Population Structure, Body Size, and Seasonal Activity of Black Swamp Snakes (Seminatrix pygaea)

2005 ◽  
Vol 4 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Christopher T. Winne ◽  
Michael E. Dorcas ◽  
Sean M. Poppy
Keyword(s):  
Population Structure ◽  
Body Size ◽  
Seasonal Activity ◽  
Seminatrix Pygaea

Size-dependent seasonal activity for males of the dung beetle Copris acutidens (Coleoptera: Scarabaeidae)

2019 ◽  
Vol 151 (6) ◽  
pp. 757-767 ◽  
Author(s):  
Mayumi Akamine
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Dung Beetle ◽  
Threshold Value ◽  
Reproductive Period ◽  
Seasonal Activity ◽  
Size Dependent ◽  
Horn Length ◽  
Female Bias ◽  
Early Activity

AbstractThis study aimed to determine differences in activities between two male morphs of the dung beetle Copris acutidens Motschulsky (Coleoptera: Scarabaeidae) during the reproductive period and to examine the size distribution of reproductive males that stayed in nests. The activities of two male morphs distinguished by a threshold value of body size were compared with those by horn length. Regardless of body size or horn length, earlier activity of minor males was observed during the reproductive period. The sex ratio showed the greatest female bias when minor males were the more abundant than major males, indicating that minor males were the most active when competition was the weakest and these could avoid direct combat with major males. In morphs distinguished by horn length, more major males than minor males stayed in nests with females although the major males became the most active from the middle of the reproductive period. Thus, longer horns may directly confer a competitive advantage to males, enabling them to stay in nests with females, whereas early activity of minor males does not always indicate the effect of horn length directly. Therefore, this behaviour may occur regardless of whether the morphs differ in body size or horn length.

scholarly journals Thermal biology, activity, and population parameters of Cnemidophorus vacariensis (Squamata, Teiidae), a lizard endemic to southern Brazil

2011 ◽  
Vol 101 (4) ◽  
pp. 283-295 ◽  
Author(s):  
Rodrigo Caruccio ◽  
Renata Cardoso Vieira ◽  
Laura Verrastro ◽  
Denise Mello Machado
Keyword(s):  
Growth Rate ◽  
Population Structure ◽  
Body Temperature ◽  
Thermal Environment ◽  
Seasonal Activity ◽  
Southern Brazil ◽  
Body Temperatures ◽  
Thermal Biology ◽  
Environment Temperature ◽  
Average Body

We investigated the following aspects of the biology of a population of Cnemidophorus vacariensis Feltrim & Lema, 2000 during the four seasons: thermal biology, relationship with the thermal environment, daily and seasonal activity, population structure and growth rate. Cnemidophorus vacariensis is restricted to rocky outcrops of the "campos de cima da serra" grasslands on the Araucaria Plateau, southern Brazil, and is currently listed as regionally and nationally threatened with extinction. Data were collected from October 2004 through September 2007 in the state of Rio Grande do Sul. Sampling was conducted randomly from 08:00 a.m. to 6:00 p.m. The capture-mark-recapture method was employed. The lizards were captured by hand, and their cloacal temperature, sex, snout-ventral length (SVL), mass, and the temperature of their microhabitat (substrate temperature and air temperature) were recorded. Individuals were then marked by toe-clipping and released at the site of capture. Body temperatures were obtained for 175 individuals, activity data for 96 individuals, and data on population structure and growth for 59 individuals. All data were obtained monthly, at different times of the day. Cnemidophorus vacariensis average body temperature was 23.84ºC, ranging between 9.6 and 38.2ºC. Temperatures ranged between 21 and 29ºC. The correlation between external heat sources, substrate and air were positive and significant and there was a greater correlation between lizard's temperature and the temperature of the substrate (tigmothermic species). The relatively low body temperatures of individuals are associated with the climate of their environment (altitude up to 1,400 m), with large variations in temperature throughout the day and the year, and low temperatures in winter. The average body temperature observed for C. vacariensis was low when compared with that of phylogenetically related species, suggesting that the thermal biology of this species reflects adaptations to the temperate region where it lives. The monthly rates of activity of lizards were related to monthly variations in the ambient temperatures. Our data suggest that the daily and seasonal activity of C. vacariensis result from the interaction between two factors: changes in the environment temperature and the relationship between individuals and their thermal environment. The population structure of C. vacariensis varied throughout the study period, with maximum biomass in January and maximum density in February (recruitment period). The sex ratio diverged from the expected 1:1. The growth analysis showed a negative relationship between the growth rate of individuals and the SVL, revealing that young individuals grow faster than adults, a typical pattern for short-lived species. The population studied showed a seasonal and cyclical variation associated with the reproductive cycle. The life strategy of C. vacariensis seems to include adaptations to the seasonal variations in temperature, typical of its environment.

scholarly journals Sex, Age, and Body Size Distributions of Western Sandpipers During the Nonbreeding Season With Respect to Local Habitat

The Condor ◽  
2006 ◽  
Vol 108 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Guillermo Fernández ◽  
David B. Lank
Keyword(s):  
Population Structure ◽  
Body Size ◽  
Local Density ◽  
Late Winter ◽  
Size Distributions ◽  
Nonbreeding Season ◽  
Age Class ◽  
Migratory Shorebirds ◽  
Western Sandpipers ◽  
Northwestern Mexico

