scholarly journals A Midsummer Night’s Diet: Snapshot on Trophic Strategy of the Alpine Salamander, Salamandra atra

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 202
Author(s):  
Luca Roner ◽  
Andrea Costa ◽  
Paolo Pedrini ◽  
Giorgio Matteucci ◽  
Stefano Leonardi ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Prey Availability ◽  
Trophic Niche ◽  
Activity Time ◽  
Optimal Diet ◽  
Individual Level ◽  
Trophic Strategy ◽  
The Individual ◽  
First Time ◽  
Short Timeframe

Information on the trophic ecology of the Alpine salamander, Salamandra atra, is scattered and anecdotal. We studied for the first time the trophic niche and prey availability of a population from an area located in Italian Dolomites during the first half of August. Considering that S. atra is a typical nocturnal species, we collected food availability separately for diurnal and nocturnal hours. Our aims were: (i) to obtain information on the realized trophic niche; (ii) to provide a direct comparison between trophic strategy considering only nocturnal preys or considering all preys; (iii) to study trophic strategy of this species at the individual level. In two samplings nights we obtained prey from 50 individuals using stomach flushing technique. Trophic strategy was determined using the graphical Costello method and selectivity using the relativized electivity index. During the short timeframe of our sample, this salamander showed a generalized trophic strategy. The total trophic availability differed significantly from nocturnal availability. Interindividual diet variation is discussed in the light of the optimal diet theory. Finally, we highlighted that considering or not the activity time of the studied taxon and its preys may lead to a conflicting interpretation of the trophic strategies.

Trophic specialization at the individual level in a terrestrial generalist salamander

2015 ◽  
Vol 93 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Sebastiano Salvidio ◽  
Fabrizio Oneto ◽  
Dario Ottonello ◽  
Andrea Costa ◽  
Antonio Romano
Keyword(s):  
Prey Availability ◽  
Trophic Niche ◽  
Generalist Predator ◽  
Trophic Specialization ◽  
Individual Level ◽  
Trophic Resources ◽  
Niche Variation ◽  
Niche Variation Hypothesis ◽  
The Individual ◽  
Specialized Diet

Information on individual trophic specialization may be relevant to better understand the ecological adaptation of populations to their environment and the evolution of their realized trophic niche. In this study, we analysed the trophic specialization at the individual level in a population of the plethodontid Northwest Italian Cave Salamander (Speleomantes strinatii (Aellen, 1958)), a terrestrial generalist predator. Salamanders were sampled in northwestern Italy on the forest floor in autumn (n = 49) and spring (n = 47) along with their available prey. In autumn, when trophic resources showed a twofold reduction in abundance, the population trophic niche width (TNW = 2.58) was significantly broader than during spring (TNW = 2.25), and in both seasons, individual specialization (IS) was significantly higher than expected by chance (P = 0.001). There were no sexual or ontogenetic differences in IS within each season, but IS in autumn was significantly higher than in spring (IS = 0.34 and IS = 0.41, respectively; P = 0.01). These findings are in accordance with the niche variation hypothesis, which predicts a positive relationship between TNW and IS. Therefore, while the population became more generalist, individual salamanders shifted towards a more specialized diet by adapting their feeding behaviour to changes in prey availability.

Trust, Ethnicity and Integrity in East Africa: Experimental Evidence from Kenya and Tanzania

2017 ◽  
Vol 2 (1) ◽  
pp. 88-123 ◽  
Author(s):  
Dominic Burbidge ◽  
Nic Cheeseman
Keyword(s):  
Ethnic Diversity ◽  
Negative Impact ◽  
Common Knowledge ◽  
Individual Level ◽  
Trust Games ◽  
Negative Effect ◽  
Experimental Games ◽  
The Individual ◽  
The Impact ◽  
First Time

AbstractPolitical economy comparisons of Kenya and Tanzania have often found the political salience of ethnicity to be far higher in the former than the latter, with a negative impact on intercommunal trust. This difference has tended to be explained on the basis of the different kinds of leadership that the two countries experienced after independence. However, these findings have typically been demonstrated using aggregate or survey data. This paper assesses the salience of ethnicity at the individual level for the first time, deploying monetized two-round trust games in urban Kenya and Tanzania. The experimental games isolate the comparative impact of common knowledge of ethnicity and integrity among a quasi-random selection of 486 citizens. Verifying previous findings, we observe higher levels of trust and trustworthiness in Tanzania as compared with Kenya. Further, in comparison with Kenya, any shared knowledge of ethnic identities in Tanzania leads players to transfer fewer resources, while common knowledge that both players are “honest” led to higher transfers there than in Kenya. These results provide robust evidence of higher levels of trust in Tanzania, and of the negative effect in that country of common knowledge of ethnicity on levels of cooperation. The findings demonstrate the way in which political context can shape the impact of ethnic diversity, and encourage further experimental research that looks at the intersubjective dynamics of social cooperation.

