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Luiselli L.,Rivers State University of Science And Technology | Capula M.,Museo Civico di Zoologia | Burke R.L.,Hofstra University | Capizzi D.,Regional Park Agency ARP
Biodiversity and Conservation | Year: 2014

Sighting frequency of tortoises (Testudo hermanni), standardized by the number of person-hours of field effort, was studied between 1992 and 2013 at three different study areas in central Italy. Although the frequency of tortoise sightings fluctuated substantially across years and among study areas, there was a significant declining trend in all the three areas, with GLM analyses showing also a significant interaction between study area and sampling year. The decreasing trend was higher in Castel Fusano than in the other two sites, with yearly frequency of sightings being independent of search effort in all of the study areas. These trends may indicate population declines, because no other explanations seem plausible. Total rainfall from previous autumn to the study period was positively correlated to tortoise sightings in only one locality. The yearly frequency of sightings of juvenile tortoises did not vary significantly among study areas and across years, thus indicating that simple differences in detectability cannot explain the observed patterns. Summer fires and forest overgrowing seem to explain the tortoise decline in two study areas (Castel Fusano and Oriolo) whereas we were not able to identify any specific reason for tortoise decline in the third study area (Manziana). © 2014, Springer Science+Business Media Dordrecht.

Capula M.,Museo Civico di Zoologia | Rugiero L.,Environmental Studies Center Demetra s.r.l. | Capizzi D.,Regional Park Agency ARP | Franco D.,Planland s.r.l. | And 4 more authors.
Ecological Research | Year: 2015

In a context of climate change, ecological and physiological adaptations of organisms are of central importance for determining the outcome of niche challenges (e.g., with potential competitors) and species persistence. Typically, long-term data on free-ranging populations are needed to investigate such phenomena. Here, long-term data on a free-ranging population of western whip snakes (Hierophis viridiflavus: Colubridae) from central Italy were used in order to test the hypothesis that snake feeding frequencies should increase in relation to climate warming, thus positively affecting individual performance because of longer annual activity period, increased daily activity and larger prey base. Data from 231 ‘female snake-years’ of records (including inter-annual recaptures) were collected were collected between 1990 and 2014. The frequency of fed snakes varied remarkably across the study period with a significant increase over the years. There was a significant positive effect of the mean annual temperature on the percentage of fed animals, whereas there was a non-significant relationship between yearly rainfall and percentage of fed animals. There was a positive relationship between mean annual temperature and yearly diversity-of-prey index. No other climatic variables were significantly correlated with yearly diversity-of-prey index. This study supported the hypothesis that global warming may be favorable for thermophilic species (such as H. viridiflavus), as it enhances their foraging performances and hence their feeding frequencies. The same may not be necessarily true for other species which have colder preferenda (e.g., Zamenis longissimus). © 2015 The Ecological Society of Japan

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