Note: IBRG welcomes presentations given by visitors of our affiliated labs. Guest presenters are indicated by an asterisk (*) in the schedule below.
|Akiko Matsumoto-Oda * (University of Ryukyus, Japan)|
|No meeting due to spring recess|
I am writing a monograph on Social Butterflies, culminating field research spanning 19 years, plus another 23 years of thinking, analysis, modeling, and trying to write. The central result is qualitative and quantitative description of behavior of the males of five species as they search for potential mates. The behaviors can be caricatured as: random vagrancy, accidental site-fidelity, trap-lining, territoriality, and resource-based leks (literal “singles’ bars”). At the conceptual level, I search for simple sensory cues and behavioral rules that can produce such varied behaviors. Book-ending these results are studies of sensory capabilities and biomechanics as they foster or constrain behavior, and plausible speculations about population consequences of random wandering versus restriction to particular pieces of real estate.
When I have difficulty writing a new chapter, it helps me to present its ideas and data in their homely larval form, the better to organize their metamorphosis into a lovely adult. So at IBRG, you will hear about the Viceroy and its territorial behavior, specifically:
(1) What cues can/do males use to choose habitat and perches that ensure potential visibility of females?
(2) Do individual males recognize particular pieces of real estate?
(3) Do they drive other males away?
I have measured the distances at which males respond to stimuli eliciting relevant behaviors, but I have yet to decide whether to begin or to end with this.
Card-carrying butterfly folk are about evenly divided between those who think that territorial behavior is already known in the Viceroy and its congeners, and those who think that territorial behavior has not been rigorously shown in any species of butterfly. Believers cite plausible answers to one or two of the preceding questions; skeptics need critical answers to all three. I seek your assessment of where I am on the spectrum.
(P.S. For hardcore IBRGers, at Beverage Hour, I can update my insights into the biomechanics of butterfly flight.)Back to schedule
Cooperatively breeding birds vary in how reproduction is divided among individuals, ranging from monopolization by a dominant pair (“high skew”) to equal sharing by co-breeders (“low skew”). Despite a plethora of theoretical models, the ecological and life-history factors that generate this variation remain poorly understood. Most studies have examined skew within a single species, making it difficult to identify variables with broad explanatory power. In this talk, I'll give an overview of a paper (currently in revision at Am Nat) that analyzes data from 83 species of cooperatively breeding birds, finding that kinship within the breeding group is a powerful predictor of reproductive sharing across species. Societies composed of nuclear families have significantly higher skew than those that contain unrelated members, a pattern that holds for both multi-male and multi-female groups. Within-species studies confirm this pattern, showing that unrelated subordinates of both sexes are more likely to breed than related subordinates are. These findings support the predictions of the original “concessions” models of reproductive skew, but they are also consistent with the hypothesis that the risk of incest in kin-based cooperative groups constrains reproduction by relatives. Given that subordinate reproduction may be limited by the availability of unrelated mates, future theoretical models should incorporate the possibility that inbreeding avoidance influences reproductive sharing.Back to schedule
The emergence and spread of savanna in Africa over the past 5 million years is often mentioned as a major factor in human evolution because, as human ancestors came out from forests to savanna, they encountered greater numbers of predators. However, there is little evidence regarding predation’s impact on behavior in non-human primates because of the difficulty of directly observing predation events. Today I will introduce an ongoing study of the influence of predation on behaviors, specifically changing sleeping sites, and mortality in a group of wild anubis baboons (Papio anubis). Our study was conducted at the Mpala Research Centre on the Laikipia Plateau, Kenya, with a group of anubis baboons that has been habituated and continuously monitored since 2010. Leopards are baboons’ main predator, and hunt baboons mostly at night, making the choice of sleeping sites relevant to survival. So: does the experience of predation influence the choices baboon groups make about where to sleep? Results showed that the group moved long distances and changed their sleeping sites on days immediately following predation events. Furthermore, I show that groups tended to avoid sleeping sites where predation occurred for a consistent period of time, indicating a period of predator memory in baboons.Back to schedule