Reading, Christopher J.; Jofré, Gabriela M.. 2015. Habitat use by smooth snakes on lowland heath ... more Reading, Christopher J.; Jofré, Gabriela M.. 2015. Habitat use by smooth snakes on lowland heath managed using 'conservation grazing'.
This document is the authors' final manuscript version of the journal article, incorporating any ... more This document is the authors' final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. There may be differences between this and the publisher's version. You are advised to consult the publisher's version if you wish to cite from this article.
Biological Journal of The Linnean Society, Aug 11, 2021
The NERC and UKCEH trademarks and logos ('the Trademarks') are registered trademarks of NERC and ... more The NERC and UKCEH trademarks and logos ('the Trademarks') are registered trademarks of NERC and UKCEH in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.
Cattle grazing is being used increasingly by landowners and statutory conservation bodies to mana... more Cattle grazing is being used increasingly by landowners and statutory conservation bodies to manage heathlands in parts of mainland Europe and in the UK, where it is called 'conservation grazing'. Between 2010 and 2013, cattle were excluded from six hectares of lowland heath, in southern England, that had been subject to annual summer cattle grazing between May 1997 and autumn 2009. Changes in grass snake Natrix natrix, common lizard Zootoca vivipara, slow worm Anguis fragilis and sand lizard Lacerta agilis numbers were recorded annually in the ungrazed area and in a four hectare area of heathland adjacent to it that continued to be grazed. The number of grass snake, common lizard and slow worm sightings were significantly higher in the ungrazed heath than the grazed heath and were associated with increased habitat structure, resulting principally from increased height and cover of grasses, particularly Molinia caerulea. Conversely, there was no significant difference in the...
The effect of environmental temperature on the growth and body condition of common toad (Bufo buf... more The effect of environmental temperature on the growth and body condition of common toad (Bufo bufo) toadlets was studied during their first terrestrial growth season, following metamorphosis, at a pond in south Dorset, UK, between 2010 and 2021. Toadlet samples were collected annually on the first day of emergence and then approximately once a week until late September/early October. In total, 15-19 samples were collected annually depending on the duration of the toadlet activity season. Toadlet snout-vent length (mm) and body mass (mg) of each captured toadlet was measured and their body condition (Scaled Mass Index: SMI) estimated both annually and for each annual quarter season. Toadlet growth rate and SMI varied between years and were significantly correlated with the duration of their first growth season and its lowest recorded temperature. Growth rate declined as the duration of the growth season increased whilst the reverse was true for SMI. Growth rates also increased as temperatures increased and vice versa for SMI. SMI was inversely correlated to growth rate and suggest that toadlets may enter their first hibernation larger, but in poorer condition, following warm summers than cool summers, and that this may have the potential to reduce their survivorship during a following mild winter. Assuming that similar relationships, between growth rates, body condition and environmental temperatures are not restricted to toadlets during their first terrestrial growth season, then this scenario may also be applicable to subsequent juvenile stages, further increasing the potential consequences for individual survival and fitness.
Cannibalism is a widespread behavioural trait in nature and snakes are no exception. In smooth sn... more Cannibalism is a widespread behavioural trait in nature and snakes are no exception. In smooth snakes (Coronella austriaca) it has only been visibly observed in captive individuals or known from faecal/stomach content analyses. Between 2009 and 2018 one incidence of cannibalism, determined from a faecal sample, and one sighting, were recorded in wild smooth snakes in Wareham Forest plantations, UK. Analysis of faecal samples and visual encounter surveys were used to estimate its frequency. Both records occurred in early autumn and our results suggest that its incidence in wild smooth snakes in southern England is low (0.1-0.3 %) and may be the result of low body condition. The circumstances resulting in cannibalism in the smooth snake may also be relevant to other animal species where cannibalism has been reported.
Accumulating evidence shows that the body size of organisms in many taxa is declining in response... more Accumulating evidence shows that the body size of organisms in many taxa is declining in response to global warming. We investigated the potential effect of rising temperatures on the body size of a common toad (Bufo bufo L.) population in southern England between 1983 and 2020. The body length (SVL; in millimetres) and body mass (in grams) of 15 550 males and 4004 females arriving at their breeding pond for the first time were recorded. Toad body condition was estimated using a scaled body mass index (SMI). Over the study period, the mean annual temperature increased by ~1.3 °C, whereas the mean SVL and SMI of both sexes declined. Multiple regression analysis showed that female and male SMI were negatively correlated with increases in mean summer temperatures, with females also being impacted minimally by mean winter rainfall. Mean body size (SVL) was positively correlated with toad abundance over the period between emergence as toadlets and arrival at the pond to breed for the fir...
The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the... more The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.
