scholarly journals Song in the cold is ‘hot’: memory of and preference for sexual signals perceived under thermal challenge

2012 ◽  
Vol 8 (5) ◽  
pp. 751-753 ◽  
Author(s):  
Michaël Beaulieu ◽  
Keith W. Sockman
Keyword(s):  
Environmental Conditions ◽  
Thermal Environment ◽  
High Elevation ◽  
Sexual Signals ◽  
Sexual Signal ◽  
Male Song ◽  
In The Wild ◽  
Melospiza Lincolnii ◽  
Recorded Temperature

The environmental conditions under which signals are perceived can affect receiver responses. Many songbird populations produce a song chorus at dawn, when, in cold habitats, they would experience thermal challenge. We recorded temperature and the song activity of Lincoln's sparrows ( Melospiza lincolnii ) on a high-elevation meadow, and determined that song behaviour is concentrated around the coldest time of the day, at dawn. We hypothesized that this is because male song in the cold is more attractive to females than song in the warm. To test this, we exposed laboratory-housed Lincoln's sparrow females to songs at 1°C and 16°C, which they naturally experience in the wild. Females spent 40 per cent more time close to the speaker during playback at 1°C than at 16°C. When tested at 16°C 1–2 days later, females biased their movement towards the speaker playing songs previously heard at 1°C over 16°C. Thus, female Lincoln's sparrows remembered and affiliated with songs they heard under thermal challenge, indicating that the thermal environment can affect the attractiveness of a sexual signal.

scholarly journals The sources of sex differences in aging in annual fishes

2020 ◽  
Author(s):  
Martin Reichard ◽  
Radim Blažek ◽  
Jakub Žák ◽  
Petr Kačer ◽  
Oldřich Tomášek ◽  
...  
Keyword(s):  
Sex Differences ◽  
Social Environment ◽  
Social Factors ◽  
Environmental Conditions ◽  
Natural Populations ◽  
Experimental Results ◽  
Survival Difference ◽  
Captive Populations ◽  
Baseline Mortality ◽  
In The Wild

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.

scholarly journals Realities of rarity: climatically and ecologically restricted, critically endangered Kandian Torrent Toads (Adenomus kandianus) breed en masse

2015 ◽  
Author(s):  
Madhava Meegaskumbura ◽  
Nayana Wijayathilaka ◽  
Nirodha Abayalath ◽  
Gayani Senevirathne
Keyword(s):  
Forest Cover ◽  
High Elevation ◽  
Habitat Associations ◽  
Egg Laying ◽  
Primary Forest ◽  
Isolated Populations ◽  
In The Wild ◽  
Suitable Habitats ◽  
Wide Geographic Distribution ◽  
Forest Habitats

Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, a few A. kandianus were rediscovered in 2012 and redescribed as "the world's rarest toad". Here we report the results of a two-year study of the occurrence, habits and habitat associations of adult and larval A. kandianus using both general surveys and quadrat sampling. We show this to be a secretive species with a patchy distribution. Non-breeding female toads dwell in primary-forest habitats, but after heavy and sudden downpours they form large mating congregations in large streams. Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but the ability to dive and vocalize underwater, and characteristics of the eggs, suggest that they lay eggs in dark recesses of the stream. Tadpoles show microhabitat partitioning within the stream, with the greatest diversity of stages in slow-flowing rocky areas. The more robust stages possessing sucker discs exploit rocky-rapids, while metamorphic stages inhabit stream margins. We use DNA-barcoding to show the existence of two disparate toad populations. Distribution modeling with forest-cover layers added, predict a very small remaining area of suitable habitats. Conservation of this climatically and ecologically restricted species hinge largely on the preservation of high-elevation primary and riparian forests and unpolluted torrents.

