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Artykuły w czasopismach na temat "White-backed"
1
Kallioinen, RUO, JM Hughes i PB Mather. "Significance of Back Colour in Territorial Interactions in the Australian Magpie". Australian Journal of Zoology 43, nr 6 (1995): 665. http://dx.doi.org/10.1071/zo9950665.
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In eastern Australia, two forms of the Australian magpie occur: a white-backed form and a black-backed form. These two forms hybridise across northern Victoria and into South Australia. In this study the response of territorial magpies to caged intruders was examined. Pairs of adult male magpies were introduced into territories. Both were adult black-backed birds, but in each case one of them had its back painted white. The pair was introduced to each territory twice, with the bird that was painted white differing between times. The experiment was run in a population of black-backed birds and a population in the hybrid zone containing white-backed, black-backed and hybrid birds. In both cases, the residents were more aggressive towards the intruder with the white-back than they were to the black-backed intruder. We suggest that this may be because a white-backed bird posed more of a threat to residents than a black-backed bird.
2
Litwińczuk, Zygmunt, Witold Chabuz, Piotr Domaradzki i Przemysław Jankowski. "Slaughter Value of Young Polish Black-and-White, White-Backed, Polish Holstein-Friesian and Limousin Bulls Under Semi-Intensive Fattening". Annals of Animal Science 12, nr 2 (1.03.2012): 159–68. http://dx.doi.org/10.2478/v10220-012-0013-7.
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Slaughter Value of Young Polish Black-and-White, White-Backed, Polish Holstein-Friesian and Limousin Bulls Under Semi-Intensive FatteningThe objective of the present study was to compare the slaughter value of young bulls of two breeds included in the genetic resources conservation programme, namely Polish Black-White and White-backed with young Polish Holstein-Friesian (dairy type) and Limousin (beef type) bulls. This is the first study to evaluate the meat performance traits of White-backed cattle in several-centuries history of the breed in Poland. It was determined that populations of White-backed and Polish Black-and-White cattle represent the dual-purpose type desirable in the genetic resources conservation programme. The indices obtained for the analysed traits of slaughter value from young Polish Black-and-White and White-backed bulls were intermediate between Polish Holstein-Friesian (dairy type) and Limousin (beef type), but closer to those of the Polish Holstein-Friesian breed. The analysed muscles of young bulls had a very similar content of basic chemical components. The relatively high amount of proteins (22.85-23.23%) in musculus longissimus lumborum and in musculus semintendinosus (22.43-23.06%) should be emphasized.
3
Martikainen, Petri, Lauri Kaila i Yrjo Haila. "Threatened Beetles in White-Backed Woodpecker Habitats". Conservation Biology 12, nr 2 (26.04.1998): 293–301. http://dx.doi.org/10.1046/j.1523-1739.1998.96484.x.
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Martikainen, Petri, Lauri Kaila i Yrjö Haila. "Threatened Beetles in White-Backed Woodpecker Habitats". Conservation Biology 12, nr 2 (7.07.2008): 293–301. http://dx.doi.org/10.1111/j.1523-1739.1998.96484.x.
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Gussoni, Carlos Otávio A., i André C. Guaraldo. "Comportamento de forrageamento do pernilongo-de-costas-brancas, Himantopus melanurus (Vieillot, 1817) (Aves: Recurvirostridae) em Santa Gertrudes, SP, Brasil". Lundiana: International Journal of Biodiversity 7, nr 2 (28.06.2007): 149–50. http://dx.doi.org/10.35699/2675-5327.2006.23155.
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The foraging behavior of two White-backed stilts (Himantopus melanurus) was studied in a lake at the municipality of Santa Gertrudes, state of São Paulo, Brazil. The foraging strategies observed were classified in two categories: pluging (65.8% of total maneuvers) and pecking (34.3%). Only in 26.8% of the foraging maneuvers the individuals captured preys (72.9% by plunging and 27.1% by pecking). When comparing both strategies, plunging was successful 29.7% of the times, but pecking only 21.2%. At the study site, individuals foraged only up to 20 m away from the lake margin. The foraging area exploited by the White-backed stilts was estimated in about 720 m2. Foraging activities lasted since before sunrise until after sunset.
Keywords: White-backed stilt, foraging behavior, plunging, pecking.
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Ouellet, Martin, i Jean-David Moore. "Silver-white Variants of the Eastern Red-backed Salamander, Plethodon cinereus, from Eastern Canada". Canadian Field-Naturalist 130, nr 2 (1.04.2016): 133. http://dx.doi.org/10.22621/cfn.v130i2.1835.
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The Eastern Red-backed Salamander (Plethodon cinereus) is well known for its colour polymorphism, which includes 8 colour phenotypes: the red-backed (striped), lead-backed (unstriped), and erythristic morphs, as well as the iridistic, albino, leucistic, amelanistic, and melanistic anomalies. Among these, the prevalence and geographic distribution of rare morphs have received little attention. In this article, we report 2 occurrences of silver-white variants of the red-backed morph of P. cinereus from Québec, Canada. To our knowledge, these variations in stripe colour on the red-backed phenotype represent the first 2 documented mentions for eastern Canada.
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Sætersdal, Magne, Ivar Gjerde i Einar Heegaard. "Woodpeckers in Western Norway: the White-backed Woodpecker is still the most common species". Ornis Norvegica 42 (25.10.2019): 28–35. http://dx.doi.org/10.15845/on.v42i0.2658.
