scholarly journals Basic considerations on seasonal breeding in mammals including their testing by comparing natural habitats and zoos

2020 ◽  
Author(s):  
Marcus Clauss ◽  
Philipp Zerbe ◽  
Laurie Bingaman Lackey ◽  
Daryl Codron ◽  
Dennis W. H. Müller
Keyword(s):  
Life History ◽  
Large Scale ◽  
Seasonal Pattern ◽  
Natural Habitat ◽  
Life History Strategies ◽  
Special Focus ◽  
Natural Habitats ◽  
Fluctuating Resources ◽  
Resource Limitations ◽  
In The Wild

Abstract Seasonal reproduction is common in mammals. Whereas specific conditions triggering a seasonal response can only be identified in controlled experiments, large-scale comparisons of reproduction in natural habitats and zoos can advance knowledge for taxa unavailable for experimentation. We outline how such a comparison can identify species whose seasonal physiology is linked to photoperiodic triggers, and those whose perceived seasonality in the wild is the consequence of fluctuating resources without a photoperiodic trigger. This concept groups species into those that do not change their aseasonal pattern between natural habitats and zoos because they are not constrained by resources in the wild, those that do not change a seasonal pattern between natural habitats and zoos because they are triggered by photoperiod irrespective of resources, and those that change from a more seasonal pattern in the natural habitat to an aseasonal pattern in zoos because the zoo environment alleviates resource limitations experienced in the wild. We explain how detailed comparisons of mating season timing in both environments can provide clues whether a specific daylength or a specific number of days after an equinox or solstice is the likely phototrigger for a taxon. We outline relationships between life history strategies and seasonality, with special focus on relative shortening of gestation periods in more seasonal mammals. Irrespective of whether such shortening results from the adaptive value of fitting a reproductive cycle within one seasonal cycle (minimizing ‘lost opportunity’), or from benefits deriving from separating birth and mating (to optimize resource use, or to reduce infanticide), reproductive seasonality may emerge as a relevant driver of life history acceleration. Comparisons of data from natural habitats and zoos will facilitate testing some of the resulting hypotheses.

scholarly journals Evolutionary heritage influences Amazon tree ecology

2016 ◽  
Vol 283 (1844) ◽  
pp. 20161587 ◽  
Author(s):  
Fernanda Coelho de Souza ◽  
Kyle G. Dexter ◽  
Oliver L. Phillips ◽  
Roel J. W. Brienen ◽  
Jerome Chave ◽  
...  
Keyword(s):  
Life History ◽  
Evolutionary History ◽  
Large Scale ◽  
Phylogenetic Signal ◽  
Life History Strategies ◽  
Relative Importance ◽  
Life History Variation ◽  
Trait Variation ◽  
Closed Canopy ◽  
Repeated Evolution

Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change.

scholarly journals Experimental illumination of natural habitat—an experimental set-up to assess the direct and indirect ecological consequences of artificial light of different spectral composition

2015 ◽  
Vol 370 (1667) ◽  
pp. 20140129 ◽  
Author(s):  
Kamiel Spoelstra ◽  
Roy H. A. van Grunsven ◽  
Maurice Donners ◽  
Phillip Gienapp ◽  
Martinus E. Huigens ◽  
...  
Keyword(s):  
Large Scale ◽  
Negative Impact ◽  
Natural Habitat ◽  
Spectral Composition ◽  
Community Level ◽  
Artificial Light ◽  
Night Time ◽  
Natural Habitats ◽  
Set Up ◽  
The Impact

Artificial night-time illumination of natural habitats has increased dramatically over the past few decades. Generally, studies that assess the impact of artificial light on various species in the wild make use of existing illumination and are therefore correlative. Moreover, studies mostly focus on short-term consequences at the individual level, rather than long-term consequences at the population and community level—thereby ignoring possible unknown cascading effects in ecosystems. The recent change to LED lighting has opened up the exciting possibility to use light with a custom spectral composition, thereby potentially reducing the negative impact of artificial light. We describe here a large-scale, ecosystem-wide study where we experimentally illuminate forest-edge habitat with different spectral composition, replicated eight times. Monitoring of species is being performed according to rigid protocols, in part using a citizen-science-based approach, and automated where possible. Simultaneously, we specifically look at alterations in behaviour, such as changes in activity, and daily and seasonal timing. In our set-up, we have so far observed that experimental lights facilitate foraging activity of pipistrelle bats, suppress activity of wood mice and have effects on birds at the community level, which vary with spectral composition. Thus far, we have not observed effects on moth populations, but these and many other effects may surface only after a longer period of time.

