Rieppeleon brevicaudatus
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Rieppeleon brevicaudatus , male |
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Rieppeleon brevicaudatus ( Syn . : Rhampholeon brevicaudatus ) is a small species of chameleon from the subfamily of the Chamaeleoninae . The species is endemic to eastern Tanzania and neighboring southern Kenya .
features
Rieppeleon brevicaudatus remains very small with a total length of about 90 mm, 1/5 of which is on the tail, like most stump tail chameleons. The species imitates a dry leaf in its external appearance ( leaf mimicry ). The body is leaf-shaped, high and strongly flattened on the sides, the legs are very graceful and flexible. The toes each have two claws , which give the animal a very good grip on thin branches. The head is small and barely separated from the body, a small helmet attachment is evident in both sexes. The mouth is relatively pointed and can be opened very wide in order to devour large prey. The tail is triangular and very short, its gripping function is only of rudimentary importance.
The large eyes , which - protected by wrinkled eyelid skin - protrude very far from the sockets and can be moved independently of one another and drawn into the eye socket in case of danger are striking . Each eye provides a three-dimensional image by means of a special lens structure , so that distances can be estimated very precisely. Eye movements are often the only sign that an otherwise perfectly camouflaged Rieppeleon brevicaudatus reveals.
Like all chameleons , this species is also able to change its body color within seconds, but this ability is only available to a limited extent in R. brevicaudatus . The available color spectrum ranges from various shades of yellow, brown and gray to a pale green to an almost black body color.
The following pictures show some typical color variations.
♂ dark stripe drawing
♂ with a single sideline
♂ one color
♂ in fading excitation color
Depending on their mood and state of health, the males in particular often have a marbled-looking pattern of spots made up of various shades of brown and green. The scales are made up of grain scales of different sizes , which give the species a rough body surface. On the throat there is a longitudinal row of two to three large, lobed scales, which give the impression of a chin beard, which distinguishes Rieppeleon brevicaudatus from all other earth chameleons and the common name of the species bearded leaf-chameleon (in English: "bearded leaf chameleon ") has brought in.
The sexes of R. brevicaudatus can be determined using secondary sex characteristics. Adult males have a longer tail and a significantly more jagged back line than their female counterparts. The higher body shape of the females can also provide information about the sex of the respective animal. In addition, the sexes often differed in their state of excitement by their coloring. While females rarely show vivid patterns, males develop a strongly contrasting stripe pattern when excited (gender dichromatism).
distribution and habitat
The occurrence of Rieppeleon brevicaudatus is limited to the east of Tanzania and the south of Kenya ( Uluguru and Usambara Mountains , Shimba Hills, Nguru and Udzungwa Mountains, Rondo Plateau, around Masisi, north of the Rovuma River and Rufiji River Plain to the Delta), where the species occurs in the rainforests and mountain forests that are only sparsely present due to clearing at altitudes between 300 and 900 m.
The climate there is predominantly warm and humid with maximum daytime temperatures of up to 25 ° C in the closed forest with constantly very high humidity. The animals primarily inhabit the lower shrub layer of the forest and are only rarely found in higher branches.
Behavior and diet
The diurnal Rieppeleon brevicaudatus spends most of the day lying in wait passively for prey . The animals often stay completely motionless for hours in a favorable location, with their very agile eyes watching their surroundings carefully.
If the animal discovers a suitable prey (usually a small insect or arachnid), it is aimed at it with both eyes and observed motionless until it is within reach of the chameleon's long tongue. As soon as this is the case, the earth chameleon pushes a small part of its tongue out of its mouth, continues to aim at its prey for a moment and then, in a split second, purposefully hurls its tongue at the prey. Due to the mechanism ( see chameleons ) of the thickened end of the tongue, the prey animal sticks to the chameleon's catching device and can thus be carried to the mouth and swallowed whole.
The swallowing movements are instinctive and therefore also carried out in the rare event of a missed shot. Only very hungry R. brevicaudatus actively search the area for suitable prey. As a source of drinking water, the animals in nature probably use dew and raindrops that collect on leaves and twigs and are licked up directly by them. Sometimes dry branches are licked briefly with the tongue - this seems to be used for the absorption of smells or tastes and thus for orientation.
Male R. brevicaudatus, in particular, behave very territorially towards other members of their sexes and defend their territory with threatening gestures. Nothing is known about actual fights between representatives of the species.
A very interesting behavior of the species is a high frequency vibration of the body in case of danger. Presumably, this vibration not only serves to deter predators, but also for intra-species communication, since the vibrations are transmitted in the thin branches and can thus signal the presence of a conspecific. Posture and coloration also play a major role in communication between males and females. The animals usually spend the night sleeping in higher branches.
