scholarly journals Age-Dependent Utilization of Shelters and Habitat in Two Reptile Species with Contrasting Intraspecific Interactions

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 995
Author(s):  
Kolanek ◽  
Bury ◽  
Turniak ◽  
Szymanowski
Keyword(s):  
Spatial Ecology ◽  
Habitat Preferences ◽  
The Body ◽  
Intraspecific Interactions ◽  
Reptile Species ◽  
Active Protection ◽  
Age Dependent ◽  
Anguis Fragilis ◽  
Coronella Austriaca ◽  
Effective Conservation

Reptiles undergo worldwide decline driven mostly by habitat change. Detailed recognition of factors underlying spatial structure and habitat utilization is therefore a prerequisite of effective conservation of this group. While the body of data on spatial ecology of reptiles is rapidly growing, studies on social factors remain still underrepresented. We studied age-specific patterns of shelter use, range size, and habitat preferences in the context of intraspecific interactions in the smooth snake Coronella austriaca—known to exhibit intraspecific predation—and the limbless lizard slow worm Anguis fragilis—with no such behavior observed. Despite smaller availability of preferred microhabitats, juveniles of smooth snakes occupied habitat and shelters located at the edge of the population range that did not overlap with adults. No such pattern was observed in the slow worm. Our study indicates that intraspecific interactions affect the spatial ecology of squamates. Passive and active protection of habitat must include wide buffers to preserve the poorly detectable young fraction of the population.

scholarly journals The prevalence of obesity in older adults in Iran: a systematic review and meta-analysis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Aliakbar Vaisi-Raygani ◽  
Masoud Mohammadi ◽  
Rostam Jalali ◽  
Akram Ghobadi ◽  
Nader Salari
Keyword(s):  
Systematic Review ◽  
Older Adults ◽  
Older Adult ◽  
Meta Analysis ◽  
The Body ◽  
Obesity Prevalence ◽  
Analysis Software ◽  
Obesity And Overweight ◽  
Age Dependent ◽  
Prevalence Of Obesity

Abstract Background one of the most important age-dependent physiologic alterations in the body composition of older adult people is obesity and overweight, increasing the risk of cardiovascular disease and mortality rate. Objective The aim of the present study is to determine the prevalence of obesity in older adults in Iran. Methods The present study was conducted via meta-analysis and systematic review method, from March 2000 to October 2018. Subject-related literature was obtained via searches in ScienceDirect, Medline (PubMed), SID, Magiran, Scopus, and Google Scholar databases. Heterogeneity of studies was assessed using the I2 index, and data were analyzed by Comprehensive-Meta analysis software. Results In the assessment of 18 studies and 29,943 persons aged over 50 years, the prevalence of obesity in older adults of Iran was 21.4% (95%CI: 26.6–16.9%) based on the meta-analysis. The highest obesity prevalence was obtained in older adults of Babol (Amir Shahr) which was 44.2% (95%CI: 41.1–47.2%) in 2007, while the minimum obesity prevalence was found in older adults of Razavi Khorasan which was 11.3% (95%CI, 10–12.8%) in 2007. Further, as the sample size and the study year increased, the obesity prevalence diminished in older Iranian adults (p < 0.05). Conclusion This study suggests that the prevalence of obesity in the older adults of Iran is high. Accordingly, healthcare planners and politicians should consider effective and practical policies to reduce obesity in older adults.

scholarly journals NOTES ON THE ECOLOGY OF THE COLOMBIAN LEAFTOED GECKO (PHYLLODACTYLUS TRANSVERSALIS), ENDEMIC TO MALPELO ISLAND

2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Mateo López Victoria ◽  
Matthias Jurczyk ◽  
Volkmar Wolters
Keyword(s):  
Population Size ◽  
Breeding Season ◽  
Habitat Preference ◽  
Habitat Preferences ◽  
Original Description ◽  
Tropical Pacific ◽  
Reference Points ◽  
Eastern Tropical Pacific ◽  
Reptile Species ◽  
Malpelo Island

The Colombian leaf-toed gecko (Phyllodactylus transversalis) is the least known reptile species of Malpelo Island (Eastern Tropical Pacific). In the 37 years since its original description, no single study strictly dedicated to this species has been conducted. With the goal of providing information on the ecology and population size of this gecko, data collected during two visits to the island are presented. Behavior and reproduction were studied by following individuals during the night and by searching for hidden individuals and eggs during the day. Population’s density and habitat preferences were estimated by classifying the island’s surfaces into four types and counting geckos inside those habitats within band transects. General morphological measurements of geckos were performed as reference points for future comparisons. Phyllodactylus transversalis lays its eggs in narrow crevices of rocks, apparently communally. Reproduction seems to take place during most of the year, probably associated with the peak breeding season of seabirds. Although conspecifics shared shelters during the day, densities during the night suggest no apparent habitat preference for foraging. Population size of this species was estimated at approximately 114000 individuals.

