|
| ||
|
|
||
Breeding Grounds (breeding + ground)
Selected AbstractsBoredom, "Trouble," and the Realities of Postcolonial Reservation LifeETHOS, Issue 1 2003Assistant professor Lori L. Jervis Perhaps because of its reputation as an inconsequential emotion, the significance of boredom in human social life has often been minimized if not ignored. Boredom has been theoretically linked to modernity, affluence, and the growing problem of filling "leisure time. "It has also been attributed to the expansion of individualism with its heightened expectations of personal gratification. Whether a reaction to the sensation ofunderstimulation or "overload," boredom appears to be, ultimately, a problem of meaning. In this article, we consider the applicability of these notions to the contemporary American Indian reservation context, examining discourse about boredom as expressed in interviews with members of a northern plains tribe. Of special interest is how boredom figures into the phenomenon of "trouble" (e.g., alcohol and drug abuse, violence, and illegal activities). Although boredom is certainly familiar to various strata of contemporary U.S. society,and arguably part of what it means to be human,we propose that the realities of postcolonial reservation life provide an especially fertile and undertheorized breeding ground for this condition, and our examination of the relationship between boredom and trouble suggests that boredom's implications for both individual subjectivity and group sociality are far from trivial. [source] Retaliatory discourse: the politics of attack and withdrawalINTERNATIONAL JOURNAL OF APPLIED PSYCHOANALYTIC STUDIES, Issue 2 2006Lynne Layton Abstract Long-term and recent sociopolitical trends in the USA pull for narcissistic ways of fashioning the self and relating to others. Discourses that sustain a split between capacities for autonomy and capacities for attachment, and discourses that sustain a split between individuals and their social surround elicit omnipotent and/or submissive modes of narcissistic relating. An increasingly vulnerable and socially abandoned population, conditioned to be ashamed of its vulnerabilities and dependency, finds itself subject to discourses that pull for various splits between "us" and "them." This situation is a breeding ground for a politics of attack, or a politics of hostile withdrawal, or both. Neoconservatism fosters a politics of attack, and liberalism fosters a politics of withdrawal. Drawing on the psychoanalytic concept of "thirdness," the paper concludes that only discourses and institutions that foster interdependence, containment of vulnerability, and the bringing together of relational and autonomous capacities can counter retaliatory politics. Copyright © 2006 John Wiley & Sons, Ltd. [source] Site fidelity and movements of humpback whales (Megaptera novaeangliae) on the Brazilian breeding ground, southwestern AtlanticMARINE MAMMAL SCIENCE, Issue 4 2010Leonardo L. Wedekin Abstract Site fidelity and movements were studied for humpback whales photo-identified from 1989 to 2006 in the Abrolhos Bank, southwestern Atlantic, Brazil. A total of 2,612 individuals were identified, 374 of which were observed on more than one occasion. The cumulative number of identified whales has increased since 1989. Recapture rate was low and varied among different years. A total of 33 whales was observed using the Abrolhos Bank for longer than 10 yr, up to a maximum of 16 yr. Our data suggest that different whales show distinct movement rates. Some whales used a large extent of the Abrolhos Bank region. Opportunistic photo-identification data (on the scale of the Brazilian coast from 4° to 23°S) revealed important information about stock identity. The longest distance between within-season resightings was over 600 km, while one whale was observed in two locations separated by more than 1,400 km in different years. Long-range movements within and between seasons support the single stock hypothesis for humpback whales wintering off the Brazilian coast. [source] Foraging geese, vegetation loss and soil degradation in an Arctic salt marshAPPLIED VEGETATION SCIENCE, Issue 1 2002Robert L. Jefferies Abstract. The North American mid-continent population of Lesser snow geese (Chen caerulescens caerulescens L.) has increased by ca. 7% per year, largely as a result of geese feeding on agricultural crops in winter and on migration. We describe the long-term effects of increasing numbers of geese at an arctic breeding ground (La Pérouse Bay, Manitoba) on intertidal salt-marsh vegetation. Between 1985 and 1999 goose grubbing caused considerable loss of graminoid vegetation along transects in intertidal marshes. Loss of vegetation led to bare sediment with a plant cover of less than 2%. Changes in vegetation could not be described by simple linear, geometric or exponential functions; most losses occurred between 1988 and 1990 and losses were staggered in time between individual transects, some of which had all vegetation removed. Between 1979 and 1999 the standing crop in July in remaining intact heavily-grazed swards of Puccinellia phry-ganodes and Carex subspathacea fell from 40,60 g m -2 to 20,30 g m -2. Intense grazing on remaining patches of sward has restricted growth of these clonal forage plants and hypersalinity of bare sediments has precluded re-establishment of vegetation. Between 1989 and 1993 numbers of faecal droppings in grazed plots reached maximum values of 15,22 droppings m -2 wk -1. Since then peak values have remained at less than 13 droppings m -2 wk -1. The loss