly specimens--not rare, but beautiful, including Luna moths and Monarch butterflies, all of whom had died of natural causes--and being dismayed, and disgusted, by the speed at which they turned into nasty blobs of dust that attracted tiresome little beetles. The beetles that eat butterfly carcasses are a different species in the same family with common carpet beetles.
Nothing but corporate greed can be said to eat beautiful butterfly photos. Mold won't grow on them, nor do they have an odor, at least unless they're printed with smelly ink. They don't take up much space, either, even when printed. Your family can't complain if you collect digital pictures of butterflies. If you stored them electronically on a device the greedheads decided to make obsolete, they'll be lost, but there are ways to deal with that.
In any case, anyone collecting butterfly carcasses should be aware that, unless you are an official government-managed museum engaged in well-regulated trade with another official government-regulated museum, buying or selling Bhutanitis carcasses is illegal. The bodies can be confiscated and you can be fined for trafficking in them. Although most butterflies fly for only a few weeks and then donate their bodies to whatever finds them, it's hard to prove that you did not kill a living butterfly when you have its body, so you could in theory have to pay a large amount of money for picking up a body that you personally saw fall out of the air and die of old age.
And, meanwhile, "ecotourists" who want to admire and photograph living creatures are likely to be a nicer, cleaner grade of tourists than usual, something the modest and tidy people of Bhutan can appreciate. Ecotourists are likely to appreciate cultural traditions, and not to complain that only a sustainable number of them are able to visit the habitats of rare lifeforms that might be harmed by too much contact with exotic humans and the germs we carry. Total win-win.
Bhutan is the home of a fantastic number of butterfly species, for its size. As a country it has other interesting features--mountains, Golden Langur monkeys, a child monarch. The old King provided for a peaceful transition to a democratic form of government but the tradition-loving people, like the British, still like the idea of having a king, so the King they have now is currently eight years old and said to be able to perform his ceremonial duties with a precocious solemnity, suited less to his age than to his station in life. Many other things in Bhutan are unique or nearly unique to Bhutan, and people in Bhutan aren't shy about hoping to find evidence of even more unique endemic subspecies.
If you ever go to Bhutan you will want field guides to the wildlife there. To be able to recognize all the beautiful things we see on a nature walk (even when we are close to home, and the wildlife is familiar) really takes a suitcase full of field guides. As this free-for-the-printing field guide to the Swallowtail butterflies of Bhutan observes, about 800 different kinds of butterflies are known to live in Bhutan. One book has room for nice clear pictures of the 42 of those species that are Swallowtails.
So what does this very rare, special, protected butterfly look like? Well...it looks a great deal like lidderdalii. One thing we learn from searching the Internet for information about ludlowi is that writers and photographers aren't always sure which species they're talking about. Lidderdalii is the Bhutan Glory. Ludlowi is Ludlow's Bhutan Glory, properly. Not all sources are proper about this.
Older sources didn't even make a distinction. Frank Ludlow didn't prove that ludlowi could be considered a distinct species until the 1930s, and it was not as if a lot of museums had a lot of specimens that needed to be relabelled when ludlowi was recognized as a species. Then "pesticide" spraying became common, several living things became less common than they'd been, and it was 2009 before anyone could prove beyond all doubt that ludlowi survived in the remote Trashiyangtse valley in Bhutan. (It had been reported in China, but was not confirmed to be living there.)
Photo from conservationleadershipprogramme.org shows that males and females look very much alike; the easiest way to tell which a butterfly is is to see whether or not it lays eggs. Females are usually a little larger, but the relatively few butterflies meausred have not varied much in size, all with wingspans of 4 to 5 inches.
Butterflies probably don't know that humans have defined international borders. The general rule with moths and butterflies is that females fly wherever they find suitable places to lay eggs, and males fly wherever they find females. (Swallowtails sometimes do things differently. In some, not all, Swallowtail species, females are ready to mate right after eclosion while males take a few days to hang out with other males and develop spermatophores, and females flutter around the edges of males' territories, watching their prospective mates grow up.) When their food plant and weather conditions are found on both sides of a border, so are the butterflies. Ludlow's Bhutan Swallowtail probably does visit China, and has also been found in India: If it is not molested and finds unsprayed Aristolochia vines growing up uncut flowering trees, it may become resident in those countries.
