Do body size, diet type or residence time explain habitat use in a vertebrate herbivore community?

2016 ◽  
Vol 64 (2) ◽  
pp. 91 ◽  
Author(s):  
S. Garnick ◽  
J. Di Stefano ◽  
M. A. Elgar ◽  
G. Coulson
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Residence Time ◽  
Relative Entropy ◽  
Red Deer ◽  
The Body ◽  
Community Organisation ◽  
Grey Kangaroo ◽  
Eastern Australia ◽  
Diet Type

Many theories attempt to explain patterns of community organisation among large herbivores. We explored the role of body size, diet type and residence time on habitat use in a community comprising four metatherians (western grey kangaroo, Macropus fuliginosus; eastern grey kangaroo, M. giganteus; red-necked wallaby, Notamacropus rufogriseus; swamp wallaby, Wallabia bicolor) and two eutherians (red deer, Cervus elaphus; European rabbit, Oryctolagus cuniculus) in south-eastern Australia. We used camera traps to estimate habitat occupancy, quantified habitat specialisation using relative entropy, and ran regressions using percentage grass consumed, log(mass) and log(time at site) as predictor variables and relative entropy as the response. If body size influenced habitat use, we predicted smaller species would occupy fewer habitats. If diet type influenced habitat use, we predicted intermediate feeders would use more habitats. If the time that a species had been present at a site predicted community organisation, newer species would use more habitats. None of these theories explained habitat use in our community. Red deer used a narrower range of habitats than expected, perhaps due to the poor suitability of habitats available in the Grampians. While interactions between our hypotheses are likely to be important, the body size model deserves further attention in this community.

scholarly journals Larval ecomorphology of 13 Libellulidae (Anisoptera, Odonata) of the Middle Rio Doce Valley, Minas Gerais, Brazil

2008 ◽  
Vol 68 (1) ◽  
pp. 211-219 ◽  
Author(s):  
HC. Giacomini ◽  
P. De Marco Jr.
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Aquatic Macrophytes ◽  
Minas Gerais ◽  
The Body ◽  
The Other ◽  
Morphological Divergence ◽  
Bottom Substrate ◽  
Morphological Distinction ◽  
Morphological Variables

In the lakes of the Middle Rio Doce, Minas Gerais (MG), two groups of larval Libellulidae are distinguished by preferences of habitat use: one uses mainly aquatic macrophytes and the other uses the bottom substrate. The goal of this work was to verify if there is a morphological distinction between the two groups of species. Thirteen body measures were taken from the larvae and analyzed. No difference was found between the two groups of species regarding the body size, but shape differences were observed for two morphological variables. The species that use mainly macrophytes tend to have larger relative measures of the labium and smaller measures of the abdomen width. Advantages in resource obtainment and in vulnerability to predation are probably the explanations for the morphological divergence among these larval groups.

Life history and ecology of the elegant snake-eyed skink (Cryptoblepharus pulcher) in south-eastern Australia

2019 ◽  
Vol 67 (1) ◽  
pp. 51
Author(s):  
David A. Pike ◽  
Elizabeth A. Roznik ◽  
Jonathan K. Webb ◽  
Richard Shine
Keyword(s):  
Life History ◽  
Body Size ◽  
Natural Habitat ◽  
The Body ◽  
Lizard Species ◽  
Tropical Environments ◽  
Eastern Australia ◽  
Taxonomic Changes ◽  
Gravid Females ◽  
Incubation Temperatures

Detailed information on life history and ecology is essential for successful conservation and management. However, we have relatively little detailed data on the life history and ecology of most small lizard species, relative to other vertebrates, especially those that have undergone recent taxonomic changes. We studied the ecology of the elegant snake-eyed skink (Cryptoblepharus pulcher), a lizard that occurs on trees, fences, walls, and rock outcroppings in eastern Australia that spans temperate to tropical environments. In our temperate-zone study population living in natural habitat, individuals are active year-round, and gravid females were found during the months of September through December. Sexual maturity is reached in 12 months, lifespan is at least three years, and clutch size is typically two eggs. In laboratory incubation experiments, larger eggs were more likely to hatch. Low incubation temperatures (averaging 23 ± 7.5°C versus high temperatures averaging 26 ± 7.5°C) increased incubation duration significantly (range 56–72 days versus 40–51 days) and reduced the body size of hatchlings significantly (17.8 mm versus 18.7 mm snout–vent length). Skinks sheltered beneath small rocks that were not shared simultaneously with predatory snakes, and that reached average temperatures that were up to 3°C warmer during the day than unused rocks. Preferred microhabitats include substrates of rock or soil, and the largest rocks were occasionally shared by up to four individuals of all body size/sex combinations (5.8% of observations were shared, 30.2% of individual rocks were shared). Our study expands upon knowledge of the widespread genus Cryptoblepharus by providing detailed life history and ecological information on C. pulcher that can serve as a baseline for future studies.