of vegetation and changes in soil conditions have resulted in the establishment of an alternative stable state (hypersaline bare sediment). [source] The Sources and Fortunes of Piranesi's Archaeological IllustrationsART HISTORY, Issue 4 2002Susan M. Dixon Susan M. Dixon earned her doctorate from Cornell University in 1991 with a dissertation on the archaeological publications of Giovanni Battista Piranesi. She studies the history of pre,scientific archaeology, from Pirro Ligorio to Piranesi, with a particular focus on illustration as a means to convey historical knowledge. She has published on this subject in a variety of venues, and is beginning a book,length manuscript on the subject. In 1995,96, she was awarded a J. Paul Getty post,doctoral fellowship to study the Accademia degli Arcadi, a society founded in 1690 primarily to restore good taste in literature, and its successes and failures in bringing about the reform of Italian society and architecture. She has written a book entitled The Bosco Parrasio: Performance and Perfectibility in the Garden of the Arcadians, which focuses on their garden meeting place as a breeding ground for a utopian society. Dr Dixon teaches art history at the University of Tulsa in Oklahoma. Giovanni Battista Piranesi (1720,1778) developed a way of representing the archaeological past by using the multi,informational image, an engraved illustration which appears to be a composite of various drawings, on various surfaces, and employing various modes of representation, scale and detail. The cartographic tradition, particularly maps from sixteenth,century Europe, offer a precedent for this type of illustration. Piranesi found theoretical underpinnings for it in contemporary discussions about the workings of the human memory, which was identified as a viable tool for those pursuing historical knowledge. His illustrations make visible the processes of memory on an assemblage of archaeological information, and they were a means to historical reconstruction. Archaeologists of the generation after Piranesi did not use the multi,informational image as the science of archaeology underwent a sea change at the end of the century. However, some compilers of travel literature, in particular Jean,Laurent,Pierre HoĂ,el, author and illustrator of Voyage pittoresque des isles de Sicile, de Malte, et de Lipari, found the format suitable to their purposes. Like Piranesi's, Hoüel's multi,informational images reveal the hand of the artist on the information he had diligently collected and ordered; Hoüel's picturesque illustrations of the southern Italian islands' people and places are self,consciously subjective. The format also makes apparent what was so appealing to many a voyager ,the apparent survival of the past in the culture of the present. [source] Geographical segregation in Dunlin Calidris alpina populations wintering along the East Atlantic migratory flyway , evidence from mitochondrial DNA analysisDIVERSITY AND DISTRIBUTIONS, Issue 5 2008Ricardo J. Lopes ABSTRACT Dunlin Calidris alpina is one of the most abundant shorebirds using coastal habitats in the East Atlantic migratory flyway, that links arctic breeding locations (Greenland to Siberia) with wintering grounds (West Europe to West Africa). Differential migration and winter segregation between populations have been indicated by morphometrics and ringing recoveries. Here, we analyse the potential of genetic markers (mitochondrial DNA , mtDNA) to validate and enhance such findings. We compared mtDNA haplotypes frequencies at different wintering sites (from north-west Europe to West Africa). All birds from West Africa had western (European) haplotypes, while the eastern (Siberian) haplotypes were only present in European winter samples, reaching higher frequencies further north in Europe. Compilation of published results from migrating birds also confirmed these differences, with the sole presence of European haplotypes in Iberia and West Africa and increasingly higher frequencies of Siberian haplotypes from south-west to north-west Europe. Comparison with published haplotype frequencies of breeding populations shows that birds from Greenland, Iceland, and North Europe were predominant in wintering grounds in West Africa, while populations wintering in West Europe originated from more eastern breeding grounds (e.g. North Russia). These results show that genetic markers can be used to enhance the integrative monitoring of wintering and breeding populations, by providing biogeographical evidence that validate the winter segregation of breeding populations. [source] Feather deuterium measurements reveal origins of migratory western loggerhead shrikes (Lanius ludovicianus excubitorides) wintering in MexicoDIVERSITY AND DISTRIBUTIONS, Issue 2 2007Guillermo E. Pérez ABSTRACT Understanding the winter distributions of migrant birds is important because productivity and recruitment are influenced by conditions at several locations and periods in the life cycle of individuals. The western loggerhead shrike, Lanius ludovicianus excubitorides, is a threatened species in Canada, and its decline is attributed to potential limitations on the wintering grounds. We examined patterns of stable-hydrogen isotope (,D) distributions in feathers of loggerhead shrikes, primarily of L. l. excubitorides, during winter at three regions in north and central Mexico, to establish relative abundance and origins of migrants. We also investigated potential movements of Mexican winter resident individuals. Using shrike museum specimens of known summer provenance, a shrike