• Publications
  • Influence
The costs of keeping cool in a warming world: implications of high temperatures for foraging, thermoregulation and body condition of an arid-zone bird.
The value of investigations of temperature-dependent behaviour in the context of impacts on body condition is demonstrated, and it is suggested that increasingly high temperatures will have negative implications for the fitness of these arid-zone birds.
Interrogating recent range changes in South African birds: confounding signals from land use and climate change present a challenge for attribution
Aim Apparent anthropogenic warming has been underway in South Africa for several decades, a period over which significant range shifts have been observed in some indigenous bird species. We asked
Cognitive performance is linked to group size and affects fitness in Australian magpies
It is shown that in wild, cooperatively breeding Australian magpies, individuals that live in large groups show increased cognitive performance, which is linked to increased reproductive success, and a positive association between the task performance of females and three indicators of reproductive success is found, thus identifying a selective benefit of greater cognitive performance.
Synchronous provisioning increases brood survival in cooperatively breeding pied babblers.
A novel explanation for provisioning synchrony is proposed: it increases brood survival by decreasing the number of temporally separate nest visits and accordingly the chance that the nest will be detected by predators.
Monogamous dominant pairs monopolize reproduction in the cooperatively breeding pied babbler
Genetic data are used from a population of cooperatively breeding pied babblers to show that reproduction is highly skewed toward behaviorally dominant birds, and helping in this species confers indirect fitness benefits on subordinates, which are likely to play an important role in the evolution and maintenance of cooperative helping behavior.
Facultative response to a kleptoparasite by the cooperatively breeding pied babbler
This work investigates the response of cooperatively breeding pied babblers to the drongo, an avian kleptoparasite that regularly follows pied babbler groups, often giving alarm calls to alert the group to predators but also occasionally giving false alarm calls in order to steal food items.
Invading together: the benefits of coalition dispersal in a cooperative bird
  • A. Ridley
  • Biology
    Behavioral Ecology and Sociobiology
  • 2011
It is found that coalition dispersal appears to be an effective strategy to ensure the success of dispersal attempts, with coalitions more successful than lone individuals at taking over the breeding position in a new group.
Handbook of the Birds of the World. Volume 12: Picathartes to Tits and Chickadees
Lynx Edicions, Barcelona, Spain 816 pages, 56 colour plates, hardcover ISBN 8496553426, price €212 Ostrich 2008, 79(2): 249–250
Deception by Flexible Alarm Mimicry in an African Bird
The results show that drongos can evade the frequency-dependent constraints that typically limit deception payoffs through flexible variation of their alarm calls.
Experimental evidence for teaching in wild pied babblers
In pied babblers, Turdoides bicolor, adults often give purr calls when feeding young and offspring subse-quently associate these calls with food delivery, and experimental playbacks show that nestlings learn to respond toPurr calls and that purr Calls must be re-liably paired with food Delivery for learning to occur.