• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 7
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aspects of the ecology and behaviour of capercaillie Tetrao urogallus L. in two Scottish plantations

Jones, Augustine Mark January 1982 (has links)
A field study of capercaillie (Tetrao urogallus) was undertaken largely in the plantations of Monaughty and Culbin in Morayshire between 1977 and 1980, with additional observations in these and other forests between 1976 and 1982. In the mixed and structurally diverse Scots pine-larch-spruce plantation of Monaughty higher population densities and a sex ratio favouring males were recorded compared to the more uniform pine plantation of Culbin. Comparisons were made of the habitat available with that in which capercaillie were recorded, especially in relation to the species composition and age of stands. Seasonal and sexual differences in habitat use were found. Drive counts with many observers and transects with a single observer were used to estimate abundance and it was concluded that both methods were worthwhile provided large enough areas could be effectively sampled. Transacts on tracks had advantages over transects off tracks and winter transects over summer ones. Scots pine and dwarf shrubs were important in the diet. A study was made of physical features and chemical composition of conifers fed on, which agreed with some predictions based on earlier work, but indicated that caporcaillie may have been selecting needles rich in crude fat. Nesting dispersion in relation to mating sites and nesting density is described. A detailed study of nesting habitat indicated that dwarf shrubs provide important cover. Important behaviour patterns and the behaviour at the lek are described and interpreted. Evolutionary costs and benefits of the patterns in mating behaviour observed at one lek which was intensively studied for several seasons are discussed. Approaches towards improved capercaillie management and conservation are suggested.
2

Ecology of capercaillie within a managed pine forest

Canham, Lois January 2009 (has links)
The capercaillie is a rare species of forest bird which is once again facing extinction in Britain. Working pine forests are thought to represent the future for capercaillie in Scotland. However, few studies have focused on capercaillie within working forests and as a result current management recommendations are based on studies conducted within semi-natural pinewoods. Therefore study of the ecology of capercaillie within working forests is vital for the survival of the species in Scotland. The present study investigated the ecology of capercaillie, based on indirect measures of capercaillie use, within Morangie Forest, a pine plantation managed by the Forestry Commission. Monthly dropping counts were collected over a 30 month period to gain insight into the capercaillie population at Morangie Forest, and to explore the use of faecal counts as a non-invasive monitoring tool. Habitat analysis, dietary analysis of droppings and genetic analysis of feathers were further conducted to fully explore ecology of capercaillie within Morangie Forest. Results showed that the capercaillie population in Morangie Forest was subject to seasonal movements and that movements were not confined to the bounds of the forest. Substantial mixing occurred with capercaillie from neighbouring Novar Forest. In addition, capercaillie within Morangie Forest selected habitat at a radius of 50m and beyond. The population of capercaillie at Morangie Forest was estimated at around 65 individuals based on measures from dropping counts and genetic determination of individuals from feathers. Results also suggested that winter dropping counts could represent a useful tool for forest managers to monitor the size and movement of capercaillie populations frequenting their forests. In addition winter dropping counts could be used in conjunction with habitat data to plan management of habitat for capercaillie. The present study contributes towards future management strategies for the conservation of capercaillie within working forests and suggests further research priorities for capercaillie in Scotland, particularly those focused at a landscape scale.
3

An historical account of the social and ecological causes of Capercaillie Tetrao urogallus extinction and reintroduction in Scotland

