Activity Patterns, Thermoregulation and Food Consumption in two Sympatric Lizard Species (Podarcis muralis and P. sicula) from Central Italy

10.2307/3928 ◽  
1978 ◽  
Vol 47 (1) ◽  
pp. 143 ◽  
Author(s):  
R. A. Avery
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Laspiur ◽  
J. C. Santos ◽  
S. M. Medina ◽  
J. E. Pizarro ◽  
E. A. Sanabria ◽  
...  

AbstractGiven the rapid loss of biodiversity as consequence of climate change, greater knowledge of ecophysiological and natural history traits are crucial to determine which environmental factors induce stress and drive the decline of threatened species. Liolaemus montanezi (Liolaemidae), a xeric-adapted lizard occurring only in a small geographic range in west-central Argentina, constitutes an excellent model for studies on the threats of climate change on such microendemic species. We describe field data on activity patterns, use of microhabitat, behavioral thermoregulation, and physiology to produce species distribution models (SDMs) based on climate and ecophysiological data. Liolaemus montanezi inhabits a thermally harsh environment which remarkably impacts their activity and thermoregulation. The species shows a daily bimodal pattern of activity and mostly occupies shaded microenvironments. Although the individuals thermoregulate at body temperatures below their thermal preference they avoid high-temperature microenvironments probably to avoid overheating. The population currently persists because of the important role of the habitat physiognomy and not because of niche tracking, seemingly prevented by major rivers that form boundaries of their geographic range. We found evidence of habitat opportunities in the current range and adjacent areas that will likely remain suitable to the year 2070, reinforcing the relevance of the river floodplain for the species’ avoidance of extinction.


2020 ◽  
Vol 47 (4) ◽  
pp. 326 ◽  
Author(s):  
Harry A. Moore ◽  
Jacob L. Champney ◽  
Judy A. Dunlop ◽  
Leonie E. Valentine ◽  
Dale G. Nimmo

Abstract ContextEstimating animal abundance often relies on being able to identify individuals; however, this can be challenging, especially when applied to large animals that are difficult to trap and handle. Camera traps have provided a non-invasive alternative by using natural markings to individually identify animals within image data. Although camera traps have been used to individually identify mammals, they are yet to be widely applied to other taxa, such as reptiles. AimsWe assessed the capacity of camera traps to provide images that allow for individual identification of the world’s fourth-largest lizard species, the perentie (Varanus giganteus), and demonstrate other basic morphological and behavioural data that can be gleaned from camera-trap images. MethodsVertically orientated cameras were deployed at 115 sites across a 10000km2 area in north-western Australia for an average of 216 days. We used spot patterning located on the dorsal surface of perenties to identify individuals from camera-trap imagery, with the assistance of freely available spot ID software. We also measured snout-to-vent length (SVL) by using image-analysis software, and collected image time-stamp data to analyse temporal activity patterns. ResultsNinety-two individuals were identified, and individuals were recorded moving distances of up to 1975m. Confidence in identification accuracy was generally high (91%), and estimated SVL measurements varied by an average of 6.7% (min=1.8%, max=21.3%) of individual SVL averages. Larger perenties (SVL of >45cm) were detected mostly between dawn and noon, and in the late afternoon and early evening, whereas small perenties (SVL of <30cm) were rarely recorded in the evening. ConclusionsCamera traps can be used to individually identify large reptiles with unique markings, and can also provide data on movement, morphology and temporal activity. Accounting for uneven substrates under cameras could improve the accuracy of morphological estimates. Given that camera traps struggle to detect small, nocturnal reptiles, further research is required to examine whether cameras miss smaller individuals in the late afternoon and evening. ImplicationsCamera traps are increasingly being used to monitor reptile species. The ability to individually identify animals provides another tool for herpetological research worldwide.


2008 ◽  
Vol 29 (3) ◽  
pp. 443-448 ◽  
Author(s):  
Giulia Gracceva ◽  
Marco Bologna ◽  
Luca Luiselli ◽  
Pierluigi Bombi

Abstract Demographic and morphological aspects of two nearby subpopulations of the common wall lizard (Podarcis muralis) were studied, by a capture-mark-recapture procedure, at an archaeological site in the surroundings of Rome, central Italy. In both sites, the births peak was observed in September. Adult sex-ratio was skewed towards males in one subpopulation, but was close to equality in the other. Morphological characteristics were consistent in the two sites, with males always exhibiting larger snout-vent-length and head size. Population size and density, computed by a Jolly-Seber index applied by using POPAN model revealed differences between subpopulations, with lizard density being much higher in the site with higher habitat heterogeneity and shelter availability. Tail condition was similar between sites. The general implications of these data are discussed.


