scholarly journals Good Things Come in Larger Packages: Size Matters for Adult Fruit-Feeding Butterfly Dispersal and Larval Diet Breadth

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 664
Author(s):  
Geraldo B. Freire ◽  
Thayane Silva ◽  
Hernani Oliveira ◽  
Chloe Collier ◽  
Hanna P. Rodrigues ◽  
...  

Introduction: In animals, body size is correlated with many aspects of natural history, such as life span, abundance, dispersal capacity and diet breadth. However, contrasting trends have been reported for the relationship between body size and these ecological traits. Methods: Fruit-feeding butterflies were used to investigate whether body size is correlated with species abundance, dispersal, permanence, and larval diet breadth in a Neotropical savanna in Brazil (Cerrado). We used Blomberg’s K and Phylogenetic Generalized Least Squares models (PGLS) to measure phylogenetic signal strength in species traits and to estimate size–dispersal–diet breadth associations, while also taking shared ancestry into account. Results: 539 individuals from 27 species were captured, and 190 individuals were recaptured, representing a 35% recapture rate. We found body size to be negatively associated with butterfly abundance, and positively associated with dispersal level, distance traveled, number of traps visited, individual permanence, and diet breadth. These results indicate that larger butterflies are more likely to disperse over longer distances. Moreover, larger butterflies have more generalized larval diets, based on the number of host plant families, genera, and phylogenetic diversity of the host plants they consume as larvae. Smaller butterflies rely on fewer resources, which is reflected in their higher survival in small patches and may explain their lower dispersal ability and higher diet specialization. Nevertheless, lower dispersal ability may, if not compensated by large population sizes, threaten small-bodied species inhabiting environments, such as the Cerrado, which have intense deforestation rates. Conclusions: Body size is positively associated with dispersal and diet breadth for the fruit-feeding butterflies collected in this study.

Author(s):  
Geraldo Freire-Jr. ◽  
Thayane Silva ◽  
Hernani Oliveira ◽  
Chloe Collier ◽  
Hanna P. Rodrigues ◽  
...  

Introduction: Body size is correlated with many aspects of an animal species' natural history, such as life span, abundance, dispersal capacity and diet breadth. However, contrasting trends have been reported for the relationship between body size and these ecological traits. Methods: Butterfly species from fruit-feeding guilds were used to investigate whether body size correlates with species abundances, dispersal, permanence, and diet breadth in a Neotropical savanna in Brazil (Cerrado). We used Blomberg’s K and Phylogenetic Generalized Least Squares models (PGLS) to measure phylogenetic signal strength in species traits, and to estimate size-dispersal-diet breadth associations while taking shared ancestry into account. Results: 539 individuals from 27 species were captured, and 190 individuals were recaptured, representing a 35% recapture rate. We found that body size negatively influenced butterfly abundance. In contrast, body size was positively associated with dispersal levels, distance traveled, number of traps visited, individual permanence, and diet breadth. These results indicate that larger butterflies have a greater proportion of dispersing individuals over longer distances, as they permanence were detected over longer periods than their smaller relatives. Moreover, larger butterflies are more generalized, based on the number of host plant families and genera they consume. Smaller butterflies demand fewer resources, which is reflected in their higher survival in small patches, and may explain their lower dispersal ability, and higher diet specialization. Nevertheless, lower dispersal ability, if not compensated by large population sizes, may threaten small-bodied species inhabiting environments with intense deforestation rates, such as the Cerrado. Conclusions: Body size positively influences dispersal and diet breadth in the fruit-feeding butterflies collected in this study.


Author(s):  
Filipe Chichorro ◽  
Fernando Urbano ◽  
Dinarte Teixeira ◽  
Henry Väre ◽  
Tiago Pinto ◽  
...  

SummaryBiodiversity is eroding at unprecedented rates due to human activity1. Species’ trajectories towards extinction are shaped by multiple factors, including life-history traits2 as well as human pressures3. Previous studies linking these factors to extinction risk have been narrow in their taxonomic and geographic scope4, thus limiting the ability for identifying global predictors. We studied the relation between 12 traits and the extinction risk of almost 900 species representing 15 groups across the tree of life (vertebrates, invertebrates and plants) at a global scale. We show that threatened species share narrow habitat breadth, poor dispersal ability, low fecundity, small altitudinal range, and are affected by a large human footprint. Other traits either show contrasting responses among groups (body size, offspring size, and change in human footprint), or relations were found for only a limited number of taxa (generation length, diet breadth, microhabitat). Our study suggests that in the absence of data on the precise distribution and population trends of species, traits can be used as predictors of extinction risk and thus help guide future research, monitoring and conservation efforts.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2181 ◽  
Author(s):  
Nicholas A. Famoso ◽  
Edward Byrd Davis