Conservation biology of the critically endangered salamander, Paradactylodon persicus gorganensis (Clergue-Gazeau & Thorn, 1979) (Amphibia: Hynobiidae) in northeastern Iran

2021 ◽  
pp. 1-12
Author(s):  
Seyyed Saeed Hosseinian Yousefkhani
Keyword(s):  
High Elevation ◽  
Quality Parameters ◽  
Critically Endangered ◽  
Ex Situ ◽  
Conservation Action ◽  
Agriculture Industry ◽  
Negative Effect ◽  
In The Wild ◽  
Future Viability ◽  
Anthropogenic Threats

Abstract Paradactylodon persicus gorganensis is a critically endangered salamander found in northeastern Iran which faces increasing major anthropogenic threats such as agriculture, industry and mining. The aim of the current study is to identify key environmental variables associated with the species’ presence. Also, measuring and comparing the water quality parameters in habitats where P. p. gorganensis is present and absent are the other aims of the study. The results indicate that high pH and dissolved oxygen values have a negative effect on the species’ presence, while its presence was strongly correlated with low mean water temperatures. The species’ range in response to the climate change will shift to the south and east, where areas of high elevation occur, because the species favors cold habitats. This study indicates that it will be particularly important to evaluate the whole range where P. p. gorganensis exists when preparing conservation action plans. It is recommended that ex-situ conservation programs are incorporated into conservation planning for the species, because the number of individuals in the wild is so low and their future viability is fragile.

scholarly journals A willow drawing from 1786: the earliest depiction of intraspecific trait variation in plants?

2020 ◽  
Author(s):  
Ulrich E Stegmann
Keyword(s):  
Environmental Conditions ◽  
18Th Century ◽  
Elevation Gradient ◽  
Experimental Studies ◽  
Fourth Century ◽  
Trait Variation ◽  
Intraspecific Trait Variation ◽  
Bavarian Alps ◽  
In The Wild ◽  
Unidentified Species

Abstract Background and Aims The study of intraspecific trait variation (ITV) in plants has a long history, dating back to the fourth century BC. Its existence was widely acknowledged by the end of the 18th century, although systematic and experimental studies commenced only a century later. However, the historiography of ITV has many gaps, especially with regard to early observations and visual documents. This note identifies an early depiction of plant ITV. Methods The botanical works of Johann Wolfgang von Goethe (1749–1832), a German writer and naturalist, were subjected to close reading. This included all publications and unpublished sources related to botany between 1785 and 1832 (e.g. notes, drafts, diaries, letters, drawings). This material is accessible in the multi-volume historical-critical edition of Goethe’s studies in natural science (Leopoldina-Ausgabe). Key Results A diary entry from 9 September 1786 described changes in leaf morphology along an elevation gradient in the Bavarian Alps. The leaves of an unidentified species of willow (Spix sp.) and gentian (Gentiana sp.) were said to become narrower with increasing elevation; leaves also stood further apart on twigs, and the latter became thinner. A crude drawing of two willow twigs illustrated the differences. Goethe conjectured that the differences were due to environmental conditions. Conclusions Goethe’s notes were anecdotal, and it is unclear whether the observed plant individuals actually belonged to the same species. Nevertheless, the notes represent an early and clear articulation of the hypothesis that changes in environmental conditions can cause ITV in a natural plant population. The drawing may be the earliest visual record of environmentally caused plant ITV in the wild.

scholarly journals Are model organisms representative for climate change research? Testing thermal tolerance in wild and laboratory zebrafish populations

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Rachael Morgan ◽  
Josefin Sundin ◽  
Mette H Finnøen ◽  
Gunnar Dresler ◽  
Marc Martínez Vendrell ◽  
...  
Keyword(s):  
Climate Change ◽  
Thermal Tolerance ◽  
Thermal Environment ◽  
Model Organisms ◽  
Acclimation Temperature ◽  
Wild Populations ◽  
Climate Change Research ◽  
Genetic Traits ◽  
In The Wild ◽  
Laboratory Acclimation

