1,720,984 research outputs found
Investigating the effects of free lactation crates on sow and piglet welfare
Full text linkFarrowing crates, which are widely used in commercial pig farming, present major animal welfare problems. Sows are severely confined, being only able to stand up and lie down and not turn around for a period of five weeks around farrowing. This study compared the welfare of sows and piglets housed in two types of farrowing accommodation, free lactation pens (Free, n = 22) and conventional farrowing crate pens (Control, n = 24). Free lactation pens allowed for temporary confinement of sows at the most critical period for piglet pre-weaning mortality, from the onset of farrowing until day 4 post-farrowing. For the remainder of the time the sows were in the pens, the crate was opened wide enough for them to turn around. Sows were monitored from entry to the farrowing room (approximately day 108 of gestation) until weaning (approximately day 26 of lactation). The study examined 675 piglets, the offspring of these sows, from birth until slaughter. A range of behaviour and physical health measures were utilised to assess animal welfare and performance. Sows in the Free treatment had greater freedom of movement, as demonstrated by their use of the available space to turn around in the crates while they were open. At weaning, Free sows had significantly lower (better) locomotory scores than those which were housed in Control pens, this may be related to their improved ability to move during the 5-week treatment period. These sows also had significantly lower (better) tear stain scores around their left eyes at weaning, indicating reduced stress. Although Free sows had higher salivary cortisol concentrations overall when compared with Control sows, this is a measure that may reflect increased activity rather than higher levels of stress.
Overall, piglets from the Free treatment performed better than those from Control pens; pre-weaning Free piglets had a tendency to be heavier than those from the Control treatment, and this difference became significant post-weaning, leading to Free pigs having a mean finishing weight of 114.73kg, compared to 110.82kg for Control pigs. This increase in weight gain did not affect ADFI (average daily feed intake) and resulted in Free pigs having a significantly better FCE (feed conversion efficiency) in the weaner stage. There was a reduction in days to slaughter with free pigs reaching the 105kg target weigh in 147.56 days compared with 149.23 days for Control pigs. This is a very promising result regarding both productivity and welfare, and could result in increased profitability for producers. Prior to weaning Free piglets tended to perform less damaging behaviour than Control piglets, although this result was not significant. Most importantly, overall mortality was unaffected by treatment with total mortality of 15.95% for Free pigs and 14.42% for Control pigs (P = 0.61). Overall, the results from this study suggest that implementing a management strategy where sows have increased freedom of movement during lactation compared to traditional farrowing crates may help to improve sow and piglet welfare. Further research investigating the best length of time to confine the sow, taking litter size into consideration, would be beneficial to developing the most effective management practices for free lactation crates
Monitoring mammals in airfield environments; a case study of the Irish hare at Dublin Airport
No full textThe number of reported wildlife-aircraft collisions (i.e., strikes) with mammal species is increasing globally with severe consequences for passenger safety, industry economics and wildlife populations. Despite this, little research has been conducted on the class Mammalia in airfield environments, with strike mitigation research efforts predominantly focused on avian species. This thesis addresses some of the wildlife hazard issues faced by the aviation industry, specifically looking to mammal species. The thesis focuses on developing ecological survey methods for mammals in airfields and exploring the role of ecological data in informing strike risk. The Irish hare (Lepus timidus hibernicus) population at Dublin airport is used as a population case study to assess survey methods in an airport environment, throughout.
As little is known about mammal strikes on a global scale, strike records with mammals from available literature and national aviation authorities are collated in chapter 1. These data highlighted that mammal strikes are widespread and identify 42 mammal families involved in strike events in 47 countries and demonstrate that reported mammal strike events have been increasing by up to 68% annually. Looking to mammal management measures on a European scale for chapter 2, the most successful mammal mitigation measures were identified as: (i) the management of watercourses within the airfield; (ii) the implementation of specific grass cutting regimes (94.4%) and (iii) the management of waste products at the airfield so as not to attract or sustain wildlife (93.8%).
Utilising historical strike data in chapter 3, it was demonstrated that hare strikes have been increasing by an average of 14% annually at Dublin Airport with over 340 recorded wildlife strikes since 1997. The kinetic energy of such an event (10,576 J) is substantial enough to inflict damage to the landing gear of an aircraft, although this has never been reported to have occurred. As the basis of effective wildlife management practices necessitates reliable estimates of the population size, design and model-based distance sampling methods were compared, alongside Random Encounter Modelling, to establish ecological survey methods suitable for monitoring mammals in airfields for chapter 5. Population estimates ranged from 29 (SE ± 9) to 133 (SE ± 19) individuals, with the most robust model (nocturnal line transects), estimating a population size of 118 (SE ± 21) hares at Dublin Airport.
A concern regarding mammal strike events is not only the strike event itself, but the secondary strike risk with a predatory or scavenger species. Camera trap surveys were utilised to identify secondary strike risk in chapter 4. It was identified that birds take an average of 2 hours and 23 minutes to detect a mammal carcass following a replicated strike event at Dublin Airport and an average of 11 hours 40 minutes for mammal species to detect a carcass. These data indicate that current clean-up practices at Dublin Airport (i.e., immediate clean-up and closing of the runway to facilitate clean-up operations) are likely adequate for reducing the likelihood of a secondary strike event.