deuterium base map for Mexico was developed from isotopic measurement of feathers of resident shrikes and use of a recently established feather base map for raptors in North America. Stable hydrogen isotope analyses of inner secondary feather (s9) of all loggerhead shrikes examined in Mexico during winter indicated that north-central (Region A), north-eastern (Region B) and south-central (Region C) sites in Mexico consisted of 28.1%, 73.7% and 63.8% of migrant individuals from northern breeding grounds, respectively. Isotopic evidence suggested movements of a few local residents birds (7.9%) into the Chihuahuan desert from south-western USA and north-eastern Mexico to winter. [source] Corruption and Entrepreneurship: How Formal and Informal Institutions Shape Small Firm Behavior in Transition and Mature Market EconomiesENTREPRENEURSHIP THEORY AND PRACTICE, Issue 5 2010Vartuhí Tonoyan This article explores the determinants of corruption in transition economies of the post-Soviet Union, Central-Eastern Europe, and Western industrialized states. We look in-depth at the East,West gap in corruption, and why entrepreneurs and small business owners become engaged in corrupt deals. Part of the answers lie in the country-specific formal and informal institutional make-up. The likelihood of engaging in corruption is influenced by the lower efficiency of financial and legal institutions and the lack of their enforcements. Also, viewing illegal business activities as a widespread business practice provides the rationale for entrepreneurs to justify their own corrupt activities. Moreover, closed social networks with family, friends, and national bureaucrats reduce the opportunism of the contracting party of the corrupt deal, thus providing breeding grounds for corruption. [source] Influence of water flow velocity, water depth and colony distance on distribution and foraging patterns of terns in the Wadden SeaFISHERIES OCEANOGRAPHY, Issue 3 2009PHILIPP SCHWEMMER Abstract Surface-feeding seabirds, such as Common (Sterna hirundo) and Arctic Terns (Sterna paradisaea) in the German Wadden Sea, are dependent on biological and physical processes that affect prey availability close to the water surface. We proposed the following four hypotheses: (i) relationships should exist between high water flow velocity and foraging activity of terns, as turbulence should enhance prey availability at the surface; (ii) the areas of highest foraging success should be located within areas of low water depth, due to enhanced biological productivity; (iii) as terns are known to have small foraging radii, the location of their breeding grounds should be related to the location of their foraging grounds; (iv) terns should forage intensely in river estuaries, as these should hold ample food supplies. The time between terns leaving the colony and their first foraging attempt differed significantly among different tidal stages: the time was shortest during flood and ebb tides (i.e., highest water flow velocities). Modelling of a long-term data set revealed the highest probability of foraging activity in conditions of high water currents, in both shallow areas and in areas of around 15,20 m depth. Foraging activity was negatively correlated with distance from colony. The distance to the closest estuary had no significant effect on foraging behaviour. Our findings emphasize the physical,biological coupling in the Wadden Sea and highlight the overall importance of small-scale physical processes in directly influencing prey availability for surface-feeding seabirds. [source] Experimental tail shortening in Barn Swallows (Hirundo rustica) affects haematocritFUNCTIONAL ECOLOGY, Issue 5 2005J. J. CUERVO Summary 1Recent studies in Scotland suggest that the outermost tail feathers of Barn Swallows (Hirundo rustica Linnaeus) may be around 10,12 mm longer than the aerodynamic optimum, with sexual selection for long tails accounting for this extra length. 2To test this hypothesis, we shortened the outermost tail feathers in male and female Barn Swallows in southern Spain by cutting 1, 11 or 21 mm from the tips of the feathers, and checked for change in haematocrit 1 month later. Haematocrit levels were high when birds arrived at the breeding grounds due to an intense effort for flight during migration, but these levels decreased during the breeding season. We predicted that this decrease would be more pronounced when tail length was closer to the aerodynamic optimum (tails shortened by 11 mm), and less pronounced as tail length was displaced from that optimum (tails shortened by 1 or 21 mm). 3Contrary to expectations, we found that the smaller the experimental reduction in tail length, the more pronounced the decrease in haematocrit. Barn Swallows with little parental effort and originally long tail feathers experienced a more pronounced decrease in haematocrit than individuals with strong parental effort and originally short tail feathers, respectively, although only in the group of birds with tails shortened by 21 mm. 4These results do not support the hypothesis that outermost tail feathers in Barn Swallows have been elongated because of sexual selection, at least in the population studied, but are consistent with tail length being at an aerodynamic optimum, or very close to it. Differences in tail length among populations might help to understand the disagreement with previous studies. [source] Do changes in climate patterns in wintering areas affect the timing of the spring arrival of trans-Saharan migrant birds?GLOBAL CHANGE BIOLOGY, Issue 1 2005Oscar Gordo Abstract