: Ecological Factors in Changing Economy and Social Organization among the Rupert House Cree . Rolf Knight.

1969 ◽  
Vol 71 (3) ◽  
pp. 512-514
Author(s):  
Eleanor Leacock
2012 ◽  
Vol 90 (9) ◽  
pp. 1102-1116 ◽  
Author(s):  
K. Norén ◽  
P. Hersteinsson ◽  
G. Samelius ◽  
N.E. Eide ◽  
E. Fuglei ◽  
...  

Canids display pronounced intraspecific variation in social organization, ranging from single breeding females to large and complex groups. Despite several hypotheses in this matter, little is understood about the ecological factors underlying this flexibility. We have used the arctic fox ( Vulpes lagopus (L., 1758)) to investigate how contrasting ecosystem conditions concerning resources and predation influence group formation. We predicted that complex groups are more common in resource-rich ecosystems with predators, whereas simple groups occur in more marginal ecosystems without predators. Samples from 54 groups were collected from four populations of arctic foxes with contrasting prey resources and predation and these samples were genotyped in 10 microsatellite loci. We found considerable variation between ecosystems and a significant relationship between resources and formation of complex groups. We conclude that sufficient amounts of food is a prerequisite for forming complex groups, but that defense against predation further increases the benefits of living in larger groups. We present a conceptual model suggesting that a trade-off between the cost of resource depletion and the benefits obtained for guarding against predators explain the differences in social organization. The variable ecology of the arctic foxes makes it is a plausible model species for understanding the connection between ecology and social organization also in other species.


Author(s):  
Nathalie Jaquet ◽  
Diane Gendron

Intra-specific variation in social organization provides valuable insights into the selective forces driving social evolution. Sperm whales are distributed globally and live far from shore, thus obtaining large sample sizes on social organization in multiple areas is logistically challenging and few comparative studies exist. In order to address how ecological factors influence sociality, we investigated the social organization of sperm whales in the Gulf of California (GoC) using a long-term study (1998–2004) and compare our results to other published studies. Standard photo-identification and behavioural observation techniques were used. Group size was calculated from photographic mark–recaptures using a Petersen estimator. Social organization was investigated using SocProg 2.3. Mean typical group sizes in the GoC were similar to those in the Galápagos Islands, Chile and Seychelles (24.7, 24.8, 30.4 and 18 individuals respectively), but substantially larger than in the Sargasso Sea, Caribbean and northern Gulf of Mexico (12.0, 6.4 and 6.9 individuals respectively). Sperm whale social organization in the GoC best fitted a constant companion/casual acquaintance model, where permanent units sizes were 12.5 individuals and two units usually associated together to form a group. This structure is similar to the situation in the Galápagos Islands and Chile areas. However, groups were more stable in the GoC than in the South Pacific, as groups stayed together for periods of about 80 days versus about ten days in the Galápagos Islands and Chile. It is likely that differences in the social organization between the study areas in the Pacific and Atlantic Oceans were due to differences in predation pressure and/or food resources. We suggest that, site-specific ecological factors are likely to influence fundamental aspects of sperm whale social organization.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sacha Zahnd ◽  
Amaranta Fontcuberta ◽  
Mesut Koken ◽  
Aline Cardinaux ◽  
Michel Chapuisat

