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

Anthropogenically-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 urbanization, and their interactions with species traits, impact body size. We tested three hypotheses of body size change across urbanization gradients; urban heat island effects, fragmentation, and resource availability. Our results unexpectedly demonstrate urbanization is more tightly linked with body size changes than temperature, most often leading to larger individuals, thus supporting the resource availability hypothesis. In addition, life history traits, such as thermal buffering, activity time, and average body size play critical roles in mediating the effects of both climate and urbanization on intraspecific body size trends. This work highlights the value of using digitized, natural history data to track how human disturbance drives morphological change.

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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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Life-history traits matter for dispersal into semi-open habitat corridors:

ARPHA Conference Abstracts ◽

10.3897/aca.2.e37233 ◽

2019 ◽

Vol 2 ◽

Author(s):

Estève Boutaud ◽

Dorothea Nolte ◽

Claudia Drees ◽

Thorsten Assmann

Keyword(s):

Life History ◽

Body Size ◽

Life History Traits ◽

Small Body ◽

Biodiversity Loss ◽

Species Traits ◽

Open Habitat ◽

Habitat Specialisation ◽

Generalized Linear Modelling ◽

Dispersal Success

Biodiversity face ever-increasing threats from the consequences of various human activities Conservation corridors have long been considered a viable solution to help counteract biodiversity loss. However, corridors simultaneously increase fragmentation for non-target habitats. To overcome this challenge, semi-open habitats, which are a mixture of open and woodland habitats, have been proposed as they may enable simultaneous dispersal of both stenotopic open and woodland species. Despite the fact that they could be used by a great range of species, strong interspecific variability exists with regards to the number of individuals effectively recorded in such environment. Consequently, generalisation about their effectiveness remains difficult. Life-history traits such as body size, hibernation stage, trophic guild, and habitat specialisation could be successfully used to enhance prediction with regards to dispersal success. We used generalized linear modelling to study the relationship of ground beetles species traits and dispersal success into semi-open habitat in two regions of Germany. Our preliminary results indicate that larger species, as well as species overwintering as larvae, tend to be more successful when dispersing into semi-open habitat than smaller species or species overwintering as adult. In addition, species locally abundant are also recorded in higher number. In the light of these results, semi-open corridors do not appear to be the best strategy to increase connectivity for species with small body size or overwintering as adult. For such species, priority should be given to traditional corridors whenever possible. Source habitats need also attention as population size will strongly determine the usefulness of such corridors.

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Differential effects on life history traits and body size of two anuran species inhabiting an environment related to fluorite mine

Ecological Indicators ◽

10.1016/j.ecolind.2018.04.065 ◽

2018 ◽

Vol 93 ◽

pp. 36-44 ◽

Cited By ~ 6

Author(s):

Manuel A. Otero ◽

Favio E. Pollo ◽

Pablo R. Grenat ◽

Nancy E. Salas ◽

Adolfo L. Martino

Keyword(s):

Life History ◽

Body Size ◽

Life History Traits ◽

Differential Effects ◽

Anuran Species

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Life history and habitat do not mediate temporal changes in body size due to climate warming in rodents

PeerJ ◽

10.7717/peerj.9792 ◽

2020 ◽

Vol 8 ◽

pp. e9792

Author(s):

Aluwani Nengovhela ◽

Christiane Denys ◽

Peter J. Taylor

Keyword(s):

Life History ◽

Body Size ◽

Climate Warming ◽

Life History Traits ◽

Vegetation Type ◽

Reproductive Rate ◽

Temporal Changes ◽

Temporal Response ◽

Extrinsic Factors ◽

African Species

Temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. Among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. Both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence of a significant temporal response of body size to climate warming but neither have been widely investigated. Using examples of rodents, we predicted that both life history traits and habitat might explain the probability of temporal response using two tests of this hypothesis. Firstly, taking advantage of new data from museum collections spanning the last 106 years, we investigated geographical and temporal variation in cranial size (a proxy for body size) in six African rodent species of two murid subfamilies (Murinae and Gerbillinae) of varying life history, degree of commensality, range size, and habitat. Two species, the commensal Mastomys natalensis, and the non-commensal Otomys unisulcatus showed significant temporal changes in body size, with the former increasing and the latter decreasing, in relation with climate warming. Commensalism could explain the increase in size with time due to steadily increasing food availability through increased agricultural production. Apart from this, we found no general life history or habitat predictors of a temporal response in African rodents. Secondly, in order to further test this hypothesis, we incorporated our data into a meta-analysis based on published literature on temporal responses in rodents, resulting in a combined dataset for 50 species from seven families worldwide; among these, 29 species showed no significant change, eight showed a significant increase in size, and 13 showed a decline in size. Using a binomial logistic regression model for these metadata, we found that none of our chosen life history or habitat predictors could significantly explain the probability of a temporal response to climate warming, reinforcing our conclusion based on the more detailed data from the six African species.

