In Portugal there are 2 species of vipers, Seoane’s viper and Lataste’s viper. Both species venom is mostly related with their hunting strategies. As low mobility predators, they wait for the prey to be close enough to inoculate the venom and waits until its dead to eat it. Their venom is just strong enough to kill their preys which usually are small animals. Vipers have their teeth on the front of their mouths making them able to inoculate the venom if they bite larger animals such as humans. Their venom won’t kill a healthy adult, but you should go to the hospital if bitten by a viper. Despite that, if threatened most of them will rather run from it than attack it, because the venom is metabolic costly. Being so, if left alone they will not attack a human being.
Lataste’s viper is the one species that occurs in Montesinho Natural Park, so we will talk a bit more about it.
Vipera latastei (Boscá, 1878) is a small viper with a maximum length of 70 cm with a triangular shaped head well differentiated from the rest of the body and a characteristic prominent snout. It has a dark dorsal zigzag pattern in a grey background in males and brown background in females, despite of the low sexual dimorphism. Both show white or greyish abdomens with random spots.
Characteristic from Mediterranean climate zones we can found Lataste’s viper generally in moist, rocky areas, in dry scrubland and woodland, hedgerows and stone walls and sometimes in coastal dunes. It has discontinuous distribution across the country with isolated populations and commonly restricted to mountain regions, being 1500m the maximum altitude where observations of this species were recorded. The small total area where it occurs, the isolation and the high fragmentation of the populations and diminished number of mature individuals make the species classified as Vulnerable (VU) at a national level but also internationally according to the IUCN Red List of Threatened Species.
The main threats affecting this viper’s populations are the loss and degradation of habitats due to fires, traditional agriculture abandonment and intensification of agricultural methods and construction of urban infrastructures. Road mortality and human persecution due to aversion, fear or superstitious reasons have impacts at a local level, such as harvesting for illegal trade.
Although people are usually fearful of snakes and vipers, in our context, they are predators of rodents. They keep populations of rodents at low levels maintaining and assuring the equilibrium of the ecosystems while being an effective natural plague control.
Main/ Cover Photo by Marco Caetano (Bioinsight work team): juvenile Lataste’s viper.
Cabral, M.J. (coord.); Almeida, J., Almeida, P.R., Delliger, T., Ferrand de Almeida, N., Oliveira, M.E., Palmeirim, J.M., Queirós, A.I., Rogado, L., Santos-Reis, M. (eds) (2005). Livro Vermelho dos Vertebrados de Portugal. Instituto da Conservação da Natureza. Lisboa. 659pp.
Loureiro, A., Ferrand de Almeida, N. Carretero, M.A., Paulo, O.S. (eds.) (2008) Atlas dos Anfíbios e Répteis de Portugal. Instituto da Conservação da Natureza e da Biodiversidade, Lisboa, 257 pp.
Jose Antonio Mateo Miras, Marc Cheylan, M. Saïd Nouira, Ulrich Joger, Paulo Sá-Sousa, Valentin Pérez-Mellado, Iñigo Martínez-Solano. 2009. Vipera latastei. The IUCN Red List of Threatened Species 2009: e.T61592A12503848. http://dx.doi.org/10.2305/IUCN.UK.2009.RLTS.T61592A12503848.en. Downloaded on 03 August 2018.