43 research outputs found
Social Networks in Wild Asses: Comparing Patterns and Processes among Populations
Asiatic wild asses inhabit some of the most arid environments in the world. All live in fissionfusion societies, but demography varies and the deserts in which they live often differ in subtle ways. Characterizing details of social structure of wild ass populations has been a challenge and has made it difficult to determine causes and consequences of any differences that might exist. We use network theory to compare the social structures of two populations of Asiatic asses/ onagers inhabiting the Negev desert, Israel and khur of the Little Rann of Kuch, India and show that populations differ in important structural ways that represent adaptive responses to variations in ecological demographic and phenotypic circumstances. Our analyses show that onagers inhabiting more variable environments then khur also live in larger, more cohesive groups than khur. Presumably networks with this structure facilitate the spread of information and foster cooperation. We also show that demography matters since social fragmentation increases as populations grow. Increases in the number of components in populations, reductions in the number of associates and diminished cliquishness within components, appear to be adaptive responses to integrating increasing numbers of individuals into social networks. We also find some support for the idea that social connectedness varies with phenotype. In our larger populations, non-lactating females who are most challenged in finding sparse feeding sites, are more selective than lactating females in their choice of strong associates. Presumably networks with this structure enhance foraging success by increasing information flow among like-minded individuals. As our study demonstrates, network analysis facilitates testing predictions about the cause of social structure and its impact on transmission processes
Social Networks in Wild Asses: Comparing Patterns and Processes among Populations
Asiatic wild asses inhabit some of the most arid environments in the world. All live in fissionfusion societies, but demography varies and the deserts in which they live often differ in subtle ways. Characterizing details of social structure of wild ass populations has been a challenge and has made it difficult to determine causes and consequences of any differences that might exist. We use network theory to compare the social structures of two populations of Asiatic asses/ onagers inhabiting the Negev desert, Israel and khur of the Little Rann of Kuch, India and show that populations differ in important structural ways that represent adaptive responses to variations in ecological demographic and phenotypic circumstances. Our analyses show that onagers inhabiting more variable environments then khur also live in larger, more cohesive groups than khur. Presumably networks with this structure facilitate the spread of information and foster cooperation. We also show that demography matters since social fragmentation increases as populations grow. Increases in the number of components in populations, reductions in the number of associates and diminished cliquishness within components, appear to be adaptive responses to integrating increasing numbers of individuals into social networks. We also find some support for the idea that social connectedness varies with phenotype. In our larger populations, non-lactating females who are most challenged in finding sparse feeding sites, are more selective than lactating females in their choice of strong associates. Presumably networks with this structure enhance foraging success by increasing information flow among like-minded individuals. As our study demonstrates, network analysis facilitates testing predictions about the cause of social structure and its impact on transmission processes
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The effects of Public-Private partnerships on partnering private sector firms
Despite an increase in governments' demand for private participation in infrastructure, Public-Private Partnerships (PPPs) have received low engagement from the private sector in the task of bridging infrastructure gaps in emerging markets. Previous literature in the field mainly focuses on the effects of PPPs from the governments' perspective and it is inconclusive in its examination of the advantages and disadvantages of the private sector's participation. This thesis addresses these issues by answering three main research questions: (i) Do PPPs benefit partnering private sector firms? (ii) Does higher reliance on the government in PPPs benefit partnering private sector firms? and (iii) Does the relationship between institutional quality and PPP projects benefit partnering private sector firms? Based on corporate finance and incomplete contract theories, PPPs, with their readily costless pledgeable government assets and their government guarantee, are hypothesized to reduce capital constraints faced by private sector firms compared to their non-PPP counterparts. My study analyzes firm market valuation, investment--cash flow sensitivity, bank lending and their determinants for partnering private sector firms. My main findings are as follows: (i) PPP announcements create positive abnormal returns for partnering private sector firms in China and India. In the long run, PPP involvement reduces investment--cash flow sensitivity in both countries' private sector