Another one bites the dust: Does incisor-arcade size affect mass gain and survival in grazing ungulates?

Incisor-arcade size affects foraging efficiency in grazing ungulates and should be under strong selective pressure. We investigated individual variation in incisor-arcade size and its relationship with body mass and survival in bighorn sheep (Ovis canadensis) at Ram Mountain, Alberta, Canada, over 9 years. In adult ewes, incisor-arcade breadth and depth decreased with age, probably as a result of tooth wear. We found no effects of incisor-arcade size on survival of lambs or adult ewes. In adult ewes, an apparent positive effect of incisor-arcade size on survival disappeared when age was accounted for. Incisor-arcade breadth and depth had no effect on summer mass gain in lambs or adult ewes. Although linear models suggested that arcade breadth in lambs was correlated with summer mass gain, a latent variable path analysis model revealed that the correlation was due to an allometric relationship of arcade breadth with body size. Variation in incisor-arcade size in bighorn sheep appears to be due to individual variation in body size and age rather than to directional selection.

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Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

Anatomy Research International ◽

10.1155/2011/831943 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

Adam Hartstone-Rose ◽

Jonathan M. G. Perry

Keyword(s):

Body Size ◽

Body Mass ◽

Individual Variation ◽

Size Variation ◽

Maximum Size ◽

Least Squares Regression ◽

Scaling Relationship ◽

Varecia Rubra ◽

Food Size ◽

The Relationship

In a recent study, we quantified the scaling of ingested food size (Vb )—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli), and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically.

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BODY SIZE VARIATION AND OPTIMAL BODY SIZE OF BUMBLE BEE QUEENS (HYMENOPTERA: APIDAE)

The Canadian Entomologist ◽

10.4039/ent12019-1 ◽

1988 ◽

Vol 120 (1) ◽

pp. 19-27 ◽

Cited By ~ 37

Author(s):

Robin E. Owen

Keyword(s):

Weight Loss ◽

Body Size ◽

Size Variation ◽

Bumble Bees ◽

Foraging Efficiency ◽

Bumble Bee ◽

Mass Variation ◽

Fixed Amount ◽

Trade Off ◽

Radial Cell

AbstractBody size and mass variation of queen bumble bees (Bombus Latr. spp.) were analyzed in relationship to hibernation survival and optimal body size. Body mass and size (measured by radial cell length) were significantly correlated in six of eight species. Also, spring queens of B. occidentalis Greene were, on average, significantly larger yet lighter than young fall queens. These observations were consistent with weight loss known to occur during hibernation coupled with greater mortality of small queens over the winter. Thus large queens may be at an advantage for this and other reasons (e.g. foraging efficiency, usurpation). However, an optimality model showed that an intermediate body size was optimal if the reproductive success of a colony (foundress queen and workers) was considered. The assumptions were that fitness did not increase linearly with body size but was a convex function, and that colonies only had a fixed amount of energy to invest in reproductive offspring leading to a trade-off between size and number.

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Urbanization effect on ground beetles (Coleoptera, Carabidae)

MOJ Ecology & Environmental Sciences ◽

10.15406/mojes.2019.04.00161 ◽

2019 ◽

Vol 4 (6) ◽

Author(s):

Raisa A Sukhodolskaya ◽

Anatoliy A Saveliev ◽

Natalya I Eremeeva ◽

Iraida G Vorobyova

Keyword(s):

Body Size ◽

Anthropogenic Impact ◽

Linear Models ◽

Size Variation ◽

Ground Beetles ◽

Ecological Niches ◽

Urbanization Effect ◽

Poecilus Cupreus ◽

Pterostichus Melanarius ◽

Regions Of Russia

We sampled beetles in different regions of Russia (Tatarstan Republic, Mariy El Republic, Udmurtia Republic, Kemerovo, Sverdlovsk, Stavropol, Cis-Ural provinces) at sites which varied in the level of anthropogenic impact and vegetation. We used linear models to clarify how urbanization affected body size variation in studied species. All of them were palearctic generalists – Carabus granulatus, Carabus cancellatus, Pterostichus melanarius, Pterostichus niger, Poecilus cupreus, and only Carabus aeruginosus was a Siberian one. Beetles we measured for six dimensional traits. In a whole 12000 specimen have been analyzed. Results showed that different traits of Ground Beetles can response to urbanization in opposite directions: e.g. in some studies species factor “city” decreased elytra length, but increased its width and vise versa. Effect of “city” and “suburbs” factors had different directions, e. g. in a given species body size decreased in cities but in suburbs it increased and verse versa. Cognate species, which occupy similar ecological niches, have responded to urbanization in opposite directions. Females and males can respond to urbanization in opposite directions, the latter lead to the significant body size sexual dimorphism in the gradient of urbanization.

