Relative forelimb–hindlimb investment is associated with flight style, foraging strategy, and nestling period, but not nest type

The Auk ◽  
2022 ◽  
Author(s):  
Jess Kotnour ◽  
Sarah J McPeek ◽  
Hannah Wedig ◽  
Jonah Dominguez ◽  
Natalie A Wright
Keyword(s):  
Life History ◽  
Body Size ◽  
Foraging Strategy ◽  
Long Bones ◽  
Nestling Period ◽  
Body Sizes ◽  
Soaring Birds ◽  
Selection For ◽  
Foraging Method ◽  
Nest Type

Abstract We investigated Dial’s 2003 hypothesis that birds that rely more heavily on flight as their primary mode of locomotion and thus invest more in their forelimbs than hindlimbs will experience selection for smaller body sizes, greater altriciality, and more complex nests. To test this hypothesis, we examined the skeletons of over 2,000 individuals from 313 species representing the majority of avian families and all major branches of the avian tree. We used the lengths of the sternal keel and long bones of the wing relative to the lengths of the leg long bones as an index of relative locomotor investment. We found that locomotor investment was predicted by flight style, foraging method, and length of nestling period, supporting Dial’s hypothesis. Soaring birds and birds with more acrobatic flight styles, birds whose foraging methods were heavily reliant upon flight, and birds whose young spent more time in the nest tended to invest more in their forelimbs relative to hindlimbs. Nest type and body size were not significant predictors of relative forelimb–hindlimb investment, however, suggesting that the relationships among flight style, locomotor investment, and life history are not as tightly intertwined as Dial originally hypothesized.

The real “fire ants”: colony size and body size of workers influence the fate of boreal sand hill ants (Hymenoptera: Formicidae) after wildfires in Alberta, Canada

2014 ◽  
Vol 147 (4) ◽  
pp. 396-404 ◽  
Author(s):  
James R.N. Glasier ◽  
Scott E. Nielsen ◽  
John H. Acorn
Keyword(s):  
Life History ◽  
Species Richness ◽  
Body Size ◽  
Colony Size ◽  
Fire Ants ◽  
Fire Ant ◽  
Pitfall Traps ◽  
Sand Hills ◽  
One Year ◽  
Nest Type

AbstractOver two summers following accidental May wildfires, total ant (Hymenoptera: Formicidae) forager catch and species richness did not change in jack pine woodlands on sand hills in central Alberta, Canada. However, one year after a fire, smaller ants, and those in smaller colonies, were more abundant in pitfall traps, based on analysis of response ratios for each ant species and relationships to a variety of life history and organismal traits. Nest type and polygyny had no effect on post-fire ant forager catch. The numerical responses of individual ant species appear to be idiosyncratic, but three species of ants that are sand specialists were found to be particularly resilient to fire.

scholarly journals Fishing-induced life-history changes degrade and destabilize harvested ecosystems

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Anna Kuparinen ◽  
Alice Boit ◽  
Fernanda S. Valdovinos ◽  
Hélène Lassaux ◽  
Neo D. Martinez
Keyword(s):  
Life History ◽  
Body Size ◽  
Network Model ◽  
Temporal Variability ◽  
Lake Ecosystem ◽  
Ecosystem Impacts ◽  
Body Sizes ◽  
Environmental Variations ◽  
Mechanistic Basis ◽  
Fish Abundances

Abstract Fishing is widely known to magnify fluctuations in targeted populations. These fluctuations are correlated with population shifts towards young, small, and more quickly maturing individuals. However, the existence and nature of the mechanistic basis for these correlations and their potential ecosystem impacts remain highly uncertain. Here, we elucidate this basis and associated impacts by showing how fishing can increase fluctuations in fishes and their ecosystem, particularly when coupled with decreasing body sizes and advancing maturation characteristic of the life-history changes induced by fishing. More specifically, using an empirically parameterized network model of a well-studied lake ecosystem, we show how fishing may both increase fluctuations in fish abundances and also, when accompanied by decreasing body size of adults, further decrease fish abundance and increase temporal variability of fishes’ food resources and their ecosystem. In contrast, advanced maturation has relatively little effect except to increase variability in juvenile populations. Our findings illustrate how different mechanisms underlying life-history changes that may arise as evolutionary responses to intensive, size-selective fishing can rapidly and continuously destabilize and degrade ecosystems even after fishing has ceased. This research helps better predict how life-history changes may reduce fishes’ resilience to fishing and ecosystems’ resistance to environmental variations.