Reproduction
Courtship behavior
Rieppeleon brevicaudatus is one of the egg-laying chameleons. The copulation is preceded by an extensive courtship in which the male tried by a magnificent play of colors, body vibration and hearty nod to draw the attention of the female up. Females who are not ready to mate evade these approaches by fleeing or by defensive vibration of their bodies. In cramped conditions (as in terrarium keeping), even females who are not ready to mate are held and mounted by sexually active males. If the female allows the male to make advances, the male will sometimes circle it several times before the male gets on his partner's back and mates.
Oviposition and development
The females carry the fertilized 2–6 eggs in their bodies for about 30 days and then usually deposit them in a previously dug pit in the warm, moist soil substrate. Depending on the temperature and humidity of the substrate, the eggs hatch after 40–90 days with a total length of around 20 mm, which reach sexual maturity after around 9 months .
Females can store the sperm in their bodies for a longer period of time and thus fertilize eggs without further mating. This seems to be an adaptation to the very hidden way of life of this species, which guarantees that a female will be able to continue producing fertilized eggs even after a long and unsuccessful search for a partner.
Camouflage and enemy defense
In addition to the already mentioned mimetics , R. brevicaudatus has other possibilities to ward off predators. The species protects itself when it touches the body directly through the high-frequency vibration mentioned above. Many predators give up instantly from such a vibrating prey. In addition, the species can excellently play dead (thanathose) - the animals let themselves fall, draw their eyes, flatten their bodies and become completely immobile. In addition, they usually change their color to dark tones to perfect the illusion. A weakened form of this behavior to defend against enemies can also be found in this species in the form of akinesia , the persistence in a complete lack of movement when threatened.
Origin of name
The old generic name of the species Rhampholeon is derived from ancient Greek and means in German something like "beak-lion" (from Greek ράμφος ( rhámphos ) for "beak" and λέων ( léōn ) for "lion"). The word part leon makes it a reference to the word "shaman leon " her and thus has the affiliation of the genus to the chameleons out. The Latin species name brevicaudatus means “short-tailed” (from Latin brevis for “short” and cauda for “tail”). A clear German name is not established, the species is usually referred to as the "earth" or "stump tail chameleon", but this name is also used for all other representatives of the genera Rhampholeon and Brookesia .
Taxonomy and systematics
Rieppeleon brevicaudatus was placed by the first describer Paul Matschie in 1892 to the genus Rhampholeon in the subfamily of the stubby-tailed chameleons (Brookesiinae), which is opposite to the subfamily of the real chameleons (Chamaeleoninae). According to a more recent study, however, this classification is in need of revision from the point of view of molecular biology . The species R. kerstenii , R. brachyurus and R. brevicaudatus differ so clearly from the other species of the genus that a transfer to an independent genus seems justified. The authors of the study therefore propose to establish the new genus Rieppeleon and to transfer the three above-mentioned species into it.
In part, this suggestion is already being implemented in specialist circles, so official sources such as ITIS (Integrated Taxonomic Information System) already list this type under Rieppeleon (June 2007). The current literature also lists the species R. brevicaudatus in the genus Rieppeleon .
Furthermore, the authors of the above-mentioned study question the assignment of the genera Rhampholeon and Rieppeleon to the subfamily Brookesiinae and suggest a closer relationship to the real chameleons of the subfamily Chamaeleoninae . Accordingly, the previously assumed close relationship between the genera Brookesia and Rhampholeon (including Rieppeleon ) would not exist. This new scientific development is explained below using two comparative graphics.
Systematic position of Rhampholeon brevicaudatus according to Matschie, 1892
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Systematic position of Rieppeleon brevicaudatus according to Matthee et al., 2004
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Terrarium keeping
Rhampholeon brevicaudatus is a relatively delicate foster animal that is rarely offered for sale and is therefore not kept very often. In addition, the species is rarely bred, which is why most of the animals offered are wild-caught from Tanzania .
- Accommodation
- To keep a couple or a male with two females, a densely planted terrarium with the minimum dimensions L 60 × D 30 × H 40 cm should be selected.
- The soil substrate layer, which is at least 3 cm high, can consist of forest soil, a mixture of sand and peat or similar materials and should be covered with a layer of leaves (e.g. oak ) at least 5 cm high . The rest of the facility should include many climbing options that are based on the size of the animals. Particular attention should be paid to well-structured hiding places so that the animals can avoid each other completely and avoid any visual contact if necessary.
