JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. Summary 1. Following introductions in the 1950s, Gammarus pulex has replaced the native Irish freshwater amphipod G. duebeni celticus in several river systems. We show that G. pulex has eliminated and replaced G. d. celticus in lower sections of the River Lagan system, N. Ireland, although G. d. celticus maintains pure populations upstream from G. pulex. More rarely, the two species may be found together. 2. We investigate the potential roles of cannibalism and mutual predation in explaining these replacement patterns. G. d. celticus was significantly more cannibalistic on moulted conspecifics than G. pulex. Mutual predation by intermoult individuals on moulted congenerics was observed in all combinations of adult males and females, including those in the precopulatory mate-guarding phase, and juveniles. In general, predation between species exceeded cannibalism within species, particularly predation by G. pulex on G. d. celticus. Predation was differentially in favour of G. pulex in most combinations. These differences in predation frequencies were not dependent on body size. 3. A model is presented incorporating resource exploitation competition, cannibalism and mutual predation. The behaviour of the model agrees with our intuitive predictions and our conclusions based on empirical findings. Cannibalism in the absence of predation promotes coexistence, whereas mutual but differential predation in the absence of cannibalism may lead to elimination, depending on relative resource competitive ability. When cannibalism and predation occur together, predation of equal magnitude or greater than cannibalism leads to rapid elimination. Predation in favour of species 1 may overcome a competitive advantage for species 2, leading to elimination of species 2. 4. We conclude that the superior abilities of G. pulex to resist predatory attacks and to prey on moulted G. d. celticus may be major features of the elimination and replacement of the latter species by the former. We encourage examination of replacements involving other crustaceans in terms of predatory behaviour and, more generally, urge adoption of approaches at the individual level to elucidate mechanisms underlying interspecific relationships. Aggressive interactions and resource competition in relation tospecies displacement among crayfish of the genus Orconectes. Journal of Crustacean Biology, 2, 486-492. Carlton, J.T. (1989) Man's role in changing the face of the Ocean: biological invasions and implications for conservation of near shore environments. Conservation Biology, 3, 265-273. Connell, J.H. (1975...
Background:The popularity of tri-axial accelerometer data loggers to quantify animal activity through the analysis of signature traces is increasing. However, there is no consensus on how to process the large data sets that these devices generate when recording at the necessary high sample rates. In addition, there have been few attempts to validate accelerometer traces with specific behaviours in non-domesticated terrestrial mammals. We fitted a collar with a tri-axial accelerometer to a tame captive Eurasian badger (Meles meles). The animal was allowed to move freely in an outside enclosure and artificial sett whilst movements were recorded using a video camera. Data were analysed using custom-written software in terms of magnitude of movement, posture and periodicity using spectral analysis, a principal component analysis, the k-nearest neighbour algorithm and a decision tree to facilitate the automated classification of behaviours. Findings:We have demonstrated that various discrete behaviours (walking, trotting, snuffling and resting) can be differentiated using tri-axial accelerometer data. Classification accuracy ranged between 77.4% and 100% depending on the behaviour and classification method employed. Conclusions:These results are an important step in defining how accelerometer data code for the behaviour of free-ranging mammals. The classification methods outlined here have the potential to be used in the construction of a behavioural database and to generate behaviour-time budgets of hitherto unparalleled detail for wild animals. This would be invaluable for studies of nocturnal, subterranean or difficult-to-observe species that are particularly sensitive to human intrusion.
Background The emergence of artificial intelligence (AI) provides opportunities for demand management of sexual and reproductive health services. Conversational agents/chatbots are increasingly common, although little is known about how this technology could aid services. This study aimed to identify barriers and facilitators for engagement with sexual health chatbots to advise service developers and related health professionals. Methods In January–June 2020, we conducted face-to-face, semi-structured and online interviews to explore views on sexual health chatbots. Participants were asked to interact with a chatbot, offering advice on sexually transmitted infections (STIs) and relevant services. Participants were UK-based and recruited via social media. Data were recorded, transcribed verbatim and analysed thematically. Results Forty participants (aged 18–50 years; 64% women, 77% heterosexual, 58% white) took part. Many thought chatbots could aid sex education, providing useful information about STIs and sign-posting to sexual health services in a convenient, anonymous and non-judgemental way. Some compared chatbots to health professionals or Internet search engines and perceived this technology as inferior, offering constrained content and interactivity, limiting disclosure of personal information, trust and perceived accuracy of chatbot responses. Conclusions Despite mixed attitudes towards chatbots, this technology was seen as useful for anonymous sex education but less suitable for matters requiring empathy. Chatbots may increase access to clinical services but their effectiveness and safety need to be established. Future research should identify which chatbots designs and functions lead to optimal engagement with this innovation.
Hedge density, structure, and function vary with primary production and slope gradient and are subject to other diverse factors. Hedgerows are emerging ecosystems with both above- and belowground components. Functions of hedges can be categorized as provisioning, regulating, cultural, and supporting ecosystem services; these functions include food production, noncrop food and wood production, firewood production, pollination, pest control, soil conservation and quality improvement, mitigation of water flux and availability, carbon sequestration, landscape connectivity and character maintenance, and contributions to biodiversity. Urban hedges provide a relatively equitable microclimate and critical connections between green spaces and enhance human health and well-being through contact with biodiversity. Soil and water conservation are well researched in tropical hedges but less is known about their contribution to pollination, pest control, and biodiversity. Establishing a minimum hedge width and longer intervals between cutting of temperate hedges would enhance biosecurity and promote carbon sequestration and biodiversity. Hedges have a global role in mitigating biodiversity loss and climate change, which restoration should maximize, notwithstanding regional character. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 51 is November 2, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Aim To examine the effect of climate change on the occurrence and distribution of Pipistrellus nathusii (Nathusius’ pipistrelle) in the United Kingdom (UK). Location We modelled habitat and climatic associations of P. nathusii in the UK and applied this model to the species’ historical range in continental Europe. Methods A binomial logistic regression model was constructed relating the occurrence of P. nathusii to climate and habitat characteristics using historical species occurrence records (1940–2006) and CORINE land cover data. This model was applied to historical and projected climate data to examine changes in suitable range (1940–2080) of this species. We tested the predictive ability of the model with known records in the UK after 2006 and applied the model to the species’ known range in Europe. Results The distribution of P. nathusii was related positively to the area of water bodies, woodland and small areas of urbanization, and negatively related to the area of peat/heathland. Species records were associated with higher minimum temperatures, low seasonal variation in temperature and intermediate rainfall. We found that suitable areas have existed in the UK since the 1940s and that these have expanded. The model had high predictive power when applied to new records after 2006, with a correct classification rate of 70%, estimated by receiver operating characteristic analysis. Based on climate projections, our model suggests a potential twofold increase in the area suitable for P. nathusii in the UK by 2050. The single most influential climate variable contributing to range increase was the projected increase in minimum temperature. When applied to Europe, the model predictions had best predictive capability of known records in western areas of the species’ range, where P. nathusii is present during the winter. Main conclusions We show that a mobile, migratory species has adapted its range in response to recent climate change on a continental scale. We believe this may be the first study to demonstrate a case of range change linked to contemporary climate change in a mammal species in Europe.
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