The life cycles of plants and animals are changing around the world in line with the predictions originated from hypotheses concerning the impact of global warming and climate change on biological systems. Commonly, the search for ecological mechanisms behind the observed changes in bird phenology has focused on the analysis of climatic patterns from the species breeding grounds. However, the ecology of bird migration suggests that the spring arrival of long-distance migrants (such as trans-Saharan birds) is more likely to be influenced by climate conditions in wintering areas given their direct impact on the onset of migration and its progression. We tested this hypothesis by analysing the first arrival dates (FADs) of six trans-Saharan migrants (cuckoo Cuculus canorus, swift Apus apus, hoopoe Upupa epops, swallow Hirundo rustica, house martin Delichon urbica and nightingale Luscinia megarhynchos), in a western Mediterranean area since from 1952 to 2003. By means of multiple regression analyses, FADs were analysed in relation to the monthly temperature and precipitation patterns of five African climatic regions south of the Sahara where species are thought to overwinter and from the European site from where FADs were collected. We obtained significant models for five species explaining 9,41% of the variation in FADs. The interpretation of the models suggests that: (1) The climate in wintering quarters, especially the precipitation, has a stronger influence on FADs than that in the species' potential European breeding grounds. (2) The accumulative effects of climate patterns prior to migration onset may be of considerable importance since those climate variables that served to summarize climate patterns 12 months prior to the onset of migration were selected by final models. (3) Temperature and precipitation in African regions are likely to affect departure decision in the species studied through their indirect effects on food availability and the build-up of reserves for migration. Our results concerning the factors that affect the arrival times of trans-Saharan migrants indicate that the effects of climate change are more complex than previously suggested, and that these effects might have an interacting impact on species ecology, for example by reversing ecological pressures during species' life cycles. [source] Is there a connection between weather at departure sites, onset of migration and timing of soaring-bird autumn migration in Israel?GLOBAL ECOLOGY, Issue 6 2006Judy Shamoun-Baranes ABSTRACT Aims, Different aspects of soaring-bird migration are influenced by weather. However, the relationship between weather and the onset of soaring-bird migration, particularly in autumn, is not clear. Although long-term migration counts are often unavailable near the breeding areas of many soaring birds in the western Palaearctic, soaring-bird migration has been systematically monitored in Israel, a region where populations from large geographical areas converge. This study tests several fundamental hypotheses regarding the onset of migration and explores the connection between weather, migration onset and arrival at a distant site. Location, Globally gridded meteorological data from the breeding areas in north-eastern Europe were used as predictive variables in relation to the arrival of soaring migrants in Israel. Methods, Inverse modelling was used to study the temporal and spatial influence of weather on initiation of migration based on autumn soaring-bird migration counts in Israel. Numerous combinations of migration duration and temporal influence of meteorological variables (temperature, sea-level pressure and precipitable water) were tested with different models for meteorological sensitivity. Results, The day of arrival in Israel of white storks, honey buzzards, Levant sparrowhawks and lesser spotted eagles was significantly and strongly related to meteorological conditions in the breeding area days or even weeks before arrival in Israel. The cumulative number of days or cumulative value above or below a meteorological threshold performed significantly better than other models tested. Models provided reliable estimates of migration duration for each species. Main conclusions, The meteorological triggers of migration at the breeding grounds differed between species and were related to deteriorating living conditions and deteriorating migratory flight conditions. Soaring birds are sensitive to meteorological triggers at the same period every year and their temporal response to weather appears to be constrained by their annual routine. [source] The challenges of conservation for declining migrants: are reserve-based initiatives during the breeding season appropriate for the Pied Flycatcher Ficedula hypoleuca?IBIS, Issue 3 2009ANNE E. GOODENOUGH Creating conservation policies for declining migrant species in response to global change presents a considerable challenge. Migrant species are affected by factors at breeding grounds, overwintering areas and during migration. Accordingly, reserve-based management during the breeding season is not always a suitable conservation strategy. Recent Pied Flycatcher population decline typifies the pattern for many migrants. The UK population has declined by 43% in the past decade, but explanations, and possible solutions, remain elusive. We use 15 years of data (1990,2004) from a declining British population to establish possible reasons for decline, considering: (1) breeding performance (including the influences of competition and predation); (2) weather patterns caused by the