Hydrophis donaldi (Elapidae, Hydrophiinae), a highly distinctive new species of sea snake from northern Australia

Zootaxa ◽  
2012 ◽  
Vol 3201 (1) ◽  
pp. 45 ◽  
Author(s):  
KANISHKA D.B. UKUWELA ◽  
KATE L. SANDERS ◽  
BRYAN G. FRY
Keyword(s):  
New Species ◽  
Habitat Preferences ◽  
The Body ◽  
Colour Pattern ◽  
Northern Australia ◽  
Nucleotide Substitutions ◽  
Sea Snake ◽  
Sea Snakes ◽  
Morphological Diagnosis ◽  
By Catch

A new species of viviparous sea snake, Hydrophis donaldi sp. nov. (Hydrophiinae), is described from the Gulf of Carpen-taria, northern Australia. Molecular analyses reveal this species as a deeply divergent lineage within the Hydrophis sub-group, and separate it from all other sampled taxa by fixed nucleotide substitutions at three independent mitochondrial andnuclear loci. The new species is assigned to Hydrophis based on the current morphological diagnosis of this large but pa-raphyletic genus, and is distinguished from all other Hydrophis species and closely allied genera by a combination of mor-phological characters relating to scalation, colour pattern and osteology. Using current keys for sea snakes, H. donaldi sp.nov. might be mistaken for H. coggeri, H. sibauensis or H. torquatus diadema but it is readily distinguished from thesespecies by a higher number of bands on the body and tail, lower ventral count, strongly spinous body scales, and a wider,more rounded head. Sea snakes have been sampled intensively in the Gulf of Carpentaria due to their vulnerability to by-catch in the region’s commercial prawn-trawl fisheries. That this highly distinctive new species has evaded discovery inthe region until now is surprising, but might be explained by its habitat preferences. All known specimens of H. donaldi sp. nov. were found in estuarine habitats that are relatively poorly surveyed and are not targeted by commercial fisheries.

scholarly journals Age-related reweighting of visual and vestibular cues for vertical perception

2019 ◽  
Vol 121 (4) ◽  
pp. 1279-1288 ◽  
Author(s):  
Bart B. G. T. Alberts ◽  
Luc P. J. Selen ◽  
W. Pieter Medendorp
Keyword(s):  
Spatial Orientation ◽  
Contextual Information ◽  
Sensory Information ◽  
The Body ◽  
Individual Subject ◽  
Noise Characteristics ◽  
Age Related ◽  
Vestibular Cues ◽  
Age Dependent ◽  
Visual Frame

As we age, the acuity of our sensory organs declines, which may affect our lifestyle. Sensory deterioration in the vestibular system is typically bilateral and gradual, and could lead to problems with balance and spatial orientation. To compensate for the sensory deterioration, it has been suggested that the brain reweights the sensory information sources according to their relative noise characteristics. For rehabilitation and training programs, it is important to understand the consequences of this reweighting, preferably at the individual subject level. We psychometrically examined the age-dependent reweighting of visual and vestibular cues used in spatial orientation in a group of 32 subjects (age range: 19–76 yr). We asked subjects to indicate the orientation of a line (clockwise or counterclockwise relative to the gravitational vertical) presented within an oriented square visual frame when seated upright or with their head tilted 30° relative to the body. Results show that subjects’ vertical perception is biased by the orientation of the visual frame. Both the magnitude of this bias and response variability become larger with increasing age. Deducing the underlying sensory noise characteristics, using Bayesian inference, suggests an age-dependent reweighting of sensory information, with an increasing weight of the visual contextual information. Further scrutiny of the model suggests that this shift in sensory weights is the result of an increase in the noise of the vestibular signal. Our approach quantifies how noise properties of visual and vestibular systems change over the life span, which helps to understand the aging process at the neurocomputational level. NEW & NOTEWORTHY Perception of visual vertical involves a weighted fusion of visual and vestibular tilt cues. Using a Bayesian approach and experimental psychophysics, we quantify how this fusion process changes with age. We show that, with age, the vestibular information is down-weighted whereas the visual weight is increased. This shift in sensory reweighting is primarily due to an age-related increase of the noise of vestibular signals.

scholarly journals Buffel grass in Queensland's semi-arid woodlands: response to local and landscape scale variables, and relationship with grass, forb and reptile species

