Yehudah Werner

• Professor Emeritus
• Research Director at Hebrew University of Jerusalem

1. This project seeks to identify determinants of the variation observed in the foraging behavior of predatory animals, especially in moonlight, using a lizard as a model. 2. Moonlight generally enhances the foraging efficiency of nocturnal visual predators and often depresses the locomotor activity of prey animals. Previous evidence has indicated...

In modern Cetacea, the ear bone complex comprises the tympanic and periotic bones forming the tympano-periotic complex (TPC), differing from temporal bone complexes of other mammals in form, construction, position, and possibly function. To elucidate its functioning in sound transmission, we studied the vibration response of 32 pairs of formaldehyd...

Eye size is interesting in snakes because in most species body length differs between the sexes, while the eye's performance depends on its absolute size. So, does the smaller sex see less well? We hypothesized that eye sexual mensural dimorphism (SMD) would be smaller than Body SMD. We found among 26 snake populations that body length SMD was fema...

Opinions differ whether tail loss in lizards is mainly caused by predators or by intra-specific fighting. Recently this dilemma was investigated through a comparison of lizard tail loss rates between mainland populations in Greece and those on nearby islands harboring fewer predators. The higher tail loss rate on the islands was interpreted as due...

Most vertebrate species are bisexual. But as well as the sexual behavior, same-sex mating-like behavior sometimes occurs. Recently, the same-sex mounting reported from chelonians was reviewed. The potential causes for such behavior that were hypothesized, such as dearth of correct mates or expression of dominance, are of the social domain. On furth...

Widely accepted major criteria for biodiversity hotspots that deserve conservation include species richness, endemism and threat. Proving that a taxon is endemic to a given area is more difficult, and therefore expensive, with animals than with plants because of the difficulty to prove absence outside the known distribution. Seeking a cost-efficien...

Body size is an ecologically important variable in animals. The geographical size variation of most snakes and some lizards counters Bergmann's rule in that, among related taxa, the larger ones live at warmer latitudes. However, exceptions notwithstanding, and despite being ectothermic, turtles as a group tend to obey Bergmann's rule. We examined t...

The geographical distribution of reptiles is known to be climate dependent. Our analysis of literature data from the Palearctic confirmed that snakes, as a group (186 species), tend to extend further to the north, into cooler climate, than lizards (460 species). This has also been reported for the Nearctic. On a smaller scale, as a model, we invest...

Gekkoninae, laying rigid, precisely mensurable eggs in invariable clutches, served to examine the relations between egg shape, egg size and mother size, at intra—and interspecific levels. Ellipticity (ratio width/length) and volume were calculated from linear measurements of 82 eggs obtained in captivity from geckos of eleven Near-Eastern taxa. Clu...

Species richness in Israel was studied by correlating the number of species of mammals, birds, and reptiles in 30 × 30 km squares with several environmental factors. The most diverse areas in Israel (in terms of number of species) were transition zones between the Mediterranean, Irano-Turanian, and Saharo-Arabian regions. For mammals and birds, the...

Contact zones between Israeli Ptyodactylus species were evaluated from museum material and hybridization experiments, the first controlled hybridization between gekkonid species. In southern Israel and Sinai P. guttatus and hasselquistii are partly sympatric, occasionally syntopic. Intermediate specimens were absent and experimental hybridization f...

Two Israeli aglyphous colubrid snakes seem to mimic venomous viperid snakes. Spalerosophis diadema cliffordi resembles sympatric desert viperids, especially Vipera persica fieldi, in girth, coloration and defensive behaviour. Coluber ravergieri nummifer resembles the sympatric Vipera palaestinae in length, coloration and defensive behaviour. Direct...

As a contribution to the study of ecological types among gekkonoid lizards, eye size, expressed as a percentage of rostrum-anus length (percra), was examined. Preliminary tests showed that preservation effects and sexual dimorphism are negligible, that ontogenetic allometry and geographic variation have to be considered, and that external spectacle...

In Israel three rear-fanged snakes (Colubridae: Boiginae) of the genus Telescopus possess a defensive display in which they coil, pose in readiness to strike, and often simultaneously flatten and triangulate the head. Thus they become similar to the venomous Viperidae in general. On indirect evidence, two of them appear to be mimics of sympatric vi...

In some gekkonomorph lizards electrophysiological audiograms were shown to be more sensitive in adults than in juveniles. We asked whether that was due to age or size. To answer this, we examined the middle-ear transfer function at the tympanic membrane (TM) by laser interferometry, in adults of 3 large species, adults of 3 related small species, a...

