Middle Eastern tree frog

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Middle Eastern tree frog
Beqikê Hêşîn.jpg

Middle Eastern tree frog ( Hyla savignyi )

Systematics
Subordination : Neobatrachia
without rank: Tree frogs (arboranae)
Family : Tree frogs i. w. S. (Hylidae)
Subfamily : Hylinae
Genre : Tree frogs ( hyla )
Type : Middle Eastern tree frog
Scientific name
Hyla savignyi
Audouin , 1827

The Middle Eastern or Asia Minor tree frog ( Hyla savignyi ) is a member of the Hylidae family, which occurs primarily in the countries of the Middle East. Until 1972 it was considered a subspecies of Hyla arborea .

features

In sexually mature male tree frogs from the Arabian Peninsula the body length is 33.4 mm (± 6.4), in females 44.4 mm (± 2.2). For the Middle Eastern tree frogs native to Cyprus, the average size given is 33 mm for the males and 36 mm for the females.

Middle Eastern tree frog

The top of the body and legs are mostly colored green. When the males call in the evening and at night, the color on the back can change to light yellow or even whitish. The males have a single, throat-like vocal sac. During the call period, the males and females are easy to distinguish, the males have yellow throats and the females white. On each side of the body, a dark brown to black stripe runs from the nostrils over the lower part of the iris, the eardrum and the flank. Around the middle of the body, the stripes dissolve into individual, dark, rows of dots that can be framed in white. The eardrum is located behind the eye, it is small, sharply defined and red-brown in color. Webbed toes are only rudimentary on the toes of the front and rear extremities; those on the toes of the rear extremities are somewhat larger than those on the front.

distribution and habitat

Hyla savignyi occurs in many countries: in central and southern Armenia, parts of Azerbaijan, in a small area of ​​Georgia, in Iraq, Iran, Lebanon, in Israel, Jordan, in a narrow area in western Saudi Arabia, in Syria and Yemen, also in eastern and southern Turkey, on the Mediterranean coast, the area includes the coastal plain of Anamur , 10 km west of it begins the range of Hyla arborea . The frog species is also found in Cyprus. In some of these countries the limits of the distribution have not yet been precisely determined. In Egypt, the occurrence appears to be limited to a small area in the northeast of the Sinai Peninsula.

The wide distribution of these tree frogs is due to the diversity of the habitats used. They live in rivers, perennial or periodic freshwater lakes, in permanent or temporary swamps, freshwater springs, canals, ditches, gardens, and also in bushland with a temperate or subtropical climate, in Mediterranean vegetation and in grassland with a temperate or subtropical climate. In general, it can be stated that the species is adapted to warm climates. This is evident from the occurrence in Armenia. In the hot and dry south of the country, Hyla savignyi occurs, in the moist and cool north, Hyla arborea .

Reproductive biology

Mating of the Middle Eastern Tree Frog

The beginning of the breeding period depends largely on the latitude and altitude of a population and the occurrence of the first rainfall. Early rains cause early calls. In Israel, males start calling between mid-December and mid-January. Call activity continues into August and then gradually declines. During the day the tree frogs stay on trees and bushes and at sunset they begin to migrate to the waters to call. The daily calling phase lasts for several hours and subsides after midnight. The lower call threshold is 9 ° C, the upper 26 ° C air temperature. During the call phase of the males, females ready to mate migrate and mate with males. The eggs are laid that same night.

Calls

Middle Eastern tree frog with a clearly recognizable sound bubble

Mating call

The mating call of the males usually consists of 15 to 50 pulse groups, at the peak of the call activity a call can also consist of 100 or more pulse groups. As the air temperature rises, the duration of the pulse groups and the intervals between them decrease linearly. According to the calculated equations, the pulse groups last 160.90 ms at 10 ° C, 135.0 ms at 20 ° C, the intervals measure 215.09 ms at 10 ° C, and 173.29 ms at 20 ° C. The number of pulses per pulse group also decreases as the temperature rises, albeit only slightly. The dominant frequency range depends on the size of the tree frogs. For a 37 mm male it is between 2.5 and 3.5 kHz, for a 47 mm tree frog between 1.8 and 3.0 kHz.