Stevenson, Gilbert Buchanan January 2007 (has links)
The capercaillie is the largest member of the grouse family extant in Scotland. This species is reported to have become extinct during the 1700s. It is also reported to have been reintroduced to Scotland from Sweden during the 1800s. There have been many assertions made about the underlying causes of the decline of the species; however the specific causal factors remain unknown. The reintroduction of the capercaillie to Scotland in the 1800s is the only successful reintroduction of a grouse species ever to have occurred in the world. The specific factors behind the success of the reintroduction also remain unknown. This thesis examines the extent to which a selection of historical documentary evidence can help to establish both the causes of the 18th century decline of the capercaillie in Scotland and the successes of the 19th century reintroduction. The methodology of this thesis incorporates facets from the fields of both environmental science and history. The methodology includes three steps. The first step involves the selection of a series of potential critical factors that may have been responsible for the decline of the species in the 1700s; these critical factors were selected from the present day understanding of the ecology and the behaviour of the capercaillie. The second step of the methodology includes the surveying of a series of historical documentary sources. From these surveys historical observations of the species were gathered. The historical documentary sources selected for examination in this thesis include what are referred to here as ‘primary historical source material’ and ‘secondary historical source material’. The majority of the primary historical source material was gathered from the hand written manuscripts of the Breadalbane estate, held at the National Archives of Scotland (NAS) and the Atholl estate held at the Blair Castle Charter Room in Blair Atholl. Other select primary historical source material consulted to a lesser extent, due to time constraints, includes the Forfeited Estates (1745) Inventory and the Baron Court Records for Strathspey and Urquhart (1617–1683) from the Grant estate muniments; both held at the NAS. The secondary historical source material was gathered from published and edited literary collections that include historical accounts of the species. The third and final step of the methodology involves the synthesis of both the historical and environmental information in order to establish to what extent the causes of both the decline of the species in the 1700s and success of its reintroduction in the 1800s can be realised. The findings from this thesis assert that the capercaillie was resident in Scotland from, at least, the end of the Medieval. Moving forward from the Middle Ages this thesis presents observations of the capercaillie throughout the historical period. These observations of the capercaillie appear in many different historical accounts. In some instances these observations are fleeting and do not form the main subject of the particular document in question. In other instances accounts of the species are much more detailed and include references to the ecology and behaviour of the bird. The level of detail included in an observation aside, the frequency with which the species is referred to in the sample of historical documents suggests that sections of the Scottish human population were familiar with the species, in various locations and at various times throughout history. By the 17th century the capercaillie is reported as beginning to become rare in some locations while still remaining comparatively abundant in others. The number of instances where the species is referred to as becoming rare in the historical documents increases between the 17th and the 19th centuries. Despite the reported scarceness of the species in Scotland from around the 17th century onwards, the capercaillie is recorded as persisting in Scotland until around the end of the 1700s. By the early 1800s the number of observations of the species in the secondary historical source material increases. All of the observations in the secondary sources from the early 1800s record the absence of the species from localities and regions of Scotland. No new evidence was found in either the primary or secondary historical source material to challenge the supposition that the capercaillie did become extinct in Scotland after 1785. No detailed quantitative data was available for analysis of the decline of the species. Thus, to investigate the extent to which the historical accounts can help explain the specific causal factors of the reported decline, a synthesis of the environmental and historical data was necessary. The findings of this synthesis suggest that the naturally occurring Scottish population of capercaillie probably persisted in the form of a metapopulation. The two hundred years between the 17th and 19th century most likely saw the extinction of capercaillie sub-populations, before the loss of the overall population of capercaillie around 1785. The sample historical documentary evidence alludes to this pattern of local and/or regional extinction of sub-populations. The cause or causes of the extinction of these sub-populations has focussed on five limiting or critical factors known to affect the species today. These five factors are climate change, particularly weather effects associated with the Little Ice Age, habitat loss and deterioration, disturbance, human hunting and predation by species other than humans also contributed to the species’ extinction. The extent to which these critical factors affected each sub-population would have varied between regions of Scotland occupied by the capercaillie in history. This thesis proposes that there was no single or combination of specific critical factors that were ultimately responsible for the decline of the capercaillie in Scotland during the 1700s. In some areas the capercaillie sub-populations would have most likely died out as a result of habitat loss and deterioration and climate change. Whereas in others predation and inbreeding may have been the critical factors responsible for the species’ demise. More detailed information referring to the capercaillie was found in the historical documentary source material for the period post-extinction (i.e. 1800 onwards). Contrary to popular understanding numerous attempts to reintroduce the capercaillie to Scotland were carried out before the Marquis of Breadalbane’s successful programme in 1837. The historical documentary evidence reports early attempts to reintroduce the species to locations such as the Isle of Arran in 1807, on the Duke of Atholl’s estate in 1822 and on the Earl of Mar’s estate in 1824. None of these reintroduction programmes are reported to have been successful in establishing a ‘wild’ population. However, in some instances the captive rearing programmes initiated did bear some fruit and captive reared birds were sent from Dunkeld by the Duke of Atholl to Kenmore and were used in Breadalbane’s successful reintroduction in 1837. The historical documents report two causes for the failure of these early reintroduction attempts. The first is the sudden death of captive birds, most likely as a result of choking due to stress as observed in recent rearing programmes (i.e. Moss 1986). The reintroduced Arran population is reported to have become extinct in this fashion. The second reported cause of failure is predation by species other than man. For example the entire population of birds brought to Scotland by the Earl of Mar were predated when released on his estate. This thesis offers two critical factors as explanations for the remarkable success of the capercaillie’s reintroduction to Scotland in the 19th century. The first is the method by which the reintroduction was carried out; specifically, the re-establishment of a series of capercaillie sub-populations in different regions of Scotland.
4

