scholarly journals Diagnosing the causes of territory abandonment by the Endangered Egyptian vulture Neophron percnopterus: the importance of traditional pastoralism and regional conservation

Oryx ◽  
2010 ◽  
Vol 44 (3) ◽  
pp. 424-433 ◽  
Author(s):  
Patricia Mateo-Tomás ◽  
Pedro P. Olea
Keyword(s):  
Linear Models ◽  
Nest Site ◽  
Spatial Scales ◽  
Conservation Strategies ◽  
Theoretic Approach ◽  
Prediction Ability ◽  
Multi Scale ◽  
Egyptian Vulture ◽  
Neophron Percnopterus ◽  
Scale Models

AbstractIdentifying threats to declining species and prescribing ways of preventing their extinction are basic challenges for biodiversity conservation. We analysed the causes underlying the loss of territories of the Endangered Egyptian vulture Neophron percnopterus in a key population at the north-western edge of its distribution in Europe by developing multi-scale models that combined factors from nest site to landscape. We used generalized linear models and an information-theoretic approach to identify the optimal combination of scales and resolutions that could explain territorial abandonment. Those models combining nest-site and landscape scales considerably improved prediction ability compared to those considering only one scale. The best combined model had a high predictive ability (96.9% of correctly classified cases). Small cliffs at high altitudes in rugged areas with declining livestock (especially of sheep and goats) increased the likelihood of territory abandonment. Our findings highlight the importance of developing region-specific multi-scale models to determine reliably the factors driving territory loss and of designing effective conservation strategies accordingly. Conservation measures for the studied population should be developed at two spatial scales. At the smaller scale it is necessary to closely control nest sites to avoid direct disturbances. At a larger scale it is essential to implement policies that can support traditional pastoralism.

scholarly journals A synthesis of scale-dependent ecology of the endangered mountain caribou in British Columbia, Canada

Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 33
Author(s):  
Robert Serrouya ◽  
Bruce N. McLellan ◽  
Clayton D. Apps ◽  
Heiko U. Wittmer
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Spatial Scales ◽  
Management Strategies ◽  
Population Level ◽  
Limiting Factors ◽  
Conservation Strategies ◽  
Integrative Approach ◽  
Rangifer Tarandus Caribou ◽  
Multi Scale

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou) that live in highprecipitation, mountainous ecosystems of southeastern British Columbia and northern Idaho. The distribution and abundance of these caribou have declined dramatically from historical figures. Results from many studies have indicated that mountain caribou rely on old conifer forests for several life-history requirements including an abundance of their primary winter food, arboreal lichen, and a scarcity of other ungulates and their predators. These old forests often have high timber value, and understanding mountain caribou ecology at a variety of spatial scales is thus required to develop effective conservation strategies. Here we summarize results of studies conducted at three different spatial scales ranging from broad limiting factors at the population level to studies describing the selection of feeding sites within seasonal home ranges of individuals. The goal of this multi-scale review is to provide a more complete picture of caribou ecology and to determine possible shifts in limiting factors across scales. Our review produced two important results. First, mountain caribou select old forests and old trees at all spatial scales, signifying their importance for foraging opportunities as well as conditions required to avoid alternate ungulates and their predators. Second, relationships differ across scales. For example, landscapes dominated by roads and edges negatively affect caribou survival, but appear to attract caribou during certain times of the year. This juxtaposition of fine-scale behaviour with broad-scale vulnerability to predation could only be identified through integrated multi-scale analyses of resource selection. Consequently we suggest that effective management strategies for endangered species require an integrative approach across multiple spatial scales to avoid a focus that may be too narrow to maintain viable populations. Abstract in Norwegian / Sammendrag:Skala-avhengig økologi og truet fjellvillrein i Britisk ColumbiaFjellvillreinen i de nedbørsrike fjellområdene i sørøstre Britisk Columbia og nordlige Idaho som er en truet økotype av skogsreinen (Rangifer tarandus caribou), har blitt kraftig redusert både i utbredelse og antall. Mange studier har vist at denne økotypen er avhengig av vinterføden hengelav i gammel barskog hvor det også er få andre klovdyr og dermed få predatorer. Slik skog er også viktige hogstområder, og å forstå økologien til fjellvillreinen i forskjellige skaleringer er derfor nødvendig for å utvikle forvaltningsstrategier som kan berge og ta vare på denne reinen. Artikkelen gir en oversikt over slike arbeider: fra studier av begrensende faktorer på populasjonsnivå til studier av sesongmessige beiteplasser på individnivå. Hensikten er å få frem et mer helhetlig perspektiv på fjellvillreinen og finne hvordan de begrensende faktorene varierer etter skaleringen som er benyttet i studiet. Oversikten vår frembragte to viktige resultater; 1) Uansett skalering så velger dyrene gammel skog og gamle trær. 2) Dyrenes bruk av et område kan variere med benyttet skalering, for eksempel vil landskap utbygd med veier og hogstflater være ufordelaktig for overlevelsen, men synes likevel å kunne tiltrekke fjellvillreinen til visse tider av året. Forholdet mellom atferd ut fra fin-skalering og stor-skalering sårbarhet hva gjelder predasjon, ville kun blitt avdekket ved flere-skaleringsanalyse av hvordan ressursene benyttes. Ut fra dette foreslår vi at forvaltningsstrategier for truete bestander som eksempelvis fjellvillreinen, må baseres på tilnærminger ut fra ulike skaleringer for å hindre at et for snevert perspektiv kan begrense muligheten for vedvarende levedyktighet.