firms. Especially, PPP private sector firms with political connections can achieve better bank financing in both economies, and this situation is even more robust under the effects of the election event in India; (ii) high reliance on government through government equity participation, political connections and contract mechanisms are more beneficial in China compared to those in India in terms of reducing capital constraints. This aligns with the evidence of increasing overinvestment problems in PPP politically connected firms in India; and (iii) the benefits of lower capital constraints and increased firm value through PPP investments are more pronounced in mature economies with high institutional quality. To my best knowledge, the study is the first comprehensive study on the effects of PPPs on partnering private sector firms using the corporate finance dimension. It contributes to the extant debatable literature on the role of PPPs, reliance on governments, contract mechanisms and institutional quality on private sector firms. It provides insights on the possible benefits of these unique contractual agreements and attempts to answer the question of whether the intended purpose of reducing underinvestment in the private sector can be fulfilled through PPP contracts. It also contributes to the extant literature on corporate investment decisions and investment efficiency. Moreover, it sheds light on the extant debate on social lending objectives, political corruption views and the role of political connection and institutions. My study provides important guidance on the direction and viability of PPPs in China and India and is extensively applicable to other economies, depending on their PPP market maturity and institutional quality
La ecología de los parásitos zoonóticos en Carnivora
El orden Carnivora incluye más de 300 especies que varían en tamaño en muchos órdenes de magnitud y habitan en todos los biomas principales, desde las selvas tropicales hasta los mares polares. La gran diversidad de parásitos carnívoros representa una fuente de posibles enfermedades emergentes en humanos. El riesgo zoonótico de este grupo puede deberse en parte, a una diversidad funcional excepcionalmente alta de las especies hospedantes en cuanto a características conductuales, fisiológicas y ecológicas. Revisamos los patrones macroecológicos globales de los parásitos zoonóticos dentro de los carnívoros y exploramos las características de las especies que sirven como anfitriones de los parásitos zoonóticos. Sintetizamos la investigación teórica y empírica y sugerimos trabajos futuros sobre el papel de los carnívoros como multiplicadores bióticos, reguladores y centinelas de enfermedades zoonóticas como fronteras de investigación oportunas
Evaluating expert-based habitat suitability information of terrestrial mammals with GPS-tracking data
Aim Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species. Location Worldwide. Time period 1998-2021. Major taxa studied Forty-nine terrestrial mammal species. Methods Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types. Results IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively. Main conclusions We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data
Moving in the anthropocene: global reductions in terrestrial mammalian movements
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission
Body size and digestive system shape resource selection by ungulates : a cross-taxa test of the forage maturation hypothesis
The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of hindgut fermenters (equids) and ruminants across biomes. Selection for intermediate forage biomass was negatively related to body size, regardless of digestive system. Selection for proximity to surface water was stronger for equids relative to ruminants, regardless of body size. To be more generalisable, we suggest that the FMH explicitly incorporate contingencies in body size and digestive system, with small-bodied ruminants selecting more strongly for potential energy intake, and hindgut fermenters selecting more strongly for surface water.DATA AVAILABILITY STATEMENT : The dataset used in our analyses is available via Dryad repository (https://doi.org/10.5061/dryad.jsxksn09f) following a year-long embargo from publication of the manuscript. The coordinates associated with mountain zebra data are not provided in an effort to protect critically endangered black rhino (Diceros bicornis) locations. Interested researchers can contact the data owner (Minnesota Zoo) directly for inquiries.https://wileyonlinelibrary.com/journal/elehj2022Mammal Research InstituteZoology and Entomolog
Publics' Opinions About Biotechnologies
Surveys eliciting opinions about biotechnology applications suggest the following conclusions. (1)People distinguish among biotechnologies. (2)Different people have different views about biotechnologies. (3)People have limited knowledge about biotechnologies and know it. (4)People have strong opinions about how biotechnologies are managed. (5)People have complex evaluative schemes and respond to evidence. As a result, there is little place for sweeping statements regarding "the public's opinion about biotechnology." Such statements demean the public and distort policy making by promoting simplistic solutions. More focused research is needed to characterize current and possible views of different publics regarding different current and possible biotechnologies.Includes bibliographical reference