Climbing geckos normally locomote appressed, with the belly close to the substratum. Ground-dwelling geckos usually locomote semi-erect, the trunk elevated on the vertical antebrachium and crus, brachium and femur being roughly horizontal. Certain Israeli psammophile geckos often rest, and apparently sometimes walk, erect-legged, on extended limbs....

The maximum longevity of geckos (Reptilia: Lacertilia: Gekkonoidea) in captivity is reported for 55 species and subspecies. Ninety-five additional maximal literature records are reviewed, yielding a total of 37 new records. Among 15 species with samples of n ≥ 10 (in the authors' care), the maximum specific longevity (after capture usually as adult...

Vocalizations of Ptyodactylus hasselquistii cf. hasselquistii from Sinai were analysed spectrographically and compared to those of its geographical neighbour, P. h. guttatus, and of other lizards. The multiple click calls (MC) of these and some other gekkonid lizards have certain basic features in common but vary specifically in details; those of P...

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed i...

The distinction of Acanthodactylus boskianus asper (AUDOUIN, 1827) from A. b. boskianus (DAUDIN, 1802) has always been debated, due to the variation within the former. We describe an overlooked qualitative pholidotic character that occurs in A. b. boskianus but not in A. b. asper or several other congeneric taxa, namely a vertebral track of smaller...

The publication entitled Description de l'Égypte, which carries scientific results from Napoleon Bonaparte's conquest of Egypt, includes illustrated descriptions of two lizards, Acanthodactylus boskianus (Daudin 1802), and the new A. asper (Audouin 1827). We note that their original drawings differ conspicuously in the degree of abruptness with whi...

The distribution of the Arabian desert lizard Acanthodactylus opheodurus Arnold, 1980 in the Levant is re-examined. West of Jordan it is almost limited to the ‘Arava Valley, absent from most of the Negev and from Sinai. This correction of an earlier report derives from re-identification of specimens, relying on the colour pattern difference from th...

The Gekkonidae (Diplodactylinae and Gekkoninae) have traditionally been considered «sit and wait» predators. Recent literature shows that some species use a more active, or a mixed, foraging strategy. This report adds occasional observations in Australia, of cases of apparent «widely foraging» practice by individuals of Diplodactylus ciliaris, D. s...

The reproductive biology of Eirenis species is little known. We report on captive reproduction episodes from two pairs of Eirenis levantinus SCHMIDTLER, 1993, from the southern limit of the range, and compare with data from the north of the twin. Individuals reproduced at least to the age of nine years. Clutch size was 3-5 eggs. Average egg size at...

After introducing the distribution and biology of Natrix tessellata in Israel, on the southern edge of its range, we address its intraspecific variation from the literature and examination of 262 museum specimens. Head pholidosis showed no significant directional asymmetry, but asymmetry in infralabial plates was significantly correlated with frequ...

1. 1. Regeneration of the caudal axial skeleton in the gekkonid lizard Hemidactylus turcicus L. was investigated, after autotomy, after intervertebral amputation and after amputation within an earlier regenerate. 2. 2. There always follows a latent period during which osteoclasts (or chondroclasts) cut off the equivalent of a quarter-vertebra which...

These notes on some Egyptian lacertid lizards contribute to faunal data for the planning of biodiversity conservation. Mesalina bahaeldini curatorum n. subsp. is described from Suez, characterized by coloration and larger (fewer) body scales. Range extensions are documented for Acanthodactylus aegyptius, Mesalina olivieri, and M. rubropunctata. The...

Animals must eat, necessitating their encounter with food. At least one of the two, predator or prey, must move for the two to meet. Many predators forage for prey by one of two strategies, or foraging modes. They forage either actively, in which case their prey may be mobile or sessile, or passively by waiting in ambush, depending on prey motility...

A case of apparent homosexual behaviour between female lizards is described and photographed in an all-female, parthenogenetic population of Lepidodactylus lugubris (Gekkonidae) in Hawau. Although other hypothetical explanations are offered, it appears most reasonable that this behaviour constitutes a demonstration of social rank. Briefly reviewed...

Prudent use of the limited conservation resources rests on solid taxonomy data. This is a critical review of a taxonomy paper aimed at conservation but in itself not fully reliable (“Genetic evidence for premature taxonomic inflation in Middle Eastern tortoises”, Parham et al., 2006, Proc. Calif. Acad. Sci. 57: 955-964). Its authors consider that u...

