For my undergraduate degree I studied zoology at Cambridge, graduating in 2007, where I received the Ellen Delf-Smith award from Girton College. I worked as a research assistant at the Kalahari Meerkat Project for 1 year, before receiving a Small Ecological Projects grant from the British Ecological Society to investigate parent-offspring foraging dynamics in pied babblers (Turdoides bicolor). I have since started a PhD at the Percy FitzPatrick Institute, University of Cape Town.
Abstract: One theory to explain the existence of conspicuous solicitation is that it is a way for young to ‘blackmail’ carers into provisioning them, by threatening their own destruction. Fledgling birds offer a unique opportunity to investi- gate the ‘blackmail theory’, as their mobility enables them to influence the predation risk they face. We investigated a novel solicitation behaviour in fledgling pied babblers (Turdoides bicolor), where fledglings use their location to influence provisioning rates. We show that fledglings face a trade-off: the ground is a much more profitable location in terms of provisioning rate fromadult carers, but theyare at greater risk frompredators owing to their lim- ited flying ability and slow response to alarm calls. Young babbler fledglings move to the ground when hungry, signalling their state, and this stimulates adults to increase their provisioning rates. Once satiated, fledglings return to the safety of cover. By experimentally increasing terrestrial predation risk, we found that adults increased their provisioning rate to terrestrial but not arboreal fledglings. Thus, by moving to a riskier location, fledglings revealed their need andwere able to manipulate adults to achieve higher provisioning rates. These results provide support for the ‘blackmail theory’.
Abstract: Many cooperative bird species have an extended period of post-fledging care. Despite the fact that this period of care can last up to several months, it remains a relatively understudied stage of chick development. This period, when young are actively begging but highly mobile, provides an opportunity for young to maximise the amount of care they receive by selectively choosing particular adults to beg from. In pied babblers Turdoides bicolor (a cooperatively breeding passerine), fledglings closely follow foraging adults and beg for food regularly (a behavioural interaction termed social foraging). Using a combination of natural observations and experimental manipulations, we found that fledgling pied babblers preferentially socially forage with adult care-givers who have high foraging success, since this results in young receiving more food. By supplementally feeding adults to artificially increase their foraging success, we increased the proportion of time that fledglings chose to socially forage with them, confirming that fledglings are selectively choosing dyadic interactions with the best adult foragers. These results indicate that pied babbler fledglings are sensitive to and can respond to short-term changes in adult foraging success, enabling them to maximize their nutritional intake, a behavioural adjustment that has long-term benefits in this system.
Abstract: The southern African subspecies of Jacobin Cuckoo Cla- mator jacobinus serratus is a brood parasite of a range of host species. While Jacobin Cuckoos do not evict host young, previous research has found that host young rarely survive the nestling period. Here we provide the first records of Jacobin Cuckoo parasitism of a new host species, the Southern Pied Babbler Turdoides bicolor.We investigate rates of brood parasitism and the survival of host young. The Southern Pied Babbler is one of the largest recorded hosts for Jacobin Cuckoos and, unusu- ally, we find that host young tend to survive the nestling period and maintain similar body mass to host young in unparasitized broods. However, host young were less likely to survive to independence than young raised in unparasitized nests, suggesting a post-fledging reproduc- tive cost to hosts.
Abstract: While egg destruction by brood parasites is a relatively well-known phenomenon, such destruction by non-brood-parasitic heterospecifics is less common. Here, we provide the first evidence of egg destruction by Wattled Starlings Creatophora cinerea on Pied Babblers Turdoides bicolor. We find that the incubation success of Pied Babblers decreases significantly following the arrival of Wattled Starlings at the study site, and we provide video evidence of Wattled Starlings destroying Pied Babbler eggs. This behaviour is costly to Pied Babblers, whose current reproductive attempt is abandoned, with subsequent reproductive attempts delayed by several weeks. We found no evidence that egg destruction occurred for nutritional benefit: Wattled Starlings never consumed the eggs they destroyed. Rather, this behaviour appears to represent a form of resource competition, since Wattled Starlings only predate babbler nests in habitats where the starlings also build their nests.
Abstract: Wherever individuals performcooperative behaviours, each should be selected to adjust their own current contributions in relation to the likely future contributions of their collaborators. Here, we use the sentinel system of pied babblers (Turdoides bicolor) to show that individuals anticipate contributions by group mates, adjusting their own contribution in response to information about internal state broadcast by others. Specifically, we show that (i) short-term changes in state influence contributions to a cooperative behaviour, (ii) individuals communicate short-term changes in state, and (iii) individuals use information about the state of group mates to adjust their own investment in sentinel behaviour. Our results demonstrate that individual decisions about contributions to a cooperative effort can be influenced by information about the likely future contribution of others. We suggest that similar pre- emptive adjustments based on information obtained from collaborators will be a common feature of cooperative behaviour, and may play an important role in the development of complex communication in social species.
Abstract: The Duke of Burgundy butterfly (Hamearis lucina) has declined severely since the 1970s and is a UK Biodiversity Action Plan Priority species. Its populations are mostly confined to scrubby calcareous grassland, where management for short-turf species can be detrimental to the butterfly. We briefly review the literature on the Duke of Burgundy and investigate their habitat preferences, sur- vival and dispersal at a chalk grassland reserve in Bedfordshire, UK. We found that adults generally preferred more sheltered locations but that their habitat preferences were less restrictive than choice of food-plants. Females chose larger plants with longer leaves in denser patches on which to lay eggs. Adults showed reasonable dispersal ability with turnover recorded between areas isolated by scrub. Our results indicate that the species is able to use isolated areas of favourable habitat at a reserve scale and that conservation could therefore involve cyclic manage- ment to provide suitable habitat year-to-year.