AbstractWe documented the local density and sex, age-class, and body size distributions of Western Sandpipers (Calidris mauri) among habitats at Bahía Santa María, northwestern Mexico, during the nonbreeding season. Three habitats were recognized: brackish flats, mangroves, and cattail marshes, which we ranked as richest to poorest in food resources and safest to most dangerous in predation danger. Western Sandpiper population structure differed among habitats. Bird densities were highest in brackish flats, the richest and safest habitat, and males and adults of both sexes were overrepresented. In cattail marshes, which appeared to be the poorest and most dangerous habitat, bird densities were lower, and the sex ratio and age ratios within each sex were more even. In mangroves, bird densities were similar to those in cattail marshes, but sex and age ratios were similar to those in brackish flats. Exposed culmen, an index of structural size, was not related to habitat use in either sex. Body mass of immature males was more variable than that of adults among habitats and immature males gained mass throughout the winter. Birds in brackish flats and mangroves were initially heavier, but tended to lose mass, whereas birds in cattail marshes were initially lighter, but tended to gain mass. Mass distributions thus converged in late winter. While the social and ecological causes and significance of differential sex and age-class distributions among habitats remain largely unquantified, evidence from this and previous studies suggests that nonbreeding population structure is a common phenomenon with important implications for migratory shorebirds.

Platypus (Ornithorhynchus anatinus) body size, condition and population structure in Tasmanian river catchments: variability and potential mucormycosis impacts

2011 ◽  
Vol 38 (4) ◽  
pp. 271 ◽  
Author(s):  
Nick Gust ◽  
Josh Griffiths
Keyword(s):  
Population Structure ◽  
Body Size ◽  
Spatial Scales ◽  
Population Level ◽  
Disease Status ◽  
Volume Index ◽  
Adult Males ◽  
Ornithorhynchus Anatinus ◽  
Size Condition ◽  
River Catchments

Context Despite widespread interest in platypus (Ornithorhynchus anatinus) conservation, it is unclear how their fundamental morphometric and demographic characteristics differ over a range of scales. This hampers impact assessments and understanding of platypus ecology. Although the ulcerative fungal disease mucormycosis has infected platypuses in Tasmania for three decades, its population level impacts and conservation significance remain unknown. Aims This study examined morphometric and demographic patterns in Tasmanian platypuses to provide a basis for investigating impacts of mucormycosis or other anthropogenic disturbances. It also sought to identify important spatial scales of natural variability and the magnitude of seasonal variation in platypus body size, condition and population structure. The hypothesis of higher mucormycosis prevalence and mortality in adult males was also investigated. Methods Extensive live-trapping surveys were conducted from January 2008 to July 2009 in 75 streams and 18 river catchments across Tasmania including King Island. The sex, age, body size, tail volume index, health and moult condition of 195 individuals were assessed, and population age and sex structures characterised. Sampling focussed on assessing variability within and between river catchments and compared populations in river catchments with contrasting disease status. Key results Differences in platypus morphometrics within and between catchments and seasonal moulting patterns were detected. Adult males had higher fat stores than adult females, especially during winter. This study also provided the first evidence of population level consequences of disease in platypuses. The demographic group most commonly affected by mucormycosis was confirmed to be adult males. Differences in male age structure among catchments of varying disease status were consistent with the hypothesis of higher adult male mortality rates and turnover in currently affected catchments. Conclusions More than 25 years after mucormycosis was first detected in Tasmanian platypuses, the disease continues to play a low-level, ongoing role in affected populations. Implications The present study provides the first systematic multi-scale spatial investigation of platypus mucormycosis, which contributes to unravelling the epidemiology of the disease and detecting its impacts. By identifying the magnitude and important scales of morphometric and demographic differences in Tasmanian platypuses the study also assists researchers choose comparable demographic groups and spatial scales for meaningful comparisons in future impact studies.

scholarly journals Divergence in Body Mass, Wing Loading, and Population Structure Reveals Species-Specific and Potentially Adaptive Trait Variation Across Elevations in Montane Bumble Bees

2021 ◽  
Vol 5 (5) ◽  
Author(s):  
Jeffrey D Lozier ◽  
Zachary M Parsons ◽  
Lois Rachoki ◽  
Jason M Jackson ◽  
Meaghan L Pimsler ◽  
...  
Keyword(s):  
Population Structure ◽  
Body Size ◽  
Body Mass ◽  
Bumble Bee ◽  
Flight Performance ◽  
Wing Loading ◽  
Trait Variation ◽  
Environmental Pressures ◽  
Environmental Correlations ◽  
High Elevations

Abstract Biogeographic clines in morphology along environmental gradients can illuminate forces influencing trait evolution within and between species. Latitude has long been studied as a driver of morphological clines, with a focus on body size and temperature. However, counteracting environmental pressures may impose constraints on body size. In montane landscapes, declines in air density with elevation can negatively impact flight performance in volant species, which may contribute to selection for reduced body mass despite declining temperatures. We examine morphology in two bumble bee (Hymenoptera: Apidae: Bombus Latreille) species, Bombus vancouverensis Cresson and Bombus vosnesenskii Radoszkowski, across mountainous regions of California, Oregon, and Washington, United States. We incorporate population genomic data to investigate the relationship between genomic ancestry and morphological divergence. We find that B. vancouverensis, which tends to be more specialized for high elevations, exhibits stronger spatial-environmental variation, being smaller in the southern and higher elevation parts of its range and having reduced wing loading (mass relative to wing area) at high elevations. Bombus vosnesenskii, which is more of an elevational generalist, has substantial trait variation, but spatial-environmental correlations are weak. Population structure is stronger in the smaller B. vancouverensis, and we find a significant association between elevation and wing loading after accounting for genetic structure, suggesting the possibility of local adaptation for this flight performance trait. Our findings suggest that some conflicting results for body size trends may stem from distinct environmental pressures that impact different aspects of bumble bee ecology, and that different species show different morphological clines in the same region.

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