For birds, red means go

New research has shown that certain Australian native flowers have shifted away from using insects as pollinators and evolved their flower colour to the red hues favoured by birds.

We demonstrate, for the first time, that Australian native flowers exclusively pollinated by birds have evolved colour spectral signatures that are best discriminated by those birds.

 We collected spectral data from over 200 flowering plants and identified the pollinators as birds or insects. We found that flowers exclusively pollinated by birds had initially evolved to suit insect vision, but more recently the spectral signature of bird-pollinated flowers had shifted towards longer wavelengths. The research showed that rather than just having any type of red reflection, bird-pollinated flowers targeted the specific wavelengths that best match the long wavelength tetrachromatic (four colour) vision of many Australian native birds.
(Photo: Adrian Dyer)

Read an example of the media coverage here

Congratulations to Will Sowersby and Nicholas Deal!

Congratulations to Will Sowersby and Nicholas Deal for each being awarded grants from the Holdsworth Wildlife Research Endowment for their PhD projects.

Small male fish use high aggression strategy

A new study is shedding light on the aggressive mating behaviour of smaller nest-holding males. We quantified initiation of aggression in a fish, the desert goby  by exposing nest-holding males to a male intruder. The perceived value of the resource was manipulated by exposing half of the residents to sexually receptive females for two days before the trial. Resident male aggression, however, was unaffected by perceived mating opportunities. It was also unaffected by the absolute and relative size of the intruder. Instead resident aggression was negatively related to resident male size. In particular, smaller residents attacked sooner and with greater intensity compared to larger residents. These results suggest that resident desert goby males used set, rather than conditional, strategies for initiating aggression. If intruders are more likely to flee than retaliate, small males may benefit from attacking intruders before these have had an opportunity to assess the resident and/or the resource.
(Photo: Andreas Svensson)

Read a popular article and accompanying video about the research here