scholarly journals Variation in levels of luteinizing hormone and reproductive photoresponsiveness in a population of white-footed mice (Peromyscus leucopus)

2010 ◽  
Vol 298 (6) ◽  
pp. R1543-R1548 ◽  
Author(s):  
Paul D. Heideman ◽  
Julian T. Pittman ◽  
Kristin A. Schubert ◽  
Christen M. R. Dubois ◽  
Jennifer Bowles ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Life History ◽  
Luteinizing Hormone ◽  
Artificial Selection ◽  
Wild Population ◽  
Peromyscus Leucopus ◽  
Life History Strategies ◽  
Life History Trait ◽  
Selection Line ◽  
In The Wild

Natural genetic variation in reproduction and life history strategies is a manifestation of variation in underlying regulatory neuronal and endocrine systems. A test of the hypothesis that genetic variation in luteinizing hormone (LH) level could be related to a life history trait, seasonal reproduction, was conducted on artificial selection lines from a wild-source population of white-footed mice ( Peromyscus leucopus ). Variation exists in the degree of suppression of reproduction by winter short-day photoperiods (SD) in wild-source individuals and in the laboratory population. In this population, most individuals from a photoperiod-responsive (R) artificial selection line are strongly suppressed reproductively in SD, while most individuals from a photoperiod-nonresponsive (NR) artificial selection line are only weakly reproductively suppressed in SD. We assayed levels of LH to test for genetic variation between lines that could contribute to variation in reproductive status in SD. Females from both lines were raised in long-day photoperiods (LD) or SD, ovariectomized under isoflurane anesthesia, and given estradiol implants. Levels of LH were significantly higher in the NR line than in the R line, indicating genetic variation for levels of LH. Levels of LH were higher in LD than in SD, indicating that levels of LH were sensitive to photoperiod treatment even with a controlled level of estradiol negative feedback. The results indicate that there is genetic variation in levels of LH that could be functionally important both in the laboratory in SD and in the wild population in winter. Thus genetic variation in levels of LH is a plausible causal factor determining winter reproductive phenotype in the wild population.

scholarly journals Coherent population dynamics associated with sockeye salmon juvenile life history strategies

2018 ◽  
Vol 75 (8) ◽  
pp. 1346-1356 ◽  
Author(s):  
Cameron Freshwater ◽  
Brian J. Burke ◽  
Mark D. Scheuerell ◽  
Sue C.H. Grant ◽  
Marc Trudel ◽  
...  
Keyword(s):  
Life History ◽  
Sockeye Salmon ◽  
Large Scale ◽  
Life History Strategies ◽  
Dynamic Factor ◽  
Fraser River ◽  
Conservation Units ◽  
Management Interventions ◽  
Salmon Juvenile ◽  
Scale Characteristics

Although the importance of diversity to maintaining metapopulation stability is widely recognized, the ecological characteristics that lead to synchronous dynamics within population aggregates are often unclear. We used a constrained dynamic factor analysis to explore patterns of covariance in productivity among 16 Fraser River sockeye salmon (Oncorhynchus nerka) conservation units (CUs). Specifically, we tested whether coherent trends in productivity covaried with five distinct ecological attributes: physical characteristics of nursery lakes, large-scale management interventions, genetic similarity, adult migration phenology, or juvenile migratory traits. The top-ranked model had two trends based on nursery lake characteristics and juvenile migratory traits. One trend represented the dynamics of CUs that rear in nursery lakes prior to ocean entry and undergo relatively rapid marine migrations. The second included a sea-type CU, Harrison River, which enters the marine environment without rearing in a nursery lake and migrates more slowly. The uniform response of lake-type CUs, as well as Harrison River CU’s unique life history, suggests that coherent trends are structured by traits that covary with broad life history type, rather than fine-scale characteristics. Furthermore, we document substantial temporal variability in the strength of synchronous dynamics among Fraser River CUs. Greater synchrony in recent years suggests that the importance of shared regional drivers, relative to local processes, may have increased.

scholarly journals Population position along the fast-slow life-history continuum predicts intraspecific variation in actuarial senescence

2019 ◽  
Author(s):  
Hugo Cayuela ◽  
Jean-François Lemaître ◽  
Eric Bonnaire ◽  
Julian Pichenot ◽  
Benedikt R. Schmidt
Keyword(s):  
Life History ◽  
Intraspecific Variation ◽  
Population Variation ◽  
Life History Strategies ◽  
Wild Populations ◽  
Captive Populations ◽  
Bombina Variegata ◽  
In The Wild ◽  
Capture Recapture

