Vipera Latastei Research Articles

Variation in the diet of the Lataste's viper Vipera latastei in the Iberian Peninsula: seasonal, sexual and size-related effects

Abstract Several life-history traits may increase vulnerability of species to extinction. Among snakes, ambush predation and dietary specialisation are factors that increase this vulnerability. European viper species, genus Vipera, display such traits and are categorised as endangered in several parts of its range. For their conservation management, a deeper knowledge of their ecology and habitat use is highly relevant. One of the species with less ecological data is the Lataste's viper Vipera latastei, a species which lives in the Iberian Peninsula and northwestern Africa. Here, we describe its diet based on the analysis of gut content of 435 museum specimens plus nine bibliographic data from the entire Iberian range. The species showed seasonal and ontogenetic shift in diet but no sexual variations. Feeding activity (percentage of vipers with prey) was low in accordance with its ambush predation tactics, being lower in spring than in summer and autumn. Prey spectrum included two main (reptiles and small mammals), and three sporadic, types of prey (arthropods, amphibians and birds). The consumption of reptiles and mammals was seasonal; the former decreased in occurrence from spring to autumn, whereas the latter showed an opposite pattern. There was an ontogenetic shift in the diet: juveniles fed mainly on reptiles and arthropods, whereas adult vipers progressively substitute this prey with insectivores, and the largest vipers primarily foraged on rodents and birds. Our results suggest that the seasonal variation in prey type was related to prey availability, whereas the ontogenetic shift was linked to gape limitation. The apparently wide prey spectrum of V. latastei must therefore be examined, taking into account that there are seasonal and ontogenetic dietary variations as well as geographic differences, the latter probably driven by climatic contrasts into the Iberian Peninsula. This new data of the endangered Iberian V. latastei can aid the effective conservation management of this species.

Morphological variability of the Lataste's viper (Vipera latastei) and the Atlas dwarf viper (Vipera monticola): patterns of biogeographical distribution and taxonomy

AbstractThe Lataste's viper Vipera latastei is a medium-sized viper distributed throughout almost the entire Iberian Peninsula and north-west of Africa. Former morphological studies noted the existence of two subspecies, V. l. gaditana and V. l. latastei, as well as a full species, V. monticola, in the High Atlas, corresponding to the prior overall range described for V. latastei. However, some results remained unclear in these former studies, e.g. the specific status of the Medium Atlas populations, the intra-subspecific differences in V. l. gaditana and, the true status of some isolated populations of the northern range. For this reason, 45 morphological characters were analysed in 672 preserved specimens covering the entire range. Categorical Principal Components Analysis (CATPCA) and Discriminant Function Analysis (DFA) were used to assess geographic variability, treating specimens individually or assigning them a priori to groups, respectively. Geographic groups were established according to the origin of specimens in isolated areas of mountain chains. As the percentage of correct assignment was low in DFA, initial groups were combined to maximize the percentage. The results from the multivariate analysis suggest morphological differentiation between populations. Some variables accounted for geographic variability: e.g. rows of dorsal scales at mid-body are taxonomically stable and clearly separate the African populations; and number of ventral scales showed a clinal variation from 126 to 143 ventrals in extreme populations. The three African groups manifested clear morphological differences, and especially specimens from the High Atlas (V. monticola) and Alger. On the contrary, a large number of initial Iberian groups were merged because of the low scores in the correct classification. The final groups showed a vast central area with low morphological differentiation as well as isolated populations in the NW, NE and SW Iberian Peninsula. This conclusion matches well with allopatric speciation processes during the Quaternary ice ages, which contributed to the contraction/expansion of range, isolation events, and peripheral population refugia. Morphological differentiation in external characters of V. latastei exhibited similar results with respect to V. aspis and V. ammodytes, the vipers occupying other southern European peninsulas. Molecular markers will contribute to elucidate the relationships between V. latastei populations and the history of colonisation across the Strait of Gibraltar.

Differential Growth and Mortality Affect Sexual Size Dimorphism in Vipera latastei

Abstract Growth, mortality and sexual size dimorphism of Vipera latastei were investigated in northern Portugal. Size structure ranged from 16–58 cm of snout–vent length (SVL), with peaks between 40–45 cm for males and 35–40 cm for females. Age structure ranged between 0 and 14 years, with peaks at 4 and 5 years for males and at 4–6 years for females. Longevity was 11 and 14 years for males and females, respectively. Sexual maturity was attained approximately at four years in males, and one year later in females, however, at a similar body size. Growth rates decreased with increasing SVL; males grew faster than females at all ages; and asymptotic body size was larger in males than in females. Mortality was higher in males than in females and increased after sexual maturity in both sexes. The sexual differences in mortality annulled an age-specific sexual size dimorphism in favor of males and produced a minor sexual size dimorphism in mean adult body size of V. latastei.

