Weidman, Riko, Ecology Program, Susquehanna University, 1858 Weber Way, 3498, Selinsgrove, PA, PA, 17870, firstname.lastname@example.org; Persons, Kelsey, Biomedical Sciences Program, Susquehanna University, 1858 Weber Way, 3498, Selinsgrove, PA, PA, 17870, email@example.com; Persons, Matthew, J., Ecology Program Susquehanna University 1858 Weber Way, 3498 Selinsgrove, PA PA,17870, firstname.lastname@example.org.
The wolf spider, Tigrosa helluo, burrows at the edges of lotic systems. These spiders range from their burrows during foraging bouts but return daily. They may also be displaced during rain or flood events which may change micro-landscape features around burrow entrances. Previous studies have shown that these spiders use environmental edge or boundary features (reference frame landmarks) to learn the location of a dry target in flooded arenas; however, the relative importance of different types or numbers of landmark cues during spatial navigation remains unknown. We used an open water arena and recorded the ability of adult female spiders to find and enter a dry target cup among flooded cups that varied in one or more landmark features. We measured variation in spatial learning by measuring time to target with no landmark (control), with a beacon (a landmark that is part of the dry target), with an associative cue (a landmark associated with a specific navigational action), and with both a beacon and an associative cue (N=92, n=23 per landmark cue treatment).
For each treatment, we tested spiders for five trials each on four consecutive days, with the last trial on the fourth day having an altered target location, totaling 19 training trials and one reversal trial (1,840 trials). Spiders took significantly less time to find the target over subsequent trials within a day and learned more quickly when landmark cues were present, but we found no difference in the type or number of landmark features in target acquisition time. After learning a target location, moving the landmark (reversal trial) significantly increased target acquisition time among landmark treatments relative to the control. Results indicate that wolf spiders can use visual beacon and associative cue landmarks both alone and when in combination and that performance improves across trials when landmarks are present.