Journal of Ornithology
Springer Science+Business Media
About: Journal of Ornithology is an academic journal. The journal publishes majorly in the area(s): Ecology (disciplines) & Population. It has an ISSN identifier of 0021-8375. Over the lifetime, 5250 publications have been published receiving 62885 citations. The journal is also known as: J. Ornithol. & Journal für Ornithologie.
Papers published on a yearly basis
TL;DR: Well der Altvogel meist zu der vergegenst~ndlichenden Reizzusammenfassung natarlicherweise eher imstande ist, als der oft ant sehr niederer Entwicklungsstufe ins Leben tretende Jungvogsel.
Abstract: VI. Der Kindkumpan. Mit etwas mehr Berechtigung ~ls wir in dem vorigen Kapitel das Bild, das die Leistungen des Elternvogels in der Umwelt des Jungvogels malen, als ,,Elternkumpan\" bezeichnet haben, obwohl wir ihn in manchen F~llen, gem~g seiner einzelnen Funktionskreise, in einen Ftihrer-, einen Fatter-, einen W~rmekumpan usw. h~tten zerreigen m~issen, wollen wir nun umgekehrt unter ,Kindkumpan\" das Bild bezeichnen, welches die den Pflegetrieben der Elterntiere entgegef~stehenden Gegenleistungen der Jungtiere in der Umwelt dieser Eltern entwerfen. Mit etwas mehr Berechtigung deshalb, well der Altvogel meist zu der vergegenst~ndlichenden Reizzusammenfassung natarlicherweise eher imstande ist, als der oft ant sehr niederer Entwicklungsstufe ins Leben tretende Jungvogel.
TL;DR: The difficulties involved in investigating migrating birds at different points on their migration routes have limited the number of studies on the influence of events during migration periods on population levels, and the evidence for these views is explored in this paper.
Abstract: Populations of migratory birds are usually considered to be limited by conditions in breeding or wintering areas, but some might be limited by conditions encountered on migration. This could occur at stopover sites where competition for restricted food supplies can reduce subsequent survival or breeding success, or during the flights themselves, when adverse weather can occasionally kill large numbers of individuals. Competition for food could act in a density-dependent manner and help to regulate populations, whereas weather effects are more likely to act in a density-independent manner. The evidence for these views is explored in this paper. When preparing for migration, birds must normally obtain more food per day than usual, in order to accumulate the body reserves that fuel their flights. Birds often concentrate in large numbers at particular stopover sites, where food can become scarce, thus affecting migratory performance. Rates of weight gain, departure weights, and stopover durations often correlate with food supplies at stopover sites, sometimes influencing the subsequent survival and reproductive success of individuals, which can in turn affect subsequent breeding numbers. Many studies have provided evidence for interference and depletion competition at stopover sites, relatively few for migration conditions influencing the subsequent breeding or survival of individuals, and even fewer for effects on subsequent breeding numbers. Migrants in flight occasionally suffer substantial mortality in storms, especially over water, sometimes involving many thousands of birds at a time. Other mass mortalities have resulted from atypical ‘winter-like’ weather, occurring soon after the arrival of summer migrants in their breeding areas or just before their departure in autumn. Again, many thousands of birds at a time have been killed in such incidents, causing reductions of 30–90% in local breeding densities. In some bird species, migration-related events can at times have substantial effects on the year-to-year changes in breeding population levels. Nonetheless, the difficulties involved in investigating migrating birds at different points on their migration routes have so far limited the number of studies on the influence of events during migration periods on population levels.
TL;DR: It is predicted that integrated population models will become a common and important tool in studies of population dynamics, both in ecology and its applications, such as conservation biology or wildlife management.
Abstract: Integrated population models (IPMs) represent the single, unified analysis of population count data and demographic data. This modelling framework is quite novel and can be implemented within the classical or the Bayesian mode of statistical inference. Here, we briefly show the basic steps that need to be taken when an integrated population model is adopted, and review existing integrated population models for birds and mammals. There are important advantages of integrated compared to conventional analyses that analyse each dataset separately and then try to make an inference about population dynamics. First, integrated population models allow the estimating of more demographic quantities, because there is information about all demographic processes operating in a population, and this information is exploited. Second, parameter estimates become more precise, and this enhances statistical power. Finally, all sources of uncertainty due to process variability and the sampling process(es) are adequately included. Core of the integrated models is the link of changes in the population size and the demographic rates via a demographic model (usually a Leslie matrix model) and the likelihoods of all existing datasets. We discuss some critical assumptions that are typically made in integrated population models and highlight fruitful areas of future research. Currently, we have found 25 studies that used integrated population models. Central to most studies was statistical development rather than their application to address an ecological question, which is not surprising given that integrated population models are still a new development. We predict that integrated population models will become a common and important tool in studies of population dynamics, both in ecology and its applications, such as conservation biology or wildlife management.
TL;DR: Relationships between the physiological and behavioural characteristics of avian personalities can be explored in detail to determine the significance of individual differences in stress responses and personalities in birds.
Abstract: Birds are constantly responding to stimuli from their environment. When these stimuli are perceived as threatening, stress responses are initiated, with activation of the hypothalamo-pituitary-adrenal axis and the release of corticosterone from the adrenal gland. The basic emotion of fear is also experienced during a stress response. Corticosterone stress responses and behavioural responses to stimuli vary markedly between individual birds, raising questions about the significance of these individual differences and about the relationship between corticosterone responses and fearfulness in birds. Although fearfulness can be challenging to measure, data from several species indicate that corticosterone responses and fear behaviour responses are linked in individual birds. Consistent profiles of behavioural responses of birds to a wide range of stimuli can be identified and are called personalities. Personalities vary along a continuum, but are usually classified as proactive or reactive. Individual corticosterone and behaviour responses depend on each bird’s personality. Birds with proactive personalities have relatively active behavioural responses and relatively low corticosterone stress responses, whilst birds with reactive personalities have relatively passive behavioural responses and large corticosterone responses. Relationships between the physiological and behavioural characteristics of avian personalities can now be explored in detail to determine the significance of individual differences in stress responses and personalities in birds.
TL;DR: In this paper, a review brings together numerous theoretical and empirical studies investigating the flight behaviour of migratory birds in relation to the wind, concluding that birds select for favorable wind conditions both at departure and aloft to save energy and that for some long-distance migrants a tail-wind is an indispensable support to cover large barriers.
Abstract: Migration is a task that implies a route, a goal and a period of time To achieve this task, it requires orientation abilities to find the goal and energy to cover the distance Completing such a journey by flying through a moving airspace makes this relatively simple task rather complex On the one hand birds have to avoid wind drift or have to compensate for displacements to reach the expected goal On the other hand flight costs make up a large proportion of energy expenditure during migration and, consequently, have a decisive impact on the refuelling requirements and the time needed for migration As wind speeds are of the same order of magnitude as birds’ air speeds, flight costs can easily be doubled or, conversely, halved by wind effects Many studies have investigated how birds should or actually do react to winds aloft, how they avoid additional costs or how they profit from the winds for their journeys This review brings together numerous theoretical and empirical studies investigating the flight behaviour of migratory birds in relation to the wind The results of these studies corroborate that birds select for favourable wind conditions both at departure and aloft to save energy and that for some long-distance migrants a tail-wind is an indispensable support to cover large barriers Compensation of lateral wind drift seems to vary between age classes, depending on their orientation capacities, and probably between species or populations, due to the variety of winds they face en route In addition, it is discussed how birds might measure winds aloft, and how flight behaviour with respect to wind shall be tested with field data