Effect of food availability and habitat on the distribution of platypus (Ornithorhynchus anatinus) foraging activity

2001 ◽  
Vol 49 (3) ◽  
pp. 263 ◽  
Author(s):  
M. Serena ◽  
M. Worley ◽  
M. Swinnerton ◽  
G. A. Williams

While the diet of the platypus (Ornithorhynchus anatinus) is known to include a wide range of benthic macro-invertebrates, little is known about how the animals distribute their feeding behaviour along a waterway. This radio-tracking study aimed to determine whether the spatial distribution of platypus foraging activity varied in relation to habitat attributes and/or the amount of food present along a southern Victorian stream. Five O. anatinus were tracked nocturnally for a total of nearly 95 h in March and April 2000. Attributes of the channel and bank were described both in the area used by the animals and adjoining unused sections of stream, and macro-invertebrates were sampled quantitatively in six substrates that varied in abundance in the used and unused areas. Eleven habitat variables showed a significant positive relationship with the occurrence of platypus activity (including the number of medium and large Eucalyptus, Acacia and Populus trees growing along the bank; presence of gravel, pebbles, cobbles, large rocks and coarse particulate organic matter in the channel substrate; amount of riffle habitat; amount of large woody debris in the channel; and amount of undercut banks). Six habitat variables showed a significant negative relationship with platypus activity (including the number of medium and large Salix trees growing along the bank; the presence of silt, solid clay and Salix roots in the channel substrate; the amount of pool habitat; and the maximum channel depth). Substrates that were relatively abundant in the area used by O. anatinus (gravel/pebbles, Eucalyptus litter, Populus litter) did not consistently support more macro-invertebrates than substrates that dominated the unused area (silt, Salix roots, Salix litter). This may reflect the fact that the platypus population was not food-limited (and hence not under pressure to optimise foraging) at the time of the study, that platypus feeding patterns were influenced by habitat features that were not considered in relation to invertebrate abundance, or that the choice of foraging areas by O. anatinus may be influenced by factors other than the total abundance of food items, e.g. the nutritional quality and/or accessibility of prey.

2007 ◽  
Vol 64 (5) ◽  
pp. 777-785 ◽  
Author(s):  
Julie Deschênes ◽  
Marco A Rodríguez

We used hierarchical linear regression to examine relationships between brook trout (Salvelinus fontinalis) density and habitat features nested at three levels: sections within reaches, reaches within streams, and streams within a basin. Brook trout density and environmental variables were quantified at 600 stream sections distributed among 120 reaches and 22 streams in the Cascapedia River basin, Quebec, Canada. Decomposition of variance showed that variation in density among streams was small relative to that among sections or reaches and not statistically significant. Density was influenced by habitat variables at both the section (current velocity, woody debris, cover) and reach (subbasin area, height increment at flood, valley width) levels. A cross-level interaction between current velocity and subbasin area pointed to a "contextual" effect: density showed stronger decline with current velocity in larger subbasins than in smaller subbasins. This result suggests that there was no single "best scale" for examining fish–environment relationships. Accounting for contextual effects by use of hierarchical models can enhance our understanding of how habitat features influence fish densities at multiple spatial scales.


2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Adiqa Kiani ◽  
Ejaz Ullah ◽  
Khair Muhammad

The main objective of this study is to investigate the impact of poverty, globalization, and environmental degradation on economic growth in the selected SAARC countries. This study is employed panel Autoregressive Distributive Lag (ARDL) technique for empirical analysis using selected SAARC regions including India, Pakistan, Bangladesh, Nepal and Sri Lanka over the period of 1980 to 2018. Globalization impacts economic growth positively and significantly.  In addition to this the significant negative relationship is found between population and economic growth. The results show that poverty is positively related with environmental degradation. Furthermore, the results indicate that globalization is positively and significantly associated with environmental degradation in the SAARC region. Finally, the results show that urbanization is positive and significantly associated with environmental degradation, which could be the serious concerns for the policy makers to control.