scholarly journals The adaptive value of habitat preferences from a multi-scale spatial perspective: insights from marsh-nesting avian species

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3164 ◽  
Author(s):  
Jan Jedlikowski ◽  
Mattia Brambilla
Keyword(s):  
Habitat Selection ◽  
Spatial Scales ◽  
Habitat Preferences ◽  
Nest Survival ◽  
Scale Model ◽  
Vegetation Density ◽  
Multi Scale ◽  
Adaptive Value ◽  
Single Scale ◽  
Scale Models

BackgroundHabitat selection and its adaptive outcomes are crucial features for animal life-history strategies. Nevertheless, congruence between habitat preferences and breeding success has been rarely demonstrated, which may result from the single-scale evaluation of animal choices. As habitat selection is a complex multi-scale process in many groups of animal species, investigating adaptiveness of habitat selection in a multi-scale framework is crucial. In this study, we explore whether habitat preferences acting at different spatial scales enhance the fitness of bird species, and check the appropriateness of single vs. multi-scale models. We expected that variables found to be more important for habitat selection at individual scale(s), would coherently play a major role in affecting nest survival at the same scale(s).MethodsWe considered habitat preferences of two Rallidae species, little crake (Zapornia parva) and water rail (Rallus aquaticus), at three spatial scales (landscape, territory, and nest-site) and related them to nest survival. Single-scale versus multi-scale models (GLS and glmmPQL) were compared to check which model better described adaptiveness of habitat preferences. Consistency between the effect of variables on habitat selection and on nest survival was checked to investigate their adaptive value.ResultsIn both species, multi-scale models for nest survival were more supported than single-scale ones. In little crake, the multi-scale model indicated vegetation density and water depth at the territory scale, as well as vegetation height at nest-site scale, as the most important variables. The first two variables were among the most important for nest survival and habitat selection, and the coherent effects suggested the adaptive value of habitat preferences. In water rail, the multi-scale model of nest survival showed vegetation density at territory scale and extent of emergent vegetation within landscape scale as the most important ones, although we found a consistent effect with the habitat selection model (and hence evidence for adaptiveness) only for the former.DiscussionOur work suggests caution when interpreting adaptiveness of habitat preferences at a single spatial scale because such an approach may under- or over-estimate the importance of habitat factors. As an example, we found evidence only for a weak effect of water depth at territory scale on little crake nest survival; however, according to the multi-scale analysis, such effect turned out to be important and appeared highly adaptive. Therefore, multi-scale approaches to the study of adaptive explanations for habitat selection mechanisms should be promoted.

scholarly journals Communal roosting of Egyptian vulture Neophron percnopterus in Uttar Pradesh, India

2020 ◽  
Vol 12 (4) ◽  
pp. 525-531
Author(s):  
Shivangi Mishra ◽  
Adesh Kumar ◽  
Ankit Sinha ◽  
Amita Kanaujia
Keyword(s):  
Endangered Species ◽  
Uttar Pradesh ◽  
Total Count ◽  
Conservation Strategies ◽  
Egyptian Vulture ◽  
Neophron Percnopterus ◽  
Communal Roosting ◽  
Tree Building ◽  
Number Of Individuals