Nutritional and genetic adaptation of galliform birds: implications for hand-rearing and restocking

Liukkonen-Anttila, T. (Tuija) 17 May 2001 (has links)
Abstract The impact of hand-rearing on the morphology and physiology of captive and wild grey partridges (Perdix perdix) and capercaillies (Tetrao urogallus) was studied in three feeding trials conducted under laboratory conditions, and two comparative studies between wild and captive birds. Finally, wild and hand-reared grey partridges from several localities in Europe were sampled and the control region 1 of mitochondrial DNA was sequenced to reveal genetic variation between populations, as well as to compare wild and captive stocks. Wild capercaillies had heavier pectoral muscles, hearts, livers and gizzards, longer small intestines than hand-reared ones, and a higher cytochrome-c oxidase activity in muscle and heart. Invertebrates were essential to the growth, primary and temperature regulation development in grey partridge chicks. Fish was not sufficient to replace invertebrates in the diet. A change in diet from commercial to natural decreased the assimilation efficiency in the grey partridge. It also increased the mass of gizzard reflecting the need for greater grinding ability. Of hepatic P450 enzymes used in this study 7-ethoxyresorufin-0-deethylase and 7-pentoxyresorufin-0-deethylase differed between wild and hand-reared birds. Coumarin-7-hydroxylase activity was higher in grey partridges than capercaillies. Diet differences may have caused these differences. Quebracho tannin added to the diet lowered nitrogen concentration in caecal feces, and elevated the level of excreted tannin. Otherwise its effects were slight. Mitochondrial control region revealed 14 variable sites between two main lineages detected. Nucleotide and haplotype diversities varied greatly between populations. The markedly deep divergence between the two lineages indicated most probably post-glacial recolonisations from geographically isolated refuges. In Finland, wild birds represented the eastern lineage, while the farmstock represented the western lineage. Surprisingly little trace, contrary to expectations, from the large-scale releasing of imported partridges could be seen in the European populations.
5

FOREST LANDSCAPE STRUCTURE OF CAPERCAILLIE (TETRAO UROGALLUS) LEK SITES IN NORTHERN SWEDEN : Analysis of lek site characteristics / Landskapsstruktur för tjäderspelplatser i norra Sverige: analys av spelplatsens egenskaper

Blomgren, Agnes January 2023 (has links)
The purpose of this study is to analyze which variables influence the capercaillie’s (Tetrao urogallus) selection of lek sites in northern Sweden by using remote sensing data. The lek site is a crucial area for the species’ reproductive success. Studies outside of northern Sweden have confirmed that the landscape structure highly influences the selection of lek sites. This study examines whether the type of vegetation, forest volume and proximity to anthropogenic disturbances influence the selection of lek sites. The findings can be used to create a prioritizing map of northern Sweden to aid in conservation management and improve future inventories. 58 lek sites within five different counties were analyzed by a use-availability design, using a generalized linear mixed model with a binary distribution of the dependent variables. The vegetation types of pine forest, wet pine forest, continuous pine forest, mixed coniferous forest and wet other mixed forest were preferred by capercaillie, while other mixed forest, mire, continuous other forest, young forest, and clear cuts were avoided. Wet pine forest was the only vegetation type that had higher probability (36%) to be chosen over pine forest. For forest volume, the probability of being chosen increased with 22 % for each additional unit (m3/ha). For distance to buildings and roads, the probability of being chosen increased with 10 % for each additional unit of distance. I conclude that vegetation type, forest volume and proximity to anthropogenic disturbances influence the capercaillie selection of lek sites in northern Sweden.
6

Host–parasite interactions of boreal forest grouse and their intestinal helminth parasites

