scholarly journals Similar foraging energetics of two sympatric albatrosses despite contrasting life histories and wind-mediated foraging strategies

2020 ◽  
Vol 223 (23) ◽  
pp. jeb228585 ◽  
Author(s):  
Caitlin E. Kroeger ◽  
Daniel E. Crocker ◽  
Rachael A. Orben ◽  
David R. Thompson ◽  
Leigh G. Torres ◽  
...  
Keyword(s):  
Energy Balance ◽  
Life Histories ◽  
Behavioral Plasticity ◽  
Environmental Changes ◽  
Behavioral Flexibility ◽  
Mass Gain ◽  
Central Place ◽  
Foraging Strategies ◽  
Wind Speeds ◽  
Ocean Environment

ABSTRACTUnderstanding the environmental and behavioral factors that influence how organisms maintain energy balance can inform us about their potential resiliency to rapid environmental changes. Flexibility in maintaining energy balance is particularly important to long-lived, central-place foraging seabirds that are constrained when locating food for offspring in a dynamic ocean environment. To understand the role of environmental interactions, behavioral flexibility and morphological constraints on energy balance, we used doubly labeled water to measure the at-sea daily energy expenditure (DEE) of two sympatrically breeding seabirds, Campbell (Thalassarche impavida) and grey-headed (Thalassarchechrysostoma) albatrosses. We found that species and sexes had similar foraging costs, but DEE varied between years for both species and sexes during early chick rearing in two consecutive seasons. For both species, greater DEE was positively associated with larger proportional mass gain, lower mean wind speeds during water take-offs, greater proportions of strong tailwinds (>12 m s−1), and younger chick age. Greater proportional mass gains were marginally more costly in male albatrosses that already have higher wing loading. DEE was higher during flights with a greater proportion of strong headwinds for grey-headed albatrosses only. Poleward winds are forecasted to intensify over the next century, which may increase DEE for grey-headed albatrosses that heavily use this region during early chick rearing. Female Campbell albatrosses may be negatively affected by forecasted slackening winds at lower latitudes due to an expected greater reliance on less energy efficient sit-and-wait foraging strategies. Behavioral plasticity associated with environmental variation may influence future population responses to climate change of both species.

Phenotypic plasticity

2018 ◽  
Author(s):  
Karen D. Williams ◽  
Marla B. Sokolowski
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Behavioral Plasticity ◽  
Behavioral Flexibility ◽  
Insect Behavior ◽  
Behavioral Variability ◽  
Gene By Environment Interactions ◽  
Affect Gene Expression

Why is there so much variation in insect behavior? This chapter will address the sources of behavioral variability, with a particular focus on phenotypic plasticity. Variation in social, nutritional, and seasonal environmental contexts during development and adulthood can give rise to phenotypic plasticity. To delve into mechanism underlying behavioral flexibility in insects, examples of polyphenisms, a type of phenotypic plasticity, will be discussed. Selected examples reveal that environmental change can affect gene expression, which in turn can affect behavioral plasticity. These changes in gene expression together with gene-by-environment interactions are discussed to illuminate our understanding of insect behavioral plasticity.

Sex differences in melanotic encapsulation responses (immunocompetence) in the damselfly Lestes forcipatus Rambur

2002 ◽  
Vol 80 (9) ◽  
pp. 1578-1583 ◽  
Author(s):  
Christopher P Yourth ◽  
Mark R Forbes ◽  
Robert L Baker
Keyword(s):  
Sex Differences ◽  
Immune Responses ◽  
Life Histories ◽  
Mass Gain ◽  
Sexually Dimorphic ◽  
Foreign Objects ◽  
Males And Females ◽  
And Gender ◽  
Parasitic Mites ◽  
Melanotic Encapsulation

