Body size, food habits, reproduction and growth in a population of black whip snakes (Demansia vestigiata) (Serpentes:Elapidae) in tropical Australia

2009 ◽  
Vol 57 (1) ◽  
pp. 49 ◽  
Author(s):  
S. Fearn ◽  
D. F. Trembath
Keyword(s):  
Body Size ◽  
Growth Rates ◽  
Food Habits ◽  
Ecological Data ◽  
North Eastern ◽  
Body Sizes ◽  
History Of ◽  
Tropical Australia ◽  
Reproductive Cycles ◽  
Composite Samples

Two species of large black whip snakes (Demansia vestigiata and D. papuensis) are morphologically and ecologically similar and have broadly overlapping distributions. A long history of taxonomic difficulties has meant that most previous taxonomic and ecological studies comprise composite samples of both taxa. Here, we provide ecological data (body sizes, food habits, reproduction and inferred growth rates) collected from captured and road-killed specimens from a tropical population of D. vestigiata at Townsville, north-eastern Queensland, Australia. Males attain larger body sizes and have longer tails than females. All food items were ectotherms (lizards and frogs). Female reproductive cycles were strongly seasonal. Clutch size is significantly positively related to maternal body size. Egg dimensions, clutch mass and neonatal size are reported. Inferred growth rates indicate that sexual maturation is attained at ~21 months for females.

Natural history of the slaty grey snake (Stegonotus cucullatus) (Serpentes:Colubridae) from tropical north Queensland, Australia

2009 ◽  
Vol 57 (2) ◽  
pp. 119 ◽  
Author(s):  
Dane F. Trembath ◽  
Simon Fearn ◽  
Eivind Andreas Baste Undheim
Keyword(s):  
Food Habits ◽  
Field Studies ◽  
Wet Season ◽  
Ecological Data ◽  
Wide Range ◽  
Body Sizes ◽  
History Of ◽  
Wet Tropics ◽  
Free Ranging ◽  
Activity Times

Slaty grey snakes (Stegonotus cucullatus) are medium to large members of the Colubridae that are common throughout the eastern and northern tropics of Australia. Although intensive field studies have been conducted on populations in the Northern Territory for over 10 years, no ecological data have been presented on free-ranging specimens of populations inhabiting tropical north Queensland. During a 10-year period we collected opportunistic data on 120 free-ranging specimens from the seasonally Wet Tropics in north Queensland. These snakes provided data on body sizes, activity times, food habits and reproduction. Male S. cucullatus were larger than females and had larger heads. More snakes were found during the warmer, humid parts of the year (wet season). S. cucullatus ate a wide range of vertebrate prey, including reptile eggs that were obtained seasonally. Females produced one clutch per year, and no relationship was found between maternal snout–vent length and clutch size.

Life history of a small form of the plethodontid salamander Desmognathus quadramaculatus

2003 ◽  
Vol 24 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Christopher Beachy ◽  
Richard Bruce
Keyword(s):  
Growth Rates ◽  
Frequency Distributions ◽  
Plethodontid Salamander ◽  
Plethodontid Salamanders ◽  
Body Sizes ◽  
Minimum Age ◽  
History Of ◽  
Desmognathus Quadramaculatus ◽  
Gravid Females ◽  
Age At Maturation

AbstractWe sampled Desmognathus quadramaculatus, one of the largest species of plethodontid salamanders in eastern North America, from a population exhibiting extremely small adult body sizes in the Bald Mountains of North Carolina (USA). In order to test the hypothesis that miniaturization in desmognathine salamanders is due to early metamorphosis and maturation, we estimated ages and sizes at metamorphosis and maturation. Analysis of size-frequency distributions suggests that most larvae metamorphose after 24 months, with the remainder metamorphosing after 36. The minimum age of sexually mature individuals in the summer months is estimated to be 4 years in males and 5 years in females; some may mature 1 year earlier. This is earlier than other reliable estimates of age at maturation in D. quadramaculatus, and appears to account for the small size of the species at this locality. Larval and juvenile growth rates are within the range of growth rates of other populations. As in other populations of D. quadramaculatus, males are smaller than females at maturation, but grow to larger sizes. Estimates of clutch sizes based on dissection of gravid females are relatively low. The other species of salamanders in this community do not appear to be miniaturized.