winter phase (December,March) of the North Atlantic Oscillation (NAO), which modify conditions experienced at wintering grounds and on migration; and (3) possible impacts of climate change on spring temperatures. We conclude that decreasing breeding performance is contributing to decline, but that non-breeding factors are more important. Winter NAO index is a strong predictor of breeding population, probably because it influences food abundance in Africa and at migratory stopover points. Importantly, however, year itself enhances the predictive model, indicating that influences on population remain unaccounted for by current research. Management strategies based on increasing breeding productivity cannot fully address population decline because non-breeding factors appear important. However, as breeding performance is declining, breeding-based strategies remain useful conservation tools. To this end, our research indicates that optimal placement of nestboxes as regards orientation and habitat management to increase larval food supplies could increase productivity significantly. [source] Wader recruitment indices suggest nesting success is temperature-dependent in Dunlin Calidris alpinaIBIS, Issue 3 2006COLIN M. BEALE Measures of annual breeding success are an important component of species monitoring programmes. It has been suggested that effective monitoring of breeding productivity for arctic breeding waders may be achieved from an analysis of annual variation in the proportion of juveniles in winter flocks. Here, we attempt to generate a recruitment index for Dunlin Calidris alpina caught during the winter in north Wales. This index revealed significant annual variation and we show that this is strongly correlated with summer temperature (but not rainfall) on the breeding grounds. Years with high recruitment were also correlated with increases in the national winter population estimate. In years of intermediate summer temperature, the recruitment index was highest and we discuss the possible implications this has for Dunlin under scenarios of future climate change. We were unable to generate a significant index for Common Redshank Tringa totanus and discuss possible reasons for this. [source] The migration route and behaviour of Eastern Curlews Numenius madagascariensisIBIS, Issue 3 2002Peter V. Driscoll Eastern Curlews Numenius madagascariensis were satellite-tracked onto breeding grounds in north-eastern Russia from south-eastern Queensland over a distance of 12 000 km. They made initial non-stop, long distance flights across the Western Pacific Ocean towards the coastlines of China and Korea followed by shorter flights, over a period of more than a month. The return journey involved a major flight-leg as well, south from the Yellow Sea region. Many birds attempted to migrate but returned to the non-breeding grounds over periods of up to several months. Islands of the Western Pacific region, the southern coastline of New Guinea and north-eastern coastline of Australia are important, particularly for birds that stop migrating. Eastern Curlews that stopped migrating generally survived, which suggests that the species has adapted to deal with adverse conditions en route and/or a physical inability to complete the migration. Such a capacity is perhaps characteristic of a large wader with low annual mortality. [source] Carry-over effects in a Pacific seabird: stable isotope evidence that pre-breeding diet quality influences reproductive successJOURNAL OF ANIMAL ECOLOGY, Issue 2 2009Marjorie C. Sorensen Summary 1Understanding the interactions between different periods of the annual cycle in migratory animals has been constrained by our inability to track individuals across seasons. In seabirds, virtually nothing is known about how diet quality during the non-breeding period, away from the breeding grounds, might influence subsequent reproductive success. 2We used stable nitrogen (,15N) and carbon (,13C) isotopes to evaluate the effects of non-breeding diet quality on the timing of breeding and egg size in a population of Cassin's auklets (Ptychoramphus aleuticus) breeding on Triangle Island, British Columbia. Adult feathers are grown during two different periods of the annual cycle, which allowed us to estimate diet quality from the previous fall (October,November) and pre-breeding (February,March) period. 3We found that the estimated proportion of energetically superior copepods (Neocalanus spp.) in the pre-breeding diet tended to be higher in females that bred earlier and laid larger eggs, whereas energetically poor juvenile rockfish (Sebastes spp.) were dominant in the pre-breeding diets of females that bred later and laid smaller eggs. We detected no effect of fall diet quality on breeding date or egg size, and no effect of pre-breeding diet quality on breeding date in males. 4Pre-breeding diet quality was not related to body condition measured 1,2 days after laying, which suggests that females may need to attain a threshold condition before they initiate breeding and successfully rear young. 