The dimorphic ear of the bullfrog, Rana catesbeiana, has long been enigmatic. The male's tympanic membrane (TM) area approximates twice the area of the female's; however, similar size differences in the area of the columellar footplate were not observed between the sexes. Hence, the male's hearing is expected to be more sensitive than the female's...

Recent arguments in the literature prompted us to compare methods for assessing sexual dimorphism in body proportions of lacertid lizards, using Acanthodactylus boskianus. Although expressing body-part measurements as proportional to head length was the most effective method, we recommend using trunk length for the baseline as a general method for...

In a study of morphological directional asymmetry (DA) on the population level, four characters were bilaterally examined in geckos (museum specimens, total n Ptyodactylus puiseuxi, P. guttatus and P. hasselquistii, from Israel and Sinai. Significant DA occurred in adults in five or six out of 12 character-taxon-combinations (CTCs): number of supra...

The definition of head length in ichthyology and herpetology varies along four dimensions. Three may be taxon-dependent: (1) the point selected as ‘the anterior end of the head’ (2) the location of ‘the posterior end of the head’ and (3) the degree of inclusion of soft structures at the posterior end of the head. But (4) is technical and has caused...

Four cases of cannibalism among Dolichophis jugularis (Serpentes: Colubridae) are reported from Cyprus and Turkey. The number of cannibalism records for this species thus rises to at least six. Due to its opportunistic euryphagy, D. jugularis is potentially cannibalistic. Although pure opportunism cannot be ruled out, cannibalistic behaviour may be...

Geographically the Levant, including Israel, is at the crossroads of Europe, Asia and Africa. In simplified ecological or geobotanical terms, Israel is divided between the southern extreme of the mesic Mediterranean environment in Israel's north, and the northern extensions of the arid Saharo-Arabian environments in Israel's south. A narrow belt of...

Do related, differently sized species differ in size-related structural or functional traits merely because they mature at different points of a uniform allometric ontogenetic growth curve, or do they evolutionarily diverge? We tested ears of gekkotan lizards through experiments distinguishing the two. Auditory sensitivity was assessed by compound...

Tail autotomy and regeneration are less known in Sphenodon (‘Reptilia’: Rhynchocephalia) than in Squamata. We examined museum specimens, Sphenodon guntheri (N = 8) and Sphenodon punctatus (N = 172), wild Sphenodon punctatus (N = 19) and Sphenodon sp. skeletons (N = 8). In S. punctatus, unlike in typical Squamata, sexes had similar relative (intact)...

The general integument of reptiles is traditionally defined as being dry, but we report here the discovery of unicellular mucoid glands (UCMG) in the dorsal skin of lizards of the genus Phelsuma (Gekkonidae). To this end, the skin of these lizards and of some others for comparison was studied by scanning electron microscopy and transmission electro...

The occurrence of striped colour patterns and of striped/non-striped polymorphism systems among snakes is reviewed from literature data augmented by some personal observations. Among 1367 species, 190 were striped or had striped morphs. Of 11 families, the striped pattern was common mainly among Colubridae, presumably in relation to the active esca...

Based on nine calls of Calodactylodes illingworthorum recorded in the wild in Sri Lanka, the ‘spontaneous’ call of the species is a very rapid series of 4–7 roughly similar chirps. Call parameters are compared to those of Ptyodactylus guttatus of Israel because the species are similar in morphology (size, proportions, digit shape, scutellation, col...

Four cases of cannibalism among Dolichophis jugularis (Serpentes: Colubridae) are reported from Cyprus and Turkey. The number of cannibalism records for this species thus rises to at least six. Due to its opportunistic eury-phagy, D. jugularis is potentially cannibalistic. Although pure opportunism cannot be ruled out, cannibalistic behaviour may b...

This project tested whether, and how, man-made changes in the environment would affect the boundary between parapatric-related taxa of Laudakia (Reptilia: Agamidae), whose distributions meet at a boundary between ecological regions. Israel is ecologically diverse with a mesic (Mediterranean) north and an arid (Saharo-Arabian) south. The lizard hard...

A new, sibling, species of tree frog of the Hyla arborea group is described from Jerusalem and the adjacent Judean hills. Hyla heinzsteinitzi sp. n. differs from the sympatric common H. savignyi of the Middle East in head shape, as the head is relatively wider and the snout more truncate; in call structure, as in each segment of its advertisement c...