The behaviour of birds to settle or rest at a place at specific times of day and night is called roosting. Some birds prefer solitary roosting while others roost communally. The Communal roosting behaviour of Egyptian vulture was studied in five districts (Sambhal, Lakhimpur Kheri, Aligarh, Bareilly and Faizabad) of Uttar Pradesh, India from January 2014- December 2017. Total count was conducted at roosting sites in all the seasons (summer, winter and monsoon). The maximum number of individuals counted at the roost site was in Sambhal followed by Lakhimpur Kheri, Aligarh, Bareilly, Faizabad. Four different roost substrates were identified: Ground, tree, building, and electric pylon. A maximum (63%) of Egyptian vultures were observed roosting on the ground, followed by electric pylon (19%), tree (10%) and minimum on building (8%). The present study confirmed that Egyptian vultures are communal roosters and a number of roosting individuals most probably depended on the availability of food of the area. Egyptian vultures are globally endangered species and so far no work has been done on their roosting behaviour in India; therefore the present study will prove beneficial to plan for their conservation strategies.

scholarly journals Comparison of single- and multi-scale models for the prediction of the Culicoides biting midge distribution in Germany

2016 ◽  
Vol 11 (2) ◽  
Author(s):  
Renke Lühken ◽  
Jörn Martin Gethmann ◽  
Petra Kranz ◽  
Pia Steffenhagen ◽  
Christoph Staubach ◽  
...  
Keyword(s):  
Land Cover ◽  
Linear Models ◽  
Predictor Variables ◽  
Buffer Zones ◽  
Biting Midges ◽  
Generalised Linear Models ◽  
Multi Scale ◽  
Land Cover Data ◽  
Scale Models ◽  
Trapping Sites

This study analysed <em>Culicoides</em> presence-absence data from 46 sampling sites in Germany, where monitoring was carried out from April 2007 until May 2008. <em>Culicoides</em> presence-absence data were analysed in relation to land cover data, in order to study whether the prevalence of biting midges is correlated to land cover data with respect to the trapping sites. We differentiated eight scales, <em>i.e.</em> buffer zones with radii of 0.5, 1, 2, 3, 4, 5, 7.5 and 10 km, around each site, and chose several land cover variables. For each species, we built eight single-scale models (<em>i.e.</em> predictor variables from one of the eight scales for each model) based on averaged, generalised linear models and two multiscale models (<em>i.e.</em> predictor variables from all of the eight scales) based on averaged, generalised linear models and generalised linear models with random forest variable selection. There were no significant differences between performance indicators of models built with land cover data from different buffer zones around the trapping sites. However, the overall performance of multi-scale models was higher than the alternatives. Furthermore, these models mostly achieved the best performance for the different species using the index area under the receiver operating characteristic curve. However, as also presented in this study, the relevance of the different variables could significantly differ between various scales, including the number of species affected and the positive or negative direction. This is an even more severe problem if multi-scale models are concerned, in which one model can have the same variable at different scales but with different directions, <em>i.e.</em> negative and positive direction of the same variable at different scales. However, multi-scale modelling is a promising approach to model the distribution of <em>Culicoides</em> species, accounting much more for the ecology of biting midges, which uses different resources (breeding sites, hosts, <em>etc</em>.) at different scales.

scholarly journals Development of a Multi-Scale Stormwater Management Modelling Methodology

2021 ◽  
Author(s):  
Preetha Haque
Keyword(s):  
Stormwater Management ◽  
Spatial Scales ◽  
Land Development ◽  
Evaluation Process ◽  
Development Project ◽  
Multi Scale ◽  
Comparison Results ◽  
Scale Models ◽  
Scale Modelling ◽  
Modelling Methodology

The evaluation process of the land development project becomes complicated, as the simulation results of Fine-Scale Models (FCM) of lands proposed for development cannot be easily transferred to the watershed Coarse-Scale Models (CSM) due to parameterization problem. In this research study, a Multi-Scale Modelling (MSM) methodology was developed to minimize the difficulty in transferring the result into the different spatial scales of the models. The developed MSM methodology was tested on Ganatsekiagon Creek’s sub-watershed, simulating several scenarios. The analyses of model results show that the CSM is generating a lower Peak Flow Rate (PFR) and Flow Volume (FV) than the MSM, while the increasing level of development with BMPs leads to a rise in FV and a decrease in PFR. The comparison results of with and without BMPs show that the stormwater management ponds are effective in PFR reduction and the implementation of LID practices can be effective in FV reduction.

scholarly journals Myxozoans as biological tags for stock identification of the Argentine hake, Merluccius hubbsi (Gadiformes: Merlucciidae)

Parasitology ◽  
2016 ◽  
Vol 143 (6) ◽  
pp. 732-740 ◽  
Author(s):  
D. M. P. CANTATORE ◽  
M. M. IRIGOITIA ◽  
A. S. HOLZER ◽  
J. T. TIMI
Keyword(s):  
Population Structure ◽  
Linear Models ◽  
Spatial Scales ◽  
Fish Population ◽  
Fish Stock ◽  
Theoretic Approach ◽  
Stock Identification ◽  
Geographical Population ◽  
Merluccius Hubbsi ◽  
Information Theoretic Approach