1989 ◽  
Vol 10 (2) ◽  
pp. 151-174 ◽  
Author(s):  
W. Helmer ◽  
H. Strijbosch ◽  
P.T. Scholte

AbstractDuring a field study in 1983-1984 in a 200 km 2 study area in the south of Evros province (Greece) the presence of 11 lizard species was established. For every species a distribution map within the area is supplied. In different parts of the area thc lizards formed different species combinations. Ophisops elegans appeared to vicariate in certain terrains with both Podarcis erhardii and P. taurica. By studying habitat selection and activity patterns of all species data on spatial and temporal niche segregation could be obtained. The activity patterns of all species were strongly influenced by exposition and altitude. In some species a strong altitude influence was also measured on growth and some other life history data. Some pairs of morphologically or ecologically related species are compared in more detail. Some species occurred in very high densities (Lacerta viridis up to 500, Ablepharus kitaibelii up to 1100 ind./ha). Tail loss frequencies of all species are given. For many birds of prey they formed an essential food source.


2019 ◽  
Author(s):  
Andrej Čerňanský ◽  
Elena V. Syromyatnikova

AbstractWe here describe the first fossil remains of a green lizardof theLacertagroup from the late Miocene (MN 13) of the Solnechnodolsk locality in southern European Russia. This region of Europe is crucial for our understanding of the paleobiogeography and evolution of these middle-sized lizards. Although this clade has a broad geographical distribution across the continent today, its presence in the fossil record has only rarely been reported. In contrast to that, the material described here is abundant, consists of a premaxilla, maxillae, frontals, parietals, jugals, quadrate, pterygoids, dentaries and vertebrae. The comparison of these elements to all extant green lizard species shows that these fossils are indistinguishable fromLacerta trilineata. Thus, they form the first potential evidence of the occurrence of this species in the Miocene. This may be also used as a potential calibration point for further studies. Together with other lizard fossils, Solnechnodolsk shows an interesting combination of survivors and the dawn of modern species. This locality provides important evidence for the transition of an archaic Miocene world to the modern diversity of lizards in Europe. In addition, this article represents a contribution to the knowledge of the comparative osteological anatomy of the selected cranial elements in lacertid. This study gives special emphasis to the green lizards, but new data are also presented for related taxa, e.g.,Timon lepidus, Podarcis muralisorZootoca vivipara. Although the green lizards include several cryptic species for which determination based on isolated osteological material would be expected to be difficult, our comparisons show several important morphological differences.


2020 ◽  
Vol 15 (2) ◽  
pp. 153-164
Author(s):  
Pedro Luis Atencia ◽  
Cristian José Castillo ◽  
Luis Fernando Montes

In this work, the microhabitat use and activity patterns of two lizard species with sympatric distribution were evaluated in a dry forest fragment within the department of Sucre, northern Colombia. Data was collected in May, June, September and October of 2017, using the active search method limited by time (7:00 and 19:00 hours). Substrates used, spatial distribution and time of capture were recorded for individuals of the species Loxopholis rugiceps (Cope 1869) and Lepidoblepharis sanctaemartae (Ruthven 1916). Complementarily, environmental and physical parameters were recorded, which allowed us to characterise the microhabitats of the species. A total of 276 lizards were recorded, 177 belonging to the species Loxopholis rugiceps and 99 to Lepidoblepharis sanctaemartae. The results showed similar resource use by the two species for the spatial dimension, with both exploiting different terrestrial elements mainly from the interior forest, followed by the riverbed stream and forest edge. Differences were found in the daily activity patterns between species, with individuals of L. sanctaemartae more frequently recorded in the morning hours and L. rugiceps in the afternoon hours. The activity patterns did not differ by age groups: juveniles and adults. Both species were more frequently found in the litter substrate within the forest, followed by rocks and bare ground. Our results indicate that both species are tolerant to matrix conditions, however, they require internal forest conditions to exploit food resources and refuge.


