4,285 research outputs found
Foot-slapping: a territorial advertisement display by a mute swan
No full textBlack JM 1986. Foot-slapping: a territorial advertisement display by a mute swan. British Birds 79, 500-501
The January 1986 Whooper Swan census in Britain, Ireland and Iceland
No full textSalmon DG & Black JM 1986. The January 1986 Whooper Swan census in Britain, Ireland and Iceland. Wildfowl 37, 172-174
Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management
No full textEffective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems
The structure and behaviour of the Whooper Swan population wintering at Caerlaverock, Dumfries and Galloway, Scotland: an introductory study
No full textBlack JM & Rees EC 1984. The structure and behaviour of the Whooper Swan population wintering at Caerlaverock, Dumfries and Galloway, Scotland: an introductory study. Wildfowl 35, 21-36
Understanding plant community responses to combinations of biotic and abiotic factors in different phases of the plant growth cycle
No full textUnderstanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors
Evaluating the effects of population management on a herbivore grazing conflict
No full textAbundant herbivores can damage plants and so cause conflict with conservation, agricultural, and fisheries interests. Management of herbivore populations is a potential tool to alleviate such conflicts but may raise concerns about the economic and ethical costs of implementation, especially if the herbivores are ‘charismatic’ and popular with the public. Thus it is critical to evaluate the probability of achieving the desired ecological outcomes before proceeding to a field trial. Here we assessed the potential for population control to resolve a conflict of non-breeding swans grazing in river catchments. We used a mathematical model to evaluate the consequences of three population management strategies; (a) reductions in reproductive success, (b) removal of individuals, and (c) reduced reproductive success and removal of individuals combined. This model gave accurate projections of historical changes in population size for the two rivers for which data were available. Our model projected that the River Frome swan population would increase by 54 %, from 257 to 397 individuals, over 17 years in the absence of population control. Removal of ≥ 60 % of non-breeding individuals each year was projected to reduce the catchment population below the level for which grazing conflicts have been previously reported. Reducing reproductive success, even to 0 eggs per nest, failed to achieve the population reduction required. High adult and juvenile survival probabilities (> 0.7) and immigration from outside of the catchment limited the effects of management on population size. Given the high, sustained effort required, population control does not represent an effective management option for preventing the grazing conflicts in river catchments. Our study highlights the need to evaluate the effects of different management techniques, both alone and in combination, prior to field trials. Population models, such as the one presented here, can provide a cost-effective and ethical means of such evaluations
The severe and disturbing decline of an iconic Mediterranean ecosystem endemic to Western Australia
No full textEucalyptus gomphocephala (Tuart) is an iconic woodland canopy tree, endemic to the Swan Coastal Plain of Western Australia, and one of few eucalypts able to dominate calcareous soils. Unfortunately, less than one third of the original E. gomphocephala woodland ecosystem remains today (Government of Western Australia 2003), largely as a result of clearing for urbanisation, agriculture and industry. Equally disturbing is a decline of complex and unknown cause(s) within Yalgorup region, south of Mandurah, 50 km south of the capital city of Perth. The decline and death of mature trees has been occurring within Yalgorup for approximately 15 years with the majority of the region affected and up to 100% mortality of E. gomphocephala in some locations
The SSC of the Generalised Jahangir’s Graph Jm,k and its Algebraic Characterizations
No full textIn this article, we present important combinatorial and algebraicproperties of spanning simplicial complex (SSC) of the generalised Jahangir’sgraph Jm,k. We describe the relation to find f−vectors associatedto Δs(Jm,k) and determine the Hilbert series for the SR-ring KΔs(Jm,k).In the end, we present the associated primes of the facet ideal IF(Δs(Jm,k))and the Cohen-Macaulay characterization of the SR-ring of Δs(Jm,k).AMS (MOS) Subject Classification Codes: Primary 13-P10, Secondary 13-F20, 13-C14, 13-H10.Corresponding Author: Agha KashifKey Words: Simplicial Complexes, f-vectors, Spanning Trees, Face Ring, Hilbert Series, CohenMacaulay
To <i>JM</i> on Its 75th Anniversary
No full text This article discusses how Journal of Marketing ( JM) has influenced marketing science and practice by publishing articles on substantive topics relevant to customers, managers, organizations, markets, and society. The journal's 75th anniversary coincides with the 50th anniversary of the Marketing Science Institute (MSI). Frequently, JM and MSI have collaborated to address important substantive marketing issues identified in MSI's Research Priorities. The author highlights seminal articles on brand equity; business-to-business marketing (including sales force management); connecting marketing information, metrics, and strategy; consumer behavior; innovation, new product development. and product management; marketing orientation and capabilities; and market research, methodology and services. She also draws attention to articles that have won the Sheth Foundation/ JM Award and the H. Paul Root Award. The article describes how JM‘s knowledge dissemination is amplified by powerful social network effects. Ideas in JM articles diffuse through the business community, influencing the mind-set of managers worldwide. </jats:p
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