Exploration influences problem solving in the fawn‐footed mosaic‐tailed rat (Melomys cervinipes)

Abstract

The relationship between an animal's personality and its problem solving ability has become a popular topic of investigation. However, results are conflicting, suggesting that these relationships may be species-specific. We investigated these relationships in a native Australian rodent, the fawn-footed mosaic-tailed rat (Melomys cervinipes).We predicted that more exploratory and less anxious mosaic-tailed rats would be better problem solvers (e.g. faster to solve the problem) as they would interact with the puzzles more and would be more willing to engage with the task. We assessed personality across two contexts (exploration in an open field and novel object test, and anxiety under simulated predation risk in a light/dark box) and over time (three repetitions). We measured problem solving using two food-baited puzzle boxes (matchbox and cylinder), a Trixie Dog Activity Board with three problems (pillars, tiles and levers) and an obstruction task. Individual mosaic-tailed rats showed consistent individual differences in personality, but not problem solving ability. Furthermore, we found a positive relationship between personality and problem solving ability, with more exploratory individuals solving more problems, and solving problems faster, than less exploratory individuals. Exploratory individuals could be better problem solvers because they are more willing to interact with objects and are less neophobic than less exploratory individuals. However, less exploratory individuals still persist in the population, possibly due to differences in cognitive abilities, such as discrimination or recognition, that allow them to compensate for poorer problem solving abilities.

Corticosterone Metabolite Concentration Is Not Related to Problem Solving in the Fawn-Footed Mosaic-Tailed Rat Melomys Cervinipes

“…In support of this, mosaic-tailed rats are capable innovators [ 24 ]. Previous studies have found that more exploratory mosaic-tailed rats are better problem solvers than avoidant individuals [ 25 ]. Mosaic-tailed rat personality has also been linked to some physiological measures (glucose and testosterone concentrations, [ 26 ]), suggesting a potential for adrenocortical effects on problem solving.…”

Problem solving in fawn‐footed mosaic‐tailed rats Melomys cervinipes is not significantly influenced by maternal care or genetic effects

“…Data collection occurred between August 2018 and March 2021. Tests were conducted during the peak activity period of mosaic‐tailed rats (18:00–22:00 h; Wood, 1971 ) under red light (except for the obstruction test, see below), which does not interfere with mosaic‐tailed rat behaviors (Paulling et al, 2019 ; Rowell & Rymer, 2021a , 2021b ). To encourage animals to interact with the food‐related puzzle tests, animals were not fed on the days of these tests until after the tests were complete.…”

“…(a) Matchbox task; (b) cylinder task with food (black circle) inside and tinfoil over one end; (c) Trixie dog activity board with pillar, tile, and lever tasks; and (d) obstruction task with a piece of crumpled paper blocking the entrance. From Rowell and Rymer ( 2021a ).…”

“…The average pup latency was the dependent variable and the mother's latency to solve was the independent variable for each model. We also considered whether the time spent interacting with the problems was heritable, as this could influence the solving success of the mosaic-tailed rats (Rowell & Rymer, 2021a). Again, we used separate parent-offspring regressions to investigate whether the scaled mother's time spent interacting (independent variable) was a significant predictor of the scaled mid-offspring value for the time spent interacting (dependent variable) for each problem type.…”

“…Problem solving is an animal's ability to move itself or an object to overcome an obstacle or barrier and access a desired goal (Rowell et al, 2021 ). Problem solving is largely dependent on an individual's exploratory behavior and learning ability (Griffin & Guez, 2014 ), as more exploratory individuals are more likely to interact with and solve problems than shy individuals (Rowell & Rymer, 2021a ), and individuals capable of learning solutions are more likely to solve similar problems in the future (Chow et al, 2017 ). As both exploration and learning have a heritable component in some species (Dingemanse et al, 2002 ; Upchurch & Wehner, 1989 ), it is possible that problem solving could, at least partially, be heritable.…”