2009 ◽  
Vol 31 (3) ◽  
pp. 293 ◽  
Author(s):  
Teresa J. Eyre ◽  
Jian Wang ◽  
Melanie F. Venz ◽  
Chris Chilcott ◽  
Giselle Whish
Keyword(s):  
Habitat Preferences ◽  
Landscape Scale ◽  
Grazing Pressure ◽  
Critical Threshold ◽  
Hierarchical Partitioning ◽  
Grass Cover ◽  
Explanatory Variables ◽  
Buffel Grass ◽  
Remnant Vegetation ◽  
Reptile Species

Buffel grass [Pennisetum ciliare (L.) Link] has been widely introduced in the Australian rangelands as a consequence of its value for productive grazing, but tends to competitively establish in non-target areas such as remnant vegetation. In this study, we examined the influence landscape-scale and local-scale variables had upon the distribution of buffel grass in remnant poplar box (Eucalyptus populnea F.Muell.) dominant woodland fragments in the Brigalow Bioregion, Queensland. Buffel grass and variables thought to influence its distribution in the region were measured at 60 sites, which were selected based on the amount of native woodland retained in the landscape and patch size. An information-theoretic modelling approach and hierarchical partitioning revealed that the most influential variable was the percent of retained vegetation within a 1-km spatial extent. From this, we identified a critical threshold of ~30% retained vegetation in the landscape, above which the model predicted buffel grass was not likely to occur in a woodland fragment. Other explanatory variables in the model were site based, and included litter cover and long-term rainfall. Given the paucity of information on the effect of buffel grass upon biodiversity values, we undertook exploratory analyses to determine whether buffel grass cover influenced the distribution of grass, forb and reptile species. We detected some trends; hierarchical partitioning revealed that buffel grass cover was the most important explanatory variable describing habitat preferences of four reptile species. However, establishing causal links – particularly between native grass and forb species and buffel grass – was problematic owing to possible confounding with grazing pressure. We conclude with a set of management recommendations aimed at reducing the spread of buffel grass into remnant woodlands.

Diversity in immature-shark communities along a tropical coastline

2015 ◽  
Vol 66 (5) ◽  
pp. 399 ◽  
Author(s):  
Peter M. Yates ◽  
Michelle R. Heupel ◽  
Andrew J. Tobin ◽  
Stephen K. Moore ◽  
Colin A. Simpfendorfer
Keyword(s):  
Life History ◽  
Spatial Ecology ◽  
Population Level ◽  
Interspecific Variation ◽  
Eastern Coast ◽  
Life History Stage ◽  
Shark Species ◽  
Life History Stages ◽  
Young Of The Year ◽  
Effective Conservation

Effective conservation and management of shark populations is complicated by our limited understanding of their spatial ecology. For example, there are scarce data on diversity in community structure and nursery function across broader geographic scales (e.g. across multiple inshore systems) and the implications of this diversity for shark populations. Accordingly, fishery-independent surveys were undertaken to investigate shark communities along ~400km of the tropical eastern coast of Australia (18.1–20.6°S, 146.0–148.8°E). A variety of shark species were encountered, with 19 species of Carcharhiniformes contributing 99.2% of the total shark catch. Of the 1806 sharks captured, 567 were immature, including 336 young-of-the-year individuals. Immature sharks from 18 species were present; however, interspecific variation in the proportions of life-history stages was apparent. Multivariate analyses identified significant spatial heterogeneity in immature-shark communities. Results also highlighted the importance of tropical coastal habitats for numerous shark species, and indicated community-wide spatial structuring of sharks on the basis of body size rather than life-history stage. In addition to building on traditional shark-nursery paradigms, these results demonstrated that data on nursery function from restricted areas may not accurately portray patterns occurring over broader geographic scales, and this diversity may provide population-level benefits for sharks.

scholarly journals Spatial capture–recapture analysis of artificial cover board survey data reveals small scale spatial variation in slow-worm Anguis fragilis density

2017 ◽  
Vol 4 (9) ◽  
pp. 170374 ◽  
Author(s):  
Benedikt R. Schmidt ◽  
Anita Meier ◽  
Chris Sutherland ◽  
J. Andy Royle
Keyword(s):  
Spatial Variation ◽  
Spatial Ecology ◽  
Ad Hoc ◽  
Conservation Management ◽  
Home Range Size ◽  
Small Scale ◽  
Ecological State ◽  
State Variables ◽  
Capture Recapture ◽  
Anguis Fragilis

