New publication: Repeatability of signalling traits in the avian dawn chorus

Our newest open access paper on repeatability of avian signalling (song)  traits just came online in the journal Frontiers in Zoology.

Repeatability, consistent individual differences, in signalling behaviour is interesting because it means that those receiving the signal (i.e. listening to the song) could reliably learn something about how the individual singer compares to other singers/competitors.

We repeatedly recorded the dawn song of great tit males throughout the breeding season and show that start time of dawn song and repertoire size are individually repeatable both before and during the egg-laying stage of the mate (when she is fertile). Surprisingly the time a male started singing appeared to be more repeatable (consistent) than repertoire size, despite that the start time was also influenced by variable overnight temperatures. Start time was also more repeatable before than during egg-laying and we suggest that this is related to the behaviour of the (assumingly) intended receivers of the song, the females.

For a subset of the singers, we also explored a potential link between the absolute song trait values, the repeatability of these values and personality. We did not find a link but follow-up studies with a larger sample size, and including additional song traits, will be needed to confirm the true absence of such a link.

Naguib M, Diehl J, van Oers K, Snijders L (2019). Repeatability of signalling traits in the avian dawn chorus. Frontiers in Zoology 16: 1-11. 


A new project! Personality and migration strategies in bats

This month, I officially started with my two-year postdoc fellowship at the Leibniz Institute for Zoo and Wildlife Research (IZW), granted by the Alexander von Humboldt-Stiftung. As of now, I am part of the Evolutionary Ecology Department, or more specifically: the Batlab, and I will study the role of personality and social associations in the movement behaviour of partially migratory noctule bats, Nyctalus noctula. In Germany they are called Abendsegler, meaning something like ‘Evening sailor’. Beautiful isn’t it? I am very much looking forward to my work at IZW and I hope to learn many new things, meet many passionate wildlife researchers and contribute some fascinating new insights into noctule bat behaviour.


Abstract of my awesome bat project:

Migratory animals vitally connect distant ecosystems worldwide, impacting key ecological processes by transporting nutrients, seeds, parasites and pathogens. As the only flying mammals, bats represent a unique and widespread group of migratory animals, serving important ecosystem functions as pollinators and pest controllers. Bats comprise one fifth of all mammal species, but little is known about their migration strategies. Yet understanding animal migration strategies provides important insights into ecosystem connectivity. Therefore, I aim to gain a better understanding of the key mechanisms that drive variation in bat migration strategies.

A single bat population can contain resident as well as migrating individuals. Such populations offer an excellent opportunity to study individual differences in migration strategies within populations. Hitherto, research on migration has mostly focused on birds, yet novel tools have recently become available to study partial migration in bats. Migration poses a trade-off: migration can lead individuals to more favourable habitats, but is also risky and energetically costly. Individuals have to balance these costs and benefits of migration and are likely to differ in how they do so. Bats fundamentally differ from many migrating bird species in key life-history traits that profoundly impact migration decisions. Knowledge about bat migration strategies, may thus lead to crucial insights into the maintenance of animal migration over evolutionary timescales.

New and improved techniques, such as non-invasive isotopic geolocation, allow for novel insights into the migration strategies of this poorly understood migratory taxon. Using this novel technique in combination with bat personality assays, social network analyses and bat banding, I will test whether individual bats consistently or plastically differ in their migration strategies and investigate the key social, physiological and behavioural factors underlying these differences.