scholarly journals “Do you Guys take Showers with your Children?”: Gendered Embodiment and the Legitimation of Italian Fathering Practices

2020 ◽  
pp. 1097184X2097672
Author(s):  
Eugenia Mercuri
Keyword(s):  
Qualitative Research ◽  
National Context ◽  
Individual Level ◽  
Hands On ◽  
Care Practices ◽  
The Individual ◽  
First Time

This work aims at investigating gendered embodiment in fathering practices in a national context, Italy, where understandings of fatherhood, at the institutional as well as the individual level, are still more centered on the provider ideal than on a model of nurturing and caring fatherhood. This qualitative research on Italian first-time fathers of children under three years of age focused on men’s participation in routine, instrumental, and material childcare practices, exploring the potential for a transformation in both the meanings attached to fatherhood as well as to aspects related to embodiment and constructions of masculinity that sustain inequalities. The findings show that, while participation in hands-on childcare plays an important role in the construction of intimate father-child relationships, a legitimation of men’s bodies’ involvement in interaction with children is still missing, especially for care practices that overlap with constructions of motherhood.

Suitability of a young deciduous-dominated forest for American marten and the effects of forest removal

2004 ◽  
Vol 82 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Kim G Poole ◽  
Aswea D Porter ◽  
Andrew de Vries ◽  
Chris Maundrell ◽  
Scott D Grindal ◽  
...  
Keyword(s):  
Populus Tremuloides ◽  
Forest Cover ◽  
Agricultural Land ◽  
Prey Availability ◽  
Population Level ◽  
Home Ranges ◽  
American Marten ◽  
Individual Level ◽  
The Individual

American marten (Martes americana (Turton, 1806)) are generally considered to be reliant upon and most successful in continuous late-successional coniferous forests. By contrast, young seral forests and deciduous-dominated forests are assumed to provide low-quality marten habitat, primarily as a result of insufficient structure, overhead cover, and prey. This study examined a moderate-density population of marten in northeastern British Columbia in what appeared to be comparatively low-quality, deciduous-dominated habitat, overgrown agricultural land primarily consisting of 30- to 40-year-old stands of regenerating trembling aspen (Populus tremuloides Michx.). Over 4 years, we monitored 52 radio-collared marten. The population appeared to be stable, as indicated by large numbers of adults, relatively constant densities, long-term residency of many individuals, low mortality rates, and older age structure. Relatively small home ranges (males, 3.3 km2; females, 2.0 km2) implied good habitat quality and prey availability. Shearing (removal of immature forest cover) of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level. Categorically, marten avoided nonforested cover types and preferred mature coniferous (>25% conifer) stands (7% of the study area) but otherwise appeared to use all forested stands relative to their availability, including extensive use of deciduous-dominated stands and deciduous stands <40 years of age. Thus, these young deciduous forests appeared to have sufficient structure, overhead cover, and prey to maintain moderate densities of resident marten on a long-term basis.

Phénologie de la floraison de populations diploïdes et tétraploïdes d'Anthoxanthum alpinum et d'Anthoxanthum odoratum

1988 ◽  
Vol 66 (11) ◽  
pp. 2258-2264 ◽  
Author(s):  
François Felber
Keyword(s):  
Time Lag ◽  
Population Level ◽  
Southern Europe ◽  
Polyploid Complex ◽  
Individual Level ◽  
In Situ Study ◽  
The Individual ◽  
First Time ◽  
Experimental Garden

The phenology of flowering was studied in an experimental garden, on diploid and tetraploid populations of Anthoxanthum alpinum A. & D. Löve and of A. odoratum L. of central and southern Europe and also in situ in a contact zone between diploid A. alpinum and tetraploid A. odoratum. In the experimental garden, the phenological parameters were studied at the individual level (onset of flowering) and at the population level (dates on which each population showed opened anthers for the first time on 40, 50, 60, 70, or 80% of the plants). Anthoxanthum alpinum flowered earlier than A. odoratum, regardless of the respective ploidy level of the two taxa. The average time lag between the appearance of the stigma and that of the stamens was about 2 days for the two A. alpinum taxa and 6 days for those of A. odoratum. Flowering was spread over the longest period for the tetraploid A. odoratum, which shows the great phenological variability of this taxon. The in situ study confirms the precocity of A. alpinum. The phenological differentiation within this polyploid complex probably coincides with the individualization of the two diploid taxa but precedes their respective polyploidization phases.