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Habitat productivity is a poor predictor of body size in rodents

Current Zoology ◽

10.1093/cz/zoz037 ◽

2019 ◽

Vol 66 (2) ◽

pp. 135-143 ◽

Cited By ~ 5

Author(s):

Bader H Alhajeri ◽

Lucas M V Porto ◽

Renan Maestri

Keyword(s):

Body Size ◽

Least Squares ◽

Body Mass ◽

Resource Availability ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Positive Association ◽

Generalized Least Squares ◽

Habitat Productivity ◽

Resource Availability Hypothesis

Abstract The “resource availability hypothesis” predicts occurrence of larger rodents in more productive habitats. This prediction was tested in a dataset of 1,301 rodent species. We used adult body mass as a measure of body size and normalized difference vegetation index (NDVI) as a measure of habitat productivity. We utilized a cross-species approach to investigate the association between these variables. This was done at both the order level (Rodentia) and at narrower taxonomic scales. We applied phylogenetic generalized least squares (PGLS) to correct for phylogenetic relationships. The relationship between body mas and NDVI was also investigated across rodent assemblages. We controlled for spatial autocorrelation using generalized least squares (GLS) analysis. The cross-species approach found extremely low support for the resource availability hypothesis. This was reflected by a weak positive association between body mass and NDVI at the order level. We find a positive association in only a minority of rodent subtaxa. The best fit GLS model detected no significant association between body mass and NDVI across assemblages. Thus, our results do not support the view that resource availability plays a major role in explaining geographic variation in rodent body size.

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Sexual dimorphism in body size and life‐history traits in a population ofTriturus alpestris alpestris

Italian Journal of Zoology ◽

10.1080/11250000409356620 ◽

2004 ◽

Vol 71 (sup2) ◽

pp. 117-120 ◽

Cited By ~ 3

Author(s):

Elena Marzona ◽

Daniele Seglie ◽

Cristina Giacoma

Keyword(s):

Life History ◽

Body Size ◽

Sexual Dimorphism ◽

Life History Traits

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Do females preferentially associate with males given a better start in life?

Biology Letters ◽

10.1098/rsbl.2011.1106 ◽

2012 ◽

Vol 8 (3) ◽

pp. 362-364 ◽

Cited By ~ 20

Author(s):

Andrew T. Kahn ◽

Julianne D. Livingston ◽

Michael D. Jennions

Keyword(s):

Life History ◽

Body Size ◽

Food Intake ◽

Compensatory Growth ◽

Life History Traits ◽

Adult Life ◽

Gambusia Holbrooki ◽

Developmental History ◽

Restricted Diet ◽

Adult Body

A poor start in life owing to a restricted diet can have readily detectable detrimental consequences for many adult life-history traits. However, some costs such as smaller adult body size are potentially eliminated when individuals modify their development. For example, male mosquitofish ( Gambusia holbrooki ) that have reduced early food intake undergo compensatory growth and delay maturation so that they eventually mature at the same size as males that develop normally. But do subtle effects of a poor start persist? Specifically, does a male's developmental history affect his subsequent attractiveness to females? Females prefer to associate with larger males but, controlling for body length, we show that females spent less time in association with males that underwent compensatory growth than with males that developed normally.

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Determinants of life-history traits in a fish ectoparasite: a hierarchical analysis

Parasitology ◽

10.1017/s003118201100014x ◽

2011 ◽

Vol 138 (7) ◽

pp. 848-857 ◽

Cited By ~ 10

Author(s):

G. LOOT ◽

N. POULET ◽

S. BROSSE ◽

L. TUDESQUE ◽

F. THOMAS ◽

...

Keyword(s):

Life History ◽

Body Size ◽

Egg Size ◽

Life History Traits ◽

Abiotic Factors ◽

Individual Characteristics ◽

Trade Off ◽

Individual Fitness ◽

Parasite Number ◽

Egg Number

SUMMARYObjective. Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We then determined the factors affecting the strength of the trade-off between egg number and egg size. Methods. To do so, we used 4-level (parasite, microhabitat, host and environment) hierarchical models coupled to a field database. Results. Variation in life-history traits was mostly due to individual characteristics measured at the parasite level. At the microhabitat level (fins of fish hosts), parasite number was positively related to body size, egg presence and egg number. Higher parasite number on fins was positively associated with individual parasite fitness. At the host level, host body size was positively related to the individual fitness of the parasite; parasites were bigger and more fecund on bigger hosts. In contrast, factors measured at the environmental level had a weak influence on life-history traits. Finally, a site-dependent trade-off between egg number and egg size existed in this population. Conclusion. Our study illustrates the importance of considering parasite life-history traits in a hierarchical framework to decipher complex links between biotic, abiotic factors and parasite life-history traits.

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