Revierruf

Males utter this call when they are less than 20–30 cm apart. The district calls cause you to move further apart. In order to trigger a quick reaction, the district calls are sometimes repeated several times. The structure of these calls is variable. An average duration of 555.20 ms was calculated from ten calls, the shortest took 388 ms, the longest 764 ms.

Solitaire call

The males emit solitary calls after the reproductive period from October to December or even until January, during the day. They sit individually on trees or bushes, mostly far from a body of water. Often other males, also sitting individually, join in, so that a small chorus is formed for a short time. The solitaire calls are made up of very short pulses, the volume of which is low.

Sense of hearing

In frogs, the bulges of the sacculus, the amphibior papilla and the basilar papilla , which are equipped with sensory cells, serve to perceive sound. According to the determination of the neural hearing thresholds, the hearing range for Hyla savignyi ranges from 100 to 6000 Hz, for some tree frogs up to 6500 Hz. Two areas with high sensitivity emerge, one in the low frequency range between 500 and 600 Hz, and another narrow range 3000 Hz. Above this, the hearing threshold rises steeply. In the low frequency range, the hearing threshold is temperature-dependent. The threshold drops up to 20 ° C; if it continues to rise, it no longer changes. According to current knowledge, frequencies of up to 1000 Hz are perceived via the amphibiori papilla and higher frequencies are perceived via the basilar papilla.

Brain irritation

The electrical stimulation was successful in male tree frogs that were in the breeding season. According to the results, the praeoptica region of the midbrain with its three core areas, the nucleus praeopticus anterior, nucleus magnocellularis and nucleus praeopticus posterior, is important for triggering the calls. The irritation at any point in the praeoptica region and also at some points in the hypothalamus led to on-call duty. The tree frogs became restless, stood up on their forelegs and partially filled the vocal sac with air. If the males were played mating calls from their own species at this stage, they made mating calls. The electrical stimulation also led to the spontaneous delivery of mating calls. The stimulus sites were in the anterior preoptic nucleus and in the vicinity of the fibers from this nucleus and in the posterior preoptic nucleus. Several minutes elapsed between the onset of irritation and the onset of calling. Slightly increased stimulus tension led to atypical reactions. Males took the signal position that is typical for females. When mating, a female uses the signal to announce the release of an egg packet to the clutching male, thereby prompting it to deliver semen. In another experiment, a female responded to the electrical stimulation with soft, rhythmic vocalizations.

Behavioral studies

The results of behavioral experiments provided information about the mechanisms of acoustic communication and at the same time confirmed the species status of Hyla savignyi . Immediately before the beginning of the evening calling phase, when the males were already on call but not yet active, they were stimulated to call by playing mating calls from both Hyla arborea and Hyla savignyi ; they responded to the species' own mating calls much faster than to them Calls from Hyla arborea .

The females also differentiated between the two mating calls. Mating calls from Hyla savignyi and Hyla arborea were broadcast from two speakers six meters apart. Females ready to mate and exposed in the middle could choose between the two mating calls. Of twelve females, eleven went to the loudspeaker that broadcast the species-specific mating call, only one female chose the call from Hyla arborea .

development

According to reliable data, embryonic development takes five to seven days, larval development 32 to 45 days. In the larvae, the gill opening is on the left side and points backwards and upwards. The anal opening is located to the right of the center of the body. After metamorphosis, the young tree frogs are 13-14 mm long.

Taxonomy

The pattern of the mating call of the Middle Eastern tree frog is specific and differs markedly from that of the European tree frog. This gave rise to the proposal to give this tree frog the status of a good species, which was accepted by the herpetological community. So far no subspecies are known. Until recently, the year when Hyla savignyi was first described by Victor Audouin has been unclear . According to the information in the literature, 1827 is correct.

The mating calls of Hyla savignyi and of Hyla japonica show very great agreement. In both cases, the duration of the pulse groups and the intervals are almost identical, as is the correlation of these two call characteristics with the temperature. Based on this match of reputation characteristics, Hyla savignyi has a closer relationship to Hyla japonica than to Hyla arborea .

Common names

Several common names are in use, including Asia Minor Tree Frog and Middle Eastern Tree Frog. The latter is the more appropriate name, as Hyla savignyi occurs predominantly in countries in the Middle East, but only populates a limited area of ​​Asia Minor.