Abstract Model organisms can be useful for studying climate change impacts, but it is unclear whether domestication to laboratory conditions has altered their thermal tolerance and therefore how representative of wild populations they are. Zebrafish in the wild live in fluctuating thermal environments that potentially reach harmful temperatures. In the laboratory, zebrafish have gone through four decades of domestication and adaptation to stable optimal temperatures with few thermal extremes. If maintaining thermal tolerance is costly or if genetic traits promoting laboratory fitness at optimal temperature differ from genetic traits for high thermal tolerance, the thermal tolerance of laboratory zebrafish could be hypothesized to be lower than that of wild zebrafish. Furthermore, very little is known about the thermal environment of wild zebrafish and how close to their thermal limits they live. Here, we compared the acute upper thermal tolerance (critical thermal maxima; CTmax) of wild zebrafish measured on-site in West Bengal, India, to zebrafish at three laboratory acclimation/domestication levels: wild-caught, F1 generation wild-caught and domesticated laboratory AB-WT line. We found that in the wild, CTmax increased with increasing site temperature. Yet at the warmest site, zebrafish lived very close to their thermal limit, suggesting that they may currently encounter lethal temperatures. In the laboratory, acclimation temperature appeared to have a stronger effect on CTmax than it did in the wild. The fish in the wild also had a 0.85–1.01°C lower CTmax compared to all laboratory populations. This difference between laboratory-held and wild populations shows that environmental conditions can affect zebrafish’s thermal tolerance. However, there was no difference in CTmax between the laboratory-held populations regardless of the domestication duration. This suggests that thermal tolerance is maintained during domestication and highlights that experiments using domesticated laboratory-reared model species can be appropriate for addressing certain questions on thermal tolerance and global warming impacts.

scholarly journals Environmental quality and evolutionary potential: lessons from wild populations

2005 ◽  
Vol 272 (1571) ◽  
pp. 1415-1425 ◽  
Author(s):  
Anne Charmantier ◽  
Dany Garant
Keyword(s):  
Environmental Quality ◽  
Environmental Conditions ◽  
Meta Analysis ◽  
Experimental Manipulation ◽  
Laboratory Animals ◽  
Wild Populations ◽  
Evolutionary Potential ◽  
Morphometric Traits ◽  
Major Step ◽  
In The Wild

An essential requirement to determine a population's potential for evolutionary change is to quantify the amount of genetic variability expressed for traits under selection. Early investigations in laboratory conditions showed that the magnitude of the genetic and environmental components of phenotypic variation can change with environmental conditions. However, there is no consensus as to how the expression of genetic variation is sensitive to different environmental conditions. Recently, the study of quantitative genetics in the wild has been revitalized by new pedigree analyses based on restricted maximum likelihood, resulting in a number of studies investigating these questions in wild populations. Experimental manipulation of environmental quality in the wild, as well as the use of naturally occurring favourable or stressful environments, has broadened the treatment of different taxa and traits. Here, we conduct a meta-analysis on recent studies comparing heritability in favourable versus unfavourable conditions in non-domestic and non-laboratory animals. The results provide evidence for increased heritability in more favourable conditions, significantly so for morphometric traits but not for traits more closely related to fitness. We discuss how these results are explained by underlying changes in variance components, and how they represent a major step in our understanding of evolutionary processes in wild populations. We also show how these trends contrast with the prevailing view resulting mainly from laboratory experiments on Drosophila . Finally, we underline the importance of taking into account the environmental variation in models predicting quantitative trait evolution.

scholarly journals Morphological differences in a population of Rufous-collared Sparrow (Zonotrichia capensis, Statius Müller, 1776) (Passerine, Emberizidae) at different elevations in the Tropical Andes

2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Ana Busi ◽  
Leydy J. Cardona-Salazar ◽  
Daniela Gómez Castillo ◽  
Paula A. Ossa-López ◽  
Fredy A. Rivera-Páez ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Morphological Changes ◽  
Tail Length ◽  
High Elevation ◽  
Molecular Techniques ◽  
Western Slope ◽  
Tropical Andes ◽  
Elevation Gradients ◽  
Wind Speeds ◽  
Zonotrichia Capensis