During 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction o... more During 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction of Bufo achalensis were studied mainly at La Ciénaga stream, Pampa de Achala, Argentina, using capture-recapture and skeletochronology methods. Breeding activity occurred from mid-August to mid-September and was explosive. Males and females congregated at night at selected, but scarce, breeding sites, resulting in a patchy distribution of small breeding populations near to the stream source. The sex ratio (♂ : ♀) of the breeding population ranged between 0.65 : 1 and 1.16 : 1. On average, breeding males were larger and older than breeding females. Although most females and males reached sexual maturity at four and five years of age, some bred for the first time at the ages of three and four years respectively. Neither size dependent nor size assortative pairings were found. Male reproductive success was not related to body size (SVL) but was related to the number of nights spent at a bree...
The diet of Smooth snakes (Coronella austriaca) inhabiting lowland heath in southern England was ... more The diet of Smooth snakes (Coronella austriaca) inhabiting lowland heath in southern England was studied over a nine-year period (2004-2012) by analysing 226 faecal samples obtained from 19 females and 41 males of varying age/size from juveniles to sexually mature adults. The main prey species belonged to the families Lacertidae (48%), Soricidae (32%) and Muridae (13%) with the remaining 7% comprising Anguidae (6%), Colubridae (0.5%) and Bufonidae (0.5%). Small mammals were absent from the diet of the smallest snakes but were a major component in the diet of large snakes. Lacertids were a major component of the diet of juvenile snakes whilst they formed a progressively smaller part of the diet of adult snakes. The data demonstrates a shift in diet, with increasing snake size, from Lacertids to small mammals. The highest number of small mammals was found in the diet during the early part of the activity period (April-June) with females apparently preying mainly upon Lacertids in late...
Amphibian and Reptile Conservation Research Reports publish the results of research and/or monito... more Amphibian and Reptile Conservation Research Reports publish the results of research and/or monitoring activities of interest to the herpetological community. Any views or opinions presented in this publication do not necessarily represent those of Amphibian and Reptile Conservation (ARC) or its collaborators. Whilst our goal is that the information herein is timely and accurate, ARC or its collaborators can accept no responsibility or liability with regards to that information. Reproduction and distribution (e.g. by photocopy or in pdf format) of this Report, acknowledging the source, is permitted for non-commercial purposes only.
A population of vizcacheras frogs Leptodactylus bufonius was studied at a man-made pond in the no... more A population of vizcacheras frogs Leptodactylus bufonius was studied at a man-made pond in the north of Córdoba Province in central Argentina during December 2000 and 2001. Breeding females were larger than breeding males with both sexes attaining sexual maturity at two years of age and most living to a maximum age of four years. The sex ratio of the breeding population was approximately 1.2♂ : 1♀. Although the numbers of eggs and tadpoles found in sealed nests was the same as the number of eggs found in the ovaries of unspawned females, between-year differences in egg production per female were found. Nests were constructed by males, at night, and then abandoned for at least 24 hours. Amplexus and spawning occurred within the nest. The nest was then vacated and the female sealed the nest aperture with wet mud. The minimum and maximum temperatures recorded inside sealed nests were less extreme than those recorded outside the nest.
The range sizes and habitat preferences of nine adult European grass snakes (Natrix natrix) were ... more The range sizes and habitat preferences of nine adult European grass snakes (Natrix natrix) were determined from radio-tracking data obtained within a landscape of mixed deciduous woodland and pastoral fields in southern England. These data were analysed using RANGES7v0.81 software. Concave polygons resulted in overall individual range size estimates that varied between 0.18-9.41 ha. However, for individuals that were radio-tracked for more than one season, annual range size estimates ranged between 1.29 ha and 3.56 ha and some snakes shifted their range between seasons. Grass snakes showed a strong preference for habitat boundaries and interfaces and an avoidance of woodland, and fields that were used for grazing. The attributes common to habitats that snakes preferred were a combination of basking site availability and a close proximity to relatively dense vegetation that offered potential protection from predators. The attributes common to habitats that snakes avoided were a lack...
Habitat selection in adult and juvenile Bufo achalensis was studied at La Ciénaga Stream, Pampa d... more Habitat selection in adult and juvenile Bufo achalensis was studied at La Ciénaga Stream, Pampa de Achala, Central Argentina from December 1998 to October 2001. Habitat preference was evaluated by comparing the observed use of each habitat type with its availability. Juveniles were surveyed on 32 occasions between January 1999 and March 2001 using 13 permanent transects. The effect of cattle on larval survivorship was also evaluated. Most adult and juvenile B. achalensis occurred within 300 m of each side of the breeding site stream. No correlation was found between body size and distances moved. Juveniles and adults selected granite outcrops after the breeding season and avoided the heavily grazed areas. Adults also selected the stream and used tall tussock grassland in proportion to its availability. Juveniles used loose, flat, relatively small stones as shelters whilst adults used larger rocks. The presence of cattle at the breeding sites directly reduced larval survivorship by t...
