Black-scarred toad
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Black- scarred toad ( Bufo melanostictus ) |
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| Bufo melanostictus | ||||||||||||
| Schneider , 1799 |
The black- scarred toad ( Bufo melanostictus , Syn . : Duttaphrynus melanostictus ) is a species of amphibian from the genus of real toads ( Bufo ) within the toad family (Bufonidae). It is the most common species of toad in Southeast Asia.
features
Black-scarred toads have a plump, stocky body and move around with short bumps. The basic color is variable gray to brown or reddish with dark spots on the upper side, dirty white on the underside and partly light brown speckled. Individual specimens can be distinguished from one another based on their individual wart pattern on the head, which run in rows along the contours. The black, partly raised strips around the eyes and on the snout give the animals a somewhat mask-like and angular appearance. The horn bumps of the warts on the body are black. These are particularly numerous on the flanks. There are also eight to nine conspicuously large and prominent warts behind the base of the head. The eardrums are clearly visible and are at least two thirds the diameter of the eyes. The poison glands ( parotid glands ) on both sides of the head are elongated, like two or three eyes in a row; in the cane toad they are more triangular and about five times the size of the eye.
The males are much smaller than the females, and there are also regional differences within the species. A female in Thailand measured 115 millimeters, a female on Borneo measured 78 millimeters and a male from there measured 68 millimeters. In Pakistan females with 150 millimeters head-body length have been observed. In males in heat, the throat turns light orange or yellow; in addition, these heat calluses develop on the insides of the first two fingers.
distribution
The black-scarred toad is the most common species of toad in South and Southeast Asia. It lives in most of India , on Sri Lanka, and is widespread north to near the Yangtze in China . They also live disjointly in a small area on China's Yellow River . In the Himalayas they can be found up to heights of 3000 meters. In the south, back India and the Great Sunda Islands to Borneo and Java are part of their distribution area. In recent years, it has spread further east in the Southeast Asian island world, which can be attributed to human releases or abductions. Examples are the islands of Bali , Sulawesi , Ambon ( Moluccas ) and the bird's head in northwest New Guinea .
In 2008 and 2009 there were reports in East Timor that the foreign troops had brought the European toad ( Bufo marinus ) into the country from Australia , which became a political issue because of the property of this species as a particularly invasive neozoon (see also: fauna of Australia ) . The frogs, known by the population as the interfet frog (“ Manduku Interfet ”), have always been identified as black- scars toads , which had only migrated to Timor from Indonesia a few years earlier . However, it is now relatively common there. The black-scarred toad has recently spread to Madagascar and threatens the native fauna there.
Way of life
The black-scarred toad is a culture follower. In Borneo it was only found in large settlements, in Java in squares and gardens in the cities. It lays its spawn in ditches and on flooded fields. In Timor they were found in cities, in coffee plantations and in the undergrowth on the coast.
The animals are nocturnal. During the day they hide under objects such as roots and stones, whereby they are sometimes sociable and can be quite local. At dusk they come out and hunt invertebrates . You can often see them under street lights, where they pick up falling insects.
Reproduction
Black-scarred toads were seen spawning all year round in the constantly rainy Java. Possibly they also orientated themselves on the phases of the moon. A larger number of spawning pairs have been observed with the waxing moon and full moon than at other times. In more temperate zones of the western Himalayas, the monsoons open the spawning season in July and August.
The males sitting on the banks of waters utter little melodious mating calls such as "curr, curr, curr", which end with a whistle. They are numerically far superior to the females and behave aggressively towards each other. As soon as a male has discovered a female, it climbs on its back and clasps it in the axillary region (axillary amplexus ). Then the couple tries to find a quieter place within the spawning water. Similar to the European common toad , the spawn is released in long, two-row jelly cords. These are anchored between aquatic plants and submerged branches by the pair swimming around during spawning. The later hatching tadpoles are colored black on top.
swell
Individual evidence
- ↑ a b c d Günther E. Freytag, Bernhard Grzimek, Oskar Kuhn & Erich Thenius (eds.): Lurche . In: Grzimeks Tierleben, Vol. 5: Fish 2, Lurche. Licensed edition in dtv, Munich 1993, ISBN 3-423-05970-2
- ↑ a b c Hinrich Kaiser et al., PhD, Department of Biology, Victor Valley College: The Herpetofauna of Timor-Leste: a First Report , (Journal ZooKeys) doi: 10.3897 / zookeys.109.1439
- ↑ Distribution map of the black-scarred toad at www.iucnredlist.org
- ↑ Wikinews, September 12, 2008, Toad Plague does not originate in Australia?
- ↑ ABCnews, December 17, 2009, Fears cane toads have hitched to E Timor
- ↑ Angelika Franz: Alien Species Threaten Madagascar's Wildlife: The Toad Invasion , Spiegel Online, May 29, 2014
- ^ Benjamin Michael Marshall, Nicholas R. Casewell, Miguel Vences, Frank Glaw, Franco Andreone, Andolalao Rakotoarison, Giulia Zancolli, Friederike Woog, Wolfgang Wüster. Widespread vulnerability of Malagasy predators to the toxins of an introduced toad. Current Biology, 2018; 28 (11): R654 DOI: 10.1016 / j.cub.2018.04.024
Web links
- Art portrait at Amphibiaweb (English)
Web links
- Nick Baker: Asian Toad. Ecology Asia, accessed December 8, 2013.
- Duttaphrynus melanostictus inthe IUCN 2013 Red List of Threatened Species . Posted by: Peter Paul van Dijk, Djoko Iskandar, Michael Wai Neng Lau, Gu Huiqing, Geng Baorong, Lue Kuangyang, Chou Wenhao, Yuan Zhigang, Bosco Chan, Sushil Dutta, Robert Inger, Kelum Manamendra-Arachchi, Muhammad Sharif Khan, 2004 Retrieved October 6, 2013.