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The pine-dominated forests of Western Norway have been found to harbour viable populations of woodpeckers, including the highly specialized White-backed Woodpecker Dendrocopos leucotos. The aim of this study was to investigate to what extent there were any changes in frequencies of woodpeckers, in particular the White-backed Woodpecker and the Grey-headed Woodpecker Picus canus, by resurveying 60 plots (each 1 km2) originally surveyed during 1994/1995. The resurvey was performed in 2013/2014. The White-backed Woodpecker was found to be the most common woodpecker species in both time periods. The Grey-headed Woodpecker was found to have a statistically significant decline from 27% of the 60 plots in 1994/95 to only 12% in 2013/14. The other four species all increased in frequency; although none of those increased frequencies were found to be statistically significant. We discuss possible explanations to why pine forests in Western Norway constitute a valuable habitat for the White-backed Woodpecker at the same time as it has drastically declined in other parts of Norway and Western Europe. In general, the reduced frequency of Grey-headed Woodpecker is not fully understood, although we suggest that cold winters during the years prior to the surveys in 2013/14 may be an important factor.
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Priyadharshini, V., R. Ayyasamy i C. Kathirvelu. "Bioefficacy of ethiprole + pymetrozine against the white-backed planthopper Sogatella furcifera (Howard), in rice (ADT – 46)". Journal of Applied and Natural Science 14, nr 1 (20.03.2022): 73–82. http://dx.doi.org/10.31018/jans.v14i1.3185.
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The nymphs and adults of white-backed planthoppers (Sogatella furcifera, Howard) remove plant sap resulting in yield loss. Indiscriminate use of insecticides, results in the development of resistance by insects and ill effects on the environment opening the new era of chemicals with novel modes of action with good bioefficacy, higher selectivity, low mammalian toxicity and safety to the environment. Therefore, the introduction of newer insecticide molecules with alternate modes of action will play a serious role in pest management programs. Hence, an experiment was conducted to evaluate the bioefficacy of ethiprole + pymetrozine against white-backed planthopper of rice (ADT – 46) under laboratory and field conditions at Annamalai University, Chidambaram during 2018-20. Ethiprole + pymetrozine @ (T1 - 36.91 + 138), (T2 - 40.13 + 150) and (T3 - 45.47 + 170) g a.i ha-1 with standard checks T4 - pymetrozine @ (150) g a.i ha-1, T5 - buprofezin @ (200) g a.i ha-1 and T6 - ethiprole + imidacloprid @ (50 + 50) g a.i ha-1 were evaluated against white-backed planthopper. The standard checks were of positive control i.e., reference insecticides which is in common use The results revealed that T3 recorded the lowest population of white-backed planthopper/hill at 15 day after spraying (1.13 hoppers/hill in August – December 2018 and 1.79 hoppers/hill in August – December 2019 respectively) giving better yield. The population of natural enemies was comparatively lower in all insecticidal treatments than in the control.
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M. SHAMIM, A. M. SHEKH, V. J. PATEL, J. F. DODIA, D. M. KORAT i A. M. MEHTA. "Effect of weather parameters on population dynamics of green leaf hopper and white backed plant hopper in paddy grown in middle Gujarat region". Journal of Agrometeorology 11, nr 2 (1.12.2009): 172–74. http://dx.doi.org/10.54386/jam.v11i2.1247.
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Nephotettix virescens Distant and Sogatella furcifera (Horv) commonly known as Green leaf hopper (GLH) and White backed plant hopper (WBPH) respectively. These are the serious pests of kharif paddy all over the world causing extensive losses. The population dynamics of Green leaf hopper and white backed plant hopper for ten consecutive years (1994 to 2004) except for 1997 were correlated with the weather parameters like maximum and minimum temperature, rainfall, relative humidity and bright sunshine hours. The results revealed that the bright sunshine hours had a positive significant correlation (r=0.166) with the population dynamics of GLH. The correlation between WBPH peak population and bright sunshine hours also showed positive significantcorrelation (r=0.269), while maximum temperature, minimum temperature, rainfall and relative humidity showed non-significant effect on population build up of both GLH and WBPH. Green leaf hopper attained peak population during 43rdstandard meteorological week; whereas white backed plant hopper reached peak population during 39th standard meteorological week and decreased considerably thereafter.
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Ryan, Peter G. "Pink-backed Pelicans feeding communally with Great White Pelicans". Ostrich 75, nr 3 (wrzesień 2004): 168. http://dx.doi.org/10.2989/00306520409485431.
Pełny tekst źródłaRozprawy doktorskie na temat "White-backed"
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Stighäll, Kristoffer. "Habitat composition and restocking for conservation of the white-backed woodpecker in Sweden". Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-46073.
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In Sweden, intense human land use, especially forestry, has led to profound changes in the landscape over time, especially within the forest ecosystems. A consequence of this is that several specialist species have become endangered. One group of specialists is the woodpeckers. The middle spotted woodpecker became extinct in Sweden in 1982 and the white-backed woodpecker is today Sweden’s most critically endangered forest-living bird. The white-backed woodpecker is dependent on old deciduous forests, rich in dead wood. The woodpecker is areademanding and hence one of the best indicators or umbrella species for biodiversity in this region. A long-term goal within the conservation of the species is to be able to make more accurate predictions of what is needed in the species habitat to establish a viable population, both in terms of composition of landscape and breeding territories. In addition to earlier studies better tools are needed for measuring the distribution of suitable and potential habitats and finding faster ways of creating optimal habitats. In an attempt to secure the future existence of the white-backed woodpecker in Sweden, restocking of birds are carried out. This presupposes availability of suitable habitats as well as strong enough landscape. Due to intense forestry the presumption for the species is, as stated above, alarming. Comparing the different populations around the Baltic Sea and Norway, great differences but also similarities can be seen, in landscape as well as in territory composition. It seems that fragmentation of foraging patches as well as amount of dead deciduous wood within the breeding territory is critical matters. Grey alder stands in Sweden should have high priority in conservation of habitat for the species.Funding agency: Swedish Society for Nature Conservation (SSNC)
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Leepile, Leungo Boikanyo L. "Changes in nesting numbers and breeding success of African White-backed Vultures in northern Botswana". Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29737.
