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CTS: Is it possible that from the tiger beetle’s point of view, the world moves really slowly, which is why he gets more time decide to open or close his jaw?
For this month’s Researcher of the Month (RotM) interview, we spoke to Dr. Daniel B Zurek, Neuroethologist and Sensory Ecologist and also the Post Doctoral Associate, studying tiger beetles in the Morehouse Lab. at the University of Pittsburgh. Dr. Daniel recently published his findings about how tiger beetles pursue their prey in the journal Biology Letters and frankly spoke about his study and his interests with us.
CTS: Why should we study hunting in tiger beetles?
DZ: I am interested in the question of how visual systems of animals are adapted to their ecological needs. Tiger beetles are extremely fast running predators, which is a challenge for visual perception. Animals that are extremes in some way can make good study systems. Finding out where their limits are, and what ways nature has found to cope with these limits, can teach us a lot about general principles that might be common in other systems. It can also reveal interesting candidates for applications in engineering.
CTS:How do we know that the beetle’s vision blurs at high speeds?
DZ: Cole Gilbert (Dr. Daniel’s Principal Investigator for the current publication) has discovered this in 1997, by analyzing their behavior when chasing fast prey. When the prey moves at high angular speeds (i.e. sideways relative to the beetle’s viewing direction), the beetle has to stop and relocate it. The duration of these stops is correlated with prey angular velocity.
CTS: Is it possible that from the tiger beetle’s point of view, the world moves really slowly, which is why he gets more time decide to open or close his jaw?
DZ: Like many fast insects, tiger beetles can perceive fast movement better than we can. Whether that means things seem to move really slowly to them is hard to answer.
CTS: How difficult was it to work with tiger beetles?
DZ: Tiger beetles are hard to catch because they’re so fast. You have to trick them by not presenting an expanding target when approaching – I crouch down as I sneak up on one, and then whip a butterfly net ahead of the beetle so that it flees into the net. Best is to find a mating couple, they can’t fly away and you get a ‘two for one deal’.
CTS: Dung beetles are known to carry 10 times their body weight. What is the Biggest prey size that tiger beetles can take on?
DZ: They usually attack prey smaller than themselves, but I wouldn’t put it past them to munch on a big caterpillar or so if they come across one.
CTS: Tiger beetles can hunt when flying as well. Have there been any studies done to determine how they manage to do so, again at high speeds.
DZ: I have not heard of any tiger beetles that do that. While some, but not all, tiger beetles can fly, they do this for dispersal or predator avoidance. They’re pretty bad fliers.
CTS: Could you tell us a little about your interest in Jumping spiders!
DZ: They’re actually my main study system, I’ve worked on their fascinating visual system during my PhD, and am now researching their color vision in context of the diversity in male coloration in this family. You can see more about them on my website at danielzurek.com, or on this page about our (now successfully funded) crowdfunding project: bit.do/spiderdance
CTS: A final question, before we end this interview. The fastest predator on earth (tiger beetle), that chases its prey, to the jumping spider that slowly stalks overcomes it with the element of surprise, who do you think will win, if pitted against each other?
DZ: I have asked myself the same question many times … If both are the same size, I think my money’s on the spider. A tiger beetle could easily kill a jumping spider if it surprised it, but these spiders are more intelligent and perceptive. If the spider sneaks up and attacks the beetle’s head he’d be paralyzed pretty quickly, but the spider would probably lose a leg. On the other hand, tiger beetle head armor is very thick … it’s really a pretty even match.
Reference
Zurek DB, Perkins MQ, & Gilbert C (2014). Dynamic visual cues induce jaw opening and closing by tiger beetles during pursuit of prey. Biology letters, 10 (11) PMID: 25376803
Reference
Zurek DB, Perkins MQ, & Gilbert C (2014). Dynamic visual cues induce jaw opening and closing by tiger beetles during pursuit of prey. Biology letters, 10 (11) PMID: 25376803