232,569 research outputs found
Bird species richness and diversity at montane Important Bird Area (IBA) sites in south-eastern Nigeria
No full textThe mountains of south-eastern Nigeria are a western extension of the Cameroon mountain range, which is classified as an endemic bird area (EBA). Unlike its eastern extension in Cameroon, most of the ornithological surveys in the western extension of the Cameroon highlands in Nigeria have produced only limited checklists and inventories. There is a clear need for quantitative baseline data so that conservation problems can be identified. Twenty line transects covering a total transect length of 28.8 km were used to survey five sites (Afi Mountain Wildlife Sanctuary, Oban and Okwangwo Division of Cross River National Park, Sankwala Mountains and Mbe Mountains) in the westernmost extension of the Cameroon Mountains EBA in south western Nigeria. Vegetation measurements were taken to control for the potential confounding effect of variation in vegetation density and structure on detectability of birds between sites. The 193 bird species recorded in Afi, 158 in Sankwala, 124 in Oban, 100 in Mbe and 73 in Okwangwo Division included most of the Cameroon highlands restricted range species. The results show that the mountains of south-eastern Nigeria are important parts of the Cameroon EBA, particularly the Afi Mountain Wildlife Sanctuary. However these sites are threatened by fire and livestock grazing on the hilltops, shifting agriculture on the hillsides and lowlands, and logging for timber in some parts, as well as wildlife hunting for bush meat.Peer reviewe
Estimating bird abundance : making methods work
No full textIn many bird monitoring Surveys, no attempt is made to estimate bird densities or abundance. instead, counts of one form or another are made, and these are assumed to correlate with bird density. Unless complete Counts Oil Sample plots are feasible, this approach can easily lead to false conclusions, because detectability of birds varies by species, habitat, observer and many other factors. Trends in time of counts often reflect trends in detectability, rather than trends in abundance. Conclusions are further compromised when surveys are conducted at unrepresentative sites. We consider how to avoid these problems. We give a brief description of distance sampling methods, which allow detectability to be estimated. We consider strategies to ease their implementation, to enhance their reliability, to adapt the methods for difficult species, and to deal with circumstances in which representative sampling is problematic. We also consider some of the common problems encountered, and suggest solutions.Peer reviewe
Cooperation bibliogram of bird flu
No full textThe published literature on Bird Flu, now a pandemic animal disease with a possible potential of evolving into a devastating human disease, was analysed primarily with respect of national and international cooperations and networks of authors and countries. The output of research-relevant papers is now around 150 per year and was less than 100 papers per year before 2003. The field is highly cooperative; nearly 90% of the articles have two or more authors. National extramural cooperation is around 50% since 1998, intramural cooperation shows a decreasing tendency and is now about 20%. Between 20% and 30% of the papers have been published in bi- or multinational cooperation. Observed and expected citation rates of international papers are twice as high as the citation rates of national papers.
47 countries are engaged in Bird Flu research, on top USA, followed by PEOPLES R CHINA, UK and JAPAN. These countries are also centers of country networks, but minor centers exist. An Asian local network with strong ties consisting of countries most affected by Bird Flu can be identified.. No strong direct connections exist between Europe and Asia; thus it seems necessary to intensify international cooperation.
