Twice a year, billions of birds migrate between breeding and wintering grounds. To facilitate migration, birds develop a suite of behavioral and physiological adjustments such as hyperphagia (overeating) and fattening, changes in circadian rhythms of activity, seasonally appropriate orientation, muscle hypertrophy, etc. These adjustments are regulated by specific neural and endocrine pathways, which can vary between spring and autumn migration. Despite the similarities in physiological and behavioral adjustments related to migration, avian species often vary in travel distances and ecology. It is well established that the expression of many migratory traits can be population- and species-specific. In contrast to short-distance migrants, most birds that migrate long distances cross ecological barriers and perform long, non-stop flights which set specific requirements on fueling strategy and energy metabolism during endurance flight. The annual cycle of long-distance migrants is more time-constrained, and as a result, the expression of physiological adjustments is under strict endogenous control. Short-distance migrants rely less on endogenous programs and environmental factors contribute much more in the regulation of their physiology and behavior. Moreover, populations of some species show a range of life history strategies, from residency to long-distance migration. This makes such species ideal for studying physiological adjustments specifically related to migration.
In this symposium we will review current knowledge and recent discoveries in migration physiology by utilizing within and among species comparisons. The symposium will highlight the following topics (1) variation in physiological adjustments related to migration itself, (2) variation in endocrine regulation of migratory physiology, and (3) integration of spring migration and reproductive physiology.
We aim to bring together migration physiologists from around the world to catalyze the development of new ideas. Understanding variation in migratory traits and the underlying mechanisms will be critical for predicting the capacity of migratory populations to respond to future environmental change.
29. The impact of weather on the behaviour, ecology and physiology of birds
Mark Mainwaring, Stuart Sharp
The main objective of this symposium is to provide a platform for scientists from across the globe to present and discuss research examining the effects of weather conditions on birds. Variation in temperature, rainfall, wind and other variables impacts birds at a range of temporal and spatial scales and at every level from individual behaviour to species distributions. Understanding these processes has become a major focus of research, and this symposium will provide the presenters, audience members and the wider ornithological community with the opportunity to evaluate the state of research into the effects of weather on birds and to discuss those areas where further work is likely to prove fruitful.
We believe the symposium is of broad significance to the ornithological community because weather conditions ubiquitously affect all aspects of avian biology. Much of the research on the effects of weather focuses on climate change and extreme weather events, but more typical or local weather conditions also have a major influence on distributions, behaviours, dispersal, reproduction, life history, ontogeny and physiology. The ability of birds to adapt in these regards has important fitness consequences because the weather directly impacts their survival and reproductive success.
Our hope is that discussions inspired by symposium speakers will prompt novel innovative studies examining how weather conditions influence birds across the globe.
There is an urgent need to predict species spatial responses to global change to ensure conservation of habitat suitable to support diversity. However, interpreting the validity of current predictive distributions is challenging due to variation in temporal and spatial resolution of data sets and the reality that many species of conservation concern may be naturally rare. The capacity of species to change their geographic ranges under global change is limited by both large scale abiotic (e.g., temperature and rainfall patterns; i.e., macrohabitat) and small scale biotic (e.g., physiological limitations and biotic interactions; i.e., microhabitat) factors. Our ability to robustly predict the most important variables contributing the probability of site occupancy may also be dictated by the detection probability of study species. Our objective with this symposium is to address whether and how current approaches to predicting bird distributions under global change align with theory and to what degree they can inform conservation initiatives around the globe. Refining predictions for anticipated range shifts with global change is important to facilitate the conservation of future suitable habitats.
M. MacPherson: “Can we predict bird distributions under global change? Linking distribution models with conservation goals”
M. Marini: “The effect of detectability on species distribution modeling: A test with Cerrado endemic forest birds”
31. The evolutionary ecology of avian senescence: patterns, processes and the prices paid
Sandra Bouwhuis, Antoine Stier
Birds, in comparison to mammals, are relatively long lived for their size and were once thought to largely escape senescence, a within-individual age-specific decline in survival probability and/or reproductive performance caused by a progressive loss of physiological and cellular function. As longitudinal studies have accumulated, it has, however, become clear that many bird species show signs of late-life deterioration after all. As such, the question of whether birds senesce has been replaced by questions regarding (i) variation in rates of senescence among traits and individuals, (ii) the mechanistic basis responsible for the observed senescent declines, and (iii) the fitness costs associated with senescence. In this symposium, we would like to start answering these questions and bring together ornithologists studying avian senescence from descriptive, mechanistic and evolutionary angles. The interdisciplinary crosstalk that we hope will be the result of this symposium should allow our research community to pursue even more promising investigations into the extent, causes and consequences of individual variation in avian senescence.