Reading, Christopher J.; Jofré, Gabriela M.. 2015. Habitat use by smooth snakes on lowland heath ... more Reading, Christopher J.; Jofré, Gabriela M.. 2015. Habitat use by smooth snakes on lowland heath managed using 'conservation grazing'.
This document is the authors' final manuscript version of the journal article, incorporating any ... more This document is the authors' final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. There may be differences between this and the publisher's version. You are advised to consult the publisher's version if you wish to cite from this article.
Biological Journal of The Linnean Society, Aug 11, 2021
The NERC and UKCEH trademarks and logos ('the Trademarks') are registered trademarks of NERC and ... more The NERC and UKCEH trademarks and logos ('the Trademarks') are registered trademarks of NERC and UKCEH in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.
Cattle grazing is being used increasingly by landowners and statutory conservation bodies to mana... more Cattle grazing is being used increasingly by landowners and statutory conservation bodies to manage heathlands in parts of mainland Europe and in the UK, where it is called 'conservation grazing'. Between 2010 and 2013, cattle were excluded from six hectares of lowland heath, in southern England, that had been subject to annual summer cattle grazing between May 1997 and autumn 2009. Changes in grass snake Natrix natrix, common lizard Zootoca vivipara, slow worm Anguis fragilis and sand lizard Lacerta agilis numbers were recorded annually in the ungrazed area and in a four hectare area of heathland adjacent to it that continued to be grazed. The number of grass snake, common lizard and slow worm sightings were significantly higher in the ungrazed heath than the grazed heath and were associated with increased habitat structure, resulting principally from increased height and cover of grasses, particularly Molinia caerulea. Conversely, there was no significant difference in the...
The effect of environmental temperature on the growth and body condition of common toad (Bufo buf... more The effect of environmental temperature on the growth and body condition of common toad (Bufo bufo) toadlets was studied during their first terrestrial growth season, following metamorphosis, at a pond in south Dorset, UK, between 2010 and 2021. Toadlet samples were collected annually on the first day of emergence and then approximately once a week until late September/early October. In total, 15-19 samples were collected annually depending on the duration of the toadlet activity season. Toadlet snout-vent length (mm) and body mass (mg) of each captured toadlet was measured and their body condition (Scaled Mass Index: SMI) estimated both annually and for each annual quarter season. Toadlet growth rate and SMI varied between years and were significantly correlated with the duration of their first growth season and its lowest recorded temperature. Growth rate declined as the duration of the growth season increased whilst the reverse was true for SMI. Growth rates also increased as temperatures increased and vice versa for SMI. SMI was inversely correlated to growth rate and suggest that toadlets may enter their first hibernation larger, but in poorer condition, following warm summers than cool summers, and that this may have the potential to reduce their survivorship during a following mild winter. Assuming that similar relationships, between growth rates, body condition and environmental temperatures are not restricted to toadlets during their first terrestrial growth season, then this scenario may also be applicable to subsequent juvenile stages, further increasing the potential consequences for individual survival and fitness.
Cannibalism is a widespread behavioural trait in nature and snakes are no exception. In smooth sn... more Cannibalism is a widespread behavioural trait in nature and snakes are no exception. In smooth snakes (Coronella austriaca) it has only been visibly observed in captive individuals or known from faecal/stomach content analyses. Between 2009 and 2018 one incidence of cannibalism, determined from a faecal sample, and one sighting, were recorded in wild smooth snakes in Wareham Forest plantations, UK. Analysis of faecal samples and visual encounter surveys were used to estimate its frequency. Both records occurred in early autumn and our results suggest that its incidence in wild smooth snakes in southern England is low (0.1-0.3 %) and may be the result of low body condition. The circumstances resulting in cannibalism in the smooth snake may also be relevant to other animal species where cannibalism has been reported.
Accumulating evidence shows that the body size of organisms in many taxa is declining in response... more Accumulating evidence shows that the body size of organisms in many taxa is declining in response to global warming. We investigated the potential effect of rising temperatures on the body size of a common toad (Bufo bufo L.) population in southern England between 1983 and 2020. The body length (SVL; in millimetres) and body mass (in grams) of 15 550 males and 4004 females arriving at their breeding pond for the first time were recorded. Toad body condition was estimated using a scaled body mass index (SMI). Over the study period, the mean annual temperature increased by ~1.3 °C, whereas the mean SVL and SMI of both sexes declined. Multiple regression analysis showed that female and male SMI were negatively correlated with increases in mean summer temperatures, with females also being impacted minimally by mean winter rainfall. Mean body size (SVL) was positively correlated with toad abundance over the period between emergence as toadlets and arrival at the pond to breed for the fir...
The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the... more The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.