5Our results suggest that changes in climatic conditions during the pre-breeding period may have severe consequences for reproductive success by influencing breeding date and egg size. Our work emphasizes the importance of determining how events are linked throughout the annual cycle for understanding the fitness and population dynamics of migratory animals. [source] Age-related change in breeding performance in early life is associated with an increase in competence in the migratory barn swallow Hirundo rusticaJOURNAL OF ANIMAL ECOLOGY, Issue 5 2007JAVIER BALBONTÍN Summary 1We investigated age-related changes in two reproductive traits (laying date and annual fecundity) in barn swallows Hirundo rustica L. using a mixed model approach to di-stinguish among between- and within-individual changes in breeding performance with age. 2We tested predictions of age-related improvements of competence (i.e. constraint hypothesis) and age-related progressive disappearance of poor-quality breeders (i.e. selection hypothesis) to explain age-related increase in breeding performance in early life. 3Reproductive success increased in early life, reaching a plateau at middle age (e.g. at 3 years of age) and decreasing at older age (> 4 years). Age-related changes in breeding success were due mainly to an effect of female age. 4Age of both female and male affected timing of reproduction. Final linear mixed effect models (LME) for laying date included main and quadratic terms for female and male age, suggesting a deterioration in reproductive performance at older age for both males and females. 5We found evidence supporting the constraints hypothesis that increases in competence within individuals, with ageing being the most probable cause of the observed increase in breeding performance with age in early life. Two mechanisms were implicated: (1) advance in male arrival date with age provided middle-aged males with better access to mates. Yearling males arrived later to the breeding grounds and therefore had limited access to high-quality mates. (2) Breeding pairs maintaining bonds for 2 consecutive years (experienced pairs) had higher fecundity than newly formed inexperienced breeding pairs. 6There was no support for the selection hypothesis because breeding performance was not correlated with life span. 7We found a within-individual deterioration in breeding and migratory performance (arrival date) in the oldest age-classes consistent with senescence in these reproductive and migratory traits. [source] Fuel reserves affect migratory orientation of thrushes and sparrows both before and after crossing an ecological barrier near their breeding groundsJOURNAL OF AVIAN BIOLOGY, Issue 1 2009Mark E. Deutschlander Fat reserves influence the orientation of migrating songbirds at ecological barriers, such as expansive water crossings. Upon encountering a body of water, fat migrants usually cross the barrier exhibiting ,forward' migration in a seasonally appropriate direction. In contrast, lean birds often exhibit temporary ,reverse' orientation away from the water, possibly to lead them to suitable habitats for refueling. Most examples of reverse orientation are restricted to autumn migration and, in North America, are largely limited to transcontinental migrants prior to crossing the Gulf of Mexico. Little is known about the orientation of lean birds after crossing an ecological barrier or on the way to their breeding grounds. We examined the effect of fat stores on migratory orientation of both long- and short-distance migrants before and after a water crossing near their breeding grounds; Catharus thrushes (Swainson's and gray-cheeked thrushes, C. ustulatus and C. minimus) and white-throated sparrows Zonotrichiaalbicollis were tested for orientation at the south shore of Lake Ontario during spring and autumn. During both spring and autumn, fat birds oriented in a seasonally appropriate, forward direction. Lean thrushes showed a tendency for reverse orientation upon encountering water in the spring and axial, shoreline orientation after crossing water in the autumn. Lean sparrows were not consistently oriented in any direction during either season. The responses of lean birds may be attributable to their stopover ecology and seasonally-dependent habitat quality. [source] Climatic effects on timing of spring migration and breeding in a long-distance migrant, the pied flycatcher Ficedula hypoleucaJOURNAL OF AVIAN BIOLOGY, Issue 5 2005Christiaan Both Climate change has advanced the breeding dates of many bird species, but for few species we know whether this advancement is sufficient to track the advancement of the underlying levels of the food chain. For the long-distance migratory pied flycatcher Ficedula hypoleuca the advancement in breeding time has been insufficient to maintain the synchrony with their main food sources. The timing of arrival in the breeding areas from their African wintering grounds is likely to constrain the advancement of breeding date. We hypothesise that this is because in Africa they cannot predict the advancement of spring in their breeding habitat. However, long-distance migrants may advance their arrival time by migrating faster when circumstances en route are favourable. In this study we show that both arrival and breeding date depend on temperatures at their main North African staging grounds, as well as on temperature at the breeding grounds. Male arrival and average laying date were not correlated, but the positive effect of temperature in North Africa on breeding dates suggests that breeding date is indeed constrained by arrival of females. Long-distance migrants thus are able to adjust arrival and hence breeding by faster spring migration, but the degree of adjustment is probably limited as timing schedules in spring are tight. Furthermore, as climate change is affecting temperatures differently along the migratory flyway and the breeding areas, it is unlikely that arrival dates are advanced at the same rate as the timing of breeding should advance, given the advancement of the underlying levels of the food chain. [source] The