Changing invaders: trends of gigantism in insular introduced rats

2018 ◽  
Vol 45 (3) ◽  
pp. 203-211 ◽  
Author(s):  
ALEXANDRA A.E. VAN DER GEER
Keyword(s):  
Body Size ◽  
Solomon Islands ◽  
Mammalian Species ◽  
Island Rule ◽  
Island Populations ◽  
Island Group ◽  
Body Sizes ◽  
History Of ◽  
Analyse Data ◽  
Insular Populations

SUMMARYThe degree and direction of morphological change in invasive species with a long history of introduction are insufficiently known for a larger scale than the archipelago or island group. Here, I analyse data for 105 island populations of Polynesian rats,Rattus exulans, covering the entirety of Oceania and Wallacea to test whether body size differs in insular populations and, if so, what biotic and abiotic features are correlated with it. All insular populations of this rat, except one, exhibit body sizes up to twice the size of their mainland conspecifics. Body size of insular populations is positively correlated with latitude, consistent with thermoregulatory predictions based on Bergmann's rule. Body size is negatively correlated with number of co-occurring mammalian species, confirming an ecological hypothesis of the island rule. The largest rats are found in the temperate zone of New Zealand, as well as on mammalian species-poor islands of Polynesia and the Solomon Islands. Carnivory in the form of predation on nesting seabird colonies seems to promote 1.4- to 1.9-fold body size increases.

Incubation temperature and clutch effects on initial body sizes and growth rates in green iguana hatchlings (Iguana iguana)

2017 ◽  
Vol 67 (3-4) ◽  
pp. 239-249 ◽  
Author(s):  
Yuleimis T. Martínez-Caballero ◽  
Brian C. Bock ◽  
Isabel Pérez ◽  
Ángela M. Ortega-León ◽  
Vivian P. Páez
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Rates ◽  
Egg Size ◽  
Incubation Temperature ◽  
Size Variation ◽  
Early Growth ◽  
Rate Variation ◽  
Body Sizes ◽  
Green Iguanas

Large initial body size and rapid early growth rate are important in many species, both because predation rates decline as individuals grow and because females that attain a larger adult body size are more fecund. To identify possible factors contributing to size and growth rate variation in hatchling green iguanas, we artificially incubated six clutches at three constant temperatures to test for effects of incubation temperature and/or clutch effects on initial size and growth rate. Higher incubation temperatures resulted in significantly shorter incubation periods but did not influence initial body size. There were significant differences among clutches in egg size, and also in initial hatchling body size, even after correcting for differences in egg size among clutches. A subset of hatchlings from each nest was reared in semi-natural conditions for four months, with individuals from the high incubation temperature condition exhibiting the slowest longer-term growth rates. No clutch effects were detected in the growth rate analyses. The observed variation in early growth rate of juvenile iguanas seems to be selectively important and this variation may be due in part to the conditions the eggs experience during incubation, but clutch effects in this study were limited to egg size and initial hatchling body size variation, but were not found for subsequent growth rates.

A new, diminutive species ofCatopsalis(Mammalia, Multituberculata, Taeniolabidoidea) from the early Paleocene of southwestern Alberta, Canada

2018 ◽  
Vol 92 (5) ◽  
pp. 896-910
Author(s):  
Craig S. Scott ◽  
Anne Weil ◽  
Jessica M. Theodor
Keyword(s):  
New Species ◽  
Body Size ◽  
Body Mass ◽  
North American ◽  
Phylogenetic Position ◽  
Early Paleocene ◽  
Body Sizes ◽  
History Of ◽  
American Clade ◽  
A New Species

AbstractMultituberculates were among the most taxonomically diverse mammals of the early Paleocene, having survived the catastrophic Cretaceous-Paleogene mass extinction and radiating soon thereafter. Although their evolution during the early Paleocene saw the advent of increasingly specialized dentitions, multituberculates generally remained small, rarely exceeding body sizes greater than those of extant rabbits. A conspicuous exception is the Taeniolabidoidea, a primarily North American clade whose members include the largest multituberculates yet discovered. Taeniolabidoidea includes several genera, with one of these,Catopsalis, being speciose and geographically wide ranging. Until recently, the chronological succession ofCatopsalisappeared to document a trend of increasing body size. We report here on a new species ofCatopsalisfrom the early Paleocene of Alberta that violates this trend and suggests that the evolutionary history ofCatopsalisis considerably more complex.Catopsalis kakwanew species is not only the smallest species ofCatopsalis, but is the smallest taeniolabidoid so far discovered, with an estimated body mass between 400 g and 660 g. In contrast to previous studies, we used recently proposed regressions based on lower cheek tooth row length to estimate body masses for North American taeniolabidoids. Our results propose more modest body mass estimates, particularly for the largest taeniolabidoids. The occurrence ofC.kakwan. sp. in the late early Paleocene implies either a significant ghost lineage, or reversal of several characters, including body size, during the latter part of the early Paleocene; the more likely of these scenarios must await a better understanding of the phylogenetic position ofC.kakwan. sp.UUID:http://zoobank.org/66d85345-49b8-4a46-ba6e-a4d4369cb3e0urn:lsid:zoobank.org:pub:AF7A5659-9068-4F2F-A6EC-5522A2BBA4CB