Abstract Background Social insects vary widely in social organization, yet the genetical and ecological factors influencing this variation remain poorly known. In particular, whether spatially varying selection influences the maintenance of social polymorphisms in ants has been rarely investigated. To fill this gap, we examined whether fine-scale habitat heterogeneity contributes to the co-existence of alternative forms of social organization within populations. Single-queen colonies (monogyne social form) are generally associated with better colonization abilities, whereas multiple-queen colonies (polygyne social form) are predicted to be better competitors and monopolize saturated habitats. We hypothesize that each social form colonizes and thrives in distinct local habitats, as a result of their alternative dispersal and colony founding strategies. Here, we test this hypothesis in the Alpine silver ant, in which a supergene controls polymorphic social organization. Results Monogyne and polygyne colonies predominate in distinct habitats of the same population. The analysis of 59 sampling plots distributed across six habitats revealed that single-queen colonies mostly occupy unconnected habitats that were most likely reached by flight. This includes young habitats isolated by water and old habitats isolated by vegetation. In contrast, multiple-queen colonies were abundant in young, continuous and saturated habitats. Hence, alternative social forms colonize and monopolize distinct niches at a very local scale. Conclusions Alternative social forms colonized and monopolized different local habitats, in accordance with differences in colonization and competition abilities. The monogyne social form displays a colonizer phenotype, by efficiently occupying empty habitats, while the polygyne social form exhibits a competitor phenotype, thriving in saturated habitats. The combination of the two phenotypes, coupled with fine-scale habitat heterogeneity, may allow the coexistence of alternative social forms within populations. Overall, these results suggest that spatially varying selection may be one of the mechanisms contributing to the maintenance of genetic polymorphisms in social organization.


Author(s):  
Sigrid S. Nielsen ◽  
Malan Johansen ◽  
Kim N. Mouritsen

Reproductive division of labour is well-known in several animal groups but the ecological factors driving the evolution of such social organization are still being discussed. Recent studies have discovered social organization in four marine species of trematode parasites having two distinct castes specialized for reproduction and defence of the clonal intra-molluscan larval colony, respectively. Here, we provide novel evidence for social structure also in colonies of the trematode Himasthla elongata infecting the common periwinkle Littorina littorea. We found two types of rediae, the parthenogenetic larval offspring of the parasite: small non-reproductive rediae and considerably larger reproductive rediae. Both redial types possessed a digestive system, collar and posterior appendages and, hence, aside from dimensions, were morphologically similar. However, in vitro experiments showed that non-reproductive morphs attacked heterospecific competing parasites at a higher rate (2–3 fold) than reproductive morphs did. No within-colony antagonism was observed. In contrast to a previous study on a congeneric trematode species, our findings suggest a relatively weak caste formation in H. elongata, possibly resulting from a corresponding weaker level of interspecific competition.


2016 ◽  
Vol 113 (15) ◽  
pp. 4104-4109 ◽  
Author(s):  
Frank Groenewoud ◽  
Joachim Gerhard Frommen ◽  
Dario Josi ◽  
Hirokazu Tanaka ◽  
Arne Jungwirth ◽  
...  

Predation risk is a major ecological factor selecting for group living. It is largely ignored, however, as an evolutionary driver of social complexity and cooperative breeding, which is attributed mainly to a combination of habitat saturation and enhanced relatedness levels. Social cichlids neither suffer from habitat saturation, nor are their groups composed primarily of relatives. This demands alternative ecological explanations for the evolution of advanced social organization. To address this question, we compared the ecology of eight populations of Neolamprologus pulcher, a cichlid fish arguably representing the pinnacle of social evolution in poikilothermic vertebrates. Results show that variation in social organization and behavior of these fish is primarily explained by predation risk and related ecological factors. Remarkably, ecology affects group structure more strongly than group size, with predation inversely affecting small and large group members. High predation and shelter limitation leads to groups containing few small but many large members, which is an effect enhanced at low population densities. Apparently, enhanced safety from predators by cooperative defense and shelter construction are the primary benefits of sociality. This finding suggests that predation risk can be fundamental for the transition toward complex social organization, which is generally undervalued.


