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

2019 ◽  
Vol 2 ◽  
Author(s):  
Estève Boutaud ◽  
Dorothea Nolte ◽  
Claudia Drees ◽  
Thorsten Assmann

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.

Author(s):  
Maggie Hantak ◽  
Bryan McLean ◽  
Daijiang Li ◽  
Robert Guralnick

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.


2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Carlos Pérez-Almazán ◽  
Norma Leticia Manríquez-Morán ◽  
Miguel Balderas-Plata ◽  
Xanat Antonio-Némiga ◽  
Saúl López-Alcaide

Life history traits are highly variable attributes that maximize organisms’s adaptation. The relationship of weight and body size with environmental changes and habitat heterogeneity has been documented in previous reports; and size and body shapes are both considered life history attributes that are associated with rainfall, that boost available resources in the environment. While in Aspidoscelis genus, clutch size and relative mass are mainly associated with latitude and altitude, in Aspidoscelis gularis, winter rainfall favors two reproductive seasons, which may determine season variable clutch size. With the aim to study this, samplings were undertaken from May-July 2013, and May-September 2015. A total of 65 individuals lizards of the Southeast clade were obtained, and body length and interaxilar distance measurements were taken; furthermore, hepatic tissue samples were taken for DNA extraction, which allowed us to analyze phylogenetic relationships through a Bayesian Inference analysis, and subsequently, to apply Phylogenetic Comparative Methods (like phylogenetic signal, phylogenetically independent contrasts and reconstruction of ancestral character). Our results showed that there is a low phylogenetic signal regarding body size and shape, while the phylogenetically independent contrasts and reconstruction of ancestral characters suggest that small body sizes are associated to locations with highest rainfall. This can be associated to an establishment of an early sexual maturity, which reflects the maximum size of adults. Furthermore, according to an ANOVA and ANCOVA, there were statistically significant differences in body size and shape respectively, which promote a system for sexual competition for males and a system for fertility in females. These results were important to determine the effect of rainfall on some life history traits, pointing out that lizards of the Southeast clade, belonging to the A. gularis complex were able to face different selection pressures, determined by the environment.


2018 ◽  
Vol 93 ◽  
pp. 36-44 ◽  
Author(s):  
Manuel A. Otero ◽  
Favio E. Pollo ◽  
Pablo R. Grenat ◽  
Nancy E. Salas ◽  
Adolfo L. Martino

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9792
Author(s):  
Aluwani Nengovhela ◽  
Christiane Denys ◽  
Peter J. Taylor

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.


2004 ◽  
Vol 71 (sup2) ◽  
pp. 117-120 ◽  
Author(s):  
Elena Marzona ◽  
Daniele Seglie ◽  
Cristina Giacoma

2012 ◽  
Vol 8 (3) ◽  
pp. 362-364 ◽  
Author(s):  
Andrew T. Kahn ◽  
Julianne D. Livingston ◽  
Michael D. Jennions

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.


Parasitology ◽  
2011 ◽  
Vol 138 (7) ◽  
pp. 848-857 ◽  
Author(s):  
G. LOOT ◽  
N. POULET ◽  
S. BROSSE ◽  
L. TUDESQUE ◽  
F. THOMAS ◽  
...  

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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