AbstractPatterns of actuarial senescence can be highly variable among species. Previous comparative analyses revealed that both age at the onset of senescence and rates of senescence are linked to the species’ position along the fast-slow life-history continuum. As there are few long-term datasets of wild populations with known-age individuals, intraspecific (i.e. between-population) variation in senescence is understudied and limited to comparisons of wild and captive populations of the same species, mostly birds and mammals. In this paper, we examined how population position along the fast-slow life history continuum affects senescence patterns in an amphibian, Bombina variegata. We used capture-recapture data collected in four populations with contrasted life history strategies. Senescence trajectories were drawn using Bayesian capture-recapture models. We show that in “slow” populations the onset of senescence was earlier and individuals aged at a faster rate than individuals in “fast” populations. Our study provides one of the few empirical examples of between-population variation in senescence patterns in the wild and confirms that the fast-slow life history gradient is associated with both macroevolutionary and microevolutionary patterns of senescence.

scholarly journals Following the outbreak: preliminary findings on the landscape effect on Dasineura oleae and its parasitoids in Central Italy

2021 ◽  
Author(s):  
Malayka Samantha Picchi ◽  
Elena Tondini ◽  
Nicola Albertarelli ◽  
Gaia Monteforti ◽  
Ruggero Petacchi
Keyword(s):  
Scale Effect ◽  
Large Scale ◽  
Gall Midge ◽  
Natural Habitat ◽  
Central Italy ◽  
Shannon Index ◽  
Small Scale ◽  
Olive Leaf ◽  
Parasitism Rate ◽  
Natural Habitats

Abstract Dasineura oleae (Angelini, 1831) (Diptera: Cecidomyiidae), the olive leaf gall midge, is a pest of olive crops that has never been problematic in Italy since 2016, when a massive infestation of this pest was reported in a small region of Central Italy. We selected infested olive orchards through farmers’ reports aiming at quantifying the pest infestation level and the parasitism rate in each site. Also, we aimed at exploring the landscape effect in both pest and parasitoids, using proportion of olive crops and semi-natural habitats, as well as the Shannon index as a measurement of the landscape diversity, estimated at four different scales (250m, 500m, 750m and 1000m buffers around the sampling points). Results showed different landscape effect depending on the organism and on the scale. We underlined a small-scale effect on the parasitism rate and a large-scale effect on the olive leaf midge mediated by the Shannon Index. Moreover, some preliminary results showed that the parasitism rate was high in sites where plants associated with D. oleae parasitoids were present in the adjacent semi-natural habitat. Further study should deepen and validate our findings on the effect of landscape and of the vegetation on natural enemies of D.oleae. These results should stimulate new approaches in the studying of the olive gall leaf midge as well as new suppression strategies.

scholarly journals Following the pest outbreak: preliminary findings on the landscape effect on Dasineura oleae and its parasitoids in central Italy

2021 ◽  
Author(s):  
Malayka Samantha Picchi ◽  
Elena Tondini ◽  
Nicola Albertarelli ◽  
Gaia Monteforti ◽  
Ruggero Petacchi
Keyword(s):  
Scale Effect ◽  
Large Scale ◽  
Gall Midge ◽  
Natural Habitat ◽  
Central Italy ◽  
Small Region ◽  
Shannon Index ◽  
Small Scale ◽  
Parasitism Rate ◽  
Natural Habitats

AbstractDasineura oleae (Angelini, 1831) (Diptera: Cecidomyiidae), the olive leaf gall midge, is a pest of olive crops that was not problematic in Italy until 2016 when a massive infestation of this pest was reported in a small region in central Italy. We identified infested olive orchards using farmers’ reports and quantified the pest infestation level and parasitism rate in each field. We also explored the effect of the landscape on both the pest and parasitoids using the abundance of olive crops and semi-natural habitats and the Shannon index, estimated at four different scales (250 m, 500 m, 750 m and 1000 m buffers around the sampling points). The results showed a small-scale effect on the parasitism rate and a large-scale effect on leaf infestation mediated by the Shannon Index. Moreover, some preliminary results showed that the parasitism rate was high in sites where plants associated with D. oleae parasitoids were present in the adjacent semi-natural habitat. Further studies are needed to validate our findings on the effect of landscape and vegetation on the natural enemies of D. oleae in order to develop new suppression strategies.

scholarly journals Complex life histories discovered in a critically endangered fish