2009 ◽  
Vol 364 (1533) ◽  
pp. 3267-3279 ◽  
Author(s):  
Robert Foley ◽  
Clive Gamble

We know that there are fundamental differences between humans and living apes, and also between living humans and their extinct relatives. It is also probably the case that the most significant and divergent of these differences relate to our social behaviour and its underlying cognition, as much as to fundamental differences in physiology, biochemistry or anatomy. In this paper, we first attempt to demarcate what are the principal differences between human and other societies in terms of social structure, organization and relationships, so that we can identify what derived features require explanation. We then consider the evidence of the archaeological and fossil record, to determine the most probable context in time and taxonomy, of these evolutionary trends. Finally, we attempt to link five major transitional points in hominin evolution to the selective context in which they occurred, and to use the principles of behavioural ecology to understand their ecological basis. Critical changes in human social organization relate to the development of a larger scale of fission and fusion; the development of a greater degree of nested substructures within the human community; and the development of intercommunity networks. The underlying model that we develop is that the evolution of ‘human society’ is underpinned by ecological factors, but these are influenced as much by technological and behavioural innovations as external environmental change.


1998 ◽  
Vol 76 (12) ◽  
pp. 2207-2213 ◽  
Author(s):  
Melanie Dunn ◽  
Paula Levin Mitchell ◽  
Laurence Packer

Fortnightly samples of foragers of Halictus ligatus Say and its recently distinguished sibling species Halictus poeyi Lepeletier were collected in an area of sympatry. Both species were active from late April until autumn, although H. ligatus ceased foraging about 1 month earlier than H. poeyi. Phenological differences were minor and insufficient to preclude hybridization opportunities between the species. The two had a similar proportion of ovarially developed workers, but the proportion that mated in H. poeyi was double that found in H. ligatus, and size dimorphism between castes was greater in H. poeyi than in H. ligatus. When these data are compared with data from other populations, in sympatry the two species appear to be more similar to each other in several sociobiological parameters than each does to allopatric conspecific populations. This suggests a prime role for ecological factors in determining details of social organization in halictine bees.


2013 ◽  
Vol 29 (6) ◽  
pp. 531-540 ◽  
Author(s):  
Lance G. Woolaver ◽  
Rina K. Nichols ◽  
Eugene S. Morton ◽  
Bridget J. M. Stutchbury

Abstract:Patterns of social organization and mating systems have been shown to be functions of ecological factors such as resource allocation and breeding density. In some species, particularly birds, social organization and genetic mating systems differ with molecular studies providing evidence of extra-pair young frequently occurring within broods of socially monogamous species. Here we examine the social and genetic mating system of an ecologically little-known forest raptor endemic to the island of Hispaniola in the Caribbean. From 2005–2009, our field observations of over 60 breeding pairs verified a social mating system of monogamy for the species. During the same time period, we collected blood samples (n= 146 birds, 48 nests) and used microsatellite profiles from 10 loci to estimate genetic relatedness among nestlings in a brood and assign putative fathers. We found no evidence of extra-pair paternity in 41 broods. We had one instance where a social male was not assigned as the putative father, however, the confidence level of this assignment was not significant since the genotypes of the social and assigned males were very similar. Our results support our hypothesis that genetic monogamy would be exhibited by Ridgway's hawk, an island-endemic tropical raptor.


2012 ◽  
Vol 17 (1) ◽  
pp. 11-16
Author(s):  
Lynn Chatfield ◽  
Sandra Christos ◽  
Michael McGregor

In a changing economy and a changing industry, health care providers need to complete thorough, comprehensive, and efficient assessments that provide both an accurate depiction of the patient's deficits and a blueprint to the path of treatment for older adults. Through standardized testing and observations as well as the goals and evidenced-based treatment plans we have devised, health care providers can maximize outcomes and the functional levels of patients. In this article, we review an interdisciplinary assessment that involves speech-language pathology, occupational therapy, physical therapy, and respiratory therapy to work with older adults in health care settings. Using the approach, we will examine the benefits of collaboration between disciplines, an interdisciplinary screening process, and the importance of sharing information from comprehensive discipline-specific evaluations. We also will discuss the importance of having an understanding of the varied scopes of practice, the utilization of outcome measurement tools, and a patient-centered assessment approach to care.


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