A few studies have shown that male and female invertebrates differ in immunity and that these differences appear related to differences in sexual dimorphism and gender differences in life histories. Melanotic encapsulation of foreign objects in insects is one form of immunity. The damselfly Lestes forcipatus Rambur is moderately sexually dimorphic, and much is known about patterns of mass gain in congeners relating to differences in life history between males and females. In this study, females were more immunoresponsive than males under controlled temperatures, following emergence, and at a time when parasitic mites were challenging these hosts. However, males and females that overlapped in mass at emergence did not differ in their immune responses. Males in better condition at emergence were more immunoresponsive than lighter males, but this relation was not found in females. Sex differences in immune expression may have implications for how females versus males are able to deal with challenges from parasites, under varying environmental conditions.

scholarly journals Diving deep into trouble: the role of foraging strategy and morphology in adapting to a changing environment

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Monique Ladds ◽  
David Rosen ◽  
Carling Gerlinsky ◽  
David Slip ◽  
Robert Harcourt
Keyword(s):  
Foraging Strategy ◽  
Central Place ◽  
Dive Duration ◽  
Foraging Strategies ◽  
Body Morphology ◽  
Sea Lions ◽  
Fur Seals ◽  
Adequate Food ◽  
Physiological Capacity ◽  
Total Body Oxygen

Abstract Physiology places constraints on an animal’s ability to forage and those unable to adapt to changing conditions may face increased challenges to reproduce and survive. As the global marine environment continues to change, small, air-breathing, endothermic marine predators such as otariids (fur seals and sea lions) and particularly females, who are constrained by central place foraging during breeding, may experience increased difficulties in successfully obtaining adequate food resources. We explored whether physiological limits of female otariids may be innately related to body morphology (fur seals vs sea lions) and/or dictate foraging strategies (epipelagic vs mesopelagic or benthic). We conducted a systematic review of the increased body of literature since the original reviews of Costa et al. (When does physiology limit the foraging behaviour of freely diving mammals? Int Congr Ser 2004;1275:359–366) and Arnould and Costa (Sea lions in drag, fur seals incognito: insights from the otariid deviants. In Sea Lions of the World Fairbanks. Alaska Sea Grant College Program, Alaska, USA, pp. 309–324, 2006) on behavioural (dive duration and depth) and physiological (total body oxygen stores and diving metabolic rates) parameters. We estimated calculated aerobic dive limit (cADL—estimated duration of aerobic dives) for species and used simulations to predict the proportion of dives that exceeded the cADL. We tested whether body morphology or foraging strategy was the primary predictor of these behavioural and physiological characteristics. We found that the foraging strategy compared to morphology was a better predictor of most parameters, including whether a species was more likely to exceed their cADL during a dive and the ratio of dive time to cADL. This suggests that benthic and mesopelagic divers are more likely to be foraging at their physiological capacity. For species operating near their physiological capacity (regularly exceeding their cADL), the ability to switch strategies is limited as the cost of foraging deeper and longer is disproportionally high, unless it is accompanied by physiological adaptations. It is proposed that some otariids may not have the ability to switch foraging strategies and so be unable adapt to a changing oceanic ecosystem.

scholarly journals Departamento de Ecología Funcional y Aplicada, Instituto de Ecología, Universidad Nacional Autónoma de México

2017 ◽  
pp. 83
Author(s):  
Victor L. Barradas
Keyword(s):  
Energy Balance ◽  
Control Systems ◽  
Environmental Changes ◽  
Heat Fluxes ◽  
Point Of View ◽  
Net Energy ◽  
Sensible Heat ◽  
Species Establishment ◽  
Physical Barriers ◽  
A Site

<p>The deforestation of a site for agriculture and/ or cattle raising purposes changes either microclimate and soil properties. These environmental changes can act as physical barriers which drastically limits tree species establishment in reforestation . From microclimatic point of view, the study of the energy balance plays a key role when the original environment is severely changed. The net energy in a site is mainly dissipated by latent and sensible heat fluxes which are associated to evapotranspiration and thermal regimes,<br />respectively. The analyses of these fluxes allow to design control systems to reduce the high evaporation rates and high temperatures registered in a deforested site. Energy balance, latent and sensible heat fluxes and other components are analysed, and some techniques to manipulate energy balance are also presented.</p>

scholarly journals Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs

2021 ◽  
Vol 14 ◽  
Author(s):  
Umer Saleem Bhat ◽  
Navneet Shahi ◽  
Siju Surendran ◽  
Kavita Babu
Keyword(s):  
Nervous System ◽  
Behavioral Plasticity ◽  
Environmental Changes ◽  
Sensory Information ◽  
Synaptic Activity ◽  
Small Peptides ◽  
C Elegans ◽  
Wide Range ◽  
Nervous System Function ◽  
Insight Into