Vague and/or ad hoc definitions of the area sampled in monitoring efforts are common, and estimates of ecological state variables (e.g. distribution and abundance) can be sensitive to such specifications. The uncertainty in population metrics due to data deficiencies, vague definitions of space and lack of standardized protocols is a major challenge for monitoring, managing and conserving amphibian and reptile populations globally. This is especially true for the slow-worm ( Anguis fragilis ), a cryptic and fossorial legless lizard; uncertainty about spatial variation in density has hindered conservation efforts (e.g. in translocation projects). Spatial capture–recapture (SCR) methods can be used to estimate density while simultaneously and explicitly accounting for space and individual movement. We use SCR to analyse mark–recapture data of the slow-worm that were collected using artificial cover objects (ACO). Detectability varied among ACO grids and through the season. Estimates of slow-worm density varied across ACO grids (13, 45 and 46 individuals ha −1 , respectively). The estimated 95% home range size of slow-worms was 0.38 ha. Our estimates provide valuable information about slow-worm spatial ecology that can be used to inform future conservation management.

scholarly journals The ecomorphology of the shell of extant turtles and its applications for fossil turtles

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10490
Author(s):  
Laura Dziomber ◽  
Walter G. Joyce ◽  
Christian Foth
Keyword(s):  
Ph Regulation ◽  
Habitat Preferences ◽  
Principal Component ◽  
3D Models ◽  
Species Group ◽  
The Body ◽  
Late Triassic ◽  
Shell Shape ◽  
Dry Land ◽  
Fossil Species

Turtles are a successful clade of reptiles that originated in the Late Triassic. The group adapted during its evolution to different types of environments, ranging from dry land to ponds, rivers, and the open ocean, and survived all Mesozoic and Cenozoic extinction events. The body of turtles is characterized by a shell, which has been hypothesized to have several biological roles, like protection, thermal and pH regulation, but also to be adapted in its shape to the ecology of the animal. However, only few studies have investigated the relationships between shell shape and ecology in a global context or clarified if shape can be used to diagnose habitat preferences in fossil representatives. Here, we assembled a three-dimensional dataset of 69 extant turtles and three fossils, in particular, the Late Triassic Proganochelys quenstedtii and Proterochersis robusta and the Late Jurassic Plesiochelys bigleri to test explicitly for a relationship between shell shape and ecology. 3D models were obtained using surface scanning and photogrammetry. The general shape of the shells was captured using geometric morphometrics. The habitat ecology of extant turtles was classified using the webbing of their forelimbs as a proxy. Principal component analysis (PCA) highlights much overlap between habitat groups. Discriminant analyses suggests significant differences between extant terrestrial turtles, extant fully aquatic (i.e., marine and riverine) turtles, and an unspecialized assemblage that includes extant turtles from all habitats, mostly freshwater aquatic forms. The paleoecology of the three fossil species cannot be determined with confidence, as all three fall within the unspecialized category, even if Plesiochelys bigleri plots closer to fully aquatic turtles, while the two Triassic species group closer to extant terrestrial forms. Although the shape of the shell of turtles indeed contains an ecological signal, it is overall too weak to uncover using shell shape in paleoecological studies, at least with the methods we selected.

scholarly journals Extreme miniaturization of a new amniote vertebrate and insights into the evolution of genital size in chameleons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Frank Glaw ◽  
Jörn Köhler ◽  
Oliver Hawlitschek ◽  
Fanomezana M. Ratsoavina ◽  
Andolalao Rakotoarison ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Body Cavity ◽  
The Body ◽  
Rrna Gene ◽  
Micro Ct ◽  
Total Length ◽  
Reptile Species ◽  
Molecular Phylogenetic ◽  
Reversed Sexual Size Dimorphism ◽  
The 16S Rrna Gene

AbstractEvolutionary reduction of adult body size (miniaturization) has profound consequences for organismal biology and is an important subject of evolutionary research. Based on two individuals we describe a new, extremely miniaturized chameleon, which may be the world’s smallest reptile species. The male holotype of Brookesia nana sp. nov. has a snout–vent length of 13.5 mm (total length 21.6 mm) and has large, apparently fully developed hemipenes, making it apparently the smallest mature male amniote ever recorded. The female paratype measures 19.2 mm snout–vent length (total length 28.9 mm) and a micro-CT scan revealed developing eggs in the body cavity, likewise indicating sexual maturity. The new chameleon is only known from a degraded montane rainforest in northern Madagascar and might be threatened by extinction. Molecular phylogenetic analyses place it as sister to B. karchei, the largest species in the clade of miniaturized Brookesia species, for which we resurrect Evoluticauda Angel, 1942 as subgenus name. The genetic divergence of B. nana sp. nov. is rather strong (9.9‒14.9% to all other Evoluticauda species in the 16S rRNA gene). A comparative study of genital length in Malagasy chameleons revealed a tendency for the smallest chameleons to have the relatively largest hemipenes, which might be a consequence of a reversed sexual size dimorphism with males substantially smaller than females in the smallest species. The miniaturized males may need larger hemipenes to enable a better mechanical fit with female genitals during copulation. Comprehensive studies of female genitalia are needed to test this hypothesis and to better understand the evolution of genitalia in reptiles.

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