scholarly journals GEOGRAPHIC VARIATION IN SELECTED LIFE HISTORY TRAITS OF THE EASTERN NARROWMOUTH TOAD, GASTROPHRYNE CAROLINENSIS (HOLBROOK, 1836), ALONG THE NORTHEASTERN EDGE OF ITS GEOGRAPHIC RANGE

2015 ◽  
pp. 1-5
Author(s):  
Walter E. Meshaka, Jr. ◽  
Pablo R. Delis ◽  
Katie Walters
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Geographic Range ◽  
Atmospheric Conditions ◽  
Female Body Size ◽  
Significant Difference ◽  
Climatic Constraints ◽  
Body Sizes ◽  
Gastrophryne Carolinensis

We examined the Eastern Narrowmouth Toad,Gastrophryne carolinensis, along the northeastern edge of its geographic range in Virginia to determine the extent to which selected life history traits in this region adhered to patterns associated with a latitudinal gradient in this species. As in studies elsewhere, a significant difference in mean adult body size between males (28.3 mm SVL) and females (30.1 mm SVL) was typical of this species as was the absence of a relationship between clutch size and female body size. Mean body sizes of both sexes appeared larger in northern populations than southern counterparts. Geographically predictable, the breeding season in Virginia was severely curtailed in response to climatic constraints despite extended fertility, and its breeding activity peaked in mid-summer as it has been reported to do throughout its geographic range. Thus, along the northern edge of its geographic range, the Eastern Narrowmouth Toad retains its ability breed for a longer season despite present climatic constraints, an advantage in the face of climate change that could alter timing and duration of acceptable breeding atmospheric conditions.

scholarly journals Analysis of quantitative inheritance of body size in mice IV. An Attempt to isolate polygenes

1961 ◽  
Vol 2 (1) ◽  
pp. 25-32 ◽  
Author(s):  
C. K. Chai
Keyword(s):  
Body Size ◽  
Small Body ◽  
Quantitative Inheritance ◽  
Breeding Scheme ◽  
Body Sizes ◽  
Selection For ◽  
Large Genes

The isolation of single inheritance units affecting body size in mice has been attempted. By using Large and Small mice as the parental strains, a breeding scheme has been carried out by repeated backcrossing to each strain with selection for both large and small body sizes in each backcross. The selections were started from the second backcross generations. The Small backcross was carried to the seventh generation and the Large to the fifth. Based on analysis of the means and variances for the parental strains and the backcross generations, it is tentatively concluded that a small number of, if not single, inheritance units may have been introduced from the Large to the Small mice. The ‘large’ genes appear to be dominant over the ‘small’ genes.

scholarly journals Within-host competition drives energy allocation trade-offs in an insect parasitoid

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8810
Author(s):  
J. Keaton Wilson ◽  
Laura Ruiz ◽  
Goggy Davidowitz
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Theory ◽  
Large Body ◽  
Ecological Impacts ◽  
Life History Strategies ◽  
Biological Organization ◽  
Trade Offs ◽  
Wide Range ◽  
Body Sizes

Organismal body size is an important biological trait that has broad impacts across scales of biological organization, from cells to ecosystems. Size is also deeply embedded in life history theory, as the size of an individual is one factor that governs the amount of available resources an individual is able to allocate to different structures and systems. A large body of work examining resource allocation across body sizes (allometry) has demonstrated patterns of allocation to different organismal systems and morphologies, and extrapolated rules governing biological structure and organization. However, the full scope of evolutionary and ecological ramifications of these patterns have yet to be realized. Here, we show that density-dependent larval competition in a natural population of insect parasitoids (Drino rhoeo: Tachinidae) results in a wide range of body sizes (largest flies are more than six times larger (by mass) than the smallest flies). We describe strong patterns of trade-offs between different body structures linked to dispersal and reproduction that point to life history strategies that differ between both males and females and individuals of different sizes. By better understanding the mechanisms that generate natural variation in body size and subsequent effects on the evolution of life history strategies, we gain better insight into the evolutionary and ecological impacts of insect parasitoids in tri-trophic systems.