2016 ◽  
Vol 44 (3) ◽  
pp. 509-517 ◽  
Author(s):  
Yanhan Zhu

The 2 types of exchange relationship perceptions—social exchange relationship perceptions (SERPs) and economic exchange relationship perceptions (EERPs)—constitute the primary concept for understanding individual behavior in the workplace. Using a sample of 581 employees from Mainland China, I explored the effects of SERPs and EERPs on employee extrarole behavior (ERB), as well as the moderating effect of organization-based self-esteem (OBSE) on the relationships between SERPs and ERB, and between EERPs and ERB. The results revealed a significant positive relationship between SERPs and ERB, a significant negative relationship between EERPs and ERB, and a significant moderating effect for OBSE. Theoretical and practical implications of these findings are discussed.


2021 ◽  
Vol 14 (6) ◽  
pp. 257
Author(s):  
Pejman Ebrahimi ◽  
Maria Fekete-Farkas ◽  
Parisa Bouzari ◽  
Róbert Magda

It is widely believed that the financial system is dependent on the banking industry, and its strength and development are vital for economic prosperity. This paper tried to show the financial performance of Iranian banks listed on the Tehran Stock Exchange (TSE) during 2013–2019, as the research population. The statistical population included 18 banks listed on the TSE from 2013 to 2019, which were sampled using a screening method. The results indicated a significant relationship between explanatory variables of capital ratio and the financial performance of banks in all models. However, a significant negative relationship was found between the inflation rate and the financial performance of banks in all models. Furthermore, it seems that banks with high asset strength are more profitable than the others. Regulators should guarantee that banks remain highly capitalized for a viable banking sector in Iran.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Raquel Serrano ◽  
Ana Pellicer-Sánchez

AbstractCombining reading with auditory input has been shown to be an effective way of supporting reading fluency and reading comprehension in a second language. Previous research has also shown that reading comprehension can be further supported by pictorial information. However, the studies conducted so far have mainly included adults or adolescents and have been based on post-reading tests that, although informative, do not contribute to our understanding of how learners’ processing of the several sources of input in multimodal texts changes with the presence of auditory input and the effect that potential differences could have on comprehension. The present study used eye-tracking to examine how young learners process the pictorial and textual information in a graded reader under reading only and reading-while-listening conditions. Results showed that readers spent more time processing the text in the reading only condition, while more time was spent processing the images in the reading-while-listening mode. Nevertheless, comprehension scores were similar for the readers in the two conditions. Additionally, our results suggested a significant (negative) relationship between the amount of time learners spent processing the text and comprehension scores in both modes.


Author(s):  
D. A. Crook ◽  
A. I. Robertson

This paper reviews studies of relationships between riverine fish and woody debris at micro- and meso-habitat scales, and discusses the potential functions of instream structure for lowland river fish. Experimental research, mainly in North America, has identified three main functions of woody debris as microhabitat for fish in upland streams: overhead cover that decreases predation risk both vertically and horizontally; horizontal visual isolation that reduces contact between fish; and velocity refuge which minimizes energetic costs. As with habitat features in other aquatic environments, increasing spatial complexity of woody debris may modify predator–prey interactions and provide greater surface areas for the growth of prey items. Woody debris may also provide spatial reference points for riverine fish to assist them in orienting within their surroundings. Lowland rivers differ from upland streams in terms of a number of physical variables, including turbidity, depth and water turbulence. Relationships between fish and woody debris in lowland rivers are likely to rely on mechanisms different to those in upland streams. Recent initiatives involving the reintroduction of woody debris into previously cleared lowland rivers to replace lost fish habitat are a positive development for lowland river restoration. However, if woody debris reintroduction is to maximally benefit lowland river fisheries, there is a requirement for better understanding of the ecological functions of woody debris in lowland rivers.


2021 ◽  
pp. 0143831X2110142
Author(s):  
Getinet Astatike Haile

The article examines the link between workplace disability (WD) and workplace job satisfaction (JS) using data from WERS2011. Controlling for a rich set of workplace characteristics including organisational culture, the study finds a significant negative relationship between JS and the share of disabled respondents within workplaces. Notably, Seemingly Unrelated Regression (SUR)-based analysis distinguishing between disabled and non-disabled respondents reveals that the negative relationship found is specific to non-disabled respondents. Moreover, disability equality policies are found to be significantly positively related with disabled respondents’ JS while they are negatively related with the JS of their non-disabled counterparts. The article ponders if there is a co-worker aspect to the WD–JS link and whether HR policies may need to take heed of co-worker dynamics in this respect.


