scholarly journals Otolith δ13C values as a metabolic proxy: approaches and mechanical underpinnings

2019 ◽  
Vol 70 (12) ◽  
pp. 1747 ◽  
Author(s):  
Ming-Tsung Chung ◽  
Clive N. Trueman ◽  
Jane Aanestad Godiksen ◽  
Peter Grønkjær

Knowledge of metabolic costs associated with maintenance, foraging, activity and growth under natural conditions is important for understanding fish behaviours and the bioenergetic consequences of a changing environment. Fish performance in the wild and within a complex environment can be investigated by analysing individual-level field metabolic rate and, at present, the natural stable carbon isotope tracer in otoliths offers the possibility to reconstruct field metabolic rate. The isotopic composition of carbon in fish otoliths is linked to oxygen consumption through metabolic oxidation of dietary carbon. The proportion of metabolically derived carbon can be estimated with knowledge of δ13C values of diet and dissolved inorganic carbon in the water. Over the past 10 years, new techniques to study fish ecology have been developed, and these can be used to strengthen the application of otolith δ13C values as a metabolic proxy. Here, we illustrate the great potential of the otolith δ13C metabolic proxy in combination with other valuable and well-established approaches. The novel approach of the otolith δ13C metabolic proxy allows us to track the effects of ontogenetic and environmental drivers on individual fish physiology, and removes a major obstacle to understanding and predicting the performance of free-ranging wild fish.

2000 ◽  
Vol 48 (3) ◽  
pp. 225 ◽  
Author(s):  
Lesley A. Gibson ◽  
Ian D. Hume

Water and energy requirements of free-living male and female greater bilbies (Macrotis lagotis) were measured over two summers and two winters on Astrebla Downs National Park in far south-western Queensland, Australia, by means of the doubly labelled water method. Mean water influx rate of the bilby (mean body mass: summer 928 g; winter 848 g) did not differ between summer (63.1 mL day–1) and winter (53.1 mL day–1), but mean field metabolic rate was significantly higher during summer (617.2 kJ day–1) than in winter (480.3 kJ day–1). The comparatively low water influx rate of the bilby (significantly lower than that predicted for a 887-g marsupial: P < 0.001) indicated that bilbies have the ability to conserve water in the wild. In contrast, field metabolic rate of the bilby did not differ significantly from that predicted for a marsupial of its body mass (P = 0.999). Bilbies were able to obtain sufficient food and water to satisfy energy and water requirements in three out of the four study periods. However, they were in negative energy and water balance during one study period, suggesting that they are susceptible to nutrient and water stress. The relatively low body fat stores of bilbies in the wild also indicate that they are vulnerable to periods of low food availability. The metabolic strategies of the bilby are only partly suggestive of adaptation to arid conditions.


2017 ◽  
Vol 284 (1856) ◽  
pp. 20170358 ◽  
Author(s):  
Brendan J. Barrett ◽  
Richard L. McElreath ◽  
Susan E. Perry

The type and variety of learning strategies used by individuals to acquire behaviours in the wild are poorly understood, despite the presence of behavioural traditions in diverse taxa. Social learning strategies such as conformity can be broadly adaptive, but may also retard the spread of adaptive innovations. Strategies like pay-off-biased learning, by contrast, are effective at diffusing new behaviour but may perform poorly when adaptive behaviour is common. We present a field experiment in a wild primate, Cebus capucinus , that introduced a novel food item and documented the innovation and diffusion of successful extraction techniques. We develop a multilevel, Bayesian statistical analysis that allows us to quantify individual-level evidence for different social and individual learning strategies. We find that pay-off-biased and age-biased social learning are primarily responsible for the diffusion of new techniques. We find no evidence of conformity; instead rare techniques receive slightly increased attention. We also find substantial and important variation in individual learning strategies that is patterned by age, with younger individuals being more influenced by both social information and their own individual experience. The aggregate cultural dynamics in turn depend upon the variation in learning strategies and the age structure of the wild population.


2012 ◽  
Vol 65 (6) ◽  
pp. 983-988 ◽  
Author(s):  
M. Poberžnik ◽  
A. Leis ◽  
A. Lobnik

CO2 gas with a special isotopic signature (δ13C = −35.2‰ vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water–supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of δ13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO2 gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method's overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage.


