Bobiri Butterfly Sanctuary Poster
Transcription
Bobiri Butterfly Sanctuary Poster
How many butterfly species are in Ghana? Known Butterfly Species in the World by Biogeographic Region Neotropical Afrotropical Oriental Palearctic Papuan/Australian Nearctic 8000 3800 2700 2000 1000 700 The Afrotropical Region is second only to the Neotropics (i.e., Central and South America) in terms of the number of butterfly species that occur. Ghana has about 900 species. Over ⅓ of these described species are considered rare or very rare. It is estimated that about 5% of Ghana’s butterfly species, those that are especially rare, have yet to be discovered. Ghana’s butterflies are overwhelmingly forest-dwelling species (~730 of 900). Most forest butterfly species generally do not venture far (if at all) into non-forested areas. Most savanna or open habitat butterfly species do not venture far (if at all) into forested areas. The butterflies you see around Bobiri guesthouse are a mixture of open habitat species and forest species. Salamis parhassus, the Forest Mother-ofPearl. This is one of Ghana’s largest and most beautiful species. The upper wing surface is silvery-white and is cast with a purplish sheen. It is a generally common species and can often be seen flying in the forest. Bobiri Forest Reserve is an example of the moist semideciduous forest habitat subtype (the other subtypes are wet evergreen, moist evergreen, and dry semideciduous). Some of Ghana’s forest butterflies do not occur at Bobiri because they require wetter conditions.. Nearly 500 butterfly species have been documented in Bobiri forest. Additional species likely exist here and would be uncovered from more exhaustive surveys of the forest. Why create a butterfly sanctuary? Forest reserves in Ghana Bobiri o g To Co te d Forest reserve condition ’Ivo 1 Excellent ire 2 Good 3 Partly degraded 4 Mostly degraded From: Hawthorne & Abu-Juam (1995) Forest Protection in Ghana. IUCN Publ. 5 Poor No significant forest Ghana’s forests are among the most critically imperiled in the world and also among the most biologically unique. It is estimated that 80-90% of original forest cover has been destroyed. Virtually no forest cover remains outside existing forest reserves. Some reserves no longer even have any forest left. As forest habitat disappears, so too do forest dependent species, such as Bobiri’s forest butterflies. Bobiri butterfly sanctuary was the brainchild of Dr. Joe Cobbinah, Director, Forestry Research Institute of Ghana, and Dr. Mike Wagner, Professor, Northern Arizona University, USA. This sanctuary was created to provide 1) protection for the species that live here, 2) an income source, which helps promote sustainable use of forest biodiversity, and 3) a place where Ghanaians and foreign nationals alike can learn about and enjoy the country’s unique and beautiful forest communities. What do butterflies eat? Most butterflies take in nourishment by sucking fluids through their proboscis or “tongue”. You are probably most familiar with the nectar feeders, that is, the butterflies that visit flowers. But many butterflies do not feed on nectar. About ¼ of Ghana’s butterfly species never visit flowers. These species feed, instead, on rotting or fermenting fruit. The large majority of fruit-feeding species in Ghana are forest dependent species. You will cause many of these to “startle up” as you walk along the forest trails. Did you know that some butterflies actually also feed on excrement and/or animal carcasses? Three forest species feeding on fruit that has fallen to the forest floor. Euphaedra perseis (top). Bebearia mardania (bottom left) and Bebearia zonara (bottom right). Many butterflies also puddle on wet sand or mud, where they take up water, minerals, and amino acids. Often large numbers will gather at a single spot and fly up en masse when disturbed. The two individuals below belong to the family, Lycaenidae. Members of this family are nectar feeders and are very small. The many types of tiny butterflies you see flying at Bobiri are Lycaenids. In fact there are more Lycaenids in the world then any other type of butterfly. Nearly ⅓ of Ghana’s butterflies are Lycaenids. Papilio nireus male puddling along the road to Bobiri Butterfly Sanctuary. This is a common forest species that visits flowers. The wings on the upper side of this butterfly are black and traversed by bright green bands; hence, its common name, the Narrow-Banded Green Swallowtail. The male of Nepheronia thalassina is a beautiful duck’s-egg-blue. These are common visitors to the flower gardens at Bobiri. Why do unrelated species look alike? Many butterfly species resemble each other in color and pattern. This is known as mimicry and results slowly over time from natural selection. Non toxic species mimic (resemble) species that are toxic or taste bad. Predators then avoid both species even though the mimetic species could be eaten without harmful results. Ghana has many mimetic species. Papilio dardanus, a common visitor to flowers at Bobiri, is a spectacular example of mimicry. P. dardanus males all look the same, but there are at least 14 different female forms in sub-Saharan Africa all of which resemble unrelated species! Some mimetic species found in Ghana. ABOVE: Papilio dardanus male (top left) and P. dardanus female (top right). Amauris niavius (bottom left) and P. dardanus female (bottom right). RIGHT: Left column, top to bottom: Acraea vestalis male, Acraea macaria male, Acraea alcinoe female, Acraea epaea male, Acraea epaea female ... Right column: Five different mimetic forms of Pseudacraea eurytus. Butterfly Behaviors Butterflies display a number of interesting behaviors, many of which are associated with finding and selecting a mate. Males locate females either by patrolling areas where females feed or lay eggs, or by perching along “flyways” in wait. Perching males will vigorously defend their space by “fighting” and actively chase other males away. Mating often involves a series of behaviors in which the male “courts” the female. Few females in nature are unmated because males will check out any butterfly that fits a basic image and attempt to mate with any female of the right species. In some species males will even collect on the pupal case or chrysalis of a female and wait for her to become an adult and emerge. Only the most competitive male gains access to the female. You may see a butterfly flying from plant to plant after briefly alighting on leaves of each. Butterflies “taste” with their “feet” and this is a female searching for the appropriate host on which to lay an egg. Euriphene barombina (above) is a common fruit-feeding forest butterfly at Bobiri. The male is easily recognizable because of its distinctive blue color and set of white dots. Females are brown and orange with a white stripe across the forewing and look nothing like the males. Euphaedra medon (below) is another very common fruit-feeding forest species. There are approximately 75 Euphaedra species in West Africa. Both of these males are “perched” on plants in sunny spots along one of Bobiri’s trails. ABOVE LEFT: Bebearia zonara male courting a B. zonara female. The male is hovering near the female, rapidly fluttering his wings. Intermittently, he will make physical contact by “shoving” the female. He is likely giving off pheromones (sex hormones) during the whole courting process. If she is receptive, they will mate. ABOVE CENTER: Kallimoides rumia, the African Leaf Butterfly, perched in typical position, i.e., head down on broad leaves about 2-3 meters above the ground. K. rumia is fond of palm wine and this particular individual is hanging out at one of the palm wine-tapper’s camps in the forest ABOVE RIGHT: Palla decius perched on a tree along the main Bobiri road. P. decius is a member of the Charaxinae subfamily. The Charaxinae are large, robust, strong flying butterflies that are especially attracted to excrement. Credits The current checklist of butterfly species at Bobiri was compiled by Dr. Torben Larsen (left) in conjunction with research for his book, Butterflies of West Africa (Apollo Books, Svenborg, Denmark, October 2005). Dr. Larsen also provided the plates depicting examples of mimicry. The photo of Nepheronia thalassina, was shot by Sky Stephens. The photographer of the Larsen photo is unknown. All other photos are by the author, J. L. Bossart, who also assumes responsibility for any factual errors. Rose-Hulman Institute of Technology (Terre Haute, IN, USA) graciously printed these posters free of charge.