Enamel patterns on the occlusal surfaces of equid teeth are asserted to have tribal-level differences. The most notable example compares the Equini and Hipparionini, where Equini have higher crowned teeth with less enamel-band complexity and less total occlusal enamel than Hipparionini. Whereas previous work has successfully quantified differences in enamel band shape by dividing the length of enamel band by the square root of the occlusal surface area (Occlusal Enamel Index, OEI), it was clear that OEI only partially removes the effect of body size. Because enamel band length scales allometrically, body size still has an influence on OEI, with larger individuals having relatively longer enamel bands than smaller individuals. Fractal dimensionality (D) can be scaled to any level, so we have used it to quantify occlusal enamel complexity in a way that allows us to get at an accurate representation of the relationship between complexity and body size. To test the hypothesis of tribal-level complexity differences between Equini and Hipparionini, we digitally traced a sample of 98 teeth, one tooth per individual; 31 Hipparionini and 67 Equini. We restricted our sampling to the P3-M2 to reduce the effect of tooth position. After calculating theDof these teeth with the fractal box method which uses the number of boxes of various sizes to calculate theDof a line, we performed at-test on the individual values ofDfor each specimen, comparing the means between the two tribes, and a phylogenetically informed generalized least squares regression (PGLS) for each tribe with occlusal surface area as the independent variable andDas the dependent variable. The slopes of both PGLS analyses were compared using at-test to determine if the same linear relationship existed between the two tribes. Thet-test between tribes was significant (p< 0.0001), suggesting differentDpopulations for each lineage. The PGLS for Hipparionini was a positive but not significant (p= 0.4912) relationship betweenDand occlusal surface area, but the relationship for Equini was significantly negative (p= 0.0177).λwas 0 for both tests, indicating no important phylogenetic signal is present in the relationship between these two characters, thus the PGLS collapses down to a non-phylogenetic generalized least squares (GLS) model. Thet-test comparing the slopes of the regressions was not significant, indicating that the two lineages could have the same relationship betweenDand occlusal surface area. Our results suggest that the two tribes have the same negative relationship betweenDand occlusal surface area but the Hipparionini are offset to higher values than the Equini. This offset reflects the divergence between the two lineages since their last common ancestor and may have constrained their ability to respond to environmental change over the Neogene, leading to the differential survival of the Equini.


2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Maggie M. Hantak ◽  
Bryan S. McLean ◽  
Daijiang Li ◽  
Robert P. Guralnick

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.


2011 ◽  
Vol 76 (3) ◽  
pp. 403-428 ◽  
Author(s):  
Jack M. Broughton ◽  
Michael D. Cannon ◽  
Frank E. Bayham ◽  
David A. Byers

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.


2016 ◽  
Vol 283 (1831) ◽  
pp. 20160477 ◽  
Author(s):  
Denon Start ◽  
Benjamin Gilbert

Patch size and isolation are predicted to alter both species diversity and evolution; yet, there are few empirical examples of eco-evolutionary feedback in metacommunities. We tested three hypotheses about eco-evolutionary feedback in a gall-forming fly, Eurosta solidaginis and two of its natural enemies that select for opposite traits: (i) specialization and poor dispersal ability constrain a subset of natural enemies from occupying small and isolated patches, (ii) this constraint alters selection on the gall fly, causing phenotypic shifts towards traits resistant to generalist and dispersive enemies in small and isolated patches, and (iii) reduced dispersal evolves in small, isolated populations. We sampled patches in a natural metacommunity and found support for all hypotheses; Eurosta 's specialist wasp parasitoid attacked fewer galls in small and isolated patches, generating a selection gradient that favoured small galls resistant to predation by a dispersive and generalist bird predator. Phenotype distributions matched this selection gradient, and these phenotypic differences were maintained in a common garden experiment. Finally, we found lower dispersal abilities in small and isolated patches, a phenotypic shift that aids in the maintenance of local adaptation. We suggest that the trophic rank and the species traits of consumers are central to evolution in metacommunities.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5370 ◽  
Author(s):  
Caterina Penone ◽  
Christian Kerbiriou ◽  
Jean-François Julien ◽  
Julie Marmet ◽  
Isabelle Le Viol

Background Citizen monitoring programs using acoustic data have been useful for detecting population and community patterns. However, they have rarely been used to study broad scale patterns of species traits. We assessed the potential of acoustic data to detect broad scale patterns in body size. We compared geographical patterns in body size with acoustic signals in the bat species Pipistrellus pipistrellus. Given the correlation between body size and acoustic characteristics, we expected to see similar results when analyzing the relationships of body size and acoustic signals with climatic variables. Methods We assessed body size using forearm length measurements of 1,359 bats, captured by mist nets in France. For acoustic analyses, we used an extensive dataset collected through the French citizen bat survey. We isolated each bat echolocation call (n = 4,783) and performed automatic measures of signals, including the frequency of the flattest part of the calls (characteristic frequency). We then examined the relationship between forearm length, characteristic frequencies, and two components resulting from principal component analysis for geographic (latitude, longitude) and climatic variables. Results Forearm length was positively correlated with higher precipitation, lower seasonality, and lower temperatures. Lower characteristic frequencies (i.e., larger body size) were mostly related to lower temperatures and northern latitudes. While conducted on different datasets, the two analyses provided congruent results. Discussion Acoustic data from citizen science programs can thus be useful for the detection of large-scale patterns in body size. This first analysis offers a new perspective for the use of large acoustic databases to explore biological patterns and to address both theoretical and applied questions.


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