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
James A. Hobbs ◽  
Levi S. Lewis ◽  
Malte Willmes ◽  
Christian Denney ◽  
Eva Bush
Keyword(s):  
Life History ◽  
San Francisco ◽  
Life Histories ◽  
Full Range ◽  
Life History Strategies ◽  
Delta Smelt ◽  
Endangered Fish ◽  
In The Wild ◽  
Conservation Of Endangered Species ◽  
Population Resilience

AbstractEffective conservation of endangered species requires knowledge of the full range of life-history strategies used to maximize population resilience within a stochastic and ever-changing environment. California’s endemic Delta Smelt (Hypomesus transpacificus) is rapidly approaching extinction in the San Francisco Estuary, placing it in the crossfire between human and environmental uses of limited freshwater resources. Though managed as a semi-anadromous species, recent studies have challenged this lifecycle model for Delta Smelt, suggesting the species is an estuarine resident with several localized “hot-spots” of abundance. Using laser-ablation otolith strontium isotope microchemistry, we discovered three distinct life-history phenotypes including freshwater resident (FWR), brackish-water resident (BWR), and semi-anadromous (SA) fish. We further refined life-history phenotypes using an unsupervised algorithm and hierarchical clustering and found that in the last resilient year-class, the FWR (12%) and BWR (7%) comprised a small portion of the population, while the majority of fish were SA (81%). Furthermore, the semi-anadromous fish could be clustered into at least four additional life-history phenotypes that varied by natal origin, dispersal age and adult salinity history. These diverse life-history strategies should be incorporated into future conservation and management efforts aimed at preventing the extinction of Delta Smelt in the wild.

scholarly journals Eco-evolutionary significance of 'loners'

2018 ◽  
Author(s):  
Fernando W Rossine ◽  
Ricardo Martinez-Garcia ◽  
Allyson E. Sgro ◽  
Thomas Gregor ◽  
Corina E Tarnita
Keyword(s):  
Life History ◽  
Large Scale ◽  
Life Stage ◽  
Life History Strategies ◽  
Evolutionary Significance ◽  
Heritable Variation ◽  
Multicellular Development ◽  
Stochastic Signal ◽  
Spatio Temporal ◽  
Dynamic Population

Loners, individuals out-of-sync with a coordinated majority, occur frequently in nature. Are loners incidental byproducts of large-scale synchronization attempts or are they part of a mosaic of life-history strategies? Here, we provide the first empirical evidence of naturally occurring heritable variation in loner behavior, using the social amoeba Dictyostelium discoideum. Moreover, we show that Dictyostelium loners, cells that do not join the multicellular life-stage, result from a dynamic population-partitioning process. Underlying this partitioning, we find evidence that each cell makes a stochastic, signal-based decision resulting in an imperfectly synchronized multicellular development affected by both abiotic (environmental porosity) and biotic (strain-specific signaling) factors. Finally, we predict that when strains differing in their partitioning behavior co-occur, cross-signaling impacts slime-mold diversity across spatio-temporal scales. Loners are therefore critical to understanding collective and social behaviors, multicellular development, and ecological dynamics in D. discoideum. More broadly, across taxa, imperfect synchronization might be adaptive by enabling diversification of life-history strategies.

scholarly journals Elevated alpha diversity in disturbed sites obscures regional decline and homogenization of amphibian diversity

2021 ◽  
Author(s):  
D. Matthias Dehling ◽  
J Maximilian Dehling
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Alpha Diversity ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Gamma Diversity ◽  
Natural Habitats ◽  
Farmland Conversion ◽  
Frog Species ◽  
Amphibian Communities

Loss of natural habitat is one of the major threats for biodiversity worldwide. Habitat conversion not only changes diversity and species composition locally (alpha diversity) but might also lead to large-scale homogenization of species communities and decrease in regional species richness (gamma diversity). We investigated the effect of farmland conversion on amphibian communities in Rwanda and compared local and regional (country-wide) taxonomic, functional and phylogenetic diversity between natural and farmland sites (agricultural marais). Alpha diversity was higher in the disturbed farmland than in natural sites. However, species turnover among farmland sites was much lower than among natural sites, resulting in highly homogenized amphibian communities and much lower country-wide taxonomic, functional and phylogenetic gamma diversity in farmland compared to natural sites. The few frog species found in farmland were mostly disturbance-tolerant species that are widespread in Eastern Africa and beyond. In contrast, most of the regionally endemic frog species that make this region a continent-scale hotspot of amphibian diversity were found only in the natural habitats. Ongoing farmland conversion might lead to a loss of regional endemism and a widespread homogenization of species communities across sub-Saharan Africa.

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