What can webcams tell us about trade-offs in swan behaviour?
Kevin A. Wood1, Rebecca Lacey2 & Paul E. Rose1,2
1Wildfowl & Wetlands Trust, United Kingdom.
2University of Exeter, United Kingdom
A growing number of nature reserves have begun to use live-streaming webcams to showcase their wildlife to the outside world. This presents an opportunity for researchers to study animal behaviour without needing to be physically present at the site. Remote data collection can also have advantages by reducing the impacts of disturbance on wildlife during the study, as well as reducing the carbon footprint associated with repeated visits to observation sites. Webcams have therefore become an increasingly popular tool among biologists.
Mute Swans engaged in an aggressive interaction. © WWT.
In a new study, published open access in PLoS One (Wood et al., 2022), we used a live-streaming webcam at the Wildfowl & Wetlands Trust’s Caerlaverock wetland reserve to study the behaviour of two swan species that spend the winter there: the Mute Swan (Cygnus olor) and Whooper Swan (Cygnus cygnus). Within Britain, both Mute and Whooper Swans have undergone substantial increases in population size since the 1980s (Wood et al., 2019; Brides et al., 2021). Their large size, white plumage, and use of open-water habitats, make them ideal focal species for studies of animal behaviour (Figure 1). For both swan species, we carried out 15-minute observations of 119 individual swans in winter 2020/21 to investigate whether the amounts of time spent engaged in key mutually exclusive behaviours (aggression, foraging, maintenance, and resting), were correlated.
We found a negative association between aggression and resting behaviours in both species, indicating that increased aggression is achieved at the expense of resting behaviour. In contrast, there was no apparent trade-off between aggression and foraging, aggression and maintenance, or maintenance and resting. Foraging and resting behaviours were negatively correlated in both species, highlighting a trade-off between these distinct modes of behaviour. A trade-off between foraging and maintenance behaviours was detected for the sedentary mute swans, but not the migratory whooper swans. The findings that we obtained show how swans can trade-off their time investments in mutually exclusive behaviours within their time-activity budgets.
Our study demonstrates how remotely-collected data can be used to investigate fundamental questions in behavioural research. Methods of collecting data remotely, such as webcams, offer a number of advantages to researchers. These include reduced impacts of disturbance on focal animals, reduced carbon footprint associated with repeated visits to observation sites, and greater accessibility for scientists who cannot physically travel to study sites. Remote methods can also offer a means to collect data during the Covid-19 pandemic, which has curtailed the ability of researchers to visit field sites to undertake traditional methods of in-person data collection. Given these advantages, we expect that remote methods of data collection will become an increasingly valued tool for behavioural research.
The full article can be found here.
References:
Brides, K., Wood, K.A., Hall, C., Burke, B., McElwaine, G., Einarsson, O. & Rees, E.C. (2021). The Icelandic Whooper Swan Cygnus cygnus population: current status and long-term (1986–2020) trends in its numbers and distribution. Wildfowl, 71, 29–57. https://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/2751
Wood, K.A., Brown, M.J., Cromie, R.L., Hilton, G.M., MacKenzie, C., Newth, J.L., Pain, D.J., Perrins, C.M. & Rees, E.C. (2019). Regulation of lead fishing weights results in Mute Swan population recovery. Biological Conservation, 230, 67–74. https://doi.org/10.1016/j.biocon.2018.12.010
Wood, K.A., Lacey, R. & Rose, P.E. (2022). Assessing trade-offs in avian behaviour using remotely collected data from a webcam. PLoS ONE 17 (7): e0271257. https://doi.org/10.1371/journal.pone.0271257