Recent evidence on directional asymmetry (DA) in species of the paraphyletic assemblage “Lacertilia” indicates a possible biological significance of this phenomenon, and we tested its occurrence in Serpentes by examining bilateral morphological characters, such as the numbers of supralabial and infralabial scutes and the diameter of the eyes, on bo...

1. This project seeks to identify determinants of the variation observed in the foraging behavior of predatory animals, especially in moonlight, using a lizard as a model. 2. Moonlight generally enhances the foraging efficiency of nocturnal visual predators and often depresses the locomotor activity of prey animals. Previous evidence has indicated...

The function of the vertebrate eye depends on its absolute size, and the size is presumably adapted to specific needs. We studied the variation of eye size at all levels, from intra-individual to inter-specific, in lid- less, spectacled, gecko lizards (Gekkonomorpha). We mea sured 1,408 museum specimens of 62 species, representing subfamilies Diplo...

A study aimed at clarifying the taxonomic status of the variable hardun population of the south Sinai mountains, hitherto included in Laudakia stellio brachydactyla, encountered the confounding role of the “Seligmann effect”—the biometrical difference between original (whole)‐tailed and regenerated (or broken)‐tailed individuals. We morphologically...

Research on the widespread and polytypic lizard Laudakia stellio (Linnaeus, 175813. Linnaeus , C. v. 1758 . “ Systema Naturae (Holmiae). ” . In 10th ed. Volume 1, Regnum Animale (Facsimile, 1956. London: British Museum (Natural History)) View all references) suffers from the lack of type specimens of the taxa included. This paper reviews the valid...

In most lizards foraging behaviour is either ‘widely foraging’ or ‘sit and wait’ but in geckos it varies and fluctuates, providing an opportunity to examine potential factors modulating the foraging mode. In an endeavour to identify these, marked individuals of Goniurosaurus kuroiwae kuroiwae (Gekkonomorpha: Eublepharidae) were observed during July...

Variation in the primarily East African snake genus Micrelaps (Atractaspididae) was investigated in the southern Levant (mainly Israel) from museum specimens and some photographs. The fossorial M. muelleri Boettger, 1880, hitherto considered rare, inhabits the mesic Mediterranean zone (n=82). Its usual colour pattern is a variable number of black a...

1.Two eublepharid gecko species were tested for their thermal preferences in a thigmothermal gradient.2.Goniurosaurus kuroiwae kuroiwae from a humid subtropical Oriental forest selected a lower body temperature (Tp; average 16.6 °C) than Eublepharis macularius from an arid Palaearctic area (25.8 °C).3.Both the locations of animals along the gradien...

The function of the ear depends in part on its absolute size and internal proportions. Thus, in both young individuals and small species, the middle ear is expected to be allometrically enlarged despite its smaller absolute size. Here we aim to compare the ontogenetic allometry of relevant middle-ear structures as observed within gecko (gekkonomorp...

Audiograms have indicated greater auditory sensitivity in larger than in smaller geckos; part of this difference, interspecifically and intraspecifically, is explained by middle-ear proportions. To investigate the contribution of the inner ear to the variation in sensitivity, we examined it in museum specimens representing 11 species and three subf...

A study aimed at testing the contested validity of the subspecies Laudakia stellio daani yielded novel insights into the essence of subspecies. We examined morphologically museum specimens from Greece, Aegean islands, and Anatolia (n = 118; not all could be used in all analyses). Beyond the conventional mensural, meristic and qualitative characters...

The reviving Hebrew language requires an artificially enriched vocabulary for animals. This is created advisedly by the Academy of the Hebrew Language and its Committee for Zoological Terms, who hold that, (a) vernacular names serve in communication and should be educational; (b) therefore they should be generally accepted, unambiguous, stable, ins...

Insectivorous lizards usually employ one of two foraging modes, ambush ‘sit-and-wait’ or active ‘widely foraging’, but in the Gekkonomorpha the situation has been unclear. Therefore we quantified the foraging mode of the eublepharid gecko Goniurosaurus kuroiwae orientalis on Tokashikijima near Okinawajima, Japan, in September 1999. The taxon is rar...

A new species of the Acanthodactylus pardalis group, A. ahmaddisii sp.n., is described from Jordan, from a single specimen which differs from A. pardalis (Lichtenstein, 1823) of eastern Libya and Egypt, and A. beershebensis Moravec et al., 1999 from Israel. Compared to the latter two populations, A. ahmaddisii is larger with smaller head and shorte...

