Long-term demographic fluctuations of the spur-thighed tortoise Testudo graeca in SW Spain

Ecography ◽  
2001 ◽  
Vol 24 (6) ◽  
pp. 707-721 ◽  
Author(s):  
Carmen Diaz-Paniagua ◽  
Claudia Keller ◽  
Ana C. Andreu
Ecography ◽  
2008 ◽  
Vol 24 (6) ◽  
pp. 707-721
Author(s):  
Carmen Díaz-Paniagua ◽  
Claudia Keller ◽  
Ana C. Andreu

1985 ◽  
Vol 117 (25-26) ◽  
pp. 662-664 ◽  
Author(s):  
K. Lawrence ◽  
J. Needham
Keyword(s):  

2002 ◽  
Vol 68 ◽  
pp. 257-287 ◽  
Author(s):  
Nico Roymans ◽  
Fokke Gerritsen

This study presents a survey of the long-term dynamics with regard to settlement and landscape in the Meuse-Demer-Scheldt region (south Netherlands/north Belgium), thereby using the results of several decades of intensive archaeological fieldwork. In a theoretical sense, this study is inspired by the work of historians from the French Annales school. We use a model of long-term agricultural cycles, set against demographic fluctuations, in an attempt to understand developments within the study region. At the same time, however, we aim to incorporate the social and ideational dimensions of these changes, which are linked to a specific ordering and arrangement of the landscape. Our particular focus is the radical transformation that occurred around the Middle and Late Iron Age, as this had a major impact on the ordering and arrangement of the landscape in later periods.


2018 ◽  
Vol 14 (5) ◽  
pp. 20180055 ◽  
Author(s):  
Marjolaine Rousselle ◽  
Maeva Mollion ◽  
Benoit Nabholz ◽  
Thomas Bataillon ◽  
Nicolas Galtier

Estimating the proportion of adaptive substitutions ( α ) is of primary importance to uncover the determinants of adaptation in comparative genomic studies. Several methods have been proposed to estimate α from patterns polymorphism and divergence in coding sequences. However, estimators of α can be biased when the underlying assumptions are not met. Here we focus on a potential source of bias, i.e. variation through time in the long-term population size ( N ) of the considered species. We show via simulations that ancient demographic fluctuations can generate severe overestimations of α , and this is irrespective of the recent population history.


Author(s):  
Eva Graciá ◽  
Roberto Carlos Rodríguez-Caro ◽  
Marcos Ferrández ◽  
Albert Martínez-Silvestre ◽  
Irene Pérez-Ibarra ◽  
...  

Chelonians are among the animal groups with the poorest conservation status. Since tortoises are long-lived species that need very long time to reach sexual maturity, they are extremely vulnerable to human pressure. Despite their endangered status, there are no common strategies for the development of conservation actions. At the “Mediterranean workshop to develop tortoise conservation strategies”, scientists, conservation associations, environmental managers, IUCN advisers and CITES inspectors met in October 2019 in Alicante (Spain). The aims were to update the diagnosis of the conservation status of the Hermann’s tortoise (Testudo hermanni) and the spur-thighed tortoise (Testudo graeca) and to suggest strategies that guarantee their preservation at the Mediterranean Region. The main conclusions are summarized by: i) Mediterranean tortoises are wild endangered species that must be protected in, and together with, their natural habitat. Their main threats are habitat loss and fragmentation and pet trade, but we should also pay attention to wildfires, spread of diseases, the introduction of exotic species or lineages and climate change. ii) Long-term efforts and stablished protocols are needed to accurately diagnose and monitor the conservation status of wild populations, as well as flows among captive and wild animals. iii)  Tortoise trade should be banned because it threatens the conservation of wild populations of tortoises. Illegal practices related to tortoises should be decidedly persecuted. People should consider tortoises as wild animals that are endangered and deserving of protection. It is possible to enjoy them by responsibly observing them in their habitat. iv) Tortoises may carry pathogens or parasites and their sanitary status cannot be fully assessed. They should always be considered potential vectors of tortoise diseases and of zoonosis. Hygiene protocols should be implemented when managing them. v) The researchers attending this workshop aimed to develop a scientific network for the long-term monitoring of graeca and T. hermanni populations in the Mediterranean Region. They will need the support from public administrations.  


Ardeola ◽  
2013 ◽  
Vol 60 (2) ◽  
pp. 305-326 ◽  
Author(s):  
Cristina Ramo ◽  
Eduardo Aguilera ◽  
Jordi Figuerola ◽  
Manuel Máñez ◽  
Andy J. Green

2006 ◽  
Vol 43 (2) ◽  
pp. 313-324 ◽  
Author(s):  
MARION PFEIFER ◽  
KERSTIN WIEGAND ◽  
WOLFGANG HEINRICH ◽  
GOTTFRIED JETSCHKE

Sign in / Sign up

Export Citation Format

Share Document