Danger

The current state of the populations of Hyla savignyi in the range is assessed differently. Hyla savignyi is represented in large numbers at some locations ; at others, for example in Syria or Lebanon, a sharp decline is reported. The general opinion is that Hyla savignyi can be threatened locally, but this is not the case with a large-scale assessment. The fact that Hyla savignyi is at home in nature reserves is beneficial for the continued existence in Georgia, Armenia and Azerbaijan . In other areas it is threatened by the destruction of habitats in the wake of urbanization, and also by the poisoning of waterways due to the high use of pesticides to destroy mosquitoes and snails. Reports on measures to protect the tree frog do not appear to be available.

Individual evidence

  1. ^ Hans Schneider: Hyla savignyi Audouin, 1827 - Middle Eastern Tree Frog. In: Kurt Grossenbacher (Hrsg.): Handbook of the reptiles amphibians in Europe. Volume 5 / II Froschlurche (Anura) II (Hylidae, Bufonidae). AULA-Verlag, Wiebelsheim 2009, pp. 141–172.
  2. ^ Hans Schneider: The distribution of Hyla arborea and H. savignyi (Anura: Hylidae) on the south coast of Turkey. In: Zoology in the Middle East. Volume 23, 2001, pp. 61-69.
  3. ↑ Nikos Poulakakis, Paschalia Kapli, Afroditi Kardamaki, Eirini Skourtanioti, Bayram Göcmen, Çetin Ilgaz, Yusuf Kumlutaş, Aziz Avci, Petros Lymberakis: Comparative phylogeography of six herpetofauna species in Cyprus: late Miocene to Pleistocene routes , in: Journalization : Biological routes to Pleistocene Linnean Society 108.3 (2013) 619-635.
  4. ^ A b c d e Hans Schneider, Eviatar Nevo: Bio-acoustic study of the yellow-lemon treefrog, Hyla arborea savignyi Audouin. In: Zoologische Jahrbücher, Physiologie, Volume 76, 2009, pp. 497-506.
  5. ↑ Edward M. Egiasarjan, Hans Schneider: In The mating calls of tree frogs in Armenia (Anura, Hylidae). In: Zoologischer Anzeiger. Volume 225, 1990, pp. 113-122.
  6. ↑ Hans Schneider: Bioacoustics of the Froschlurche. Native and related species. In: Journal of Field Herpetology. Supplement 6., Laurenti Verlag, Bielefeld 2005, ISBN 3-933066-23-9 .
  7. ↑ Ludger Hubl, Hans Schneider: In: Temperature and auditory thresholds: Bioacoustic studies of the frogs Rana r. ridibunda , Hyla a. arborea and Hyla a. savignyi (Anura, Amphibia). In: Journal of Comparative Physiology. Volume 130, 1979, pp. 17-27.
  8. ↑ Andreas Knorr: Central control of mating call production and spawning in the tree frog Hyla arborea savignyi (Audouin): Results of electrical stimulation of the brain. In: Behavioral Processes, Volume 1, 1976, pp. 295-317.
  9. ^ Josef Brzoska, Hans Schneider, Eviatar Nevo: Territorial behavior and vocal response in male Hyla arborea savignyi (Amphibia: Anura). In: Israel Journal of Zoology. Volume 31, 1982, pp. 27-37.
  10. ↑ Hans Schneider, Eviatar Nevo, G. Heth, S. Samson, Josef Brzoska: Auditory discrimination tests of female near eastern tree frogs and reevaluation of the systematic position (Amphibia, Hylidae). In: Zoologischer Anzeiger. Volume 213, 1984, pp. 306-312.
  11. ↑ Mitsuru Kuramoto: Mating calls of treefrogs (Genus Hyla) in the Far East, with description of a new species from Korea. In: Copeia 1980, pp. 100-108.
  12. ^ E. Balletto, MA Cherchi, J. Gasperetti: Amphibians of the Arabian Peninsula. In: W. Büttiker, F. Krupp (Ed.): Fauna of Saudi Arabia. 7, 1985, pp. 318-392. Jeddah & Basle.