One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.

scholarly journals The importance of paraphyletic groups in mammalian paleobiology

1992 ◽  
Vol 6 ◽  
pp. 148-148
Author(s):  
Christine Janis
Keyword(s):  
Environmental Changes ◽  
Late Eocene ◽  
Foraging Strategies ◽  
Practical Reasons ◽  
Phylogenetic Systematics ◽  
The Status ◽  
Early Neogene ◽  
Drying Trend ◽  
Cladistic Taxonomy ◽  
Early Paleogene

The introduction of cladistic techniques in phylogenetic systematics have revolutionized many concepts in mammalian taxonomy: most notably, many early groups have been relegated to the status of paraphyletic or polyphyletic assemblages (e.g. the “Condylarthra” or “stem ungulates” and the “Proteutheria” insectivorans.). While it is important to recognize truly polyphyletic groups (e.g. the “Amblypoda” or Paleogene “pachyderm” analogs), all non-monophyletic groups are now commonly assigned to a similar “wastebasket” status, rendering all events associated with their evolution as “pseudo-events” on the grounds of taxonomic impurity.I am uncomfortable with this tendency for two reasons. The first is philosophical. Monophyly is a time-dependent system of classification: all taxa were monophyletic at their inception and the more successful (i.e. generative) ones must inevitably pass into paraphyly. Cladistic taxonomy claims to be independent of stratigraphic bias, but seemingly has no problem with using an arbitrary cut-off point in the geological record (the Recent) as a means of imposing taxonomic nomenclature. The second is for practical reasons concerning information contained in many of these paraphyletic taxa that is relevant to issues other than phylogenetic systematics.I examine closely the evolutionary histories of early Paleogene “miacoid” carnivores and late Paleogene “gelocid” artiodactyls. The extinction of miacoid species in the Late Eocene (giving rise to families of larger, apparently more actively hunting carnivores) and the extinction of gelocid species in the Late Oligocene (giving rise to families of larger ruminants apparently better equipped to ingest and process fibrous vegetation) were both coincident with major climatic and environmental changes. The change from non-seasonal to seasonal climates in the Northern hemisphere in the late Eocene may have influenced a change in predator adaptive strategies; likewise, the drying trend and spread of more open habitats in the early Neogene may have influenced ruminant foraging strategies. I submit that while not all paraphylectic groups may be useful in this fashion, at least in the above instances much paleobiological information is lost if these groups are dismissed because of their paraphyletic status: their demise reflects not artificial “pseudoextinction” but rather a real loss of archaic adaptations in a changing world.

Three-Dimensional Ocean Wave Simulation Based on Directional Spectrum

2011 ◽  
Vol 94-96 ◽  
pp. 2074-2079 ◽  
Author(s):  
Qiu Ying Guo ◽  
Zun Yi Xu ◽  
Ying Jun Sun
Keyword(s):  
Navigation System ◽  
Three Dimensional ◽  
Ocean Waves ◽  
Directional Spectrum ◽  
Wind Speeds ◽  
Simulation Speed ◽  
Spreading Function ◽  
Interaction Simulation ◽  
Ocean Environment ◽  
Key Techniques

Simulating real virtual ocean environment is necessary for the research of interaction simulation of underwater gravity aided inertial navigation system. One of the key techniques of realizing virtual ocean environment is modeling and simulating three-dimensional ocean waves. Numerical simulation of three-dimensional ocean waves in the case of different wind speeds is realized using MATLAB based on directional spectrum composed of Pierson-Moscowitz frequency spectrum and directional spreading function. Experiments show that the simulation speed is fast and the simulation results are vivid if suitable simulation frequency band, interval of wave frequency and interval of direction angle are selected. The simulation can provide some technological supports for interaction simulation of gravity aided navigation system for underwater vehicles.

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