Fast and slow life histories of carnivores

2011 ◽  
Vol 89 (8) ◽  
pp. 692-704 ◽  
Author(s):  
Evi Paemelaere ◽  
F. Stephen Dobson
Keyword(s):  
Life History ◽  
Body Size ◽  
Litter Size ◽  
Life Histories ◽  
Life History Traits ◽  
Life Cycles ◽  
Age At Maturity ◽  
Negatively Associated ◽  
Trade Offs ◽  
Body Sizes

The fast–slow continuum hypothesis explains life-history traits as reflecting the causal influence of mortality patterns in interaction with trade-offs among traits, particularly more reproductive effort at a cost of shorter lives. Variation among species of different body sizes produce more or less rapid life cycles (respectively, from small to large species), but the fast–slow continuum remains for birds and mammals when body-size effects are statistically removed. We tested for a fast–slow continuum in mammalian carnivores. We found the above trade-offs initially supported in a sample of 85 species. Body size, however, was strongly associated with phylogeny (ρ = 0.79), and thus we used regression techniques and independent contrasts to make statistical adjustments for both. After adjustments, the life-history trade-offs were not apparent, and few associations of life-history traits were significant. Litter size was negatively associated with age at maturity, but slightly positively associated with offspring mass. Litter size and mass were negatively associated with the length of the developmental period. Gestation length showed weak but significant negative associations with age at maturity and longevity. We conclude that carnivores, despite their wide range of body sizes and variable life histories, at best poorly exhibited a fast–slow continuum.

scholarly journals No evidence that warmer temperatures are associated with selection for smaller body sizes

2019 ◽  
Vol 286 (1907) ◽  
pp. 20191332 ◽  
Author(s):  
Adam M. Siepielski ◽  
Michael B. Morrissey ◽  
Stephanie M. Carlson ◽  
Clinton D. Francis ◽  
Joel G. Kingsolver ◽  
...  
Keyword(s):  
Body Size ◽  
Time Window ◽  
Temperature Data ◽  
Directional Selection ◽  
Wild Populations ◽  
Evolutionary Response ◽  
Body Sizes ◽  
Selection For ◽  
Genetic And Environmental Factors ◽  
Meta Analyses

Reductions in animal body size over recent decades are often interpreted as an adaptive evolutionary response to climate warming. However, for reductions in size to reflect adaptive evolution, directional selection on body size within populations must have become negative, or where already negative, to have become more so, as temperatures increased. To test this hypothesis, we performed traditional and phylogenetic meta-analyses of the association between annual estimates of directional selection on body size from wild populations and annual mean temperatures from 39 longitudinal studies. We found no evidence that warmer environments were associated with selection for smaller size. Instead, selection consistently favoured larger individuals, and was invariant to temperature. These patterns were similar in ectotherms and endotherms. An analysis using year rather than temperature revealed similar patterns, suggesting no evidence that selection has changed over time, and also indicating that the lack of association with annual temperature was not an artefact of choosing an erroneous time window for aggregating the temperature data. Although phenotypic trends in size will be driven by a combination of genetic and environmental factors, our results suggest little evidence for a necessary ingredient—negative directional selection—for declines in body size to be considered an adaptive evolutionary response to changing selection pressures.

scholarly journals Life history of the Rio Grande leopard frog (Lithobates berlandieri) in Texas

2018 ◽  
Author(s):  
Daniel F. Hughes ◽  
Walter E. Meshaka
Keyword(s):  
Life History ◽  
Body Size ◽  
Rio Grande ◽  
Leopard Frog ◽  
Minimum Size ◽  
Late Winter ◽  
Adult Males ◽  
Adult Females ◽  
Body Sizes ◽  
Gravid Females

ABSTRACTWe ascertained various life-history traits from an examination of 310 museum specimens of the Rio Grande leopard frog (Lithobates berlandieriBaird, 1859) collected during 1907–2016 from Texas, USA.Lithobates berlandieriwas captured during every month of the year except November, and adults were most frequently encountered during January–September with a distinct peak in May. Mean body size of adult males (69.5 mm) was smaller than that of adult females (77.5 mm), and both sexes were larger in mean body sizes than those of New Mexico populations (M = 64.4 mm; F = 73.5 mm). Females were gravid during January–September, and most gravid females were captured from late-winter to early-summer. Gonadal enlargement in males was generally high throughout January–September with no detectable seasonal increase. Feeding became widespread in both sexes during May–June shortly after a spring breeding bout. Spent females were common in July and lipid deposition increased in June/July, signaling oogenesis for breeding in the fall. From 15 gravid females, we estimated a mean clutch size of 3,107 eggs which was correlated with female body size, yet egg diameter was not related to clutch or body size. Age to metamorphosis was likely 2 to 4 months depending upon whether eggs were laid in the winter/spring or late fall. If metamorphosis occurred in May/June, the minimum size at sexual maturity in adult males (50.1 mm) could have been reached in 3–4 months and in 6–7 months for adult females (57.2 mm). Mean adult body sizes, however, may have taken 12 to 17 months to reach. A synthesis across Texas populations suggests that the breeding season extends almost continuously from the fall through the winter and spring until mid-summer and is interrupted by winter and summer peaks in seasonal temperatures.

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