2021 ◽  
Author(s):  
◽  
Joanne Marie Hoare

<p>Biotas that evolved in isolation from mammalian predators are susceptible to degradation due to recent human-mediated introductions of mammals. However, behavioural, morphological and life historical adaptations of prey to novel mammalian predators can allow prey to persist in mammal-invaded areas. Lizards in New Zealand are an ideal group for exploring the effects of invasive mammals on vertebrate prey because: (1) the ca. 80 endemic species evolved without mammals as a major influence for 80 my, (2) mammalian introductions during the past 2000 y have differentially affected lizard species, and (3) some species coexist with mammals on the mainland as well as occurring on mammal-free offshore islands. I tested three hypotheses: (1) lizard populations that have persisted on New Zealand’s mainland are no longer declining in the presence of introduced mammalian predators, (2) introduced mammals induce behavioural shifts in native lizards, and (3) lizard behavioural patterns and chemosensory predator detection abilities vary according to exposure to introduced mammals. Trends in capture rates of five sympatric native lizard populations over a 23 year (1984-2006) period demonstrate that not all lizard populations that have persisted thus far on New Zealand’s mainland have stabilised in numbers. Large, nocturnal and terrestrial species remain highly vulnerable at mainland sites. Introduced kiore, Rattus exulans, induce behavioural changes in Duvaucel’s geckos, Hoplodactylus duvaucelii. A radio telemetric study demonstrated that geckos start reverting to natural use of habitats within six months of kiore eradication. Activity patterns of common geckos, H. maculatus, and common skinks, Oligosoma nigriplantare polychroma, in laboratory trials are also correlated with their exposure to mammalian predators. Lizard activity (time spent moving) increases relative to freeze behaviour with greater exposure to mammals. However, specific antipredator behaviours are not elicited by chemical cues of either native (tuatara, Sphenodon spp) or introduced (ship rat, R. rattus) predators. Lizard populations may persist by changing their behaviours in the presence of invasive mammals. However, the continued declines of particularly vulnerable mainland lizard taxa suggest that mammal-induced behavioural shifts may only slow population declines rather than enabling long-term survival. Eradicating pest mammals from offshore islands has proven effective at restoring both populations and behaviours of native lizards, but lizard populations on the mainland also deserve conservation priority. Research directed at understanding the synergistic effects of invasive species that are causing continued lizard population declines and mammal-proof fencing to protect the most vulnerable mainland populations from extinction are both urgently required.</p>


2021 ◽  
Author(s):  
Lorenzo Gordigiani ◽  
Andrea Viviano ◽  
Francesca Brivio ◽  
Stefano Grignolio ◽  
Lorenzo Lazzeri ◽  
...  

Abstract An increase of nocturnal activity of ungulate species may represent a compensatory opportunity for energy intake, when activity in daylight is hindered by some disturbance events (e.g. hunting or predation). Therefore, mostly-diurnal and crepuscular species may be active in bright moonlight nights whereas others may shift their diurnal activity towards darkest nights to limit their exposure to predators. In natural and undisturbed conditions, the wild boar may be active both during the day and the night, with alternating periods of activity and resting. In this work, we tested whether activity patterns of wild boar, a species with poor visive abilities, were dependent on moon phases and environmental lightening. We aimed to assess if nocturnal activity could be better explained by variations of the lunar cycle or by the variations of environmental lightening conditions, evaluated by means of different measures of night brightness. Data were collected through camera-trapping in Central Italy in 2019–2020. Despite the poor visive abilities of the wild boar, we observed that this ungulate significantly reduced their activity by avoiding the brightest nights. In our study area, the wild boar has to cope with both human pressure (i.e. mostly hunters and poachers) and predation by the grey wolf. Furthermore, the nocturnal activity of wild boar peaked in mid-Autumn, i.e. when hunting pressure is the highest and when leaf fall may bring wild boar to range for long distances to find suitable resting sites for diurnal hours.


2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Tommy Norin ◽  
Josefin Sundin ◽  
Rachael Morgan ◽  
Anna H. Andreassen ◽  
Mirjam Amcoff ◽  
...  

2010 ◽  
Vol 67 (3) ◽  
pp. 580-595 ◽  
Author(s):  
Guillaume Guénard ◽  
Daniel Boisclair ◽  
Ola Ugedal ◽  
Torbjørn Forseth ◽  
Bror Jonsson ◽  
...  

A common environment experiment was conducted to assess the magnitude of the difference in growth, consumption, activity rate, and spatial and temporal patterns of habitat use between morphologically different populations of Arctic char ( Salvelinus alpinus ) originating from two Norwegian lakes. These two lakes contrasted sharply in terms of surface area, depth, elevation, length of the winter period, and fish community structure (presence–absence of brown trout, Salmo trutta ). The experimental framework encompassed four littoral enclosures (average volume, 146 m3) stocked with char from either of the two populations with duplicated treatments. Char morphology was quantified with numerical image analysis, food consumption was estimated using caesium analysis (133Cs), and activity cost and patterns were determined using video cameras. Char populations were morphologically distinct and reacted differently in growth (1.9-fold difference between populations), food consumption (3-fold difference), and spatial activity patterns (20-fold difference) to the conditions prevailing in the enclosures. The results highlight that functional differences between morphologically distinct char may drive important differences in their bioenergetic and behavioural responses when exposed to similar environmental conditions. Such functional differences should be incorporated when developing habitat or trophic cascade models.


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