Hormonal mechanisms and consequences of divorce in the zebra finch

Our paper focused on the experimental divorce of zebra finch pairs has been published in the January volume of the journal Hormones and Behavior. The link to the paper is hereThe paper was led by Ondi Crino and is based on bidivorcerd work at Macquarie together with hormone assays that she did when she moved to Deakin, to take a new position in Kate Buchanan’s group. The main findings in the study were that new pairs that formed after an experimental divorce took longer to lay their clutch, and their offspring had higher levels of stress than those of their counterparts that stayed together. The study helps us to understand why so many birds remain with their partners from one breeding attempt to the next – serial monogamy.

Lack of clear genetic structuring in wild populations of the endangered Gouldian finch

Peri’s paper characterising the population genetics of the Gouldian finch in the wild was published last week in the open access PLosOne. This paper focuses on birds sampled from across the range of the Gouldian finch including samples from Mornington and Wyndham in the Kimberley, Western Australia; a number of sites in the Northern Territory, and Chidna in Queensland. DNA extracted from blood samples taken from the wild birds was analysed using three molecular approaches and indicates that there is no clear genetic structuring across the sampled areas. This is consistent with a view that Gouldians are quite mobile, and individuals may be found across a wide range. An implication of this molecular work is that the species may be more difficult to reliably census than species which have a higher level of genetic structuring, and are more restricted to particular areas or sites.

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Network connecting mitochondrial control region haplotypes from the different sampling localities (Figures from Bolton et al 2016, in PLosONE)

The rationale for undertaking this work was to help inform management of this species, and this work was part of our submission to the committee responsible for the Federal Environmental Protection and Biodiversity Conservation Act, who on the 7th December announced their decision to retain the status of the Gouldian finch as ‘endangered’ which is a great outcome and maintains a good degree of protection for the species and its habitat.

The full paper is open access and can be found here.

Egg diversity

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Bowerbird eggs in the ANWC collection

We’re spending a few days in Canberra at the amazing egg collection in the Australian National Wildlife collection, measuring variation in size, coloration and patterning across the Australian passerines. The data will be analysed as part of our ongoing research into the way that the environment affects nesting and reproductive investment. The collection holds specimens from most species and reveals the stunning diversity across birds in the amount of pigmentation and patterning.

 

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Why is there so much variation in colour and patterning?

Drone workshop at Fowlers

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A UAV working at Gap Hills, one of our long-term study sites at Fowlers Gap

UAV’s or drones are increasingly being used in environmental science, as a great way of gathering imagery and deploying sensors. In mid September, Richard Lucas, from UNSW organised a fantastic meeting, which brought together a range of different UAV’s and sensors for a few days of frenetic data gathering. We were lucky enough to get involved, and helped to set up ‘challenges’ and ground truth some of the data acquired. The data that has now been gathered in Lake Paddock (the central area for the chestnut-crowned babbler project), and Gap Hill (the key area for our work on zebra finches), will provide excellent insight into the link between landscape, vegetation and avian ecology, once it is all processed and analysed.

The evolution of nest shape

Although not yet published there is a nice story in Science News about our work on the

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The domed nest of a zebra finch

evolution of nest shape. The story can be found here. The work is currently under review for publication but was presented by lead author Jordan Price at the recent North American Ornithological Congress. Jordan did this work with us whilst on Sabbatical early this year.

The cost of being social

One of the papers from Enrico Sorato’s PhD work was published today in the Journal of Animal Ecology. In the paper, we showed that in the chestnut-crowned babbler,

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Chestnut-crowned babbler (picture Jodie Crane)

individuals suffer a cost of hanging around with their group mates, even if they are not actively involved in feeding offspring. That’s because over the course of a breeding attempt the foragers have to move further into the territory away from the nest to find enough food, incurring greater costs of moving and foraging. This cost, which has not been considered before may help to understand individual decisions about when to stay and when to leave a social group, and will contribute to the optimal group size. The paper is entitled The price of associating with breeders in the cooperatively breeding chestnut-crowned babbler: foraging constraints, survival and sociality, and can be found here.