Niche partitioning within a population of sea snakes is constrained by ambient thermal homogeneity and small prey size

2020 ◽  
Vol 129 (3) ◽  
pp. 644-651 ◽  
Author(s):  
Claire Goiran ◽  
Gregory P Brown ◽  
Richard Shine
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
New Caledonia ◽  
Niche Partitioning ◽  
Thermal Conditions ◽  
The Body ◽  
Small Prey ◽  
Sea Snakes ◽  
Local Extirpation ◽  
Free Ranging

Abstract In many populations of terrestrial snakes, the phenotype of an individual (e.g. body size, sex, colour) affects its habitat use. One cause for that link is gape limitation, which can result in larger snakes eating prey that are found in different habitats. A second factor involves thermoregulatory opportunities, whereby individuals select habitats based upon thermal conditions. These ideas predict minimal intraspecific variation in habitat use in a species that eats small prey and lives in a thermally uniform habitat, such as the sea snake Emydocephalus annulatus, which feeds on tiny fish eggs and lives in inshore coral reefs. To test that prediction, we gathered data on water depths and substrate attributes for 1475 sightings of 128 free-ranging E. annulatus in a bay near Noumea, New Caledonia. Habitat selection varied among individuals, but with a preference for coral-dominated substrates. The body size and reproductive state of a snake affected its detectability in deep water, but overall habitat use was not linked to snake body size, colour morph, sex or pregnancy. A lack of ontogenetic shifts in habitat use allows extreme philopatry in E. annulatus, thereby reducing gene flow among populations and, potentially, delaying recolonization after local extirpation events.

Factors affecting antler investment in Iberian red deer

2012 ◽  
Vol 52 (9) ◽  
pp. 867 ◽  
Author(s):  
J. A. Gómez ◽  
F. Ceacero ◽  
T. Landete-Castillejos ◽  
E. Gaspar-López ◽  
A. J. García ◽  
...  
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Red Deer ◽  
Good Method ◽  
The Body ◽  
Allometric Relationship ◽  
Factors Affecting ◽  
Iberian Red Deer ◽  
Mineral Deposition ◽  
Antler Growth

Antler constitutes such a costly trait that the skeleton of the deer undergoes a process similar to osteoporosis to meet the high demands of mineral deposition in the antler. The allometric relationship between antler and body size is one of the oldest known. However, no study has assessed the proportion that antlers constitute with regard to the skeleton (from which most of the material is drawn), nor which factors influence this investment. To assess this, we studied 171 males (aged 1–5 years), determined their antler and bodyweights and scored their body condition. Then we calculated antler investment as antler weight relative to estimated skeletal weight. Results showed that antler investment in males ≥2 years old (i.e. excluding yearlings) depended on age rather than the whole bodyweight or body condition. Antler investment increased from 6% in yearlings to 35% in 5-year-old males, with a mean of 19%. A GLMM showed that in males ≥2 years old, within age, the heavier the male and the better the body condition at the start of antler growth, the greater the investment in antlers. In yearlings, antler investment did not depend on bodyweight or body condition. In conclusion, antler weight relative to skeleton weight is a good method to assess antler investment. This investment is influenced by age and, in males ≥2 years old, also by bodyweight or condition at the start of antler growth.

Is body size variation in the platypus (Ornithorhynchus anatinus) associated with environmental variables?

2011 ◽  
Vol 59 (4) ◽  
pp. 201 ◽  
Author(s):  
Elise Furlan ◽  
J. Griffiths ◽  
N. Gust ◽  
R. Armistead ◽  
P. Mitrovski ◽  
...  
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Size Variation ◽  
The Body ◽  
Body Size Variation ◽  
Temperature Regimes ◽  
Ornithorhynchus Anatinus ◽  
Eastern Australia ◽  
Lower Temperature ◽  
Latitudinal Range

The body size of the platypus (Ornithorhynchus anatinus) is known to vary across both its latitudinal range and relatively short geographic distances. Here we consider how variation in platypus length and weight associates with environmental variables throughout the species’ range. Based on data from over 800 individuals, a Bergmann’s cline (increased body size in regions of lower temperature) was detected across the species latitudinal range. The opposite association, however, was present at smaller scales when comparing platypus body size and temperature within southern mainland Australia, or within an individual river basin. Temperature regimes alone clearly did not dictate body size in platypuses, although disentangling the effects of different climatic variables on body size variation was difficult because of correlations amongst variables. Nevertheless, within suitable platypus habitat in south-eastern Australia, areas of relatively lower rainfall and higher temperatures were typically associated with larger-bodied platypuses. The potential benefits to larger-bodied animals living under these conditions are explored, including consideration of variation in energy expenditure and food availability. Assuming these associations with environmental variables are biologically significant, a shift in platypus body size is anticipated in the future with predicted changes in climate.