Pythons in the pergola: the ecology of 'nuisance' carpet pythons (Morelia spilota) from suburban habitats in south-eastern Queensland

2001 ◽  
Vol 28 (6) ◽  
pp. 573 ◽  
Author(s):  
S. Fearn ◽  
B. Robinson ◽  
J. Sambono ◽  
R. Shine
Keyword(s):  
Body Size ◽  
Food Habits ◽  
Sexual Size Dimorphism ◽  
Activity Patterns ◽  
Dietary Composition ◽  
Seasonal Activity ◽  
Size Dimorphism ◽  
South Eastern ◽  
Two Cities ◽  
Body Sizes

Carpet pythons (Morelia spilota) are large (to >4 m, 11 kg) non-venomous snakes that are widely distributed across mainland Australia. In many parts of their range, viable populations persist even in highly disturbed urban and suburban habitats. Over a six-year period, we collected 258 ‘nuisance’ pythons from two cities (Brisbane and Ipswich) in south-eastern Queensland. Most of these snakes were reported by members of the general public, often after the snakes had consumed domestic pets or cage-birds. We provide data on seasonal activity patterns, body sizes, sexual size dimorphism, reproduction and food habits of these snakes. Snakes were active and fed year-round, primarily on domestic and commensal birds and mammals. Dietary composition shifted with body size: one small snake consumed a lizard, intermediate-sized snakes took mostly mice, rats and parrots, and large snakes fed on larger items such as cats, brushtail possums and poultry. Adult male pythons engaged in combat bouts during the breeding season, and (perhaps as an adaptation to enhance success in such bouts) grew larger and were more heavy-bodied than conspecific females.

scholarly journals Body size and shape in insular environments and applications of the island rule in biological anthropology

2021 ◽  
Author(s):  
◽  
Colleen Brennan Young
Keyword(s):  
Body Size ◽  
Biological Anthropology ◽  
Human Populations ◽  
Size And Shape ◽  
Island Fox ◽  
Research Areas ◽  
Reduced Body ◽  
Island Evolution ◽  
Body Sizes ◽  
History Of

The discovery of small-bodied hominin fossils in 2004 on the island of Flores, Indonesia, unearthed a large debate within biological anthropology. This debate has exemplified that there are questions and research areas that biological anthropologists do not understand about island evolution. To improve understanding on the causes and products of evolution within island areas for biological anthropologists, this dissertation addresses three overarching research areas relevant to the biological anthropology community. The first is an analysis of how primate body sizes vary on islands, with interpretations that are anchored in the evolutionary history of body sizes of primates. Primates that initially evolved body sizes to survive within a frugivorous niche, with elongated life spans to improve survival in unpredictable environments, have body sizes distributed among islands in relation to the presence of absence of these pressures. Smaller islands contain more large, bodied primates overall, whereas larger islands contain more small-bodied ones. Second, an analysis of island fox body size and shape indicates that island foxes have reduced body sizes and divergent skeletal traits compared to mainland, closely related counterparts. Distinct body proportions are likely due to selection because allometric scaling of limb lengths to body mass are divergent for the island fox. Further, the island fox is not a scaled down version of the mainland fox, with limbs decreasing in size at a faster rate compared to the mainland. Last, an investigation on the diversity of two human populations in the Baja California peninsula demonstrates that Amerindians who migrated to and survived in these regions were impacted by ecogeographic pressures in different degrees, likely related to access to resources. Heat-adapted skeletal traits are apparent in both human populations who inhabited this hot desert, but body size is distinct for the two groups. Body size is smaller for individuals with less access to marine resources and increased susceptibility to periods of drought and starvation. Body size is larger for humans with convenient access to oceanic and terrestrial resources. These studies demonstrate that primates, omnivores, and humans are not immune to the effects of insularity as has been suggested. Rather, interpreting body size and shape alterations requires contextualizing the organism with their evolutionary histories and subsequent interactions within the island areas. Body size alterations are the result of shifting selective pressures from competing with other community members to competing with other individuals within a population over finite resources. As such, body shape can also be divergent compared to closely related mainland counterparts due to adaptation to local ecogeographic pressures. Skeletal traits of organisms need to be interpreted in relation to their migratory journeys and adaptation to local ecogeographic pressures within the island. For humans, contextualizing these variables with cultural and behavioral characteristics is imperative to understand a body size response within a sociocultural omnivorous niche.