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African White-backed Vultures have recently been uplisted to Critically Endangered by the IUCN due to declines across their range mainly linked to high levels of poisoning. Botswana likely supports significant numbers of this species, but as yet there is no published information on their population trends or their breeding success in this country. However, in recent years within Botswana and neighbouring countries there have been multiple incidents of mass poisonings, which have resulted in the deaths of thousands of White-backed Vultures. I therefore expected that nesting numbers of this species may have declined in this region, with potential additional negative impacts to breeding success. I used information from aerial surveys conducted between 2006 and 2017 in Khwai and Linyanti, two of the most important breeding areas for this species in northern Botswana to examine changes in nesting numbers and breeding success. The results showed a 53.5% decline in nesting numbers from these colonies, from 99 pairs in 2007 to 46 in 2017; with a greater decline in Linyanti than in Khwai. In both areas breeding success was significantly lower in 2017 than it was ten years ago. Current breeding success rates were generally lower than for other populations in South Africa. A population viability analysis suggested that if the productivity levels detected in 2017 were a true indication of current levels of productivity for this population, and if recent poisoning rates continue, this population has a high probability of extinction in the next 5 to 13 years.
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Rankka, Elias. "Factors influencing the white-backed woodpeckers' (Dendrocopos leucotos) choice of feeding trees in the Umeå region". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187169.
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Saving the white-backed woodpecker (Dendrocopos leucotos) from extinction in Sweden has been an ongoing struggle for decades. Despite this, there have been remarkably few studies on the species ecology in Sweden, especially in the north. The aim of this study was to investigate if the white-backed woodpeckers living in the Umeå region show a preference regarding what kind of trees they use for foraging, based on the factors tree species, tree condition (dead/alive), and tree size. Data were gathered at three sites in the vicinity of the lower Umeå River region and was made up of holes left by the woodpeckers from excavating trees for food. By comparing the trees carrying these traces with a representative sample of remaining trees at the sites, a test for preference could be performed. The results from this study indicate that the local white-backed woodpeckers strongly favour trees of the Salix genus when deep-boring, and that they also have a preference for dead trees independent of species. No significant effect of tree size on foraging choice could be found, although this would ideally require further studies. These findings provide knowledge on the local behaviour of the white-backed woodpecker that could potentially be of importance for implementing precise conservation efforts for this area-demanding species.
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Durrant, Kate, i n/a. "The Genetic and Social Mating System of a White-Backed Population of the Australian Magpie (Gymnorhina tibicen tyrannica)". Griffith University. Australian School of Environmental Studies, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040716.093636.
Pełny tekst źródłaStreszczenie:
The Australian magpie (Gymnorhina tibicen) is a large, sedentary, omnivorous passerine. In some populations, individuals live in groups, and some of these groups breed cooperatively. The white-backed magpie (G. t. tyrannica) from the south-eastern corner of the continent, has had relatively little study, and few details are known of its mating system, social structure, and method of parental care. I conducted an observational study on a population of white-backed magpies, recording details of their demography, dispersal, breeding system, and parental care. In conjunction, I conducted a genetic analysis of the population, to determine if the genetic mating system matched the observed social system, to detect instances of extra-group mating, and to sex juvenile birds. Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. I made a comparison of extra-group paternity (EGP) rates between two races of the Australian magpie, to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. I predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie. The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season leave the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin. The reproductive success of a male bird is often correlated with measurable traits that predict his intrinsic quality. Females are thought to select mates based on their quality to gain their 'good genes'. Male Australian magpies of the white-backed race were trapped in two breeding seasons. Measurements were taken of morphometric and other characteristics in order to discover whether particular traits of males were associated with: a) number of fledglings produced in the territory per season; b) percentage of offspring sired in the territory; and c) whether females select males for their 'good genes'. The only variable that was correlated with number of territorial offspring was feather lice load. Males with high numbers of lice were less likely to produce territorial fledglings in one season and across both seasons. Males of inferior quality may be subject to increased conspecific territorial intrusions, leading to more time spent on defence, more failed breeding attempts, less time allocated to grooming and thus high parasite loads. Males that produced many territorial fledglings were more likely to gain genetic paternity of at least some of them, although again this was significant for only one season. Also, across both seasons, a high number of females in the group was correlated with increased paternity within the group. The general lack of correlation between the variables and level of genetic paternity may be due to females engaging in extra-group mating primarily to avoid breeding with a close relative rather than to choose a quality male. In this scenario, males would not have to be 'high quality', but merely genetically different to the female's social mate. Extra-group paternity (EGP) can affect paternal effort. It may also influence the helping effort of auxiliary birds in cooperatively breeding species. If helping is driven by kin selection, helpers should decline to provision unrelated young. Relatedness becomes difficult to assess however, when females mate outside the group. Alternative rewards may then become important in helper decisions. In my study population of Australian magpies, 38% of fledglings were sired by males outside the territorial group. In a second population (G. t. dorsalis), 82% of fledglings were sired by extra-group males. I observed within-group male and helper feeding effort over three breeding seasons in the first population and obtained data recorded over a single season in the second population. In both populations, males provisioned young regardless of relatedness, as did helpers. Males provisioned less than the nesting female on average. Paternal effort did not reduce with an increase in the rate of EGP between populations. In the population with intermediate levels of EGP, the white-backed magpies, I observed helpers in about half of the sampled territories that produced fledglings. Helpers did not increase the production of young. In the population with high levels of EGP, western magpies, I detected helping behaviour in proportionally more territories. It appears that Australian magpie helpers provide help in order to pay 'rent' and remain on the natal territory. I discuss these results in light of the differences between the two races of magpie and the major theories regarding male parenting decisions and helper activity. Finally, I examine the relatively high rates of EGP's in the Australian magpie from a phylogenetic perspective. Although inbreeding avoidance is strongly supported by this study as the major reason EGP is so common in magpie populations, there may be an element of phylogenetic inertia that maintains the frequency of this behavioural trait. I comment upon the use of single-population estimates of species EGP rates in comparative analyses, given the intraspecific variation discovered between Australian magpie populations. Future directions for the study of mate choice in the Australian magpie are outlined with a proposal to study variation at the major histocompatibility complex between mated pairs.