effect of wind, season and latitude on the migration speed of white storks Ciconia ciconia, along the eastern migration routeJOURNAL OF AVIAN BIOLOGY, Issue 1 2003Judy Shamoun-Baranes The relation between wind, latitude and daily migration speed along the entire migration route of white storks was analysed. Mean daily migration speed was calculated using satellite telemetry data for autumn and spring migration of white storks from their breeding grounds in Germany and Poland to wintering grounds in Africa and back. The National Center for Environmental Prediction (NCEP) reanalysis data were used to systematically fit 850 mb wind vectors to daily migration speed along the migration route. White storks migrated significantly faster and had a shorter migration season in autumn (10 km/h) compared to spring (6.4 km/h). In autumn mean daily migration speed was significantly slower in Europe (8.0 km/h) than in the Middle East (11.1 km/h) and Africa (11.0 km/h). In spring mean daily migration speed was significantly faster in Africa (10.5 km/h) as birds left their wintering grounds than in the Middle East (4.3 km/h). Migration speed then increased in Europe (6.5 km/h) as birds approached their breeding grounds. In both spring and autumn tailwind (at 850mb) and latitude were found to be significant variables related to daily migration speed. [source] Density and habitat associations of Henslow's Sparrows wintering in saline soil barrens in southern ArkansasJOURNAL OF FIELD ORNITHOLOGY, Issue 4 2008William C. Holimon ABSTRACT Although the habitat requirements of breeding populations of Henslow's Sparrow (Ammodramus henslowii) have been examined, less is known about their habitat requirements and ecology during the nonbreeding season. We estimated population densities and quantified habitat associations of Henslow's Sparrows wintering in saline soil barrens in southern Arkansas. Densities of Henslow's Sparrows in the saline soil barrens were similar to those in the Longleaf Pine (Pinus palustris) Ecosystem of the southeastern United States, considered by many to be their primary wintering habitat. Henslow's Sparrows were closely associated with open areas with greater cover of Aristida spp. and globe beaksedge (Rhynchospora globularis), greater stem density at 11,20 cm above ground, more lichens, more herbaceous cover, more bare ground, greater occurrence of little bluestem (Schizacyrium scoparium) as the tallest vegetation, less moss, and less shrub cover than randomly selected sites. In contrast to the results of studies conducted in the Longleaf Pine Ecosystem, the presence of Henslow's Sparrows in our study was not correlated with the height of the tallest vegetation. Our results indicate that saline soil barrens of southern Arkansas support a high density of wintering Henslow's Sparrows and do so for longer postdisturbance periods than longleaf pine savanna. We also found that stem density near the ground was similar to that reported from longleaf pine savanna, but only about half that observed on their breeding grounds. Areas used by Henslow's Sparrows had more lichen and less moss cover, suggesting that those areas were drier than random sites within the barrens. Further research is needed to determine if large populations of Henslow's Sparrows winter in other saline soil barrens and if fire influences habitat associations and densities in the barrens. SINOPSIS Aunque los requisitos de hábitat para las poblaciones reproductivas de Ammodramus henslowii han sido determinadas, se conoce muy poco sobre su ecología y requerimientos de hábitat durante la temporada no-reproductiva. Estimamos la densidad poblacional y cuantificamos el hábitat asociado a Gorrión de Henslow que pasan el invierno en un salitral con suelo empobrecido en el sur de Arkansas. La densidad de las aves en el salitral resultó similar a lo encontrado en Ecosistemas de Pinos (Pinus palustris) en el sureste de los EUA, considerado por muchos como el principal hábitat invernal para la especie. Los gorriones estuvieron altamente asociados a áreas abiertas con covertura de Aristida spp. y Rhynchospora globularis, con mayor densidad de tallos, altura entre 11,20 cm sobre el suelo, mayor cantidad de líquenes, mayor cubierta herbácea, más suelo desnudo, mayor presencia de Schzacyrium scoparium (como la vegetación de mayor tamańo), menos musgos, y menos arbustos que localidades seleccionadas al azar. En contraste a los resultados de estudios conducidos en Ecosistemas de Pinos, la presencia del gorrión en nuestra área de estudio no estuvo correlacionada con la altura de la vegetación de mayor tamańo. Nuestros resultados indican que las salinas en Arkansas sostienen una alta densidad de aves invernales, y lo hacen por periodos más largos, después de disturbios, que en las savanas de pinos. También encontramos que la densidad de tallos, cerca del suelo, era similar a la informada en savanas de pinos, pero tan solo la mitad de lo indicado para lugares en donde las aves se reproducen. Las áreas utilizadas tienen más líquenes, pero menos musgos, lo que sugiere que dichas áreas son más secas que lugares con suelo empobrecido muestreados al azar. Se necesitan más trabajos para determinar si otras grandes poblaciones del gorrión de Henslow pasan el invierno en otras salinas con suelos empobrecidos y si eventos como fuegos incluyen en la asociación del hábitat y densidades en los lugares con suelo empobrecido. [source] SWIMMING SPEEDS OF SINGING AND NON-SINGING HUMPBACK WHALES DURING MIGRATIONMARINE MAMMAL SCIENCE, Issue 3 2007Michael J. Noad Abstract Limited data exist