Pierre Bize: “What can natural bird populations tell us on why we don’t all age at the same rate”
Sandra Bouwhuis: “Avian Escape Artists? Patterns, Processes and Costs of Senescence in Wild Birds”
32. The “Anthropause”, a natural experiment: Leveraging ornithological studies during the COVID-19 lockdowns to develop conservation strategies for a post-pandemic world
Nicola Koper, Olivia Sanderfoot
During the height of the first wave of the COVID-19 pandemic, more than 50% of the world’s population was under some type of lockdown. This resulted in a sudden, rapid decline in human mobility, often referred to as the “Anthropause.” This unprecedented moment in human history also became a once-in-a-lifetime global experiment in altering the human footprint on wildlife. Researchers around the world took advantage of the event to learn more about how such large shifts in travel, commerce, and other human activities impacted birds. The effects of the pandemic were not felt equally around the world, offering valuable insight into the many different mechanisms that link human activity to the ecology and conservation of birds. In this session, speakers will highlight and discuss the ways in which changes in human behavior during the Anthropause influenced the behavior, presence, and abundance of birds. Contributed talks will assess impacts of the Anthropause on avian productivity and behavior, and compare the roles of factors such as traffic, noise, and pollution. Speakers will explore what those results can teach us about the value of ongoing and future conservation efforts, especially in urban environments where human impacts are felt the most. In a post-pandemic world, which conservation strategies are most promising, and where should societies invest increasingly limited conservation dollars to ensure that birds thrive?
Amanda E. Bates: “Overview of COVID-19 lockdown impacts on birds and implications for avian conservation”
Elizabeth Derryberry: “Singing in a silent spring: birds respond to a half-century soundscape reversion during the Anthropause”
33. Using full annual cycle research to improve conservation of migratory species
Almut E. Schlaich, Peter P. Marra
Migratory bird species are in decline globally. From climate change, to the intensification of agriculture and deforestation, to direct mortality from cats and collisions, where and when these threats operate throughout the annual cycle remains poorly understood. To understand major stressors and increase the effectiveness of conservation efforts, full annual cycle approaches are essential. Migratory species spent parts of their annual cycle in often widely separate areas, where different factors and processes can act on populations and individuals. To date, although there is a severe breeding season research bias for most species, more studies are investigating how events operating during different stages of the annual cycle interact and operate at individual (carry-over effects) or population levels (density-dependent effects) to drive ecological and evolutionary traits. This is exciting and essential from a biological perspective but also so we can direct conservation efforts to reverse population declines of many long-distance migrants. During the symposium, the state of affairs regarding full annual cycle research and its conservation implications will be summarized and examples of inclusive studies from different flyways will be presented.
Peter Marra: “Studying birds in the context of the full annual cycle.”
Almut Schlaich: “Individual tracking, aeroecological monitoring and behaviour-based modelling – a multi-tiered approach to conserving migratory species”
34. The ecology and evolution of moult in tropical birds
Gabriel A. Jamie, Chima Nwaogu
Avian feathers perform crucial functions for flight, thermoregulation and communication. However, their effectiveness can be altered over time due to wear. Birds must therefore replace their feathers at regular intervals (moult), a process which forms an essential, but often overlooked, aspect of their life history. While the importance of moult ranks alongside, and may determine the outcome of, other essential activities such as breeding and migration it has received only a fraction of the research.
Most studies that do exist on moult come from temperate systems. This presents a biased picture of how, when and why moult occurs in tropical systems. The tropics contain the majority of the world’s avian biodiversity and show markedly different seasonalities and ecologies to temperate regions. These differences may even allow the timing of some activities in the annual cycles of tropical birds to be decoupled from environmental seasonality. Thus, it is crucial that we have a coherent framework with which to explore the moult of tropical birds and contrast it with the received wisdom obtained from studies on temperate species. How do tropical birds fit moult into their annual cycle alongside other competing demands? How do moult strategies evolve across tropical species radiations? How are moult strategies adapted to a tropical species’ ecology? What role do divergent moult adaptations play in the process of speciation? Is the terminology we use to describe moults and their resultant plumages adequate to capture the diversity of moult strategies found in tropical species?