In 2020 it was found in Phrumsengla National Park. Though shown sipping nectar from low-growing summer asters, it's still flying at about 3,300 metres above sea level--more than a mile high! All species of Bhutanitis are such high flyers that ludlowi is sometimes called the "Mystical" species, the idea being that humans enter "mystical" states of hypoxemia when we visit its habitat.
Photo with news story at https://kuenselonline.com/bhutanitis-ludlowi-spotted-in-phrumsengla-national-park/
Every source seems to spell the place name differently. One word or two? Trashi or Trasi? Yangse, Yangtzee, Yangsi, Yangtsi? The most correct spelling wouldn't use our alphabet so there seems to be no consensus. It's a scenic nature preserve in eastern Bhutan, and the presence of this rare butterfly was taken into consideration during discussions about allowing farmers to raise buckwheat in or near the preserved land. This blog post was written during the period of discussion, in 2012.
Since few people are able to visit the nature preserve where this butterfly lives, a video recording of the highlights of a visit has done fairly well on Youtube:
What made ludlowi a distinct species is that, while living in the same general area and eating the same species of Aristolochia, it consistently looks different--though only slightly different--from lidderdalii. Its wings are broader, and the pinstripes are grey rather than white. Its life cycle has been studied in detail by Tshering Dendup et al.:
In the earlier stages of life ludlowi are even more distinctive: eggs are paler in color and tend to be laid in piles, and hatchling caterpillars are yellow rather than blackish. The differences seem to matter to the butterflies; they're not known to hybridize. In both species the mother butterfly perches on the edge of a leaf and carefully places a batch of eggs, by ones, on the underside. Ludlowi covers a pile of eggs with a transparent sticky layer that helps hold the pile together.
While other Bhutanitis eggs are laid in small flat clusters of 20 to 50, ludlowi are laid in a pyramidal pile of 60 to 140. Eggs are smaller than those of the other species. Caterpillars are apparently more gregarious. Larval lidderdalii line up wide by side to nibble at the edge of a leaf while they're small enough to fit on one leaf, which continues to grow while they chew it up. Once the caterpillars grow a little bigger, they go their separate ways. Larval ludlowi separate into smaller groups as the caterpillars grow bigger, but seem to feel safest with at least one side touching a sibling all through their caterpillar lives.
Hatchlings of this species do eat their own eggshells. There their appetite seems to stop. They do not go on, as some shell-eating caterpillars do, to eat nearby eggshells with their younger siblings still inside them. A time-lapse video showed that hatchling caterpillars approached and touched intact eggs, apparently heard or felt siblings inside, and left the eggs alone. This might seem like basic survival intelligence but it's closer to real survival intelligence than many Swallowtail caterpillars get. Small slow-moving animals can get a lot of survival benefit from sticking together, camouflaging themselves as something large, amorphous, and probably not edible.
Caterpillars eat their way through eight skins, each creatively ugly in a slightly different way. The general idea seems to be to look like something already rejected from the body of a very sick bird. The caterpillars are, in fact, toxic to birds. They start out amber-yellow with big black heads, then molt into light gray and then darker gray skins with red-orange warts.
Bhutanitis ludlowi can pupate for long times. A brood being cage-reared under normal weather conditions remained in the pupal form for 188 days. They can take their time developing through each of the other stages of their lives, too, so that the whole life cycle can be over in six weeks or can last two years. In laboratory conditions that seemed optimal for survival, they spent a little over five months being caterpillars, a little over six months pupating, and about two weeks flying, mating, and laying eggs. Eggs took two or three weeks to hatch.
They have few predators but a kind of snail and a kind of spider are able to eat them, and are most likely to attack helpless pupae. Some ants, wasps, and mantids also survived eating individuals of this species, according to this illustrated report.
Even more illustrations, perhaps more than you want, including close-up photos of tail ends::
No comments:
Post a Comment