on swimming speeds of humpback whales (Megaptera novaeangliae) and none on swimming speeds of singing whales during migration. We tracked humpback whales visually and acoustically during migration from the breeding grounds past our study site on the east coast of Australia (latitude 26°28,S). The mean swimming speed for whales while singing was 2.5 km/h, significantly less than for non-singing whales with a mean of 4.0 km/h but significantly greater than the mean of 1.6 km/h observed for singing whales on the Hawaiian breeding grounds. Between song sessions, there was no significant difference in speeds between whales that had been singing and other whales. Migration speeds were less for whales while singing but increased during the season. Although humpback whales can swim rapidly while singing (maximum observed 15.6 km/h), they generally do not do so, even during migration. Slower migration by singers would delay their return to the polar feeding areas and may be costly, but may be a strategy to provide access to more females. [source] Fine-scale natal homing and localized movement as shaped by sex and spawning habitat in Chinook salmon: insights from spatial autocorrelation analysis of individual genotypesMOLECULAR ECOLOGY, Issue 14 2006H. M. NEVILLE Abstract Natal homing is a hallmark of the life history of salmonid fishes, but the spatial scale of homing within local, naturally reproducing salmon populations is still poorly understood. Accurate homing (paired with restricted movement) should lead to the existence of fine-scale genetic structuring due to the spatial clustering of related individuals on spawning grounds. Thus, we explored the spatial resolution of natal homing using genetic associations among individual Chinook salmon (Oncorhynchus tshawytscha) in an interconnected stream network. We also investigated the relationship between genetic patterns and two factors hypothesized to influence natal homing and localized movements at finer scales in this species, localized patterns in the distribution of spawning gravels and sex. Spatial autocorrelation analyses showed that spawning locations in both sub-basins of our study site were spatially clumped, but the upper sub-basin generally had a larger spatial extent and continuity of redd locations than the lower sub-basin, where the distribution of redds and associated habitat conditions were more patchy. Male genotypes were not autocorrelated at any spatial scale in either sub-basin. Female genotypes showed significant spatial autocorrelation and genetic patterns for females varied in the direction predicted between the two sub-basins, with much stronger autocorrelation in the sub-basin with less continuity in spawning gravels. The patterns observed here support predictions about differential constraints and breeding tactics between the two sexes and the potential for fine-scale habitat structure to influence the precision of natal homing and localized movements of individual Chinook salmon on their breeding grounds. [source] Polymorphic microsatellite loci for assigning parentage in least flycatchers (Empidonax minimus)MOLECULAR ECOLOGY RESOURCES, Issue 3 2001S. A. Tarof Abstract Least flycatchers (Empidonax minimus) are socially monogamous birds that form tight territorial aggregations on the breeding grounds. We designed five polymorphic microsatellite loci for assigning parentage to offspring within least flycatcher clusters. The number of alleles per locus ranged from 7 to 18. Mean polymorphic information content was 83.8%; the probability of exclusion with known maternal genotype was 0.999. These microsatellites are powerful DNA markers for identifying extra-pair paternity in this species. Preliminary data also suggest that these loci may be useful for other members of this genus. [source] The Pelagos Sanctuary for Mediterranean marine mammalsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2008Giuseppe Notarbartolo-di-Sciara Abstract 1.In February 2002, France, Italy and Monaco agreed to establish an international sanctuary for Mediterranean marine mammals. The resulting Pelagos Sanctuary encompasses over 87500 km2 of the north-western Mediterranean Sea, extending between south-eastern France, Monaco, north-western Italy and northern Sardinia, and surrounding Corsica and the Tuscan Archipelago. 2.The Pelagos Sanctuary illustrates how the tenets of Marine Protected Area (MPA) design can be reconciled with the dynamic nature of oceanic systems, because its spatial scale was defined by oceanographic and ecological considerations, specifically the location of the Ligurian permanent frontal system. 3.By expanding protective measures beyond national waters, the Pelagos Sanctuary also sets a precedent for the implementation of pelagic protected areas in the high seas. The Pelagos Sanctuary will contribute to the conservation of the Mediterranean Sea at two scales: (i) locally, by protecting important cetacean foraging and breeding grounds in the Ligurian Sea, and by providing ,umbrella' protection to other marine predators in this area; and (ii) regionally, by empowering other conservation measures, such as the Specially Protected Areas Protocol of the Barcelona Convention and the wider goals of the Agreement on the Conservation of Cetaceans of the Black and Mediterranean Seas (ACCOBAMS). 4.However, because few cetacean species are resident within the Sanctuary, their effective long-term conservation will require large-scale management and coordinated monitoring throughout the Mediterranean basin. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||