The objective of this symposium is to bring together researchers studying moult globally but with keen interest in the moult pattern of species in different tropical environments. What generalities can we derive about moult in tropical birds? How do moult adaptations differ across tropical ecosystems? In so doing, we hope to develop debate both on research methodologies for studying and scoring moult in the tropics and to generate conceptual insights with which to understand them. By situating moult at the centre rather than the periphery of their annual cycles, we hope this symposium will enable a deeper understanding of the life histories of tropical birds to emerge.
35. Paleobiology of Mesozoic Birds
Luis M. Chiappe, Anusuya Chinsamy-Turan
In the last few decades, fossil discoveries have demonstrated the existence of numerous extinct lineages of birds that lived during the Mesozoic Era. This wealth of fossils—many preserving soft tissues and gut contents—have transformed our knowledge of the early history of birds, thus providing much evidence for understanding the origin and evolution of their modern relatives. For two centuries, the diversity of Mesozoic birds was composed of just a handful of archaic lineages—the familiar Archaeopteryx, Hesperornis, and Ichthyornis—but we now know that the predecessors of modern birds underwent dramatic adaptive radiations resulting in a wide range of body forms and lifestyles, occupying all continents and many different environments. The recent discoveries have filled significant gaps in the phylogeny of early birds, illustrated the morphological transitions that took place across different anatomical systems, and documented the diversity of flight styles, ecologies, and life history strategies of these birds. Over the broad spectrum of phylogenetic divergences spanning 85 million years of avian evolution, from the Late Jurassic Archaeopteryx to the earliest modern birds of the latest Cretaceous, today’s fossil evidence documents the evolution of the unique biological systems of living birds from animals that were biologically more akin to their dinosaurian forerunners. In this symposium, the Keynote Speakers and Oral Presenters will review the recent advances pertaining to the early history of birds, focusing on the evidence documenting their life history attributes, and ecological and aerodynamic specializations, as well as their implications for understanding the rise of modern birds.
Luis Chappe: “Overview of early avian evolution”
Anusuya Chinsamy-Turan: “Life history strategies of early birds”
Jingmai O’Connor: “Trophic ecology in Mesozoic birds”
Francisco Serrano: “Flight performance and diversity in early birds”
Jesus Marugan-Lobon: “Polymorphism in the early evolution of birds”
36. Drone Research: From scientific advances to applied conservation
Petra Sumasguter, David Bird, Shane McPherson
Over the past decade, the use of unmanned aerial vehicles (UAVs, hereafter ‘drones’), has exploded in popularity in ecological studies. As a cutting-edge tool, drones have many advantages over traditional survey and research techniques, most importantly, saving biologists’ lives lost in crashes of manned aircraft. They minimize disturbance and allow data collection of large and/or inaccessible areas; an accurate repetition of flight routes; flexible control of spatial and temporal resolution; and the possibility of carrying optical or thermal sensors and/or base stations for remote data downloads. While some of the current uses are preliminary or “proof-of-concept”, drone technology can significantly reduce sampling and management costs/efforts and allow high-intensity and high-quality data collection. However, a growing number of studies indicate potential ethical concerns over the exposure of wildlife to drones, yet few explicitly address this issue and our knowledge on behavioral and specifically physiological responses to drones is still limited.
Our objectives are to first introduce various applications of drones to both ornithology and bird conservation (keynote 1: “Drones: More than an emerging technology for ornithologists”). Specifically, we are interested in the latest advances in accessing nests, counting flocks and detecting birds (incl. the use of infrared cameras), radiotracking, and dispersing nuisance birds. Second, we will highlight our current knowledge of behavioral and physiological responses to drones obtained from a literature review and an individually-based experimental study (key note 2: “Behavioral and physiological responses of wild birds to drones”).
Our intended outcomes are three-fold. First, we wish to bring together experts who have been using drones in ornithological applications and those who are merely contemplating their use in their fields to encourage the latter to use this pioneering technology. Second, we expect to discuss failures and successes as a means of assisting those in need of help. Finally, we hope that a face-to-face discussion among both experts and potential users of drones will result in future research collaborations.