151 research outputs found
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Depleted suburban house sparrow Passer domesticus population not limited by food availability
Are changes in breeding habitat responsible for recent population changes of long-distance migrant birds?
Capsule: The direction and magnitude of changes in structure of UK woodlands since the 1980s, are inconsistent with them playing a causative role in the declines of four migrant bird species in upland oak woods. /
Aims: To investigate whether changes in woodland structure were a possible cause of population changes of four Afro-Palearctic migrants (Wood Warbler Phylloscopus sibilatrix, Tree Pipit Anthus trivialis, Pied Flycatcher Ficedula hypoleuca and Common Redstart Phoenicurus phoenicurus) in the upland oakwoods of western and northern Britain. /
Methods: Bird population estimates and measures of woodland structure were recorded in two time periods 1982–85 and 2003–04 across six regions of the UK. We modelled the effect of habitat change and initial habitat state on population changes between the two time periods. The predicted effects of habitat change on populations were then compared with observed population changes across the different regions. /
Results: All four species underwent population declines; there were also significant increases in ground cover and understorey cover. The number of birds in 2003–04 was influenced by habitat structure at this time in addition to showing regional differences. Change in bird numbers varied between regions and was affected by both the initial habitat state and change in habitat structure, with regional variation in the effect of habitat change. There was however no relationship between the predicted effect of change in habitat structure on population size and observed regional population changes. /
Conclusions: Changes in woodland structure are unlikely to be the main driver of population change in these four migrant bird species, and large-scale factors affecting demographics in other parts of their breeding range or in their wintering areas are likely reasons for local population declines
Habitat characteristics of wintering Wood Warbler Phylloscopus sibilatrix in the Centre Region of Cameroon: conservation implications
Populations of many Afro-Palearctic birds have declined, with those wintering in sub-Saharan Africa, such as Wood Warbler Phylloscopus sibilatrix, particularly affected. In this study we investigated the relationship between habitat characteristics and Wood Warbler presence/absence in the Centre Region of Cameroon. A total of six transects were established in three habitat types (forest, forest–savanna transitional zone and savanna). Call playback surveys were conducted monthly from November 2015 to April 2016 to determine Wood Warbler presence/absence. Detailed habitat measurements were also recorded in each transect. A total of 86 responses were recorded: 33 (mean 6.6 ± 2.3) in forest habitat, 47 (mean 9.4 ± 3.36) in the forest–savanna transitional zone, and 6 (mean 2 ± 1.1) in savanna habitat. Wood Warbler presence increased significantly with the number of trees between 3 and 7 m in height, and decreased significantly with the number of shrubs between 0.5 and 3 m in height. Anthropogenic disturbance such as the agricultural cycle and burning were not found to have an effect on Wood Warblers presence/absence. We conclude that Wood Warblers overwinter in all three habitat types with probability of detection greatest in the forest–savanna transitional habitat with a relatively low canopy and an open understorey. Forest clearance in sub-Saharan Africa potentially threatens wintering habitat for Wood Warblers
Out of sight but not out of harm’s way: human disturbance reduces reproductive success of a cavity-nesting seabird
While negative effects of human disturbance on animals living above the ground have been widely reported, few studies have considered effects on animals occupying cavities or burrows underground. It is generally assumed that, in the absence of direct visual contact, such species are less vulnerable to disturbance. Seabird colonies can support large populations of burrow- and cavity-nesting species and attract increasing numbers of tourists. We investigated the potential effects of recreational disturbance on the reproductive behaviour of the European storm petrel <i>Hydrobates pelagicus</i>, a nocturnally-active cavity-nesting seabird. Reproductive phenology and outcome of nests subject to high and low levels of visitor pressure were recorded in two consecutive years. Hatching success did not differ between disturbance levels, but overall nestling mortality was significantly higher in areas exposed to high visitor pressure. Although visitor numbers were consistent throughout the season, the magnitude and rate of a seasonal decline in productivity were significantly greater in nests subject to high disturbance. This study presents good evidence that, even when humans do not pose a direct mortality risk, animals may perceive them as a predation risk. This has implications for the conservation and management of a diverse range of burrow- and cavity-dwelling animals. Despite this reduction in individual fitness, overall colony productivity was reduced by ≤1.6% compared with that expected in the absence of visitors. While the colony-level consequences at the site in question may be considered minor, conservation managers must evaluate the trade-off between potential costs and benefits of public access on a site- and species-specific basis
