scholarly journals Thermal strategies vary with life history stage

2018 ◽  
Vol 221 (8) ◽  
pp. jeb171629 ◽  
Author(s):  
Manuela Truebano ◽  
Phillip Fenner ◽  
Oliver Tills ◽  
Simon D. Rundle ◽  
Enrico L. Rezende
Keyword(s):  
Life History ◽  
Life History Stage

Relationships between temperature and Pacific hake distribution vary across latitude and life-history stage

2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Effects ◽  
Environmental Conditions ◽  
Vancouver Island ◽  
Additive Models ◽  
Life History Stage ◽  
Fish Stocks ◽  
Merluccius Productus ◽  
Multiple Dimensions ◽  
Effects Of Temperature

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.

Evidence of long and discontinuous juvenile periods in Trillium catesbaei under contrasting levels of herbivory

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Christopher R. Webster ◽  
Michael A. Jenkins
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Age Structure ◽  
Morphological Characteristics ◽  
Population Viability ◽  
Plant Age ◽  
Life History Stage ◽  
Structure And Morphology ◽  
Single Leaf ◽  
Poor Indicator

We investigated the influence of chronic herbivory by white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) on the age structure and morphology of Trillium catesbaei Elliott. At sites with contrasting histories of deer abundance (Cades Cove, high; Whiteoak Sink, low), we measured morphological characteristics and determined minimum plant age for 60 plants (30 per site) in the single-leaf life-history stage. We chose this stage because its presence is considered an indication of successful reproduction by the previous generation, but its value could be inflated if plants regress or remain in this stage for extended periods. Our results suggest that T. catesbaei may spend upwards of a decade in this stage. Cades Cove single leaves were significantly older (p = 0.011) than those at Whiteoak Sink. Rhizome recession (decay of the oldest portion) was more common at Cades Cove, suggesting greater regression to this stage from three-leaf stages. Although minimum plant age was significantly associated with vegetative attributes (p < 0.002) at Whiteoak Sink, these attributes were decoupled at Cades Cove (p ≥ 0.642). Collectively, our results suggest that chronic herbivory may lead to a long and regressive residency period in the single-leaf stage. Consequently, in Trillium populations heavily impacted by deer, the number of single-leaf plants may be a poor indicator of reproductive success and population viability.

scholarly journals Effects of life history stage and climatic conditions on fecal egg counts in plains zebras (Equus quagga) in the Serengeti National Park

2020 ◽  
Vol 119 (10) ◽  
pp. 3401-3413
Author(s):  
Peter A. Seeber ◽  
Tetiana A. Kuzmina ◽  
Alex D. Greenwood ◽  
Marion L. East
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
National Park ◽  
Climatic Conditions ◽  
Life History Stage ◽  
Gastrointestinal Parasite ◽  
Serengeti Ecosystem ◽  
Life History Stages ◽  
Lactating Females ◽  
Host Life

Abstract In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains zebras are affected by life history stage, environmental conditions, and co-infection.

scholarly journals Genetic variation in herbivore resistance and tolerance: the role of plant life-history stage and type of damage

2010 ◽  
Vol 23 (10) ◽  
pp. 2185-2196 ◽  
Author(s):  
A. MUOLA ◽  
P. MUTIKAINEN ◽  
L. LAUKKANEN ◽  
M. LILLEY ◽  
R. LEIMU
Keyword(s):  
Genetic Variation ◽  
Life History ◽  
Life History Stage ◽  
Herbivore Resistance ◽  
Plant Life

Winter corticosterone and body condition predict breeding investment in a nonmigratory bird

2019 ◽  
Vol 30 (6) ◽  
pp. 1642-1652 ◽  
Author(s):  
Chloé Montreuil-Spencer ◽  
Kelsey Schoenemann ◽  
Ádám Z Lendvai ◽  
Frances Bonier
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Body Condition ◽  
Reproductive Investment ◽  
Phenotypic Traits ◽  
Residual Body ◽  
Life History Stage ◽  
Nonbreeding Season ◽  
Fat Reserves ◽  
Fat Score