The influence of evolutionary history and body size on partitioning of habitat resources by mammalian herbivores in south-eastern Australia

2017 ◽  
Vol 65 (4) ◽  
pp. 226 ◽  
Author(s):  
Naomi E. Davis ◽  
Ian R. Gordon ◽  
Graeme Coulson
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Introduced Species ◽  
Resource Partitioning ◽  
Evolutionary History ◽  
Species Coexistence ◽  
European Rabbit ◽  
Niche Complementarity ◽  
Mammalian Herbivores ◽  
Eastern Australia

Habitat use is the most common dimension along which sympatric species partition resources to reduce competition. We conducted faecal pellet counts at Wilsons Promontory National Park, Victoria, to examine habitat use by an assemblage of mammalian herbivores with disparate evolutionary histories and varying body size: introduced European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus), and native eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus). Overlap in habitat use was low between four pairs of species, suggesting spatial partitioning of resources to reduce the potential for interspecific competition. More generally, however, overlap in habitat use was high, particularly between native and introduced grazers. These results indicate the potential for competition if resources were limiting and suggest that assemblages of species with independent evolutionary histories have inherently less resource partitioning to facilitate coexistence than assemblages of species with common evolutionary histories. Despite evidence of high overlap in habitat use between native and introduced species at a broad scale, and variation in the competitive ability of species, coexistence was likely facilitated by niche complementarity, including temporal and fine-scale partitioning of spatial resources. There was no relationship between body size and the diversity of habitats used. In contemporary assemblages of native and introduced species, evolutionary history is likely to have a strong influence on resource partitioning.

The Body Size of Headstarted and Wild Juvenile European Pond Turtles (Emys orbicularis)

2017 ◽  
Vol 25 (2) ◽  
pp. 161
Author(s):  
Sławomir Mitrus ◽  
Bartłomiej Najbar ◽  
Adam Kotowicz ◽  
Anna Najbar
Keyword(s):  
Body Size ◽  
The Body ◽  
Emys Orbicularis

scholarly journals First record of Pachycrocuta brevirostris (Gervais, 1850) from Ukraine on the background of the European occurrence of the species

2021 ◽  
Author(s):  
Adrian Marciszak ◽  
Yuriy Semenov ◽  
Piotr Portnicki ◽  
Tamara Derkach
Keyword(s):  
Body Size ◽  
First Record ◽  
The Body ◽  
Crocuta Crocuta ◽  
Early Pleistocene ◽  
Eastern Asia ◽  
South Eastern

AbstractCranial material ofPachycrocuta brevirostrisfrom the late Early Pleistocene site of Nogaisk is the first record of this species in Ukraine. This large hyena was a representative of the Tamanian faunal complex and a single specialised scavenger in these faunas. The revisited European records list ofP.brevirostrisdocumented the presence of this species in 101 sites, dated in the range of 3.5–0.4 Ma. This species first disappeared in Africa, survived in Europe until ca. 0.8–0.7 Ma, and its last, relict occurrence was known from south-eastern Asia. The main reason of extinction ofP.brevirostrisprobably was the competition withCrocuta crocuta. The cave hyena was smaller, but its teeth were proportionally larger to the body size, better adapted to crushing bones and slicing meat, and could also hunt united in larger groups.

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

scholarly journals Insect body size changes under future warming projections: a case study of Chironomidae (Insecta: Diptera)

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rungtip Wonglersak ◽  
Phillip B. Fenberg ◽  
Peter G. Langdon ◽  
Stephen J. Brooks ◽  
Benjamin W. Price
Keyword(s):  
Body Size ◽  
Ambient Temperature ◽  
Wing Length ◽  
The Body ◽  
Mesocosm Experiments ◽  
Future Warming ◽  
Increasing Temperature ◽  
Emergence Date ◽  
Average Body

AbstractChironomids are a useful group for investigating body size responses to warming due to their high local abundance and sensitivity to environmental change. We collected specimens of six species of chironomids every 2 weeks over a 2-year period (2017–2018) from mesocosm experiments using five ponds at ambient temperature and five ponds at 4°C higher than ambient temperature. We investigated (1) wing length responses to temperature within species and between sexes using a regression analysis, (2) interspecific body size responses to test whether the body size of species influences sensitivity to warming, and (3) the correlation between emergence date and wing length. We found a significantly shorter wing length with increasing temperature in both sexes of Procladius crassinervis and Tanytarsus nemorosus, in males of Polypedilum sordens, but no significant relationship in the other three species studied. The average body size of a species affects the magnitude of the temperature-size responses in both sexes, with larger species shrinking disproportionately more with increasing temperature. There was a significant decline in wing length with emergence date across most species studied (excluding Polypedilum nubeculosum and P. sordens), indicating that individuals emerging later in the season tend to be smaller.

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