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Durrant, Kate. "The Genetic and Social Mating System of a White-Backed Population of the Australian Magpie (Gymnorhina tibicen tyrannica)". Thesis, Griffith University, 2004. http://hdl.handle.net/10072/366788.
Pełny tekst źródłaStreszczenie:
The Australian magpie (Gymnorhina tibicen) is a large, sedentary, omnivorous passerine. In some populations, individuals live in groups, and some of these groups breed cooperatively. The white-backed magpie (G. t. tyrannica) from the south-eastern corner of the continent, has had relatively little study, and few details are known of its mating system, social structure, and method of parental care. I conducted an observational study on a population of white-backed magpies, recording details of their demography, dispersal, breeding system, and parental care. In conjunction, I conducted a genetic analysis of the population, to determine if the genetic mating system matched the observed social system, to detect instances of extra-group mating, and to sex juvenile birds. Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. I made a comparison of extra-group paternity (EGP) rates between two races of the Australian magpie, to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. I predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie. The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season leave the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin. The reproductive success of a male bird is often correlated with measurable traits that predict his intrinsic quality. Females are thought to select mates based on their quality to gain their 'good genes'. Male Australian magpies of the white-backed race were trapped in two breeding seasons. Measurements were taken of morphometric and other characteristics in order to discover whether particular traits of males were associated with: a) number of fledglings produced in the territory per season; b) percentage of offspring sired in the territory; and c) whether females select males for their 'good genes'. The only variable that was correlated with number of territorial offspring was feather lice load. Males with high numbers of lice were less likely to produce territorial fledglings in one season and across both seasons. Males of inferior quality may be subject to increased conspecific territorial intrusions, leading to more time spent on defence, more failed breeding attempts, less time allocated to grooming and thus high parasite loads. Males that produced many territorial fledglings were more likely to gain genetic paternity of at least some of them, although again this was significant for only one season. Also, across both seasons, a high number of females in the group was correlated with increased paternity within the group. The general lack of correlation between the variables and level of genetic paternity may be due to females engaging in extra-group mating primarily to avoid breeding with a close relative rather than to choose a quality male. In this scenario, males would not have to be 'high quality', but merely genetically different to the female's social mate. Extra-group paternity (EGP) can affect paternal effort. It may also influence the helping effort of auxiliary birds in cooperatively breeding species. If helping is driven by kin selection, helpers should decline to provision unrelated young. Relatedness becomes difficult to assess however, when females mate outside the group. Alternative rewards may then become important in helper decisions. In my study population of Australian magpies, 38% of fledglings were sired by males outside the territorial group. In a second population (G. t. dorsalis), 82% of fledglings were sired by extra-group males. I observed within-group male and helper feeding effort over three breeding seasons in the first population and obtained data recorded over a single season in the second population. In both populations, males provisioned young regardless of relatedness, as did helpers. Males provisioned less than the nesting female on average. Paternal effort did not reduce with an increase in the rate of EGP between populations. In the population with intermediate levels of EGP, the white-backed magpies, I observed helpers in about half of the sampled territories that produced fledglings. Helpers did not increase the production of young. In the population with high levels of EGP, western magpies, I detected helping behaviour in proportionally more territories. It appears that Australian magpie helpers provide help in order to pay 'rent' and remain on the natal territory. I discuss these results in light of the differences between the two races of magpie and the major theories regarding male parenting decisions and helper activity. Finally, I examine the relatively high rates of EGP's in the Australian magpie from a phylogenetic perspective. Although inbreeding avoidance is strongly supported by this study as the major reason EGP is so common in magpie populations, there may be an element of phylogenetic inertia that maintains the frequency of this behavioural trait. I comment upon the use of single-population estimates of species EGP rates in comparative analyses, given the intraspecific variation discovered between Australian magpie populations. Future directions for the study of mate choice in the Australian magpie are outlined with a proposal to study variation at the major histocompatibility complex between mated pairs.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
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Huber, Ottar. "Lövskogsgynnande åtgärders effekt på vitryggig hackspett : En studie över hur lövskogsåtgärder påverkar födoinsekter för den vitryggiga hackspetten (Dendrocopos leucotos) i Västerbotten". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-174913.