Spatial behavior and habitat use in widely separated breeding and wintering distributions across three species of long-distance migrant <i>Phylloscopus</i> warblers
Aim: To investigate the ecological relationship between breeding and wintering in specialist and generalist long-distance migratory species, and the links between densities and range sizes. Location: Denmark, Senegal and Ghana. Methods: We use radio tracking to study spatial behavior and habitat use in three morphologically and ecologically similar and closely related Phylloscopus species on their widely separated breeding and wintering distributions. During wintering and breeding, willow warblers P. trochilus (winter: n = 9, breeding: n = 13), chiffchaffs P. collybita (n = 11, n = 7), and wood warblers P. sibilatrix (n = 17, n = 14) were tracked. Results: Willow warblers P. trochilus increased home range sizes in winter, whereas it was similar in chiffchaffs P. collybita and wood warblers P. sibilatrix, in both seasons. Home ranges overlapped more in winter than in the breeding season. In winter, home range overlap was similar among species but larger overlap during breeding was indicated for willow warblers. Tree cover was unrelated to home range size but significantly higher in breeding than in winter in all species. However, whereas willow warblers and wood warblers maintained some degree of tall tree cover inside their home ranges in winter, chiffchaffs changed from more than 80% to <1% tree cover, indicating a niche shift. Main conclusions: Individuals of all three species showed changes between breeding and wintering areas in spatial behavior and habitat availability, with larger overlap in winter. The differences in patterns were potentially related to being generalist (willow warbler) or specialist (chiffchaff and wood warbler). These ecological relationships are important for the conservation of migrants and for understanding the link between breeding and wintering distributions and ecology
Centro de innovación y transferencia tecnológica de Paja Toquilla y OrfebrerÃa en el Distrito de Catacaos - Piura 2020
Hoy en dÃa, la ciudad de Catacaos carece de equipamiento donde los
cataquenses puedan obtener la capacitación adecuada para el mejoramiento de
sus habilidades, tampoco posee un ambiente ideal para el comercio y difusión
cultural. Debido a este problema, se propone un Centro de Innovación y
Transferencia Tecnológica (CITE) en el cual se aumente y refuerce este sector en
base a generar carreras técnicas artesanales que cumplan con las necesidades
de la ciudad de Catacaos mediante una estructura y un orden y asà impulsando el
desarrollo artesanal con un enfoque responsable.
En el proyecto nos podemos dar cuenta que implica la captación de la población
local hacia esta zona mediante actividades artÃsticas tradicionales, como la
artesanÃa de paja toquilla y la orfebrerÃa. También se tendrá en cuenta el
esparcimiento para generar espacios de compra y venta de los productos.
Además, el cite no solo albergarÃa artesanos locales, sino además de otras zonas
aledañas como Simbilá, La Unión, Piura, etc. quienes no han recibido ningún tipo
de capacitación y no cuentan con las condiciones necesarias. La educación es
local y se da en espacios poco frecuentes, de uso común y las ventas son en las
calles de la ciudad.
El plan de Desarrollo Concertado de Catacaos promueve la participación
artesanal en ferias tanto nacionales como internacionales. El CITE buscará
proponer sus ambientes para que se realicen dichos eventos dotándolo de
equipamiento necesario.
La finalidad de este proyecto es analizar e identificar la situación actual por la que
atraviesan los artesanos de Catacaos, solucionando mediante un proyecto de
arquitectura que cumpla con las necesidades, sirva de ejemplo para el desarrollo
artesanal mediante reforzar y educar artesanos competentes y protagonistas de
su propio desarrollo en este mundo.Today, the city of Catacaos lacks equipment where Cataquenses can obtain
adequate training to improve their skills, nor does it have an ideal environment for
trade and cultural dissemination. Due to this problem, a Center for Innovation and
Technology Transfer (CITE) is proposed in which this sector is increased and
strengthened based on generating artisanal technical careers that meet the needs
of the city of Catacaos through a structure and an order and thus promoting
artisanal development with a responsible approach.