literature

  • Václav Gvoždik, Jiři Moravec, Cornelya Klütsch, Petr Kotlik: Phylogeography of the Middle Eastern tree frogs (Hyla, Hylidae, Amphibia) as inferred from nuclear and mitochondrial DNA variation, with a description of a new species. In: Molecular Phylogenetics and Evolution. Volume 55, 2010, pp. 1146-1166.
  • Hans Schneider, Eviatar Nevo: Bio-acoustic study of the yellow-lemon treefrog, Hyla arborea savignyi Audouin. In: Zoologische Jahrbücher, Physiologie, Volume 76, 2009, pp. 497-506.
  • Andreas Knorr: Central control of mating call production and spawning in the tree frog Hyla arborea savignyi (Audouin): Results of electrical stimulation of the brain. In: Behavioral Processes, Volume 1, 1976, pp. 295-317.
  • Ludger Hubl, Hans Schneider: Temperature and auditory thresholds: Bioacoustic studies of the frogs Rana r. ridibunda , Hyla a. arborea and Hyla a. savignyi (Anura, Amphibia). In: Journal of Comparative Physiology. Volume 130, 1979, pp. 17-27.
  • Cornelya FC Klütsch, Wolf-Rüdiger Große, Bernhard Misof, Abdul Karim Nasher, Clas M. Naumann: Distribution of the Yellow-lemon tree frog, Hyla savignyii (Audouin, 1827), in southern Arabia: updates and extensions of previous records. Zoology in the Middle East. Volume 31, 2004, pp. 47-52.
  • Mitsuru Kuramoto: Mating calls of treefrogs (Genus Hyla) in the Far East, with description of a new species from Korea. In: Copeia 1980, pp. 100-108.
  • Josef Brzoska, Hans Schneider, Eviatar Nevo: Territorial behavior and vocal response in male Hyla arborea savignyi (Amphibia: Anura). In: Israel Journal of Zoology. Volume 31, 1982, pp. 27-37.
  • Hans Schneider, Eviatar Nevo, G. Heth, S. Samson, Josef Brzoska: Auditory discrimination tests of female near eastern tree frogs and reevaluation of the systematic position (Amphibia, Hylidae). In: Zoologischer Anzeiger. Volume 213, 1984, pp. 306-312.
  • Emilio Balletto, MA Cherchi, J. Gasperetti: Amphibians of the Arabian Peninsula. In: W. Büttiker, F. Krupp (Ed.): Fauna of Saudi Arabia. Volume 7, 1985, pp. 318-392. Jeddah & Basle.
  • Eduard M. Egiasarjan, Hans Schneider: In The mating calls of tree frogs in Armenia (Anura, Hylidae). In: Zoologischer Anzeiger. Volume 225, 1990, pp. 113-122.
  • Hans Schneider: The distribution of Hyla arborea and H. savignyi (Anura: Hylidae) on the south coast of Turkey. In: Zoology in the Middle East. Volume 23, 2001, pp. 61-69.
  • Hans Schneider: Bioacoustics of the frogfish. Native and related species. In: Journal of Field Herpetology. Supplement 6., Laurenti Verlag, Bielefeld 2005, ISBN 3-933066-23-9 . Audio samples: 21.1,21.2.
  • Hans Schneider: Hyla savignyi Audouin, 1827 - Middle Eastern tree frog. In: Kurt Grossenbacher (Ed.): Handbook of the reptiles and amphibians in Europe. Volume 5 / II Froschlurche (Anura) II (Hylidae, Bufonidae). AULA-Verlag, Wiebelsheim 2009, pp. 141–172.

Web links

Commons : Middle Eastern Tree Frog  - Collection of images, videos and audio files
  • Hyla savignyi inthe IUCN 2012 Red List of Threatened Species . 2. Posted by: Sergius Kuzmin, Ahmad Mohammed Mousa Disi, Gad Degani, David Tarkhnishvili, Boris Tuniyev, Max Sparreboom, Ismail H. Ugurtas, Nasrullah Rastegar-Pouyani, Steven Anderson, Riyad Sadek, Souad Hraoui-Bloquet, Avital Gasith, Eldad Elron, Sarig Gafny, U? Ur Kaya, 2009. Retrieved May 28, 2013.