Author(s):  
Miikka Palvalin ◽  
Maiju Vuolle ◽  
Aki Jääskeläinen ◽  
Harri Laihonen ◽  
Antti Lönnqvist

Purpose – New Ways of Working (NewWoW) refers to a novel approach for improving the performance of knowledge work. The purpose of this paper is to seek innovative solutions concerning facilities, information technology tools and work practices in order to be able to “work smarter, not harder.” In order to develop work practices toward the NewWoW mode there is a need for an analytical management tool that would help assess the status of the organization’s current work practices and demonstrate the impacts of development initiatives. This paper introduces such a tool. Design/methodology/approach – Constructive research approach was chosen to guide the development of the Smart ways of working (SmartWoW) tool. The tool was designed on the basis of previous knowledge work performance literature as well as on interviews in two knowledge-intensive organizations. The usefulness of the tool was verified by applying it in four organizations. Findings – SmartWoW is a compact questionnaire tool for analyzing and measuring knowledge work at the individual level. The questionnaire consists of four areas: work environment, personal work practices, well-being at work and productivity. As SmartWoW is a standardized tool its results are comparable between organizations. Research limitations/implications – SmartWoW was designed a pragmatic managerial tool. It is considered possible that it can be valuable as a research instrument as well but the current limited amount of collected data does not yet facilitate determining its usefulness from that perspective. Originality/value – This paper makes a contribution to the existing literature on knowledge work measurement and management by introducing an analytical tool which takes into account the NewWoW perspective.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liisa Hämäläinen ◽  
William Hoppitt ◽  
Hannah M. Rowland ◽  
Johanna Mappes ◽  
Anthony J. Fulford ◽  
...  

AbstractSocial transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities. Demonstrating this in the wild, however, has been challenging. Here we show by field experiment that social transmission among predators can shape how selection acts on prey defences. Using artificial prey and a novel approach in statistical analyses of social networks, we find that blue tit (Cyanistes caeruleus) and great tit (Parus major) predators learn about prey defences by watching others. This shifts population preferences rapidly to match changes in prey profitability, and reduces predation pressure from naïve predators. Our results may help resolve how costly prey defences are maintained despite influxes of naïve juvenile predators, and suggest that accounting for social transmission is essential if we are to understand coevolutionary processes.


Field Methods ◽  
2018 ◽  
Vol 31 (2) ◽  
pp. 150-166 ◽  
Author(s):  
Céline Rojon ◽  
Almuth McDowall ◽  
Mark N. K. Saunders

This article examines and appraises a novel approach for generating shared group constructs through aggregative analysis: the application of Honey’s aggregation procedure to repertory grid technique (RGT) data. Revisiting personal construct theory’s underlying premises and adopting a social constructivist epistemology, we argue that, while “implicit theories” of the world, elicited via RGT, are unique to individuals, the constructs on which they are founded may be shared collectively. Drawing on a study of workplace performance, we outline a protocol for this novel use of Honey’s approach, demonstrating how it can be utilized to generate shared constructs inductively to facilitate theory building. We argue that, unlike other grid aggregation processes, the approach does not compromise data granularity, offering a useful augmentation to traditional idiographic approaches examining individual-level constructs only. This approach appears especially suited to addressing complex and implicit topics, where individuals struggle to convey thoughts and ideas.


2009 ◽  
Vol 57 (1) ◽  
pp. 23 ◽  
Author(s):  
A. J. Munn ◽  
T. J. Dawson ◽  
S. R. McLeod ◽  
D. B. Croft ◽  
M. B. Thompson ◽  
...  

Sustainable management of pastures requires detailed knowledge of total grazing pressure, but this information is critically lacking in Australia’s rangelands where livestock co-occur with large herbivorous marsupials. We present the first comparative measure of the field metabolic rate (an index of food requirement) of Australia’s largest marsupial, the red kangaroo (Macropus rufus), with that of domestic sheep (Ovis aries; merino breed). We tested the assumption that the grazing pressure of red kangaroos is equivalent to 0.7 sheep, and show this to be a two-fold overestimation of their contribution to total grazing. Moreover, kangaroos had extraordinarily lower rates of water turnover, being only 13% that of sheep. Consequently, our data support arguments that the removal of kangaroos may not markedly improve rangeland capacity for domestic stock. Furthermore, given the low resource requirements of kangaroos, their use in consumptive and non-consumptive enterprises can provide additional benefits for Australia’s rangelands than may occur under traditional rangeland practices.


Sign in / Sign up

Export Citation Format

Share Document