Hyla meridionalis usually grows to 50 mm, with females up to 65mm in
length. Slender, long-legged tree frog, with smooth skin. The head is broader than long.
Adhesive discs on all digits, with those on the fingers being larger than on
the toes. The back is mostly green, but a yellowish, gray, brown or spotted
coloration also occurs. Color change is physiological. The venter is whitish.
A dark stripe is present from the nostril across the eye and tympanum to the
shoulder. The iris is brownish golden, the pupils are horizontal.
The tympanum is clearly visible and about half the diameter of the eye.
Males posses a vocal sac which can be inflated to a size half the
snout-vent length. At rest, the vocal sac is longitudinally folded and yellow
to brownish in color. The throat of females is somewhat lighter than the
venter. Taken from Noellert and Noellert (1992) and Bons and Beniez (1996).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Algeria, France, Italy, Monaco, Morocco, Portugal, Spain, Tunisia
The general area occupied by H. meridionalis in Europe extends from
S France and NW Italy, to S Portugal and Spain, including Menorca, in the
Balearic Islands, and the Canary Islands. Its European range includes two main general groups of
populations. A southern group occupies S and W Spain and Portugal, and
a northern group extends from NE Spain and S France to NW Italy. The
southern group occupies mainly Central and S Portugal and SW Spain; it is
prolonged eastwards by three discontinuous groups of populations. One
group occurs along the Spanish Mediterranean coast from the provinces of
Huelva and Cádiz to the region of Murcia. The second group inhabits Sierra
Morena on the southern slopes of the Central Plateau. And the third group
runs along the Tajo River, which acts as a corridor for the penetration of
the western populations inside the Central Plateau, across the provinces
of Toledo and Avila. The northern group of populations is separated from
the southern one by a long gap across the E Spanish Mediterranean coast
from Murcia to Cataluña. This group shows populations in the eastern
portions of Cataluña in NE Spain, in a wide area of S France, and across
the Liguria region to the province of Genova in NW Italy. The populations
from S France are widely spread along the Mediterranean coast, running
along the Rhône Valley as far as the Dr6me, and along the southeastern
slopes of the Massif Central as far as the northwestern portions of the
Charente-Maritime département. Some isolated populations have been reported
from the south of the Landes region, in the département of
Pyrenées-Atlantiques in France and in the Basque Country in Spain.
H. meridionalis is also present in the Balearic Archipelago
but restricted to Menorca Island, where it occurs throughout the island.
Little is known of the northern limits of the range. In Iberia its
distribution seems to be limited by the cold and dry regions of the
Central Plateau, but the northwestern and eastern limits along the
coasts are uncertain. There is no actual continuity between the
populations of the northern Mediterranean coast and the southern
Mediterranean ones. The northern and the southwestern limits of its
distribution in France are uncertain. H. meridionalis is usually
found at low altitudes, from sea level up to 450 m in Portugal and 650m
in France. Exceptionally it can exceed 1000 m in NE Spain (Montseny,
province of Barcelona), and S France (Gasc 1997).
H. meridionalis also occurs in NW Africa. Here it occurs in
the humid Mediterranean regions of the Mahgreb. In Morocco it occurs
in the Moyen et Haut Atlas. It is found up to an altitude of 2650 m
in Oukaimedene in the Haut Atlas (Schleich et al. 1996).
different form is found in the Anti Atlas Mountains the southernmost
part of the range of the species (Bons and Beniez 1996).
Life History, Abundance, Activity, and Special Behaviors
Mating occurs in March and April in North Africa, while the European
populations mate from April to June (France) or from December to January
(Portugal). Males call from water as well as from land and trees. The
individual call is a deep, resonant "Cra-a-ar", repeated not much faster
than every second and typically much slower (Burton and Arnold 1978).
Calling can also occur in duo's, trio's or choruses, and is sometimes
deafening. Calling can be heard from kilometers away during the calling
peak in the breeding season. Amplexus lasts several hours to some days.
Fleeing reactions are greatly reduced in mated couples. For oviposition
they prefer plant accumulations near the shore. The female searches an
object to attach her eggs to and expulses some spawn. This is the signal
for the male to dip his hindbody down and inseminate the eggs. Oviposition
is repeated at many places until the female has no more eggs to expel. Even
then she continues to act as before, but when the male notes that there
are no more eggs he quits. When breeding is finalized the frogs leave the
vicinity of the water and move away into trees etc. where they call mainly
during the afternoon or evening hours until aestivation begins.
The eggs are 800-1000 in number, deposited in lumps of 10-30 each, mostly
on plants, but some sink to the bottom. Ovum diameter is 1.1 to 1.5mm, with
a gelatinous envelope of 3-5mm. Tadpoles hatch after 8-10 days with a total
length of 5-8mm. The tadpoles have high fins relative to their total length.
They grow up to 4cm, with a maximum of 5.5cm. Metamorphosis occurs 3-4 months
after hatching. The diet consists of various arthropods like spiders, bugs,
beetles, butterflies, flies and ants, which are caught from ambush by day
and by foraging at night (Schleich et al. 1996).
Trends and Threats
The main areas of distribution of the species in SW Iberia and S France seem
to maintain a relatively high number of populations, although the rapid
destruction of breeding biotopes and the intense use of pesticides, both
a consequence of the loss of traditional agricultural methods, could
modify the present situation in a short period of time. The populations
of the southeastern Mediterranean coast and the isolated populations in
the Basque Country could be considered the most endangered populations
in Spain. The latter, limited to a few ponds in sandy soil, have recently
been recorded again, but the possibilities of continuity appear to be very low
Honnegger (1981) notes that the species is suffering
from an intensive anti-mosquito campaign along the Mediterranean coast.
Relation to Humans
Reaches high population densities in banana plantations in the Canary Islands
(Schleich et al. 1996).
Possible reasons for amphibian decline
General habitat alteration and loss
Intensified agriculture or grazing
Local pesticides, fertilizers, and pollutants
Bons, J. and Beniez, P. (1996). Amphibiens et Reptiles du Maroc (Sahara occidental compris). Asociacion Herpetologica Española, Barcelona.
Burton, J. A., and Arnold, E. N. (1978). Reptiles and Amphibians of Britain and Europe. Collins, London.
Gasc, J.-P. (1997). Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica, Bonn, Germany.
Honegger, R. E. (1981). Threatened Amphibians and Reptiles in Europe. Akademische Verlagsgesellschaft, Wiesbaden.
Nöllert, A. and Nöllert, C. (1992). Die Amphibien Europas. Franckh-Kosmos Verlags-GmbH and Company, Stuttgart.
Schleich, H. H., Kastle, W., and Kabisch, K. (1996). Amphibians and Reptiles of North Africa. Koeltz Scientific Publishers, Koenigstein.
Stumpel-Rieks, S. E. (1992). Nomina Herpetofaunae Europaeae. AULA-Verlag, Wiesbaden.
Originally submitted by: Arie van der Meijden (first posted 1999-09-29)
Edited by: Kellie Whittaker (2021-01-26)
Species Account Citation: AmphibiaWeb 2021 Hyla meridionalis: Mediterranean Tree Frog <https://amphibiaweb.org/species/867> University of California, Berkeley, CA, USA. Accessed Mar 20, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Mar 2023.
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