Cross-Subsidization of Teacher Pension Costs: The Case of California

2019 ◽  
Vol 14 (2) ◽  
pp. 327-354 ◽  
Author(s):  
Robert M. Costrell ◽  
Josh McGee
Keyword(s):  
Current System ◽  
Pension Plans ◽  
Individual Level ◽  
Pension Costs ◽  
The Individual ◽  
Pension Benefits ◽  
Gains And Losses ◽  
First Time ◽  
Cross Subsidization ◽  
Age Of Entry

The value of pension benefits varies widely, by a teacher's age of entry and exit. This variation is masked by the uniform rate of annual contributions, as a percent of pay, to fund benefits for all. For the first time, we unmask that variation by calculating annual costs at the individual level. In California, we find that the value of a teacher's benefits ranges from about 4 to 22 percent of pay, and exhibits some idiosyncratic patterns, as is endemic to traditional pension plans. The variation in individual cost rates generates an extensive but hidden array of cross-subsidies, as winners receive benefits worth more than the uniform contribution rate, and losers receive less. Almost two thirds of all entering teachers, past and present, are losers in California. By contrast, a prominently invoked study finds that nearly all active teachers are winners there. That result is shown to be highly skewed by excluding the losses of prior entrants who left early, thereby violating the funding fact that the gains and losses of winners and losers must offset each other. Our main policy conclusion is that cash balance plans can rationalize or eliminate the current system of cross-subsidies and provide the transparency lacking in traditional plans.

Territory fidelity, reproductive success and prey choice in the brown falcon, Falco berigora: a flexible bet-hedger?

2003 ◽  
Vol 51 (4) ◽  
pp. 399 ◽  
Author(s):  
Paul G. McDonald ◽  
Penny D. Olsen ◽  
D. J. Baker-Gabb
Keyword(s):  
Prey Availability ◽  
Population Level ◽  
Breeding Strategy ◽  
Territorial Defence ◽  
Individual Level ◽  
Nest Sites ◽  
Mate Fidelity ◽  
Dietary Breadth ◽  
Territory Fidelity ◽  
The Individual

The brown falcon, Falco berigora, is one of Australia's most common and widespread raptors, inhabiting a broad array of habitats and most climatic zones across Australia. We monitored a large, marked population (44–49 pairs) over three annual breeding seasons in southern Victoria. Reproductive parameters such as clutch size and the duration of parental care were constant across years. However, there were marked differences in brood size and the proportion of pairs breeding. Both sexes of falcons were found to have high territory and mate fidelity, with only 10% of members of each sex changing territories during the study. Falcons were flexible in their choice of nest sites, using a variety of tree species and even isolated nest trees. Nest sites and territories were regularly distributed throughout the study area, with the density of the population the highest on record for this species. The diet of the population as a whole was very broad, but each pair predominantly specialised on either lagomorphs, small ground prey, small birds, large birds or reptiles. Individuals that changed territory within the study area also switched their diet according to the predominant land-use within the new territory and thus prey availability. We argue that, at the population level, broad dietary breadth, flexibility in choice of nest site, and a conservative, static breeding strategy allows the species to persist in a broad range of environments, possibly through 'bet-hedging'. At the individual level, changeable dietary specialisation, high territory fidelity, strong year-round territorial defence, confining breeding to years when individual conditions were favourable and adjusting brood sizes when required appear to be the main strategies enabling brown falcons to thrive under a variety of conditions.

scholarly journals A hitchhiker guide to manta rays: Patterns of association between Mobula alfredi, M. birostris, their symbionts, and other fishes in the Maldives

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253704
Author(s):  
Aimee E. Nicholson-Jack ◽  
Joanna L. Harris ◽  
Kirsty Ballard ◽  
Katy M. E. Turner ◽  
Guy M. W. Stevens
Keyword(s):  
Species Interactions ◽  
Community Dynamics ◽  
Spatial And Temporal Variation ◽  
Ecological Processes ◽  
Individual Level ◽  
Near Term ◽  
Complex Relationships ◽  
The Individual ◽  
Future Work ◽  
First Time