Author network show interesting cluster structures which must be studied in detail
The design and construction of a flying bird robot
No full textThe purpose of this project is to investigate the issues surrounding the design and construction of a flying bird robot. The ideal would be to re-create a model of a bird that looks like bird, functions like a bird with regard to the biomechanical issues involved in flight and uses control systems that emulate the ones used by the bird to control the flight path
Two men standing on a railroad trestle
No full textThis undated postcard written to Mr. Roy Bird from Blanche shows two men on a railroad trestle in flooded waters and is part of the William E. Bird Collection. On the back of the postcard is written “Hello, Read your card all O. K. was pleased to get a card from you. I sure had a lovely time at the fair. Was sorry I didn’t get acquainted with you. Yes be sure and come to Beta the 3rd Sunday. Your almost awkward friend ‘Blanche.’” William Ernest Bird (1890-1975) was born in the Qualla community of Jackson County, NC. Bird served Western Carolina University in various capacities during his long career. Bird’s roles at WCU included head of the English Department, Dean of Men, Acting President, and President. In 1963, he published The History of Western Carolina College: The Progress of an Idea. He was married to Myrtle Wells (1891-1983)
Relationships between hedgerow characteristics and bird communities:: a multivariate approach
No full textFifty 100m hedge transects were selected within 10km of Durham City, North England. The bird community of the hedge transects was censused six times between May and July, and characteristics of the hedge and surrounding landscape were recorded. The data was analysed using multivariate methods to determine the importance of the microstructure of the hedge in relation to aspects of the bird community. Stepwise Multiple Regression selected the scores of the first axis of a Detrended Correspondance Analysis of shrub abundance data (related to the height and width of the hedge) as the best predictor of Bird species richness and density. Individual species were related to different aspects of the hedge microstructure. The use of transformed independent data improved the predictive value of most of these relationships. A Detrended Correspondance Analysis found that major source of variation in the bird species abundances was due to the number of trees in the hedge. Canonical Correspondance Analysis was used to analyse how a community responds to a set of external factors. The CANOCO first axis was related to an increase in the area of nearby woodland in the positive end and an increase in the number of trees in the negative end. The position of the species scores in relation to these environmental gradients was analysed. The habitat preferences of 4 common species of bird was explored using "sector” analysis, whereby the mean density of the species is plotted against the major sources of variation in the environmental variables, different habitat preferences between species are apparent. The importance of trees to the bird community was elucidated using Linear Discriminant Analysis. The analysis was carried out with hedges with no trees and hedges with 3 or more trees as the two a priori groups. Eighty-three percent of the sites were placed in the correct groups, using 14 common bird species as variables. The importance of the microstructure of the hedge to the bird community is discussed
Study Design and Testing of Structural Configurations for the bird-strike compliance of aeronautical components
No full textThis work is the result of a collaborative research project between the univer-
sity (Department of Aerospace Engineering at University of Naples "Federico
II") and an industrial partner (Alenia Aeronautica at Pomigliano d'Arco).
The aim of this project was to design, with the help of nite element analy-
sis and the experimental tests, an aircraft wing leading edge structure with
innovative materials, that satises the optimization of requirements such as
weight and performance. This study was driven by the industrial demand
to improve the design rules necessary to the evaluation of the structural
response of a leading edge when subjected to bird-strike.
The rst step was the material characterization: an extensive series of
materials was tested to determine stiness and strength properties on glass-
based ber metal laminate. Static tests were performed to determine the
stress-strain curve, dynamic tests to evaluate material strain rate sensitivity
at medium rate regime and, impact tests to determine the threshold for
impact energy which correspond to visible impact damage.
Afterwards several congurations of an one-bay component of a typical
wing leading edge were built and subjected to the bird-strike tests carried
out at Alenia plant by an air pressure gas gun facility. Various materials,
lay-up distribution and boundary conditions were investigated. The numer-
ical nite element simulations were performed using the commercial explicit
integration code MSc/Dytran. This work describes the basic assumptions of the analyses, i.e. bird properties, composite failure modes, and the way in
which the simulations have been carried out in an industrial environment.
Numerical simulations were able to predict that the bird did not penetrate
the leading edge skin. The nal correlation between numerical and experi-
mental showed that good correlation was achieved.