Isomursu, M. (Marja) 29 January 2014 (has links)
Abstract Parasites are an inseparable part of the life of wild birds. They may cause morbidity, mortality or reduction in fecundity. Parasite distribution in hosts is typically not uniform and many host factors (e.g. age) may affect the pattern of distribution. Under certain conditions, parasites even have the potential to regulate the host population. The grouse species of Finnish forests — the capercaillie Tetrao urogallus , the black grouse Lyrurus tetrix and the hazel grouse Tetrastes bonasia — harbour several species of intestinal helminth parasites. The populations have fluctuated in cyclic manner but the mechanisms behind the cycles are largely unknown. I studied the interactions of forest grouse and their intestinal helminth parasites by using intestinal samples collected by hunters in five game management districts during eight years (1995–2002). The most common parasite species in the samples was the nematode Ascaridia compar. Also, three species of cestodes (Skrjabinia cesticillus, Paroniella urogalli and Hymenolepis sp.) were found. Large size, male gender and age over 1 year were connected with an increased probability and intensity of A. compar infection. Juvenile grouse were commonly infected with cestodes while in adults infections were quite rare. The influence of inbreeding on the susceptibility to parasite infections was studied in the capercaillie by analysing microsatellite heterozygosity. The less heterozygous birds were more likely to be infected with A. compar and were more intensely infected suggesting negative influence of inbreeding on parasite resistance. An indirect negative effect of parasites was found by comparing bags hunted with a trained dog or without a dog. Grouse infected by cestodes were significantly more common in the dog-assisted bag. Thus, cestode infection seemed to make grouse more vulnerable to canine predation. The interaction between grouse population dynamics and parasites was studied by analyzing the grouse densities obtained from annual wildlife counts and parasite indices. A. compar was most common and most abundant in the years of grouse population decline. The grouse population growth rate was negatively correlated with the annual mean abundance of A. compar. Relative survival but not breeding success decreased as the abundance of A. compar increased. The findings suggest that A. compar influences the dynamics of Finnish grouse even though regular cyclic dynamics are no longer evident. / Tiivistelmä Loiset kuuluvat erottamattomana osana luonnonvaraisten lintujen elämään. Ne voivat aiheuttaa sairautta, kuolleisuutta tai hedelmällisyyden alentumista. Tyypillisesti loiset ovat levinneet isäntäpopulaatioon epätasaisesti ja monet isännän ominaisuudet (esim. ikä) vaikuttavat levinneisyyteen. Tietyissä oloissa loiset voivat jopa säädellä isäntäpopulaatiotaan. Suomalaiset metsäkanalinnut — metso Tetrao urogallus, teeri Lyrurus tetrix ja pyy Tetrastes bonasia — ovat useiden suolistoloismatolajien isäntiä. Metsäkanapopulaatiot ovat vaihdelleet syklisesti, mutta syklejä aiheuttavat mekanismit ovat yhä tuntemattomia. Tutkin metsäkanalintujen ja niiden suolistoloisten välisiä vuorovaikutuksia käyttäen metsästäjien vuosina 1995–2002 viidestä eri riistanhoitopiiristä keräämiä suolistonäytteitä. Yleisin loislaji näytteissä oli kanalintusuolinkainen, Ascaridia compar. Myös kolme heisimatolajia (Skrjabinia cesticillus, Paroniella urogalli ja Hymenolepis sp.) todettiin. Suuri koko, koirassukupuoli ja yli yhden vuoden ikä olivat yhteydessä suurempaan kanalintusuolinkaistartunnan todennäköisyyteen ja voimakkuuteen. Nuorilla (alle 1 v.) linnuilla heisimadot olivat yleisiä, kun taas aikuisilla tartunnat olivat varsin harvinaisia. Sisäsiittoisuuden vaikutusta loistartuntaherkkyyteen tutkittiin metsolla mikrosatelliittiheterotsygotian perusteella. Vähemmän heterotsygoottiset metsot olivat todennäköisemmin ja voimakkaammin suolinkaisten infektoimia, mikä viittaa sisäsiittoisuuden negatiiviseen vaikutukseen loisten vastustuskykyyn. Loisten epäsuora haitallinen vaikutus havaittiin, kun verrattiin koiran kanssa ja ilman koiraa metsästettyä lintusaalista. Heisimadot olivat selvästi yleisempiä linnuilla, jotka oli metsästetty koiran kanssa kuin ilman koiraa metsästetyillä. Heisimatotartunta näytti siis altistavan metsäkanoja koiraeläinten saalistukselle. Metsäkanalintu- ja loispopulaatioiden välistä vuorovaikutusta tutkittiin analysoimalla vuosittaisia metsäkanatiheyksiä ja loisten runsautta. Kanalintusuolinkainen oli yleisimmillään ja runsaimmillaan metsäkanatiheyden laskuvuosina. Metsäkanapopulaation vuosittainen kasvuvauhti korreloi negatiivisesti kanalintusuolinkaisen vuosittaisen runsauden kanssa. Suhteellinen elossasäilyvyys laski kanalintusuolinkaisen runsauden lisääntyessä, mutta lisääntymistuloksen suhteen ei ollut samaa ilmiötä. Löydökset viittaavat siihen, että kanalintusuolinkaisella on vaikutusta suomalaisten metsäkanalintukantojen vaihteluihin, vaikka syklisiä kannanvaihteluja ei enää havaitakaan.
7