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Due to heavily managed forests in Sweden, there has been a rapid decline of deadwood and deciduous-rich areas since the 1950s. As a result of this, 2000 forest species are now red-listed of which 700 is in heavy need of deadwood. The white-backed woodpecker Dendrocopos leucotos, an umbrella species whose food choice consists of insects living in dead and decaying wood, has become critically endangered due to the lack of food and nesting areas. Preservation actions aimed towards saving the white-backed woodpecker are not only essential for itself but for 200 other species dependent on the same environmental requirements. The purpose of this study was to determine if the restoration for deciduous trees has favoured the white-backed woodpecker in four different areas: Ängsbacka, Degersjön, Ålidberget, and Kvillträsk in Västerbotten. By placing two different kinds of insect traps (window traps, and malaise traps) to analyze the different insects in restoration areas compared with control areas, I could investigate if there had been an increase in the number of insects preferred by the white-backed woodpecker. I could also investigate if there was a higher diversity of these preferred insects. There was no sign of an increase in numbers of preferred insects nor in numbers of preferred species. A higher diversity could neither be proven, however all four forests were deciduous-rich with high amount of dead-wood and has proven to show good potential for a future increase in saproxylic insects if restoration continues.
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Phipps, W. L. (William Louis). "Spatial patterns of land-use by immature African white-backed vultures (Gyps africanus) captured in the North-West Province, South Africa". Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/24947.
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As obligate scavengers Gyps vultures provide an important ecosystem service as the main consumers of ungulate carcasses in African savannas. Throughout the continent, however, multiple threats are causing vulture populations to decline, especially outside protected areas. Although the African white-backed vulture Gyps africanus is the most numerous and widely distributed Gyps species in Africa, its foraging ecology and land use preferences remain poorly understood. Furthermore, while protected areas are known to be important for vultures in East and West Africa, their role in South Africa has not been fully investigated. This study uses GPS-GSM tracking units to investigate the movement and land-use patterns of six immature African white-backed vultures that were caught at Mankwe Wildlife Reserve in the North West Province of South Africa. Immature individuals were chosen because they were expected to travel extensively and be exposed to the full range of threats. The tracking units recorded the GPS location, speed, altitude and direction of travel three times per day. The size and extent of the vultures‟ foraging ranges were estimated using three methods: minimum convex polygons (MCPs), fixed kernel density estimation (KDE) and grid cell range (GCR) estimation. The vultures‟ use of protected areas and areas of different cattle densities (zero, low, medium and high) was assessed to determine whether they were visited more or less than expected based on the area they occupied within the vultures‟ foraging ranges. The distances travelled by the vultures and their flight speeds and altitudes were also calculated, as well as the amount of time that they spent in the vicinity of supplementary feeding sites. The vultures were tracked for between 101 and 313 days and the GPS tracking units acquired 99.44% of expected GPS locations. The vultures ranged extensively and generally travelled in a nomadic manner. While three individuals occupied foraging ranges (mean 95% KDE contour area = 106,282.33 km2) either side of the South African borders between Botswana and Zimbabwe, the other three travelled more extensively through southern Africa, entering six different countries (mean 95% KDE contour area = 563,564.67 km2). The vultures rarely visited protected areas in South Africa but two of the vultures regularly used protected areas in northern Botswana and Zimbabwe. Areas of high cattle density were used less than expected by all vultures, but not at a significant level, while two of the vultures used areas with zero cattle density more than expected due to their regular use of supplementary feeding sites in those areas. Areas of medium cattle density were the most regularly used, containing an average of 30.72% of each vulture‟s stationary GPS locations. The vultures travelled an average of 33 km/day and a maximum of 267 km/day, flying at an average of 50 km/h (maximum = 107 km/h) at 561 m above ground level (maximum = 2,267 m). This study provides the first description of movement and land-use patterns of immature African white-backed vultures tracked continuously from South Africa. Their extensive foraging ranges and limited use of protected areas implies that the vultures could potentially encounter the full range of threats in the region, and it is clear that their future conservation will depend upon conservation strategies that extend across international borders. CopyrightDissertation (MSc)--University of Pretoria, 2011.
Paraclinical Sciences
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Beverskog, Lynx. "Klassificering av skogar förvitryggig hackspettsmöjligheter till häckning vidnedre Dalälven". Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105479.
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Studien har använt ny metod för att klassificera vitryggig hackspetts skogarförutsättningar för häckande revir. 287 hektar skog värdeklassades med minstav värdeklass 1 (42 ha) och mest av värdeklass 2 (195 ha). Död ved måste ökaför att populationen av vitryggig hackspett ska öka. De åtgärder som behövergöras är ringbarkning och att minska granvolymen för att värdeklasserna ska nånästa värdeklass. Resultatet tyder på att förutsättningarna för häckningsrevir ärgoda, dock måste vissa restaureringar göras för att vitryggig hackspett skaetablera sig i området.
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Hallbäck, Christoffer. "Inmätning och utvärdering av potentiellt habitat för Dendrocopos leucotos vid Erken : Mätning och beräkning av mängden levande och döda lövträd". Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67597.
