CIE Seminar Series – 2020: Costs, benefits and the evolution of seasonal plumage colours

SPEAKER: Dr Alexandra McQueen, Associate Research Fellow, Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University

DATE & TIME: Friday, 26th June 2020 @ 12:00 noon

LOCATION: Seminar to be streamed via Zoom. Click HERE to connect.


Many animals use elaborate ornaments, such as conspicuous colours, to intimidate rivals and attract mates. Understanding ornament costs is essential for understanding animal communication and the evolution of traits under sexual selection. However, measuring costs is challenging because ornaments often co-vary with other factors, such as the propensity to take risks and available resources.

During my PhD, I investigated the costs of a conspicuous sexual ornament in superb fairy-wrens (Malurus cyaneus). In this species, males undergo an annual colour change from a brown, non-breeding plumage to a bright, ultraviolet-blue and black plumage.

I show that males perceive themselves as facing a higher risk of predation when in blue plumage, while the production of the male’s conspicuous ornament entails only minor physiological costs. I find that male fairy-wrens do not spend more time preening while blue, and instead maintain vivid colours by replacing feathers throughout the breeding season.

These results suggest that predation risk is a key cost of displaying conspicuous colours. The need for blue males to maintain increased predator-avoidance behaviour, combined with age constraints and small, physiological costs, could explain why female fairy-wrens prefer extra-pair males that are blue for the longest time each year.


Dr Alexandra McQueen is an Associate Research Fellow at Deakin University. Alex completed her PhD on the costs of colour signals and the evolution of colour change in birds at Monash University in 2019.

As a behavioural and evolutionary ecologist, Alex is interested in the evolution of the colours and shapes of birds.

Currently, Alex is investigating how birds use their beaks for thermoregulation, and the evolution of beak size in response to climate change, as part of a research team with A/Prof. Matthew Symonds and Prof. Marcel Klaassen.

For more info click HERE.

As a courtesy, we request that when connecting to the seminar that you mute your microphone unless you are required to speak, this would ensure that the sound from the speaker to the audience is not disrupted by feedback from your microphone.

Thanking you in advance!