This thesis presents some of the first data collected through remote monitoring methods (camera traps/ GPS trackers) to inform of airside wildlife hazard. These methods, in addition to overlap analysis and cross correlation functions have demonstrated that recorded strike times are closely associated with hares’ circadian activity and largely dissociated with aircraft movements (chapter 6). Additionally, data collected via GPS tracking devices in chapter 7 demonstrated that the hares at Dublin Airport have an average home range size of 0.28 km2 (±SD 0.1 km2), based on 95% Kernal Density Utilisation Distribution. What’s more, it is demonstrated that the hares incorporate active area habitat types (i.e., runways and taxiways) into their home ranges with up to 13% of one individual’s movements incorporating these areas. These data have fed directly into the Wildlife Hazard Management Plan at Dublin Airport and instigated targeted strike mitigation measures.
Throughout this thesis, the importance of ecological data for informing strike risk and mammal management in airfield environments is highlighted. While the Irish hare is used as a case study for ecological field methods in airfield environments, this thesis also broadly demonstrates the extent of mammal related issued at airfields worldwide. Thus, although here the focus is on a specific species at a specific airport, the developed methodologies are suitable for cohort of terrestrial mammals inhabiting airfield environments worldwide
Ecology of frontier populations of the invasive grey squirrel (Sciurus carolinensis) in Ireland
Full text linkThe rise in invasive species, together with habitat destruction, is associated with worldwide declines in biodiversity and ecosystem functioning. Management of invasive species, as well as amelioration of invasion impacts, provide challenges to species and ecosystem ecologists and conservation managers. Although any species can become invasive if it is transported to, establishes in and spreads in a new environment outside of its native range, rodents are a particularly frequent invader. Rodent introductions are often inadvertent but are also commonly intentional as these animals are traded and transported as pets and may escape from captivity. Tree squirrel species are attractive to humans and are able to establish populations with only a few founding individuals, making them a group well suited to performing the role of biological invaders. The eastern grey squirrel (Sciurus carolinensis) is the most commonly introduced squirrel species worldwide. This research addressed the grey squirrel invasion and frontier population biology. Novel results were generated through diverse research techniques. Public sighting surveys and hairtube surveys were used to locate the southern frontier of grey squirrel range expansion in Ireland. A 22-month intensive live trapping study of two frontier populations facilitated the collection of personality and demographic data from squirrels in increasing populations. A systematic literature search on grey squirrel demography provided context for the studied populations, among frontier and established introduced populations, as well as those in the native range. Advanced spatially explicit population modeling techniques predicted future range expansion and objectively compared the outcomes of 12 grey squirrel management strategies. The methods and results are discussed in both a basic scientific and applied invasion management context. An improved understanding of the behaviour, population dynamics, and future scenarios at the frontier of species invasions is crucial for managers worldwide and this is provided here for the grey squirrel in Ireland
The ecology and phylogeography of the common lizard (Zootoca vivipara) in Ireland
No full textPartial RestrictionIreland has only one native terrestrial reptile, the common lizard Zootoca vivipara. Many people are unaware of its presence in Ireland and little research has been conducted on the species here. However, understanding the ecology of the common lizard in Ireland could greatly help with the conservation of our only native lizard. Here we show that records of common lizards in Ireland are predominantly from coastal areas and that it occupies smaller microhabitats, such as banks or stone walls, which potentially have microclimates that offer advantages for thermoregulation. Using records of Z. vivipara sightings from the National Biodiversity Data Centre, this research identified data gaps within the distribution of Z. vivipara in Ireland, but it is uncertain if these gaps are explained by unsuitable habitat type or low sampling effort. In addition, distribution of records were found to be centred around coastal areas and sites popular with human outdoor recreation. Recorder bias, habitat suitability, and coastal sunshine hours were identified as potential factors influencing the distribution of records.
A focused study on the Iveragh Peninsula, in the south-west of Ireland, observed Z. vivipara from habitat types such as upland peatland/heath (23%), gardens (17%) and old stone walls/ruins (16%). Wind speed, air temperature, and relative humidity were environmental parameters examined in this research to investigate the influence of microclimates within the microhabitats which lizards occupy. Wind speed was found to be significantly lower at ground level (P<0.05) compared to 2m height, and thus, wind may have an influence on where lizards are found within habitats.
In addition, through genetic analysis, we confirm for the first time, that Irish Z. vivipara belong to the Western viviparous clade. This brings Irish phylogeographic research on the species up to date with similar research in other parts of the species’ range. We also identify that unique haplotypes are present in Ireland and that unique lineages also exist within geographically disparate populations here. Additional genetic sampling is recommended to fully understand how Z. vivipara colonised Ireland post-glacially.
It is recommended that a long-term study is established to perform focused surveys for lizard presence/absence in areas where data gaps occur in sightings records of the species in Ireland. This focused study should also identify reasons for data gaps, such as habitat suitability or recorder effort. A population dynamics and behavioural study is needed to examine how environmental parameters influence Z. vivipara presence/absence in certain habitats. Finally, additional samples for genetic sequencing would greatly benefit the research into the different haplotypes identified in this study. A more geographically widespread range of samples, including from off-shore islands, would aid in understanding how Z. vivipara arrived and dispersed in Ireland
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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