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Den vitryggiga hackspetten har sedan 1970 varit en starkt hotad art i Sverige tack vare förändrade habitat till följd av ett industrialiserat skogsbruk med stor fokus på barrträd vilket inte är ett optimalträd för den vitryggiga hackspetten. Idag finns det cirka 3 häckande par kvar i Sverige. I Finland och Lettland uppvisar den vitryggiga hackspetten en stark närvaro med en stor population då skogsbruket i dessa länder skiljer sig markant mot Sverige i form av typ av träd och hantering av död ved. Syftet med studien som utförts i den här rapporten är att bedöma om ett område vid sjön Erkens norra strand kallat Hasselhorn i Stockholms län uppnår de riktlinjer Naturvårdsverket har satt på minst 20m3/ha död lövved i trakten samt en medelålder på >80 år för att ett område ska anses vara ett optimalområde för den vitryggiga hackspetten. Fokustrakten identifierades med IR-bilder för att avgöra om området var rikt på lövträd och ett område på 110ha ritades in. Sextio stickprov slumpades ut i området där levande och döda träd mättes in med klave och höjdmätare för att beräkna m3/ha och ålder bedömdes visuellt för varje mätområde. Studien påvisar att Hasselhorn idag inte uppnår optimal status för alla parametrar som satts upp av Naturvårdsverket för att det ska utgöra ett lämpligt habitat för den vitryggiga hackspetten. Däremot uppnår området kravet på mer än 20m3/ha och mer än 75 % lövträd satta av Naturvårdsverket. Området uppnår dock inte medelåldern >80 år. Även artfördelningen i regionen av levande träd visar på mycket lite barrträd och stor tillgång på asp som anses vara det främsta trädet för födosök för den vitryggiga hackspetten som visar på att Hasselhorn kan uppnå god status inom ett fåtal år om särskilda naturvårdsåtgärder sker i området.The white-backed woodpecker has been a highly threatened in Sweden since 1970 due to drastically changed habitats as a result from industrialized forestry methods with a high focus on conifers. Today there are only 2 known breeding pairs left at Dalälven in Sweden. Compared to Finland and Latvia the white-backed woodpecker exhibits a strong presence with large populations as the forestry industry in these countries differs from Sweden in terms of what type of trees they use and how they manage dead wood. The purpose of this study is to assess whether an area at lake Erken’s northern shore called Hasselhorn in Stockholm County achieves the guidelines determined by Naturvårdsverket. Naturvårdsverket has determined that the white-backed woodpecker at least need 20m3/ha dead deciduous trees in a habitat and an average age of >80 years to be considered as an optimal area for the white-backed woodpecker. The focus area was localized with IR-images to determine an area rich with deciduous trees and an area of 100ha was drafted. Sixty sample points were randomized in the area. All living and dead trees at each points were measured with a tree caliper and clinometer to determine the amount of wood in m3/ha. Age was determined visually for each sample point. The study showed that Hasselhorn currently does no achieve the optimal status for all parameters in the study to make it a suitable habitat for the white-backed woodpecker. On the other hand, the area does meet the guideline set by Naturvårdsverket of more than 20m3/ha dead deciduous wood and more than 75% deciduous trees in the area, however it does not show an average age of >80 years. Species distribution of living deciduous trees exhibits large volumes of aspen, which is considered to be a main source of food since they contain the type of bugs preferred by the white-backed woodpecker. With the right conservation methods, the study shows that Hasselhorn can become a viable habitat for the white-backed woodpecker in the near future.
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Steinwall, Anders. "To do or not to do : dealing with the dilemma of intervention in Swedish nature conservation". Licentiate thesis, Umeå universitet, Statsvetenskapliga institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-128925.
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Nature conservation is often seen as being primarily about shielding parts of nature from human intervention, e.g. by protecting areas. Over the last decades, however, intervention is increasingly being seen as necessary for nature to regain or retain its values, through ecological restoration and active management. This complicates simple assumptions that ‘nature knows best’ and raises dilemmas which are hotly debated in the scholarly literature around ecological restoration, protected area management, environmental ethics and green political theory. However, how these dilemmas are dealt with in actual policy struggles among the conservation professionals who make management decisions is less studied. This thesis explores how issues regarding active intervention in nature are represented, debated and institutionalized within Swedish nature conservation, and to what effect. The empirical focus lies on policy struggles around the designation and management of protected forests and around efforts to save a nationally threatened bird species, the white-backed woodpecker. My analytical framework is informed by Argumentative Discourse Analysis and Political Discourse Theory, to which I contribute a further elaboration of the notion of discourse institutionalization. Based on documents and interviews with conservation professionals, I identify competing articulations of the ends and means of conservation and relate these to scholarly debates around ecological restoration and interventionist conservation management. The analysis further focuses on how elements of the different policy discourses are institutionalized in rules, routines or official policy documents. Two main competing policy discourses are found: one focused on leaving pristine nature to develop freely, and one focused on active, adaptive management for biodiversity. While the former has previously been said to characterize the Swedish conservation bureaucracy, my analysis shows it is now widely seen as outdated. Arguments which in the scholarly literature are associated with an ethically informed defense of nature’s autonomy are here dismissed as emotional, aesthetic and thus unscientific concerns, delegitimizing them within the rational, science-based public administration for nature conservation. In contrast, biodiversity is broadly forwarded as a self-evident goal for active intervention, in line with both science and policy requirements. Adaptive management for biodiversity is in that sense the dominant discourse. Still, the older discourse is institutionalized in the purposes and management plans of existing nature reserves, and its defenders have also succeeded in strengthening that institutionalization through new and more restrictive guidelines. The findings suggest that this has been possible not only because of the gate-keeping role of a few centrally placed actors, but also because their restrictive stance resonates with the outside threat of exploitation which organizes the common order of discourse. Naturalness, a term described as irrelevant by some proponents of adaptive management for biodiversity, is also shown to remain a shared concern in several ways. The results thus highlight the importance of both entrenched common sense and institutionalization of certain logics or arguments in authoritative documents. The main theoretical contribution of the thesis consists in clarifying the effects of such discourse institutionalization — using the terms durability, legibility and leverage — and showing how the processes of negotiation, re-interpretation and modification of institutions are more dynamic than some accounts of discourse institutionalization suggest. Rather than trying to resolve (and thus remove) the dilemma of intervention, the thesis points to the importance of keeping open discussion of the ultimately unanswerable questions about intervention in nature alive in both theory and practice.Ecosystem restoration in policy and practice: restore, develop, adapt (RESTORE)
Książki na temat "White-backed"
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Jefferson, Thomas A. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Bethesda, MD: Wildlife Society, 2000.