In the project we can realize that it involves attracting the local population to this
area through traditional artistic activities, such as toquilla straw crafts and
goldsmithing. Recreation will also be taken into account to generate spaces for the
purchase and sale of products.
In addition, the cite would not only house local artisans, but also other nearby areas
such as Simbilá, La Unión, Piura, etc. who have not received any type of training
and do not have the necessary conditions. Education is local and takes place in
infrequent spaces, of common use and sales are in the streets of the city.
The Catacaos Concerted Development plan promotes artisan participation in both
national and international fairs. The CITE will seek to propose its environments so
that these events can be held, providing it with the necessary equipment.
The purpose of this project is to analyze and identify the current situation that the
artisans of Catacaos are going through, solving it through an architecture project
that meets the needs, serves as an example for artisan development by reinforcing
and educating competent artisans and protagonists of their own development in
this worldTesi
Accounting for predator species identity reveals variable relationships between nest predation rate and habitat in a temperate forest songbird.
Nest predation is the primary cause of nest failure in most ground-nesting bird species. Investigations of relationships between nest predation rate and habitat usually pool different predator species. However, such relationships likely depend on the specific predator involved, partly because habitat requirements vary among predator species. Pooling may therefore impair our ability to identify conservation-relevant relationships between nest predation rate and habitat. We investigated predator-specific nest predation rates in the forest-dependent, ground-nesting wood warbler Phylloscopus sibilatrix in relation to forest area and forest edge complexity at two spatial scales and to the composition of the adjacent habitat matrix. We used camera traps at 559 nests to identify nest predators in five study regions across Europe. When analyzing predation data pooled across predator species, nest predation rate was positively related to forest area at the local scale (1000 m around nest), and higher where proportion of grassland in the adjacent habitat matrix was high but arable land low. Analyses by each predator species revealed variable relationships between nest predation rates and habitat. At the local scale, nest predation by most predators was higher where forest area was large. At the landscape scale (10,000 m around nest), nest predation by buzzards Buteo buteo was high where forest area was small. Predation by pine martens Martes martes was high where edge complexity at the landscape scale was high. Predation by badgers Meles meles was high where the matrix had much grassland but little arable land. Our results suggest that relationships between nest predation rates and habitat can depend on the predator species involved and may differ from analyses disregarding predator identity. Predator-specific nest predation rates, and their relationships to habitat at different spatial scales, should be considered when assessing the impact of habitat change on avian nesting success
Evidence for strain-specific virulence of <i>Trichomonas gallinae</i> in African columbiformes
Infection by parasites or pathogens can have marked physiological impacts on individuals. In birds, infection may affect moult and feather growth, which is an energetically demanding time in the annual cycle. Previous work has suggested a potential link between clinically visible Trichomonas gallinae infection and wing length in turtle doves Streptopelia turtur arriving on breeding grounds. First, T. gallinae infection was characterized in 149 columbids from 5 species, sampled on turtle dove wintering grounds in Senegal during the moulting period, testing whether infection by T. gallinae is linked to moult. Trichomonas gallinae prevalence was 100%, so rather than testing for differences between infected and uninfected birds, we tested for differences in moult progression between birds infected by different T. gallinae strains. Twelve strains of T. gallinae were characterized at the internal transcribed spacer 1 (ITS1)/5.8S/ITS2 region, of which 6 were newly identified within this study. In turtle doves only, evidence for differences in wing length by strain was found, with birds infected by strain Tcl-1 having wings nearly 6 mm longer than those infected with strain GEO. No evidence was found for an effect of strain identity within species on moult progression, but comparisons between infected and uninfected birds should be further investigated in species where prevalence is lower
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