scholarly journals Variation in environmental conditions in a subtidal prey refuge: effects of salinity stress, food availability and predation on mussels in a fjord system

2011 ◽  
Vol 422 ◽  
pp. 201-210 ◽  
Author(s):  
SR Wing ◽  
JJ Leichter
Keyword(s):  
Food Availability ◽  
Salinity Stress ◽  
Environmental Conditions ◽  
Prey Refuge ◽  
Fjord System

scholarly journals Incorporating temporal heterogeneity in environmental conditions into a somatic growth model

2017 ◽  
Vol 74 (3) ◽  
pp. 316-326 ◽  
Author(s):  
M.C. Dzul ◽  
C.B. Yackulic ◽  
J. Korman ◽  
M.D. Yard ◽  
J.D. Muehlbauer
Keyword(s):  
Food Availability ◽  
Growth Model ◽  
Environmental Conditions ◽  
Colorado River ◽  
Growth Models ◽  
Somatic Growth ◽  
Environmental Data ◽  
Fish Growth ◽  
Positive Temperature ◽  
Environmental Controls

Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared with sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark–recapture data where time between captures can range from months to years). We assess effects of temperature, turbidity, food availability, flow variability, and trout abundance on subadult humpback chub (Gila cypha) growth in two rivers, the Colorado River (CR) and the Little Colorado River (LCR), and we use out-of-sample prediction to rank competing models. Environmental covariates explained a high proportion of the variation in growth in both rivers; however, the best growth models were river-specific and included either positive temperature and turbidity duration effects (CR) or positive temperature and food availability effects (LCR). Our approach to analyzing environmental controls on growth should be applicable in other systems where environmental data vary over relatively short time scales compared with animal observations.

scholarly journals Parental control: ecology drives plasticity in parental response to offspring signals

2021 ◽  
Author(s):  
Shana Caro ◽  
Adara C Velasco ◽  
Tjomme van Mastrigt ◽  
Kees van Oers ◽  
Ashleigh S Griffin ◽  
...  
Keyword(s):  
Food Availability ◽  
Environmental Conditions ◽  
Meta Analysis ◽  
Bird Species ◽  
Parus Major ◽  
Food Distribution ◽  
Offspring Quality ◽  
Information Availability ◽  
Parental Response ◽  
Signalling Systems

Different bird species have completely different parent-offspring interactions. When food is plentiful, the chicks that are begging the loudest are fed the most. When food is scarce, bird species instead feed the largest offspring. While this variation could be due to parents responding to signalling differently based on food availability, it could equally be due to offspring adjusting their behaviour, or to variation in information availability. We tested between these competing explanations experimentally, by manipulating food availability in a population of wild great tits, Parus major, while standardising offspring behaviour and size. We found that when food was more plentiful, parents were: (1) more likely to preferentially feed the chicks that were begging the most; and (2) less likely to preferentially feed larger chicks. In addition, we consistently found these same patterns, in a meta-analysis across 57 bird species. Overall, our results suggest that parents have more control over food distribution than offspring do, and that they flexibly adjust how they respond to both offspring signals and cues of offspring quality in response to food availability. Consequently, depending upon environmental conditions, predictably different signalling systems are favoured.

scholarly journals Feeding habits of coypu (Myocastor coypus Molina 1978) in the wetlands of the Southern region of Brazil

2010 ◽  
Vol 82 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Ioni G. Colares ◽  
Raquel N. V. Oliveira ◽  
Rafael M. Liveira ◽  
Elton P. Colares
Keyword(s):  
Plant Species ◽  
Food Availability ◽  
Aquatic Plants ◽  
Environmental Conditions ◽  
Feeding Habits ◽  
Southern Region ◽  
Myocastor Coypus ◽  
Frequent Species ◽  
Poaceae Family ◽  
Irrigated Crops