Modélisation de l'habitat des tétraonidés dans le massif du Jura : apport de la télédétection LiDAR aéroportée / Habitat modeling of Tetraonidae in the Jura massif : contribution of LiDAR airborne remote sensing

Glad, Anouk 14 December 2018 (has links)
Dans le contexte général de l’érosion de la biodiversité, deux espèces d’oiseaux forestiers, le Grand Tétras (Tetrao urogallus) et la Gélinotte des bois (Bonasa bonasia), présentes dans le massif Jurassien sont menacées par la perte et la fragmentation de leur habitat à l’échelle régionale. En particulier, dans le massif Jurassien l’extension progressive des tâches de régénération du hêtre induit la transformation du couvert végétal constitué de myrtilles et d’herbacées favorable en un habitat fermé défavorable. Le destin de ces deux espèces emblématiques dépend pour la première d’actions de gestions et pour la seconde d’une meilleure connaissance de la distribution et de la dynamique des populations. La coupe des zones de régénération fait partie des principales actions envisagées pour restaurer l’habitat forestier. Cependant ces actions de gestion ou de suivi des populations sont couteuses en temps et en argent. Ainsi, l’opportunité d’utiliser deux jeux de données LiDAR (Light Detection and Ranging) couvrant la majorité de l’aire de distribution des deux espèces dans le massif Jurassien a initié le projet de cartographie des habitats de chaque espèce et de la présence des tâches de régénération du hêtre en utilisant des modèles de distribution d’espèces (SDMs). L’objectif est de soutenir les gestionnaires dans leurs décisions et actions grâce à la production de prédictions spatiales adaptées. La réalisation de cet objectif dépend de la fiabilité des modèles produits, mais aussi de la bonne transmission des résultats par le chercheur aux gestionnaires qui ne sont pas familiers avec les méthodes utilisées. Dans un premier temps, le choix d’une méthode de modélisation appropriée (correction du biais d’échantillonnage, échelles, algorithmes) par rapport aux caractéristiques des jeux de données et aux objectifs a été évalué. Dans un second temps, l’utilisation de variables environnementales LiDAR orienté-objet (arbres et trouées) pour faciliter l’appropriation des résultats par les gestionnaires a été testée. Enfin, les résultats obtenus ont permis la création de modèles multi-échelles et de carte de prédictions pour chacune des espèces démontrant la capacité du LIDAR de représenter la structure de la végétation qui influence la présence des espèces d’oiseaux forestières étudiées. Des modèles de distribution de la régénération du hêtre ont pu aussi être créés à une échelle fine. / In the general context of biodiversity erosion, two forest bird species occurring in the French Jura massif, the Capercaillie (Tetrao urogallus) and the Hazel Grouse (Bonasa bonasia), are threatened by habitat loss and fragmentation at the regional scale. In particular, intensive beech regeneration patches extension in the Jura massif is leading to the transformation of the understory cover, once suitable with bilberry and herbaceous vegetation, to closed unfavorable habitat. The fate of those two emblematic species is depending for the first on future management actions and for the second on a better knowledge of the species population’s dynamics and occurrences. In particular, the cutting of the beech regeneration patches is one of the efficient management actions undertaken to restore the habitat. However, management actions and surveys are money and time consuming due to the large area that need to be covered. The opportunity to use two Light Detection and Ranging (LiDAR) datasets covering a major part of the distribution of the two species in the Jura massif initiated the phD project, with the objective to support managers in their decisions and actions by the creation of adapted distribution predicted maps using Species Distribution Models (SDMs) (Hazel Grouse, Capercaillie and beech regeneration). The realization of this objective is depending on the reliability of the models produced and on the capacity of the researcher to transfer the results to managers who are not familiar with modeling methods. In a first step, the choice of the appropriate modeling method regarding the datasets characteristics and the objectives was investigated (sampling bias correction, scales, and algorithms). In addition, the use of object-oriented LiDAR predictors (trees and gaps) pertinent from both species and managers point of view to facilitate the results transfer was tested. The results obtained were used to create appropriate multi-scale SDMs and to predict distribution maps for both target species, demonstrating the capacity of LiDAR to represent vegetation structures that influence the targeted forest bird species occurrences. Models at a fine scale were also created to map the beech regeneration distribution in the Jura massif.

Page generated in 0.0734 seconds