2021 ◽  
Vol 36 (6) ◽  
pp. 1216-1216
Author(s):  
Holly E Cooke ◽  
Claudia Jacova

Abstract Objective This study aimed to understand the implications that smartphones have for prospective memory (PM) performance. We examined normal adults’ performance on an event-based PM task embedded in an online survey, and its relationship with the PM strategies used prior to the PM cue. Method Participants included 349 individuals aged >18— (M = 38.31; SD = 11.15); 62% male; non-Hispanic (83.38%); with education = HS diploma or less (8.31%), some college (12.61%), and college degree (79.08%)—recruited through Amazon Mechanical Turk. Participants completed the survey on their smartphones. The PM task required participants to respond “N/A” to a question presented later in the survey. Follow-up questions were asked about the use of external reminders, internal monitoring, recollections, and level of importance participants attributed to the PM task. Results One third of participants were successful on the PM task. Of those who had PM success, 11.50% used external reminders, 53.10% used internal monitoring strategies, 62.83% had recollections, and 95.56% considered the task at least somewhat important to remember. Logistic regression revealed that non-Hispanic ethnicity, ≤ high school education, and high perceived importance predicted PM success (Table 1). Interestingly, 40% of individuals with PM failure used external reminders, showing a significant negative relationship with PM success. Conclusions We found that external reminders, internal monitoring, and recollections may make PM success less likely during smartphone use—strategies which were associated with PM success in previous research. Only perceived importance predicted PM success, akin to previous findings. Implications reveal that smartphones may change the demands of PM tasks.


2021 ◽  
Vol 15 (7) ◽  
pp. 2068-2071
Author(s):  
Avneet Kaur ◽  
Shwetha T.S

Existing literature has explored the role of mindfulness and mind-wandering on creative processes. However, it has overlooked the diversity in the creative domains as well as the experience of the artist while accounting for their relationship. In the present study, mindfulness and mind wandering- deliberate and spontaneous were explored among performing artists, i.e. musicians, theatre artists, and dancers. The study also looked at the artists’ experience in their field. After an initial screening using a creativity tool, 66 performing artists were recruited, following which two self-report indices that assessed mind wandering and mindfulness were administered. The data collected was subjected to quantitative data analysis in SPSS. A Oneway ANOVA showed significant effect of the creative domain on mindfulness for the three groups, with a significant difference between musicians and dancers. Among the musicians, a significant negative relationship between mind wandering spontaneous and years of experience was seen. Among the dancers, there was a significant positive association between mind wandering spontaneous, mind wandering deliberate and years of experience. The current study highlighted the need to approach the study of creativity using a contextual perspective. Keywords: Creativity, Dance, Music, Theatre.


2021 ◽  
Author(s):  
Elham Abdullah Ghobain ◽  

This study observes a particular group of students learning medical terms (MT) implicitly through studying medical subjects. That is, based on the policy followed in the context of the study, students shall not receive any deliberate terms instruction. This paper investigates their experiences and attitudes towards acquiring MT in such a situation. Students’ acquisition and proficiency, hypothesizing a positive relationship between the two constructs, are self-assessed through pre- and post-test surveys. The surveys included 114 and 95 students in each phase, respectively. Prior to the surveys, focus group discussions were conducted, according to which the questionnaire was developed. A statistical correlational Pearson test was done to examine the relationship between students’ proficiency and incidental terms acquisition. The results indicated a significant negative relationship between the two constructs tested. The study also tested the effect of time on increasing acquisition through conducting a paired independent t-test between the two sets of data. The results found that a more extended period was significant to incidental acquisition. Overall, through comparing the means, modes, and medians in the two phases (pre- and post-test), the findings reveal an increase in the students’ terms acquisition volume. However, students seem not to favour the approach and still advocate explicit instruction for technical terms.


Sign in / Sign up

Export Citation Format

Share Document