- Climatic conditions
- Rhampholeon brevicaudatus prefers daytime temperatures between 20 and 25 ° C with a night drop of 2-3 ° C. The humidity should be constantly high (70-100%), which is achieved by spraying the terrarium every day.
- It is also important to have a sufficient supply of fresh air to avoid sticky air and waterlogging.
- The animals are susceptible to permanently high temperatures and usually do not get very old under these circumstances.
- Lining
- As in nature, the species feeds on small insects and arachnids up to a size of 2 cm in the terrarium. Corresponding feed animals are z. B. medium-sized crickets , flies and Drosophila . A varied feeding increases the well-being of the animals. In order to prevent deficiency symptoms, the insects should be well nourished before feeding and occasionally pollinated with mineral and vitamin preparations.
- The chameleons use water droplets as a source of liquid, which stick to furnishings after daily spraying.
- Conduct in captivity
- The species is known to be very calm and tolerable. Females can usually be socialized very well with one another, while males should never be kept together in a terrarium, as their pronounced territorial behavior puts each other under stress, which in the long term can lead to health damage.
- Offspring
- The offspring of R. brevicaudatus in human hands has been successful several times and over several generations. If kept correctly, the animals will readily mate and bury their clutches in the soil.
- The eggs can be matured in the holding tank or separately at room temperature (22–24 ° C). The approximately 20 mm large young hatch at these temperatures after around 50-70 days and can be fed with Drosophila and micro home soon after hatching .
Danger
Little is known about the existence of the species because of the hidden way of life and the only scant scientific research. Since the rainforests of the Uluguru and Usambara regions have already been cleared to a large extent and this development is continuing, a threat cannot be ruled out. In addition, depending on the season, large numbers of specimens are taken from nature to meet the needs of reptile keepers in Europe, Asia and America. A project of the Wildlife Conservation Society that has existed since 1999 to protect the remaining primeval forests in the Uluguru Mountains is pursuing protective measures for the resident populations of the species, and further measures for the targeted protection of the genus are being discussed (status autumn 2005).
literature
- Dominik Kieselbach, Rolf Müller, Ulrike Walbröl: Chameleons (= your hobby. Vol. 7). BeDe-Verlag, Ruhmannsfelden 2001, ISBN 3-933646-34-0 .
- Günter Masurat: Multiplication of chameleons. Basics, instructions, experiences. Herpeton, Offenbach 2005, ISBN 3-936180-06-7 .
- Petr Nečas, Wolfgang Schmidt: Stubby-tailed chameleons. Miniature kites of the rainforest. Edition Chimaira, Frankfurt am Main 2004, ISBN 3-930612-48-8 .
Individual evidence
- ^ Petr Nečas, Wolfgang Schmidt: Stummelschwanzchamäleons. Miniature kites of the rainforest. 2004, p. 181 ff.
- ↑ Stephen Spawls, Kim Howell, Robert Drewes, James Ashe: A Field Guide to the Reptiles of East Africa. Kenya, Tanzania, Uganda, Rwanda and Burundi. Academic Press, San Diego CA et al. 2002, ISBN 0-12-656470-1 .
- ↑ Kim M. Howell, Charles A. Msuya, Philip M. Kihaule: A preliminary biodiversity (Fauna) assessment of the Rufiji Floodplain and Delta (= Rufiji Environment Management Project. Technical Report. No. 9). Rufiji Environment Management Project, Dar es Salaam2000, online .
- ↑ T. Hildenhagen: On the biology and distribution of Tanzanian stub-tailed chameleons of the new sub-genus Rhinodigitum Matthee, Tilbury & Townsend, 2004 with comments on keeping and reproduction. In: Elaphe. NF Vol. 13, No. 4, 2005, ISSN 0943-2485 , pp. 31-41.
- ↑ Conrad A. Matthee, Colin R. Tilbury, Ted Townsend: A phylogenetic review of the African leaf chameleons: genus Rhampholeon (Chamaeleonidae): the role of vicariance and climate change in speciation. In: Proceedings of the Royal Society of London. Series B: Biological Sciences. Vol. 271, No. 1551, 2004, pp. 1967–1975, doi : 10.1098 / rspb.2004.2806 , digital version (PDF; 268.68 kB) .
- ^ Rhampholeon brevicaudatus in the Integrated Taxonomic Information System (ITIS). Retrieved January 30, 2007.
- ↑ Rolf Müller, Wolfgang Schmidt: Stubby-tailed chameleons of the genus Rieppeleon. (Care and reproduction). Herpeton-Verlag Elke Köhler, Offenbach 2008, ISBN 978-3-936180-24-4 .
