35 research outputs found
Diurnal variation in the production of vocal information about food supports a model of social adjustment in wild songbirds
Protective effects against abortion and fetal infection following exposure to bovine viral diarrhea virus and bovine herpesvirus 1 during pregnancy in beef heifers that received two doses of a multivalent modified-live virus vaccine prior to breeding
Speedy revelations: how alarm calls can convey rapid, reliable information about urgent danger.
In the perpetual struggle between high-speed predators and their prey, individuals need to react in the blink of an eye to avoid capture. Alarm calls that warn of danger therefore need to do so sufficiently rapidly that listeners can escape in time. Paradoxically, many species produce more elements in their alarm calls when signalling about more immediate danger, thereby increasing the reliability of transmission of critical information but taking longer to convey the urgent message. We found that New Holland honeyeaters, Phylidonyris novaehollandiae, incorporated more elements in alarm calls given to more dangerous predators, but video analysis revealed that listeners responded in 100 ms, after only the first element. Consistent with this rapid response, the acoustic structure of the first element varied according to the danger, and playbacks confirmed that birds need hear only the first element to assess risk. However, birds hid for longer and were more likely to flee, after calls with more elements. The dual mechanisms of varying both element structure and number may provide a widespread solution to signalling rapidly and reliably about immediate danger.This work was supported by a NERC studentship award (grant no. 1395214) to J.R.M, support from the Research School of Biology at the Australian National University, and funding from an ARC Discovery grant (DP150102632) to R.D.M., A. Radford and E. Fernández-Juricic