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Jefferson, Thomas A. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Bethesda, MD: Wildlife Society, 2000.
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Cardon, Nathan. Introduction. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190274726.003.0001.
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The introduction argues that the Atlanta and Nashville international expositions were spaces through which white and African American southerners exhibited themselves as modern citizens committed to joining the nation in an imperial future. For the New South ideologues who backed the fairs, the expositions were more than celebratory carnivals advertising the region’s resources; they were didactic events that would modernize the region’s rural population and convince the world of the South’s modernity. The introduction contextualizes the fairs within the New South, provides a history of Atlanta and Nashville as quintessential New South cities, offers a definition of modernity, and poses the question of why mass and speed were alien to turn-of-the-century southerners.
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Kelley, Robin D. G. President Obama. University of Illinois Press, 2017. http://dx.doi.org/10.5406/illinois/9780252036453.003.0016.
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The chapter argues that President Obama had to “transcend” race by invoking a politics of color-blindness, building unity not by collectively acknowledging that the nation has a race problem, but through forgetting and ignoring the past and present. Moreover, anyone who believes an Obama administration is willing or able to challenge neoliberalism or has an interest in dismantling empire is deluded. He is president, and halfway into his first term he had made his political agenda clear: he has escalated the war in Afghanistan, is reluctant to reverse Bush policies of extraordinary rendition or refusing terror suspects trial, backed a watered-down health care reform bill, and the list goes on. Of course, he also faces the worst economic crisis since the Great Depression and intractable House and Senate Republicans. Obama may have been shaped by abolition democracy, but it is simply impossible to be a drum major for justice in the White House.
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Rich Dorman, Sara. Understanding Zimbabwe. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190634889.001.0001.
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This book seeks to understand the state, nation and political identities that are being forged in modern Zimbabwe, and the nature of control that Robert Mugabe’s ZANU exercises over those political institutions. Focusing on the perspective and experiences of societal groups including NGOs, churches, trade unions, students and academics the book explores how the construction of consent, threat of coercion and material resources are used to integrate social groups into the ruling nationalist coalition, but also how they resist and frame competing discourses and institutions. Taking seriously the discursive and institutional legacies of the nationalist struggle and the liberation war in shaping politics, it explores how independent Zimbabwe’s politics were molded by discursive claims to foster national unity that delegitimize autonomous political action outside the ruling party. Building a new societal coalition entailed the "demobilization" of ZANU(PF)’s original nationalist constituency which had backed it during the liberation war, and the "inclusion" of new groups including donors, white farmers and business interests. It also shows how legal practices and institution-building defused and constrained opportunities for contestation, even while the regime used the security forces to suppress those who challenged its political monopoly or who otherwise resisted incorporation. It thus presents a complex picture of how individuals and groups became bound up in the project of state- and nation-building, despite contesting or even rejecting aspects of it.
Części książek na temat "White-backed"
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Chen, Hongyan, Wei Wu i Taiyun Wei. "Establishment of White-Backed Planthopper Cell Lines". W Methods in Molecular Biology, 197–205. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1835-6_19.
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"GRAY-BACKED WHITE-HEADED GULLS". W Gulls Simplified, 85–142. Princeton University Press, 2018. http://dx.doi.org/10.1515/9780691185521-006.
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Kendall, Corinne J., i Claire E. Bracebridge. "Ecology and Conservation of African White-backed Vultures (Gyps africanus)". W Reference Module in Earth Systems and Environmental Sciences. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-12-821139-7.00160-4.
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Gershenhorn, Jerry. "It Was a Wonder I Wasn’t Lynched". W Louis Austin and the Carolina Times. University of North Carolina Press, 2018. http://dx.doi.org/10.5149/northcarolina/9781469638768.003.0008.
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During the second half of the 1960s, Austin developed a complex relationship with the Black Power movement. During these years, he continued to fight for school integration and black political power. Austin worked closely with the Durham Committee on Negro Affairs, leading to the election of more black officials in Durham and throughout the state. When, in the midst of public school integration, white officials shut down many black schools and fired black principals and teachers, Austin publicized these injustices and backed lawsuits to protect black educators’ jobs. While he criticized the Black Panthers and other organizations that employed violent rhetoric and advocated black separatism, Austin championed the efforts of local activist Howard Fuller, who was considered a militant by many during that era. Austin also backed efforts by Fuller and other activists to combat poverty and ensure fair and decent housing for African Americans.
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Bildstein, Keith L. "Species Descriptions and Life Histories". W Vultures of the World, 20–97. Cornell University Press, 2022. http://dx.doi.org/10.7591/cornell/9781501761614.003.0003.