Finally the tests were useful to design and test a new conguration of
leading edge structure able to satisfy the bird-strike requirement according
to the Federal Aviation Regulation (FAR part 25, section 25.631 "Bird-strike
Damage"). Compliance with this section we studied the conguration of the
C27J aircraft, that presents a cruise velocity of 464km/h (=250kts), so the
impact speed with an 8-pound bird is a potentially serious and damaging
event that must be accounted for the design of
ight critical aircraft com-
ponents. The starting thickness of the n C27J airplane's aluminium alloy
leading edge was 0.8mm with a weight of 12.1kg. Before this work, to satisfy
the airworthiness standards about the bird-strike damages, the thickness of
the aluminium alloy leading edge was increased to 3.2mm with a skin weight
of 36.8kg, this thickening involved a weight increasing of 305% related to
skin thickness of 0.8mm.
After this research work, to certicate the empennage structure after im-
pact with an 8-pound bird according to requirements, a innovative composite
conguration has been studied, which oered an amount weight of 18.2kg
producing a weight conservation of 51% related to leading edge in aluminium
alloy with a thickness of 3.2mm. Furthermore this research project allows to
validate a ribless conguration about the leading edge; this solution aided
the manufacturing reducing the rib's installation onto the leading edge struc-
ture. The leading edge conguration in the ber metal laminate and ribless
has been tested at impact with an 8-pound bird at a speed of 250kts and
the test has been considered highly satised and it has met the quality of
requirements
Automatic large-scale classification of bird sounds is strongly improved by unsupervised feature learning
No full textAutomatic species classification of birds from their sound is a computational tool of increasing importance in ecology, conservation monitoring and vocal communication studies. To make classification useful in practice, it is crucial to improve its accuracy while ensuring that it can run at big data scales. Many approaches use acoustic measures based on spectrogram-type data, such as the Mel-frequency cepstral coefficient (MFCC) features which represent a manually-designed summary of spectral information. However, recent work in machine learning has demonstrated that features learnt automatically from data can often outperform manually-designed feature transforms. Feature learning can be performed at large scale and “unsupervised”, meaning it requires no manual data labelling, yet it can improve performance on “supervised” tasks such as classification. In this work we introduce a technique for feature learning from large volumes of bird sound recordings, inspired by techniques that have proven useful in other domains. We experimentally compare twelve different feature representations derived from the Mel spectrum (of which six use this technique), using four large and diverse databases of bird vocalisations, classified using a random forest classifier. We demonstrate that in our classification tasks, MFCCs can often lead to worse performance than the raw Mel spectral data from which they are derived. Conversely, we demonstrate that unsupervised feature learning provides a substantial boost over MFCCs and Mel spectra without adding computational complexity after the model has been trained. The boost is particularly notable for single-label classification tasks at large scale. The spectro-temporal activations learned through our procedure resemble spectro-temporal receptive fields calculated from avian primary auditory forebrain. However, for one of our datasets, which contains substantial audio data but few annotations, increased performance is not discernible. We study the interaction between dataset characteristics and choice of feature representation through further empirical analysis
Bird, C R, WX9017
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/371901Surname: BIRD
Given Name(s) or Initials: C R
Military Service Number or Last Known Location: WX9017
Missing, Wounded and Prisoner of War Enquiry Card Index Number: 33799182821
Item: [2016.0049.04228] "Bird, C R, WX9017
Black Stork Down: Military Discourses in Bird Conservation in Malta
No full textTensions between Maltese hunters and bird conservation NGOs have intensified over the past decade. Conservation NGOs have become frustrated with the Maltese State for conceding to the hunter lobby and negotiating derogations from the European Union’s Bird Directive. Some NGOs have recently started to organize complex field-operations where volunteers are trained to patrol the landscape, operate drones and other surveillance technologies, detect illegalities, and lead police teams to arrest poachers. We describe the sophisticated military metaphors which conservation NGOs have developed to describe, guide and legitimize their efforts to the Maltese public and their fee-paying members. We also discuss why such groups might be inclined to adopt these metaphors. Finally, we suggest that anthropological studies of discourse could help understand delicate contexts such as this where conservation NGOs, hunting associations and the State have ended in political deadlock
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