During 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction o... more During 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction of Bufo achalensis were studied mainly at La Ciénaga stream, Pampa de Achala, Argentina, using capture-recapture and skeletochronology methods. Breeding activity occurred from mid-August to mid-September and was explosive. Males and females congregated at night at selected, but scarce, breeding sites, resulting in a patchy distribution of small breeding populations near to the stream source. The sex ratio (♂ : ♀) of the breeding population ranged between 0.65 : 1 and 1.16 : 1. On average, breeding males were larger and older than breeding females. Although most females and males reached sexual maturity at four and five years of age, some bred for the first time at the ages of three and four years respectively. Neither size dependent nor size assortative pairings were found. Male reproductive success was not related to body size (SVL) but was related to the number of nights spent at a bree...
The diet of Smooth snakes (Coronella austriaca) inhabiting lowland heath in southern England was ... more The diet of Smooth snakes (Coronella austriaca) inhabiting lowland heath in southern England was studied over a nine-year period (2004-2012) by analysing 226 faecal samples obtained from 19 females and 41 males of varying age/size from juveniles to sexually mature adults. The main prey species belonged to the families Lacertidae (48%), Soricidae (32%) and Muridae (13%) with the remaining 7% comprising Anguidae (6%), Colubridae (0.5%) and Bufonidae (0.5%). Small mammals were absent from the diet of the smallest snakes but were a major component in the diet of large snakes. Lacertids were a major component of the diet of juvenile snakes whilst they formed a progressively smaller part of the diet of adult snakes. The data demonstrates a shift in diet, with increasing snake size, from Lacertids to small mammals. The highest number of small mammals was found in the diet during the early part of the activity period (April-June) with females apparently preying mainly upon Lacertids in late...
Amphibian and Reptile Conservation Research Reports publish the results of research and/or monito... more Amphibian and Reptile Conservation Research Reports publish the results of research and/or monitoring activities of interest to the herpetological community. Any views or opinions presented in this publication do not necessarily represent those of Amphibian and Reptile Conservation (ARC) or its collaborators. Whilst our goal is that the information herein is timely and accurate, ARC or its collaborators can accept no responsibility or liability with regards to that information. Reproduction and distribution (e.g. by photocopy or in pdf format) of this Report, acknowledging the source, is permitted for non-commercial purposes only.
A population of vizcacheras frogs Leptodactylus bufonius was studied at a man-made pond in the no... more A population of vizcacheras frogs Leptodactylus bufonius was studied at a man-made pond in the north of Córdoba Province in central Argentina during December 2000 and 2001. Breeding females were larger than breeding males with both sexes attaining sexual maturity at two years of age and most living to a maximum age of four years. The sex ratio of the breeding population was approximately 1.2♂ : 1♀. Although the numbers of eggs and tadpoles found in sealed nests was the same as the number of eggs found in the ovaries of unspawned females, between-year differences in egg production per female were found. Nests were constructed by males, at night, and then abandoned for at least 24 hours. Amplexus and spawning occurred within the nest. The nest was then vacated and the female sealed the nest aperture with wet mud. The minimum and maximum temperatures recorded inside sealed nests were less extreme than those recorded outside the nest.
The range sizes and habitat preferences of nine adult European grass snakes (Natrix natrix) were ... more The range sizes and habitat preferences of nine adult European grass snakes (Natrix natrix) were determined from radio-tracking data obtained within a landscape of mixed deciduous woodland and pastoral fields in southern England. These data were analysed using RANGES7v0.81 software. Concave polygons resulted in overall individual range size estimates that varied between 0.18-9.41 ha. However, for individuals that were radio-tracked for more than one season, annual range size estimates ranged between 1.29 ha and 3.56 ha and some snakes shifted their range between seasons. Grass snakes showed a strong preference for habitat boundaries and interfaces and an avoidance of woodland, and fields that were used for grazing. The attributes common to habitats that snakes preferred were a combination of basking site availability and a close proximity to relatively dense vegetation that offered potential protection from predators. The attributes common to habitats that snakes avoided were a lack...
Habitat selection in adult and juvenile Bufo achalensis was studied at La Ciénaga Stream, Pampa d... more Habitat selection in adult and juvenile Bufo achalensis was studied at La Ciénaga Stream, Pampa de Achala, Central Argentina from December 1998 to October 2001. Habitat preference was evaluated by comparing the observed use of each habitat type with its availability. Juveniles were surveyed on 32 occasions between January 1999 and March 2001 using 13 permanent transects. The effect of cattle on larval survivorship was also evaluated. Most adult and juvenile B. achalensis occurred within 300 m of each side of the breeding site stream. No correlation was found between body size and distances moved. Juveniles and adults selected granite outcrops after the breeding season and avoided the heavily grazed areas. Adults also selected the stream and used tall tussock grassland in proportion to its availability. Juveniles used loose, flat, relatively small stones as shelters whilst adults used larger rocks. The presence of cattle at the breeding sites directly reduced larval survivorship by t...
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