Abstract Reproduction is an energetically demanding life history stage that requires costly physiological and behavioral changes, yet some individuals will invest more into reproduction and breed more successfully than others. To understand variation in reproductive investment, previous studies have evaluated factors during breeding, but conditions outside of this life history stage may also play a role. Using a free-ranging population of black-capped chickadees (Poecile atricapillus), we assessed the repeatability of plastic traits relating to energetic condition (circulating initial corticosterone concentrations and body condition) during the nonbreeding season and evaluated whether these traits predicted reproductive investment in the subsequent breeding season. We found that initial corticosterone concentrations and an index of body condition, but not fat score, were moderately repeatable over a 1-week period in winter. This trait repeatability supports the interpretation that among-individual variation in these phenotypic traits could reflect an intrinsic strategy to cope with challenging conditions across life history stages. We found that females with larger fat reserves during winter laid eggs sooner and tended to spend more time incubating their eggs and feeding their offspring. In contrast, we found that females with higher residual body mass delayed breeding, after controlling for the relationship between fat score and timing of breeding. Additionally, females with higher initial corticosterone in winter laid lighter eggs. Our findings suggest that conditions experienced outside of the breeding season may be important factors explaining variation in reproductive investment.

scholarly journals Interactions with humans are jointly influenced by life history stage and social network factors and reduce group cohesion in moor macaques (Macaca maura)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kristen S. Morrow ◽  
Hunter Glanz ◽  
Putu Oka Ngakan ◽  
Erin P. Riley
Keyword(s):  
Social Networks ◽  
Life History ◽  
Social Network ◽  
Interindividual Variation ◽  
Life History Stage ◽  
The Road ◽  
Network Position ◽  
Moor Macaques ◽  
Structure Changes ◽  
Social Network Structure

AbstractHuman-wildlife encounters are becoming increasingly frequent across the globe, often leading people to interact with and feed wild animals and impacting animal behaviour and ecology. Although the nature of human-wildlife interactions has been well documented across a number of species, we still have limited understanding as to why some individual animals interact more frequently with humans than others. Additionally, we lack a comprehensive understanding of how these interactions influence animal social networks. Using behavioural data from a group of moor macaque monkeys (Macaca maura), we used permutation-based linear regression analyses to understand how life history and social network factors jointly explain interindividual variation in tendency to interact with humans along a provincial road in South Sulawesi, Indonesia. As our study group spent only a portion of their time in proximity to humans, we also examined how social network structure changes in response to human presence by comparing social networks in the forest to those along the road. We found that sex, individual network position, and associate network position interact in complex ways to influence individual behaviour. Individual variation in tendency to be along the road caused social networks to become less cohesive when in proximity to humans. This study demonstrates that nuanced intragroup analyses are necessary to fully understand and address conservation issues relating to human-wildlife interactions.

scholarly journals Are elder siblings helpers or competitors? Antagonistic fitness effects of sibling interactions in humans

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122313 ◽  
Author(s):  
Aïda Nitsch ◽  
Charlotte Faurie ◽  
Virpi Lummaa
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Life History Stage ◽  
Same Sex ◽  
Fitness Effects ◽  
Sibling Interactions ◽  
Fitness Consequences ◽  
Opposite Sex ◽  
Fitness Measures

Determining the fitness consequences of sibling interactions is pivotal for understanding the evolution of family living, but studies investigating them across lifetime are lacking. We used a large demographic dataset on preindustrial humans from Finland to study the effect of elder siblings on key life-history traits. The presence of elder siblings improved the chances of younger siblings surviving to sexual maturity, suggesting that despite a competition for parental resources, they may help rearing their younger siblings. After reaching sexual maturity however, same-sex elder siblings' presence was associated with reduced reproductive success in the focal individual, indicating the existence of competition among same-sex siblings. Overall, lifetime fitness was reduced by same-sex elder siblings' presence and increased by opposite-sex elder siblings' presence. Our study shows opposite effects of sibling interactions depending on the life-history stage, and highlights the need for using long-term fitness measures to understand the selection pressures acting on sibling interactions.

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