The aim of this study was to determine the diet of coypu (Myocastor coypus) in two areas (Santa Isabel do Sul wetlands - Area 1, and Santa Marta Farm - Area 2) in the Southern region of Brazil, using microhistological analyses of feces. Twenty-four plant species were identified from collected feces samples. Among the identified species, nine are common in the animals' diet in both areas; the presence of Oriza sativa was not detected in any of the samples. Among the identified species, 84% and 54% of the coypu's diet from Areas 1 and 2, respectively, are aquatic plants. Poaceae family was most common, being found in 82% of the samples from both areas. Paspalum disthichum (Area 1) and Panicum tricholaenoides (Area 2) were the most frequent species on the coypu's diet. The diet comparison for both areas indicates that feeding habits vary depending on the type of habitat, environmental conditions and food availability. The absence of rice in our analysis may be an indication for the preservation of native areas around watercourses, so as to prevent coypu from invading irrigated crops.

scholarly journals Male bats respond to adverse conditions with larger colonies and increased torpor use during sperm production

2020 ◽  
Vol 100 (6) ◽  
pp. 611-620
Author(s):  
Zuzanna Hałat ◽  
Dina K. N. Dechmann ◽  
Marcin Zegarek ◽  
Ireneusz Ruczyński
Keyword(s):  
Food Availability ◽  
Environmental Conditions ◽  
Colony Size ◽  
Adverse Conditions ◽  
Energy Expenditures ◽  
Wind Speeds ◽  
Lactating Females ◽  
Limited Food ◽  
Adverse Environmental Conditions ◽  
Low Wind Speeds

AbstractChanges in environmental conditions can have strong energetic effects on animals through limited food availability or increased thermoregulatory costs. Especially difficult are periods of increased energy expenditures, such as reproduction. Reproductive female bats from the temperate zone often aggregate in maternity colonies to profit from social thermoregulation to reduce torpor use and buffer the effects of poor conditions. The much rarer male colonies may form for similar reasons during testes development. Male colonies thus allow us to study the influence of environmental conditions on energy budget and colony size, without the confounding effects of parental care. We remotely monitored skin temperature and assessed colony size of male parti-coloured bats Vespertilio murinus during summer, and correlated those variables with environmental conditions and food availability (i.e. insect abundance). As we had hypothesized, we found that colony size increased at colder temperatures, but decreased at low wind speeds. Also as predicted, torpor use was relatively low, however, it did increase slightly during adverse conditions. Male sociality may be an adaptation to adverse environmental conditions during sexual maturation, but the pressure to avoid torpor during spermatogenesis may be lower than in pregnant or lactating females.

scholarly journals Differential effects of food availability on minimum and maximum rates of metabolism

2016 ◽  
Vol 12 (10) ◽  
pp. 20160586 ◽  
Author(s):  
Sonya K. Auer ◽  
Karine Salin ◽  
Agata M. Rudolf ◽  
Graeme J. Anderson ◽  
Neil B. Metcalfe
Keyword(s):  
Food Availability ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Salmo Trutta ◽  
Positive Function ◽  
Energetic Cost ◽  
Metabolic Rates ◽  
Metabolic Power ◽  
Aerobic Scope ◽  
Cost Of Living

Metabolic rates reflect the energetic cost of living but exhibit remarkable variation among conspecifics, partly as a result of the constraints imposed by environmental conditions. Metabolic rates are sensitive to changes in temperature and oxygen availability, but effects of food availability, particularly on maximum metabolic rates, are not well understood. Here, we show in brown trout ( Salmo trutta ) that maximum metabolic rates are immutable but minimum metabolic rates increase as a positive function of food availability. As a result, aerobic scope (i.e. the capacity to elevate metabolism above baseline requirements) declines as food availability increases. These differential changes in metabolic rates likely have important consequences for how organisms partition available metabolic power to different functions under the constraints imposed by food availability.

scholarly journals Animal abundance and food availability: some comments

2001 ◽  
Vol 81 (6) ◽  
pp. 1065-1068 ◽  
Author(s):  
J.J. Beukema ◽  
G.C. Cadée
Keyword(s):  
Food Availability ◽  
Environmental Conditions ◽  
Benthic Invertebrates ◽  
Food Supply ◽  
Wadden Sea ◽  
High Food ◽  
Soft Bottom ◽  
Animal Abundance ◽  
Primary Consumers

We challenge a conclusion reached by Barnes & de Villiers in a paper that was recently published in this Journal, viz that certain benthic invertebrates occur in lower abundances in lagoons than in intertidal soft-bottom areas and that this difference is due to lower food supply at lagoon bottoms. Our experience in the Wadden Sea shows that food does not limit the abundance of primary consumers in areas where environmental conditions are harsh. Such conditions prevail in most of the upper half of the intertidal which is characterized by low abundance of zoobenthos despite a high food supply.