Abstract Populations that breed along steep elevation gradients show diverse physiological and morphological changes in response to the different environmental conditions. The latter has been discussed by Bergmann’s and Allen’s ecogeographic rules about body and appendage sizes and environmental temperature. We compared morphometric measures (mass, bill width, tarsus, wing, and tail length) of a Zonotrichia capensis population in two localities at different elevations with similar latitudes and photoperiods on the western slope of the Colombian Central Andes. We compared a Low Elevation locality (LE) at 1800 m a.s.l. and a High Elevation locality (HE) at 3853 m a.s.l. that have approximate wind speeds of 1.3 m/s and 8.4 m/s, respectively. During 12 months of sampling, we captured 46 adults using mist-nets; 26 in the LE and 20 in the HE. Each individual was sexed using molecular techniques at the Laboratory of Genetics of the Department of Biological Sciences of Universidad de Caldas. Individuals (males + females) from the HE had longer wings and tails than those from the LE (F1,44 = 5.93; P = 0.019). Also, wings of males in the HE were longer than those of females in both localities and tails of males in the HE were longer than those of LE males. Our results did not agree with what was expected according to Allen’s and Bergmann’s ecogeographic rules. Longer wings and tails increase sustainment, maneuverability, and balance in low atmospheric pressures and strong air currents and these conditions are found at high elevation habitats. Most likely, the longer wings found for HE males allow greater movement during territorial behavior. Further, these differences in morphological traits along elevational gradients could result from micro-evolutionary changes between localities or phenotypic plasticity of individuals exposed to different environmental conditions.

scholarly journals Headwaters fed by subterranean ice: potential climate refugia for mountain stream communities?

2019 ◽  
Author(s):  
Lusha M. Tronstad ◽  
Scott Hotaling ◽  
J. Joseph Giersch ◽  
Oliver J. Wilmot ◽  
Debra S. Finn
Keyword(s):  
Large Scale ◽  
Thermal Environment ◽  
High Elevation ◽  
Climatic Conditions ◽  
Habitat Characteristics ◽  
Mountain Stream ◽  
Suitable Habitat ◽  
Teton Range ◽  
Stream Biodiversity ◽  
Surface Ice

ABSTRACTNear-term extirpations of macroinvertebrates are predicted for mountain streams worldwide as a warming climate drives the recession of high-elevation ice and snow. However, hydrological sources likely vary in their resistance to climate change and thus streams fed by more resistant sources could persist as climate refugia for imperiled biota. In 2015-2016, we measured habitat characteristics and quantified macroinvertebrate community structure along six alpine streams in the Teton Range, Wyoming, USA. Strong differences in habitat characteristics (e.g., temperature, bed stability, conductivity) confirmed three major stream sources: surface glaciers, perennial snowfields, and subterranean ice. Subterranean ice-fed streams – termed “icy seeps” – appear common in the Teton Range and elsewhere yet are globally understudied. Midges in the family Chironomidae dominated our study sites, representing 78.6% of all specimens sampled, with nematodes, caddisflies (Neothremma), and mayflies (Epeorus) also common. At the community-scale, glacier-and snowmelt-fed streams differed significantly in multivariate space, with icy-seep communities intermediate between them, incorporating components of both assemblages. Because the thermal environment of subterranean ice, including rock glaciers, is decoupled from large-scale climatic conditions, we predict that icy seeps will remain intact longer than streams fed by surface ice and snow. Furthermore, our results suggest that icy seeps are suitable habitat for many macroinvertebrates occupying streams fed by vulnerable hydrological sources. Thus, icy seeps may act as key climate refugia for mountain stream biodiversity, an idea in need of further investigation.

EarLocalizer

2019 ◽  
pp. 137-159
Author(s):  
Aman Kamboj ◽  
Rajneesh Rani ◽  
Aditya Nigam
Keyword(s):  
Environmental Conditions ◽  
Crucial Role ◽  
Healthcare Sector ◽  
Biometric Authentication ◽  
Face Images ◽  
Proposed Model ◽  
In The Wild ◽  
Side Face ◽  
Background Clutter ◽  
Overall Performance

With much concern over security, it has become essential to maintain the identity and track of an individual's activities in the modern healthcare sector. Although there are biometric authentication systems based on different modalities, recognition of a person using the ear has gained much attention as ears are unique. Ear localization is a first step for ear-based biometric authentication systems, and this needs to be accurate, since it plays a crucial role in the overall performance of the system. The localization of ear in the side face images captured in the wild possess great challenges due to varying angles, light, scale, background clutter, blur and occlusion, etc. In this chapter, the authors have proposed EarLocalizer model to localize the ear, which is inspired by Faster-RCNN. The model is evaluated on two wild ear databases, UBEAR-II and USTB-III, and has achieved an accuracy of 95% and 99.08%, respectively, at IOU (Intersection over Union) = 0.5. The results of the proposed model signify that the model is invariant to the environmental conditions.

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