Texas field crickets (Gryllus texensis) use visual cues to place learn but perform poorly when intra- and extra-maze cues conflict.

Central place foraging field crickets are an ideal system for studying the adaptive value of learning and memory, but more research is needed on ecologically relevant cognition in these invertebrates. Here, we test the visuospatial place learning of Texas field crickets (Gryllus texensis) in a radial arm maze. Our study expands previous work on G. texensis cognition for accuracy measures and extends our previous findings on females to both sexes. Additionally, our study examines whether crickets use intra- or extra-maze cues to locate a food reward using a maze rotation that puts the cues in conflict. We found that male and female crickets improved performance over trials when measured by accuracy variables but not latency variables. Thigmotaxis negatively impacted performance in both sexes. In a reward-absent trial, both male and female crickets demonstrated place memory. When intra- and extra-maze cues conflicted during a rotation trial, crickets' performance was not better than chance. Our rotation results suggest that crickets may experience reciprocal overshadowing of conflicting cues - a result most often seen in other taxa with conflicting multi-modal cues. We conclude that crickets do not rely solely on: (1) a single-cue association, (2) route-following, or (3) their own scent cues to navigate the maze. Instead, male and female Texas field crickets seem to learn the location of the reward using a combination of proximal and distal cues. The possibility to test large numbers of wild-caught or laboratory-reared individuals opens the door to future investigations on the evolutionary ecology of visuospatial learning in these invertebrates.

Great tits who remember more accurately have difficulty forgetting, but variation is not driven by environmental harshness.

The causes of individual variation in memory are poorly understood in wild animals. Harsh environments with sparse or rapidly changing food resources are hypothesized to favour more accurate spatial memory to allow animals to return to previously visited patches when current patches are depleted. A potential cost of more accurate spatial memory is proactive interference, where accurate memories block the formation of new memories. This relationship between spatial memory, proactive interference, and harsh environments has only been studied in scatter-hoarding animals. We compare spatial memory accuracy and proactive interference performance of non-scatter hoarding great tits (Parus major) from high and low elevations where harshness increases with elevation. In contrast to studies of scatter-hoarders, we did not find a significant difference between high and low elevation birds in their spatial memory accuracy or proactive interference performance. Using a variance partitioning approach, we report the first among-individual trade-off between spatial memory and proactive interference, uncovering variation in memory at the individual level where selection may act. Although we have no evidence of harsh habitats affecting spatial memory, our results suggest that if elevation produced differences in spatial memory between elevations, we could see concurrent changes in how quickly birds can forget.