scholarly journals Flight Activities and Pollen Load of Lepidotrigona terminata Smith (Apidae: Meliponinae)

2020 ◽  
Vol 27 (2) ◽  
pp. 97
Author(s):  
Anggun Wicaksono ◽  
Tri Atmowidi ◽  
Windra Priawandiputra
Keyword(s):  
Light Intensity ◽  
Food Availability ◽  
Environmental Conditions ◽  
Selection Index ◽  
Pollen Grains ◽  
Stingless Bee ◽  
Pollen Load ◽  
Pollen Type ◽  
Plant Family ◽  
Pollen Types

Worker bees actively forage to supply colony necessity i.e., pollens, nectar, and resin. Flight activities of the worker bees are influenced by food availability and environmental conditions. This study aimed to measure flight activities of Lepidotrigona terminata in terms of leaving and returning to the nest (including carrying of pollen and pollen type) and their relation to environmental conditions. The observation of flight activities of L. terminata were conducted from August to December 2016, at 07.00-17.00 for 1 minute with 1 hour interval. Pollen load and pollen types were analyzed by the acetolysis method. Flight activities of leaving and returning to the nest were lower at 07.00-08.00 (1 individual/min) and at 16.00-17.00 (2 individuals/min). However, the peak activities occurred at 10.00 until 13.00 (8 and 6 individuals/min for leaving and returning to the nest, respectively). Temperature and light intensity were positively correlated with flight activities of bees that carried nectar and resin, as well as leaving the nest without garbage. The returned workers averagely carried 32,696 pollen grains from four pollen types. Based on selection index values, this stingless bee species mostly preferred Araceae (ⱳi=1.522) plant family for pollen resources to others, Anacardiaceae, Aceraceae, and Acanthaceae (x2=39.32, p<0.01).

The response of drought-tolerant sugar beet to salinity stress under field and controlled environmental conditions

2018 ◽  
Vol 41 (20) ◽  
pp. 2660-2672
Author(s):  
Zahra Abbasi ◽  
Maryam Golabadi ◽  
Samar Khayamim ◽  
Mohammad Pessarakli
Keyword(s):  
Sugar Beet ◽  
Salinity Stress ◽  
Environmental Conditions ◽  
Drought Tolerant

scholarly journals Investigating Life History Tradeoffs in an Opportunisitc Bredding Songbird, the Red Crossbill (Loxia Curvirostra) in Grand Teton National Park

2011 ◽  
Vol 34 ◽  
pp. 39-46
Author(s):  
Thomas Hahn ◽  
Elizabeth Schultz
Keyword(s):  
Immune Function ◽  
Food Availability ◽  
Environmental Conditions ◽  
National Park ◽  
Investment Strategies ◽  
Loxia Curvirostra ◽  
Grand Teton National Park ◽  
Annual Cycles ◽  
Available Energy ◽  
Survival And Reproduction

Because available energy is finite, organisms must be selective with how and when energetic resources are allocated to demanding physiological processes such as reproduction or self-maintenance like immune function. Historically, research to understand how organisms orchestrate their annual cycles with respect to these costly and conflicting processes has focused narrowly on seasonal breeders that constrain reproduction to times of year when thermoregulatory demand is low (i.e., summer), which provide limited opportunities to reveal how physiological costs of different processes may interact with environmental conditions to influence the evolution of investment strategies. In this study, we are examining seasonal and interannual variation in environmental conditions (temperature, precipitation, food supply) and investment patterns in survival and reproduction in a reproductively flexible songbird, the red crossbill (Loxia curvirostra), which can reproduce opportunistically in both summer and winter in Grand Teton National Park. In addition, crossbills provide a perfect model to investigate these environmental and physiological interactions. Preliminary results from this study have indicated that food availability may play an important role in determining how much crossbills will invest in survival (specifically immune function) and reproduction; e.g., crossbills will invest more in innate immunity and reproduction when food availability is high. Overall, results from this study will provide information on how species in general and crossbills specifically respond to rapidly changing environments, which has become increasingly important in light of the effects of anthropogenic change.

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