Taxonomic families of insectivorous lizards are usually characterized by one of two distinct foraging modes, namely ambush 'sit-and-wait' or active 'widely foraging'. In the Gekkonomorpha the situation has been unclear and in dispute, and among these, that in the Sphaerodactylini is almost unreported. We, therefore, examined the foraging mode of th...

In lizards and Sphenodon, often the fourth toes of individuals with intact tails have more subdigital lamellae on the right than on the left side, and the opposite situation frequently occurs in individuals with injured tails. The difference between intact and injured individuals in morphological directional asymmetry was statistically significant...

In the present pilot study the effect of the venom of the Israeli yellow scorpion (Leiurus quinquestriatus hebraeus (Birula, 1908)) on two Israeli fan-toed gecko lizards (Ptyodactylus guttatus von Heyden, 1827 and P. puiseuxi Boutan, 1893) was examined through (1) observations on feeding behaviour and (2) toxicity assays. It was shown that (1) the...

Congenital morphological differences between injured and intact individuals in a population may reflect adaptations to avoid injury, to survive injury, or both. We explore the possible occurrence of such adaptations, analysing the relationship between tail state (original, 0; regenerated, R) and morphology (20 scale characters) in 23 taxa of Lacert...

Textbooks lump the middle ears of 'submammalian Tetrapoda' as being 'one-ossicle ears'. Conventionally the anuran middle ear is depicted with a shaft-like skeletal unit connecting the tympanic membrane to the inner ear. This shaft comprises mediad a long bony columella and laterad a short cartilaginous extracolumella. But dissection of Rana catesbe...

The systematics of the Middle-Eastern dwarf-snake Eirenis coronella has caused confusion in the past, but since 1978 this name has been used for a small dwarf-snake with 15 dorsal scale rows, dorsally coloured beige with dark transverse bands. Its distribution: Sinai in the west to southwestern Iran in the east; southern Turkey in the north to Saud...

Previous studies of electrophysiological audiograms in gekkonomorph lizards revealed greater sensitivity in adults than in juveniles. We investigated whether this difference, as far as it is affected by the middle ear, is due to animal age or size. The velocity transfer function of the tympanic membrane (TM) was examined using laser interferometry...

Brief observations on the little-known 'rock-gecko' Cnemaspis kendallii in the Bukit Timah Nature Reserve, Singapore, in November-December 1999, augmented by examination of museum specimens, have increased the knowledge of its behaviour, biology and ecological morphology. It inhabits both tree trunks of assorted types up to 2.5 m and granite rocks....

Wishing to assess the effects of the dimensions of the middle ear on the auditory sensitivity of gekkonoid lizards, we measured middle ear components in preserved geckos, which in life had yielded 'cochlear microphonics' audiograms. We examined two to seven specimens of 14 species. The measures of middle ear elements varied relative to head or body...

This report, derived mainly from intensive observations of Gonatodes humeralis (on trees) on Trinidad and G. ocellatus (in culverts) on Tobago, islands of the West Indies, in May-June, 2000. It shows that these geckos are sit-and-wait foragers that prefer a perch posture with the head pointing down, irrespective of the height above the ground. This...

Gonatodes vittatus was observed in Trinidad, both in the field and in captivity. In the field it occurred on trees and masonry walls, and on and inside wooden houses. At least some individuals showed great site fidelity to their retreats. Males and females were territorial; in captivity males required about twice the area that females did, and in t...

This study examines three artificial factors likely to cause variation between results from different investigations of auditory function, at least in lizards. Controlled tests were performed on gecko lizards, by external laser interferometry of the middle ear transfer function at the tympanic membrane (TM). In conclusion, studies of middle ear fun...

Resting metabolic rate (RMR) and evaporative water loss (EWL) were measured, and resistance (R) to evaporative water loss and water use index (WUI = EWL/RMR) were calculated, for 22 species of Western Australian gecko. For all available gecko data, body mass and temperature explained 85% of the variability in RMR (=14.5 mass0.833 100.0398 Ta µL h–1...

The middle-ear system of all vertebrates improves the efficiency of sound transmission from the surrounding medium, be it air, water, or ground, to the inner ear. The process by which this is achieved is similar across both mammalian and nonmammalian forms. The specific structures and mechanisms that have evolved to accomplish this task, however, v...

Field studies of nocturnal geckos have revealed that many species actively thermoregulate during both the day and the night. Data from laboratory studies indicate that geckos prefer body temperatures greater than those experienced during activity in the field, but data on diel patterns of temperature preference are inconsistent. We measured preferr...