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Independent evolution towards larger body size in the distinctive Faroe Island mice

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkaa051 ◽

2021 ◽

Author(s):

Ricardo Wilches ◽

William H Beluch ◽

Ellen McConnell ◽

Diethard Tautz ◽

Yingguang Frank Chan

Keyword(s):

Body Size ◽

Meta Analysis ◽

Small Body ◽

Laboratory Mouse ◽

Large Body ◽

Natural Populations ◽

Size Variation ◽

Phenotypic Traits ◽

Island Population ◽

Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

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Mammalian body size is determined by interactions between climate, urbanization, and ecological traits

Communications Biology ◽

10.1038/s42003-021-02505-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Maggie M. Hantak ◽

Bryan S. McLean ◽

Daijiang Li ◽

Robert P. Guralnick

Keyword(s):

Body Size ◽

Resource Availability ◽

Critical Role ◽

Size Variation ◽

Ecological Factors ◽

Species Traits ◽

Body Size Variation ◽

Resource Availability Hypothesis ◽

Urban Heat ◽

Thermal Buffering

AbstractAnthropogenically-driven climate warming is a hypothesized driver of animal body size reductions. Less understood are effects of other human-caused disturbances on body size, such as urbanization. We compiled 140,499 body size records of over 100 North American mammals to test how climate and human population density, a proxy for urbanization, and their interactions with species traits, impact body size. We tested three hypotheses of body size variation across urbanization gradients: urban heat island effects, habitat fragmentation, and resource availability. Our results demonstrate that both urbanization and temperature influence mammalian body size variation, most often leading to larger individuals, thus supporting the resource availability hypothesis. In addition, life history and other ecological factors play a critical role in mediating the effects of climate and urbanization on body size. Larger mammals and species that utilize thermal buffering are more sensitive to warmer temperatures, while flexibility in activity time appears to be advantageous in urbanized areas. This work highlights the value of using digitized, natural history data to track how human disturbance drives morphological variation.

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Detecting Instruction Effects—Deciding Between Covariance Analytical and Change-Score Approach

Educational Psychology Review ◽

10.1007/s10648-020-09590-6 ◽

2021 ◽

Author(s):

Carmen Köhler ◽

Johannes Hartig ◽

Alexander Naumann

Keyword(s):

Latent Variable ◽

Outcome Measurement ◽

Predictor Variable ◽

Change Score ◽

Regression Coefficients ◽

Outcome Variable ◽

Analysis Model ◽

Hypothetical Data ◽

Instructional Research ◽

Time Point

AbstractThe article focuses on estimating effects in nonrandomized studies with two outcome measurement occasions and one predictor variable. Given such a design, the analysis approach can be to include the measurement at the previous time point as a predictor in the regression model (ANCOVA), or to predict the change-score of the outcome variable (CHANGE). Researchers demonstrated that both approaches can result in different conclusions regarding the reported effect. Current recommendations on when to apply which approach are, in part, contradictory. In addition, they lack direct reference to the educational and instructional research contexts, since they do not consider latent variable models in which variables are measured without measurement error. This contribution assists researchers in making decisions regarding their analysis model. Using an underlying hypothetical data-generating model, we identify for which kind of data-generating scenario (i.e., under which assumptions) the defined true effect equals the estimated regression coefficients of the ANCOVA and the CHANGE approach. We give empirical examples from instructional research and discuss which approach is more appropriate, respectively.

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Prey Body Size and Ranking in Zooarchaeology: Theory, Empirical Evidence, and Applications from the Northern Great Basin

American Antiquity ◽

10.7183/0002-7316.76.3.403 ◽

2011 ◽

Vol 76 (3) ◽

pp. 403-428 ◽

Cited By ~ 56

Author(s):

Jack M. Broughton ◽

Michael D. Cannon ◽

Frank E. Bayham ◽

David A. Byers

Keyword(s):

Body Size ◽

Great Basin ◽

Diet Breadth ◽

Foraging Theory ◽

Return Rate ◽

The Body ◽

Foraging Efficiency ◽

Large Prey ◽

Abundance Indices ◽

Game Hunting

The use of body size as an index of prey rank in zooarchaeology has fostered a widely applied approach to understanding variability in foraging efficiency. This approach has, however, been critiqued—most recently by the suggestion that large prey have high probabilities of failed pursuits. Here, we clarify the logic and history of using body size as a measure of prey rank and summarize empirical data on the body size-return rate relationship. With few exceptions, these data document strong positive relationships between prey size and return rate. We then illustrate, with studies from the Great Basin, the utility of body size-based abundance indices (e.g., the Artiodactyl Index) when used as one component of multidimensional analyses of prehistoric diet breadth. We use foraging theory to derive predictions about Holocene variability in diet breadth and test those predictions using the Artiodactyl Index and over a dozen other archaeological indices. The results indicate close fits between the predictions and the data and thus support the use of body size-based abundance indices as measures of foraging efficiency. These conclusions have implications for reconstructions of Holocene trends in large game hunting in western North America and for zooarchaeological applications of foraging theory in general.

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