RESEARCH
Neurophysiological techniques provide a window into the sensory experiences of animals, and data collected with these methods can be used to test many basic hypotheses concerning the evolution of sensory systems and their relationship to animal behavior and ecology. I use an interdisciplinary approach to investigate questions in sensory ecology at three levels:
- the physiology of the sensory cells that capture the information from the environment
- the behavior of the individual that is elicited by this information
- the impact of this individual's behavior on other individuals in the community, such as predators, prey, mates, and competitors
In addition, by combining lab and field experiments, a high degree of both control and biological relevance can be achieved.
My main study system has been bats and their insect prey. Insectivorous bats find their prey using echolocation or by listening to prey sounds, and many insects have ears that are sensitive to the ultrasonic calls of bats, a testament to the pressure exerted on nocturnal insects by these predators. Thus, in this system, both predators and prey use the single modality of hearing to detect each other. Two of the most intensely studied insect orders with respect to auditory physiology are the Lepidoptera (moths) and Orthoptera (crickets and katydids). When moths hear the echolocation calls of bats, they perform flight maneuvers that reduce their chances of being captured. Orthopterans present a more complicated example in which hearing is used for both predator detection and social communication.
|
Anti-predator defenses: Although strong relationships between morphology and behavior are known, fewer studies have considered the relationship between sensory capabilities and behavioral and evolutionary ecology. The simple ears of moths, with only 1-4 receptor cells per ear, allow us to quantify the total neural input to the auditory pathway and assess how such a small amount of information can be used to trigger appropriate reactions to predatory bats in different situations.
| Goerlitz HR*, ter Hofstede HM*, Holderied MW (2020) Neural representation of bat predation risk and evasive flight in moths: a modelling approach. Journal of Theoretical Biology 486: 110082. |
| Gordon SD, ter Hofstede HM (2018) The influence of bat echolocation call duration and timing on auditory encoding of predator distance in noctuoid moths. J Exp Biol 221: a171561. |
| ter Hofstede HM, Ratcliffe JM (2016) Evolutionary escalation: the bat-moth arms race. J Exp Biol 219: 1589-1602 |
| ter Hofstede HM*, Goerlitz HR*, Ratcliffe JM, Holderied MW, Surlykke A (2013) The simple ears of moths are tuned to the calls of their sympatric bat community. J Exp Biol 216: 3954-3962 |
|
|
|
|
Predation strategies: I am interested in learning if and how predators have adapted to the defenses of their prey. Bats provide an enormous amount of information to their prey due to their reliance on echolocation, but some bat species might adapt their echolocation behavior to make themselves less conspicuous to their prey. This provides an interesting opportunity to investigate sensory-based predator-prey coevolution.
| Geipel I, Kernan C, Litterer AS, Carter GG, Page RA*, ter Hofstede HM* (In press) Predation risks of signalling and searching: bats prefer katydids in motion. Biology Letters. |
| Falk JJ*, ter Hofstede HM*, Jones PL, Dixon MM, Faure PA, Kalko EKV, Page RA (2015) Sensory-based niche partitioning in a multiple predator - multiple prey community. Proc R Soc B 282: 20150520 |
| Goerlitz HR*, ter Hofstede HM*, Zeale MRK*, Jones G, Holderied MW (2010) An aerial-hawking bat uses stealth echolocation to counter moth hearing. Curr Biol 20:1568-1572 |
| ter Hofstede HM, Ratcliffe JM, Fullard JH (2008) The effectiveness of katydid (Neoconocephalus ensiger) song cessation as antipredator defence against the gleaning bat Myotis septentrionalis. Behav Ecol Sociobiol 63:217-226 |
|
|
|
|
Interactions between natural and sexual selection: Predators that eavesdrop on mating signals select for less conspicuous signals, whereas mates select for more conspicuous signals, and these conflicting selection pressures can have complex evolutionary consequences. Orthopteran insects such as crickets and katydids are known for producing loud calling songs, and they use hearing for detecting predators, mates, and rivals. Some species of gleaning bats (those that capture prey off surfaces) use the calling songs of orthopterans to locate them as prey. I am interested in how the conflict between attracting mates and avoiding predation has shaped both the sensory systems and behavioral ecology of these insects.
| Benavides-Lopez JL, ter Hofstede HM*, Robillard T* (2020) Novel system of communication in crickets originated at the same time as bat echolocation and includes male-male multimodal communication. The Science of Nature 107: 9. |
| Symes L, Martinson S, Hoeger LO, Page RA, ter Hofstede HM (2018) From understory to canopy: In situ behavior of Neotropical forest katydids in response to bat echolocation calls. Frontiers in Ecology and Evolution. 6: 227. |
| Symes LB, Page RA, ter Hofstede HM (2016) Effects of acoustic environment on male calling activity and timing in Neotropical forest katydids. Behav Ecol Sociobiol online first DOI 10.1007/s00265-016-2157-4 |
| ter Hofstede HM*, Schoneich S*, Robillard T, Hedwig B (2015) Evolution of a communication system by sensory exploitation of startle behavior. Curr Biol 25: 1-8 |
|
|
|
* indicates equal contribution of authors
|
|