Despite being among the largest and most charismatic species in the marine environment, considerable gaps remain in our understanding of the behavioural ecology of manta rays (Mobula alfredi, M. birostris). Manta rays are often sighted in association with an array of smaller hitchhiker fish species, which utilise their hosts as a sanctuary for shelter, protection, and the sustenance they provide. Species interactions, rather than the species at the individual level, determine the ecological processes that drive community dynamics, support biodiversity and ecosystem health. Thus, understanding the associations within marine communities is critical to implementing effective conservation and management. However, the underlying patterns between manta rays, their symbionts, and other hitchhiker species remain elusive. Here, we explore the spatial and temporal variation in hitchhiker presence with M. alfredi and M. birostris throughout the Maldives and investigate the factors which may influence association using generalised linear mixed effects models (GLMM). For the first time, associations between M. alfredi and M. birostris with hitchhiker species other than those belonging to the family Echeneidae are described. A variation in the species of hitchhiker associated with M. alfredi and M. birostris was identified, with sharksucker remora (Echeneis naucrates) and giant remora (Remora remora) being the most common, respectively. Spatiotemporal variation in the presence of manta rays was identified as a driver for the occurrence of ephemeral hitchhiker associations. Near-term pregnant female M. alfredi, and M. alfredi at cleaning stations, had the highest likelihood of an association with adult E. naucrates. Juvenile E. naucrates were more likely to be associated with juvenile M. alfredi, and a seasonal trend in E. naucrates host association was identified. Remora were most likely to be present with female M. birostris, and a mean number of 1.5 ± 0.5 R. remora were observed per M. birostris. It is hoped these initial findings will serve as the basis for future work into the complex relationships between manta rays and their hitchhikers.

scholarly journals CNRS researchers' popularization activities: a progress report

2007 ◽  
Vol 06 (03) ◽  
pp. A01 ◽  
Author(s):  
Pablo Jensen ◽  
Yves Croissant
Keyword(s):  
Statistical Study ◽  
Progress Report ◽  
Annual Reports ◽  
Individual Level ◽  
Scientific Disciplines ◽  
Geographical Regions ◽  
Science Popularization ◽  
The Individual ◽  
First Time

We have analyzed the popularization activities undertaken by ten thousand CNRS researchers by means of their annual reports for the years 2004, 2005 and 2006. This is the first time that such an extensive statistical study on science popularization practices is carried out. Our main findings are : - the majority of researchers is not involved in popularization (51% has not done any popularization over the three-year period, two thirds have been involved in no more than one popularization action). - popularization practices are extremely diverse, both at the individual level (we have identified three subpopulations that feature distinctive attitudes towards popularization), and at the level of scientific disciplines (researchers in Humanities are twice as active as the average), as well as in laboratories or geographical regions. - the number of actions reported in 2005 greatly increased compared to 2004 (+ 26%), while they slightly diminished in 2006.

How service quality and perceived value affect behavioral intentions of ecolodge guests: The moderating effect of prior visit

2021 ◽  
pp. 135676672110426
Author(s):  
Joowon Ban ◽  
Bruce Prideaux ◽  
Hyoje Jay Kim ◽  
Ben Sheehan
Keyword(s):  
Customer Satisfaction ◽  
Service Quality ◽  
Perceived Value ◽  
Individual Level ◽  
Segmentation Strategy ◽  
Psychological Attributes ◽  
The Individual ◽  
First Time ◽  
The Relationship ◽  
Repeat Visits

Psychographic segmentation is popular within the tourism literature. It is useful in describing a prototypical customer, however psychological attributes are hard to detect at the individual level and by front-line staff. This paper tests the viability of prior visits (first-time vs. repeat visits) as a segmentation strategy, given this information is readily available to tourism operators. We test an interaction effect between prior visits, service quality, and perceived value using the ECOSERV model, a well-established model of ecotourism customer satisfaction. Using a sample of ecolodge guests, we demonstrate that a prior visit attenuates the relationship between perceived value and customer satisfaction. Among repeat guests, perceived value has less impact upon customer satisfaction and intentions to revisit or recommend an ecolodge. Conversely, service quality continues to predict satisfaction for both first-time and repeat guests. The data suggest attracting first-time guests requires appeals to the setting, features and price of an offering. Meanwhile, strategies to maximize repeat guests should emphasize non-monetary qualities of the experience.

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