Seasonal Variation in Movements, Home Range, and Habitat Use by Male Vipera latastei in Northern Portugal

Snakes usually exhibit seasonal variations in movement patterns, home-range size and habitat use. This study evaluates the seasonal variation in movement rates, home-range size, habitat use, and microhabitat use by male Lataste's Vipers (Vipera latastei) in northern Portugal using radio-telemetry. Estimates of movement rate revealed short movements (5.4 m/day) and small home range size (0.24 ha) throughout the year, except in September when there was an increase in both movement rates (21.5 m/day) and home-range size (1.52 ha). Male vipers used different habitats and microhabitats during the year: forested areas for hibernation, open forest with bushes for foraging, and in the proximity of water in the summer.

Seasonal and daily activity patterns of Vipera latastei in northern Portugal

AbstractThe annual and daily activity cycles of Vipera latastei were investigated in northern Portugal from 1999 to 2001, based on field observations, radio-tracking data and road killed snakes. Annual activity was extended from early March to late October, although some snakes were active during winter. Two annual peaks of activity were observed, a minor one in March-May and a major one in September-October. The daily activity pattern of vipers in spring and autumn was unimodal, whereas in summer they expanded their activity from early morning to late afternoon, and were also active at night. Activity and body exposure of adult males were correlated with meteorological variables. Females had shedding periods in June and July, whereas males shed their skin more frequently in June and August. Sperm was detected in the vas deferens of males in October to December. Females ovulated in June and new-born vipers were found from early August. Mating season is apparently restricted to autumn, and spring mating is either absent or very reduced.

Muscle extract of hedgehog, Erinaceus europaeus, inhibits hemorrhagic activity of snake venoms

The antihemorrhagic activity of muscle extract of hedgehog, Erinaceus europaeus, was tested on various snake venoms with hemorrhagic activity. The extract inhibited strongly hemorrhagic activity of venoms from Bitis arietans, Bothrops jararaca and Vipera latastei gaditana, and remarkably that of venoms from Agkistrodon halys blomhoffi, Bitis gabonica rhinoceros, Bitis nasicornis, Bothrops atrox asper, Crotalus horridus horridus and Vipera berus. The antihemorrhagic activity against eight other snake venoms was below the detection level.

Preliminary studies on the characterization of venom from Vipera latastei latastei collected at NW of Portugal: A. P. Arez,1G. D. Laing,2V. do Rosário1 and R. D. G. Theakston2 (1Centro de Malária e outras Doenças Tropicais (IHMT), Rua da Junqueira, 96, 1300 Lisboa, Portugal; and 2Venom Research Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, U.K.)

Preliminary studies on the characterization of venom from Vipera latastei latastei collected at NW of Portugal: A. P. Arez,1G. D. Laing,2V. do Rosário1 and R. D. G. Theakston2 (1Centro de Malária e outras Doenças Tropicais (IHMT), Rua da Junqueira, 96, 1300 Lisboa, Portugal; and 2Venom Research Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, U.K.)

Inhibition of hemorrhagic activities of various snake venoms by purified antihemorrhagic factor obtained from Japanese Habu snake

T. Omori-Satoh, Y. Nagaoka, Y. Yamakawa and D. Mebs. Inhibition of hemorrhagic activities of various snake venoms by purified antihemorrhagic factor obtained from Japanese Habu snake. Toxicon 32, 365–368, 1994.—The ability of purified antihemorrhagic factor isolated from the serum of Japanese Habu ( Trimeresurus flavoviridis) was tested on 17 snake venoms to inhibit their hemorrhagic activity. The factor strongly inhibited that of the venoms of Crotalus horridus horridus and Vipera latastei gaditana in addition to that of the homologous ( T. flavoviridis) venom. Hemorrhagic activity of Agkistrodon halys blomhoffi, Agkistrodon contortrix contortrix, Bothrops atrox asper and Crotalus atrox venoms was also remarkably inhibited, but that of Vipera mauretanica to less extent. The hemorrhagic activities of nine other snake venoms were not inhibited.

Estimation of neurotoxic and myotoxic activities of snake venoms using a simple in vitro assay

T. Omori-Satoh, Y. Nagaoka, Y. Yamakawa and D. Mebs. Inhibition of hemorrhagic activities of various snake venoms by purified antihemorrhagic factor obtained from Japanese Habu snake. Toxicon32, 365–368, 1994.—The ability of purified antihemorrhagic factor isolated from the serum of Japanese Habu (Trimeresurus flavoviridis) was tested on 17 snake venoms to inhibit their hemorrhagic activity. The factor strongly inhibited that of the venoms of Crotalus horridus horridus and Vipera latastei gaditana in addition to that of the homologous (T. flavoviridis) venom. Hemorrhagic activity of Agkistrodon halys blomhoffi, Agkistrodon contortrix contortrix, Bothrops atrox asper and Crotalus atrox venoms was also remarkably inhibited, but that of Vipera mauretanica to less extent. The hemorrhagic activities of nine other snake venoms were not inhibited.