SUMMARYMyxozoans have been successfully used as tags for fish stock identification around the world. However, few studies using myxozoan tags have been carried out in the Southern Atlantic, a region with complex oceanography that constitutes a potentially suitable scenario for testing the utility of myxozoans as indicators. Its usefulness was tested using six samples of Merluccius hubbsi in two different regions of the Argentine Sea. Generalized linear models were performed to assess the effects of fish size and sex, and year and region of capture and selected using the Information Theoretic approach. Three myxozoan species were recorded: Kudoa rosenbuschi, Myxoproteus meridionalis and Fabespora sp. Results of modelling species individually showed differential capabilities for detecting geographical population structure at different spatial scales, with K. rosenbuschi and Fabespora sp. allowing the discrimination of northern and southern stocks, but Fabespora sp. also as a promissory indicator of intrapopulation sub-structure due to different migratory routes during non-reproductive periods. This work confirms that myxozoans offer a set of suitable markers at different spatial scales, which can be selected individually or in any combination, depending on the geographical extent of the study, constituting tools adaptable to the objectives of further research on fish population structure.

Nest site selection of South Georgia Diving-petrels Pelecanoides georgicus on Codfish Island, New Zealand: implications for conservation management

2017 ◽  
Vol 28 (2) ◽  
pp. 216-227 ◽  
Author(s):  
JOHANNES H. FISCHER ◽  
IGOR DEBSKI ◽  
GRAEME A. TAYLOR ◽  
HEIKO U. WITTMER
Keyword(s):  
New Zealand ◽  
Site Selection ◽  
Nest Site ◽  
Nest Site Selection ◽  
Conservation Strategies ◽  
Slope Aspect ◽  
Theoretic Approach ◽  
Seabird Species ◽  
South Georgia ◽  
Invasive Predators

SummarySmall seabird species are often threatened by predation from invasive species at their breeding colonies and considerable efforts are invested into mitigating this threat. However, invasive predators may not be the only onshore threat affecting small seabird species. The South Georgia Diving-petrel Pelecanoides georgicus (SGDP) is a small seabird species, considered ‘Nationally Critical’ in New Zealand. Our objective was to identify terrestrial threats to the species at their sole remaining breeding colony in New Zealand, Codfish Island (Whenua Hou), following the successful eradication of invasive predators. To achieve our objective, we assessed the influence of five physical, three competition/attraction and three plant variables on SGDP nest site selection with generalised linear models (GLMs) and compared models using an information theoretic approach. Models including the distance to sea, slope, aspect, and sand flux outperformed other models and showed selection for steep seaward-facing foredunes with mobile soils. No invasive plant and competition/attraction variables were included in the best performing models. These results suggest that, due to the proximity of their preferred nesting habitat to the springtide line and the overall fragility of the foredunes, SGDPs on Codfish Island are extremely vulnerable to stochastic events and catastrophes, such as storms and storm surges. Eradication efforts directed at invasive predators on Codfish Island appear thus insufficient to safeguard this SGDP colony, necessitating further conservation strategies to secure the continued survival of this population.

scholarly journals Development of a Multi-Scale Stormwater Management Modelling Methodology

2021 ◽  
Author(s):  
Preetha Haque
Keyword(s):  
Stormwater Management ◽  
Spatial Scales ◽  
Land Development ◽  
Evaluation Process ◽  
Development Project ◽  
Multi Scale ◽  
Comparison Results ◽  
Scale Models ◽  
Scale Modelling ◽  
Modelling Methodology

The evaluation process of the land development project becomes complicated, as the simulation results of Fine-Scale Models (FCM) of lands proposed for development cannot be easily transferred to the watershed Coarse-Scale Models (CSM) due to parameterization problem. In this research study, a Multi-Scale Modelling (MSM) methodology was developed to minimize the difficulty in transferring the result into the different spatial scales of the models. The developed MSM methodology was tested on Ganatsekiagon Creek’s sub-watershed, simulating several scenarios. The analyses of model results show that the CSM is generating a lower Peak Flow Rate (PFR) and Flow Volume (FV) than the MSM, while the increasing level of development with BMPs leads to a rise in FV and a decrease in PFR. The comparison results of with and without BMPs show that the stormwater management ponds are effective in PFR reduction and the implementation of LID practices can be effective in FV reduction.

Sign in / Sign up

Export Citation Format

Share Document