Natural history of the common tree snake, Dendrelaphis punctulatus (Serpentes:Colubridae), in the wet - dry tropics of north Queensland

2010 ◽  
Vol 58 (6) ◽  
pp. 384 ◽  
Author(s):  
S. Fearn ◽  
D. F. Trembath
Keyword(s):  
Body Size ◽  
Natural History ◽  
Reproductive Period ◽  
Museum Specimens ◽  
Dry Tropics ◽  
History Of ◽  
Tropical Australia ◽  
The Common ◽  
Common Tree ◽  
Prey Items

Common tree snakes, Dendrelaphis punctulatus, are medium to large colubrid snakes that are relatively common in the eastern and northern parts of tropical Australia. The only previous study on this species involved museum specimens from across the taxon’s range. During a seven-year period we collected data on 131 field-caught specimens from a melanotic population in the Townsville district of north Queensland. Dendrelaphis punctulatus was found to be primarily diurnal, with a peak in activity centred around the reproductive period during the transition from dry to wet seasons. Females were larger than males with respect to all measured parameters, including mass and head size. Reproduction in females was strongly seasonal and clutch size was related to maternal body size. Prey items consisted of frogs, lizards and locusts.

Giant snakes in tropical forests: a field study of the Australian scrub python, Morelia kinghorni

2005 ◽  
Vol 32 (2) ◽  
pp. 193 ◽  
Author(s):  
S. Fearn ◽  
L. Schwarzkopf ◽  
R. Shine
Keyword(s):  
Body Size ◽  
Field Study ◽  
Large Body ◽  
Adult Males ◽  
Heating Rates ◽  
Wet Season ◽  
Ecological Data ◽  
Eastern Australia ◽  
Body Sizes ◽  
Initial Capture

Studies on species that attain very large body sizes provide a powerful opportunity to clarify the ecological correlates and consequences of body size, but logistical obstacles mean that most ‘giant’ species have attracted little field-based research. The Australian scrub python, Morelia kinghorni (= M. amethistina in earlier literature), is the largest Australian snake. Our three-year field study in the Tully River Gorge of tropical north-eastern Australia provides the first detailed ecological data on this species. Snakes aggregate in the gorge during the dry season for reproductive activities (combat, courtship and mating), and these aggregations consist primarily of large adult males. Wet-season samples from a nearby road contained more females, and more juvenile animals. Body temperatures of diurnally active pythons averaged 25.2°C, and were highly correlated with air and substrate temperatures. Larger snakes were cooler than smaller conspecifics, perhaps reflecting their slower heating rates. Recapture of marked individuals suggests that pythons of both sexes and all body sizes maintain fixed home ranges, as the distance from initial capture did not increase through time; most animals were recaptured <100 m from their initial capture point, but some dispersed at least 1.5 km. Adult male pythons spanned a massive range in body sizes (1.3–3.76 m in snout–vent length, 0.30–11 kg in mass), and larger males were more likely to engage in combat, exhibit combat-related injuries (bite wounds) and obtain matings. Presumably reflecting the reproductive advantage of larger body size, males attained much larger maximum sizes than did females within our study population.

scholarly journals Temperature Variation and Species Interactions in Aquatic Systems in Grand Teton National Park

1992 ◽  
Vol 16 ◽  
pp. 140-145
Author(s):  
Bruce Woodward ◽  
Sandra Mitchell
Keyword(s):  
Body Size ◽  
Temperature Variation ◽  
Growth Rates ◽  
Species Interactions ◽  
National Park ◽  
Simple Experiment ◽  
Grand Teton National Park ◽  
Caddisfly Larvae ◽  
Body Sizes ◽  
Salamander Larvae

Temperature variation and species interactions were examined in small montane ponds in Grand Teton National Park during summer 1991. Temperature variation was pronounced, both over time and from place to place within one pond or across ponds. The magnitude of the temperature variation is such that it is likely to lead to large differences in the growth rates of poikilotherms that occupy these ponds. Growth rates determine body sizes at any one point in time. Tadpole body size influenced the probability of predation by salamander larvae in these montane ponds in Grand Teton National Park. Given the natural body size ratios of predator and prey (observed in 1991}, salamanders biased predation towards smaller tadpoles. Other predation experiments revealed that the salamander larvae biased predation towards tadpoles and away from damselfly naiads. This suggests that damselflies may experience lower predation by salamanders when in the presence of tadpoles than when in the absence of tadpoles. Several species, including snails, caddisfly larvae, and tadpoles were very abundant in some ponds, but could be essentially absent from others. These three taxa appear to share similar diets. A simple experiment revealed the Pseudacris tadpoles and the snails compete, and that presence of salamander larvae had no effect on the strength of their competitive interaction.

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