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This chapter describes the various species of obligate scavenging birds of prey and their life histories. Vultures are widespread geographically; their populations are most numerous and their diversity highest in tropical and subtropical regions. Substantial differences in both the distributions and the abundances of individual species occur, and together with their different phylogenies and their anatomical and behavioral characteristics, all species distinguish themselves as unique biological entities. New World vultures include the Black Vulture, Turkey Vulture, Lesser Yellow-headed Vulture, Greater Yellow-headed Vulture, King Vulture, California Condor, and Andean Condor. Old World vultures include the Palm-nut Vulture, Bearded Vulture, Egyptian Vulture, Hooded Vulture, Indian Vulture, Slender-billed Vulture, White-rumped Vulture, Griffon Vulture, Rüppell's Vulture, Himalayan Vulture, White-backed Vulture, Cape Vulture, Red-headed Vulture, White-headed Vulture, Cinereous Vulture, and Lappet-faced Vulture.
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Lechtreck, Elaine Allen. "School Desegregation". W Southern White Ministers and the Civil Rights Movement, 11–53. University Press of Mississippi, 2018. http://dx.doi.org/10.14325/mississippi/9781496817525.003.0002.
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On 17 May 1954, the Supreme Court of the United States ruled unanimously in Brown v The Board of Education that segregated public schools are unconstitutional. This chapter describes massive resistance organized by politicians and white supremacist groups throughout the South. Crises are described at Clinton High in Tennessee, Central High in Little Rock, Arkansas, the Universities of Mississippi and Alabama, Tuskegee High School in Alabama, and Clemson University in South Carolina as well as the courage of the Reverends Turner, Boggs, Cartwright, Ogden, Campbell, Gray, Davis, Sellers, Morris, Cousins, Lyles, Jackson, and Webster at these locations. It includes statements in support of the decision by the governing boards of major religious denominations, twenty-eight young ministers of the Mississippi Methodist Conference, and contributors to South Carolinians Speak, a booklet on moderation. Later the Supreme Court backed away from enforcing school integration. Scholars Wright, Jacoway, Wolters, Bell, Higgins, and Snider comment.
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Moser, Patrick. "Renewing a Royal Sport at Waikīkī". W Surf and Rescue, 24–40. University of Illinois Press, 2022. http://dx.doi.org/10.5622/illinois/9780252044441.003.0003.
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Freeth learned how to surf at Waikīkī on a wooden board, renewing interest in a traditional Native sport that had been discouraged throughout the nineteenth century by a powerful Caucasian community in Honolulu that associated it with laziness, gambling, and promiscuity. But Freeth and the sport caught the interest of local businessmen and the Hawaii Promotion Committee, who wanted to market the sport to increase tourism and draw white residents to the Islands. Freeth’s mixed-race background (and light skin) may have played a role in their support of him. Freeth gave surf lessons to promoter Alexander Hume Ford and writer Jack London, both of whom backed his idea of teaching surfing in Los Angeles. Freeth arrived in Venice, California, in July 1907.
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De Boever, Arne. "Revisiting The Bonfire of the Vanities". W Finance Fictions. Fordham University Press, 2018. http://dx.doi.org/10.5422/fordham/9780823279166.003.0002.
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Following other critics of the so-called “finance fiction” or “fi-fi” genre, the chapter begins by observing that finance doesn’t play a major role in Tom Wolfe’s The Bonfire of the Vanities: It is limited to the pages about a gold-backed bond and the neoliberalization of black power, an issue that Wolfe had already addressed in his earlier “Radical Chic.” Instead, the chapter identifies “psychosis” as a major theme in this contemporary finance fiction. While many critics have focused on racism in the novel, and in some cases on what they perceive to be the racism of the novel (which, in its avowedly all-inclusive representation of New York City privileges the upper-class white perspective), its revisionist reading lays bare what I consider to be the novel’s central drama: how both its white, upper-class protagonist Sherman McCoy and its black, lower-class protagonist Henry Lamb are caught up in psychotic situations created by money, politics, and the media—situations over which they have no control. The chapter ultimately turns to Cristina Alger’s The Darlings as an example of how this is borne out in post-2008 financial fiction.
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Smith, Adam I. P. "The ‘Fortunate Banner’: Languages of Democracy in the United States, c.1848". W Re-imagining Democracy in the Age of Revolutions, 28–39. Oxford University Press, 2013. http://dx.doi.org/10.1093/acprof:oso/9780199669158.003.0003.
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By the mid-nineteenth century, inhabitants of the United States generally agreed that they lived in a democratic state and society. But uses of the term were complicated by the fact that it also had partisan associations: one group of politicians claimed to be par excellence leaders of ‘the Democracy’. This party had no single or unchanging political identity: it was strongly backed in slave states, but also had white working-class supporters who pushed egalitarian notions hard. Their Whig opponents were not prepared to surrender the language of democracy to them, yet they were more ambivalent about endorsing it, and sometimes distinguished restrained and principled forms of democracy, which they favoured, from vulgar populist forms. The effect of the European revolutions of 1848 in the United States was to encourage the drawing of such distinctions.
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Clark, Shannan. "The Cold War in New York’s Culture Industries". W The Making of the American Creative Class, 244–92. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780199731626.003.0007.
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Chapter 6 examines the impact of the domestic Cold War on white-collar workers in New York’s culture industries. As relations between the United States and the Soviet Union rapidly deteriorated during the late 1940s, anticommunists’ attacks on the Popular Front and its supporters within the culture industries became more intense and more effective. Changes in labor law targeted unions like the United Office and Professional Workers of America that had procommunists among the leadership, while congressional investigations and blacklisting ruined the careers of numerous writers, artists, and other culture workers who had strongly backed the Popular Front. By the 1950s, the unions in the city’s culture industries were weakened or destroyed from the onslaught, diminishing the options for workers in publishing, advertising, broadcasting, and design to fight for improved working conditions and greater creative autonomy.