13th EOU Congress 2022
March, 15, 2022
photo: Daniel Jakli
Behavioural ecology of birds in urban environments
Veronika Bókony, Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Budapest, Hungary
Urbanization is one of the most salient forms of human-induced environmental change currently affecting Earth’s biota. The past two decades have seen a flourishing in evolutionary-ecological research aimed at understanding the effects of habitat urbanization on wild animals at the individual and population levels, and birds have been playing a major role as model organisms in this endeavour. This plenary provides an overview of characteristic examples of how urbanization changes birds’ morphology, physiology and behaviour, and how this might contribute to their adaptation to city life in terms of exploiting novel resources, dealing with predation risk and human disturbance, withstanding heat stress, and raising offspring in an altered “foodscape”. I will highlight the similarities and differences in avian responses to urbanization by comparing the findings on two species: the Great Tit, a former forest specialist that has colonized urban habitats in the previous century and is generally perceived as a pleasant bird by the public, and the House Sparrow, a human commensalist that has been evolving in anthropogenic habitats for thousands of years and has traditionally been regarded as a pest. I will also point out the most important knowledge gaps that future research needs to fill for a comprehensive understanding of the mechanisms behind, and the consequences of, phenotypic changes observed in urban populations.
How migrating birds find their way: compasses and maps
Nikita Chernetsov, Zoological Institute RAS, St. Petersburg, Russian Federation and St. Petersburg State University, St. Petersburg, Russian Federation
Billions of birds move between their breeding and non-breeding quarters annually, often covering hundreds and thousands of kilometres. To perform these feats, the birds need a positioning system (a map) and a compass system, as conceptualized by Gustav Kramer some 70 years ago. Most students of avian navigation agree that migratory birds are able to use the sun, the star pattern and the geomagnetic field for compass orientation. Current advances in this area mainly concern the molecular, cellular and neurobiological bases of magnetoreception which remained enigmatic until very recently. Another intriguing topic in the study of avian compass systems is how different systems interact and result in migrating birds choosing the correct direction of flight on the basis of multiple sources of information. Unlike compass systems, there is less agreement on the physical nature and sensory basis of positioning systems of long-distance migrants. Two kinds of maps seem to be relevant for migrating birds: magnetic maps and olfactory maps. For a long period, these two hypotheses were considered to be alternative and mutually exclusive. It seems that the proponents of both hypotheses were right to some degree: migrating birds seem to use both magnetic and olfactory positioning systems, possibly at different spatial scales. Positioning systems based on the gradients of the geomagnetic field alone cannot account for the remarkable spatial accuracy of navigation shown by migrating birds. Fine-tuning must be based on another physical, and this sensory, principle, and it is entirely possible that this is olfaction.
Moult: an essential, but underrated, process with multiple effects on a bird’s biology
Lukas Jenni, Swiss Ornithological Institute, Sempach, Switzerland
Feathers, being dead structures, are subject to wear and hence must be replaced periodically during moult. However, the replacement of feathers presents several difficulties: feathers cannot grow continuously, like hair or claws; feathers can only be renewed from follicles existing since embryonic times; a feather can only be replaced after the old one has fallen off; a growing feather must finish growth, it cannot interrupt growth. Therefore, the replacement of feathers inevitably results in temporary gaps in the plumage which vary in number depending on the number of concurrently growing feathers (i.e., moult speed). In this talk, I will explore the constraints imposed by moult during the moult period, such as the question of how energetically expensive moult is, what the physiological consequences and interactions with other processes are, and how moult can be fitted into the annual cycle. I will also show how conditions during moult affect the quality of the new feathers, ornamental and non-ornamental, and hence the performance of the individual bird, aspects which are particularly interesting for behavioural ecologists.
CREAF-CSIC, Barcelona, Spain
The real genius of birds: Ecological and evolutionary implications of innovative behaviours
Daniel Sol, CREAF-CSIC, Barcelona, Spain
Many animals are capable of solving problems by learning new behaviors, a form of intelligence known as innovation. While being innovative has obvious benefits, given that animals that are frequently exposed to new challenges, only a few species are considered to be highly innovative. The evolutionary origin of such a capacity is puzzling if we think that innovating means responding to problems that the animal has rarely experienced before, and is therefore unlikely to be selected by itself. Solving this puzzle is however crucial to understanding the ecology and evolution of animals because the ability to innovate has the potential to profoundly alter the relationship of animals with their environment. It follows that innovation can be relevant in a variety of processes such as range expansions, migratory movements, extinctions and speciation events. In this talk I will use birds to discuss recent progress in our understanding of the evolutionary origin of innovativeness and to highlight some of the implications for their ecology and evolution.
Department of Zoology, University of Cambridge
Show me the honey: the natural history of a bird-human mutualism
Claire Spottiswoode, University of Cape Town, Cape Town, South Africa and University of Cambridge, Cambridge, United Kingdom
Greater honeyguides are remarkable mutualistic partners of our own species, whom they lead to wild bees’ nests. Honeyguides know where bees’ nests are located and eat beeswax, whereas human honey-hunters know how to subdue the bees and open the nest, exposing wax for the honeyguides and honey for the humans. Human and honeyguide populations vary intriguingly in whether and how they rely upon, communicate with and reward one another, and how their mutualism influences the surrounding ecosystem. This talk will share our team’s research from Mozambique and Tanzania that investigates how such learnt traits influence how the mutualism is maintained, giving rise to a hypothesis of cultural coevolution between species. Reciprocal learning may have led to a geographical mosaic of honeyguide behavioural variation that maps onto the cultures of their human partners, across those places in Africa where this part of our own evolutionary history still thrives.