Mate searching context of prey influences predator-prey space race

Predation risk is a strong driver of prey distribution and movement.
However, fitness-influencing behaviours, such as mating, can alter risk
and influence predator-prey space-use dynamics. In tree crickets,
Oecanthus henryi, mate searching involves acoustic signalling by immobile
males and phonotactic movement by females. Space-use patterns in tree
crickets relative to their primary predators, green lynx spiders (Peucetia
viridans), should therefore depend on their current mate-searching state;
whether males are calling or non-calling and whether females are
phonotactic or non-phonotactic. We first measured the degree of spatial
anchoring of crickets to specific bushes in the field, and whether that
influenced the probability of broad-scale spatial overlap with spiders. In
the absence of spiders, all crickets, independent of sex or male calling
status, were found to be spatially anchored to specific types of bushes
and not uniformly distributed on the landscape. At the broad spatial
scale, spiders were more likely to be found on bushes with female
crickets, and to a lesser degree, calling male crickets. At a finer
spatial scale within a bush, movement strategies of crickets not only
varied depending on the presence or absence of a spider, but also on their
current mate searching state. Phonotactic females showed clear predator
avoidance, whereas calling and non-calling males moved towards the spider
instead of away, similar to predator-inspection behaviour seen in many
taxa. As the strongly-selected sex, males are more likely to undertake
risky mate searching activities, which includes inspection of predator
positions. Overall, we found that all crickets were predictably anchored
at the landscape scale, but their sex and mate seeking behaviour
influenced the degree of overlap with predators, and their antipredator
movement strategies. Reproductive strategies within a prey species,
therefore, can alter predator-prey space race at multiple spatial scales.