T-maze navigation by juvenile wolf spiders provides evidence for learning

Mobile animals must effectively navigate through their environments to locate resources and avoid threats. In this study we designed a protocol to examine navigation in cursorial spiders and tested it on the wolf spider Tigrosa helluo . Using a modified T-maze, we explored the ability of T. helluo spiderlings (N = 15) to successfully locate a hide and avoid aversive stimuli of heat and light produced from heat lamps. The hide was paired with either a gray or black-and-white background pattern to explore potential use of visual stimuli to navigate. The novel paradigm deployed here involved pairing the hide with the non-preferred pattern. Spiderlings underwent 50 trials in the maze over five consecutive days and demonstrated significant improvement in hide entering latency and reliability both within and across days. Performance plateaued after the second day, with some differences in performance between clutches. Examination of spiderlings' first side entries (choices) and entry into the terminal portions of the arms (decisions) suggested that they were not associating the patterns with the presence of the hide, but highlighted changes in choice and decision behaviors over time. When choices and decisions mismatched, however, spiderlings more often made a wrong choice-correct decision combination than the reverse, hinting that some evaluation was indeed occurring once inside an arm. Whereas our results suggest that the spiderlings learned to navigate to the hide better over time, further investigations are needed to determine the mechanism(s) they may be employing to do so.