Are There Personality Differences between Rural vs. Urban-Living Individuals of a Specialist Ground Beetle, Carabus convexus?

Abstract

The world-wide, rapid urbanization is leading to substantial changes in environmental and habitat conditions. These changes, as well as disturbances accompanying urbanization have considerable effects at various levels of the biological organization on wildlife. Understanding behavioral responses to such changes is essential for identifying which organisms may successfully adapt to the altered conditions. In this study, individuals of a forest specialist ground beetle, Carabus convexus, from rural and urban forest patches were tested for their exploratory and risk-taking behavior. Beetles responded consistently in the different contexts; furthermore, by behaving consistently over time, demonstrated that they had personalities. Agglomerative cluster analysis identified two groups of behavioral traits: the exploratory and the risk-taking dimension of personality. Urban females were significantly more exploratory than urban males which can be an adaptation to find high quality food needed to mature eggs in urban habitats, as well as to select favorable microsites for oviposition. Moreover, urban females and males showed more risk-taking behavior than rural females. Urban beetles with more risk-taking behavior may be better able to cope with frequent urbanization-driven disturbance events.

Keywords: carabid; exploratory behavior; human disturbance; personality; risk-taking behavior; urbanization.

Figure 1

The relationship between the tested behavioral measures of C. convexus by agglomerative cluster analysis using the Spearman rank correlations (agglomerative coefficient: 0.8431) and the possible personality dimensions indicated by boxes with dashed lines (A), moreover the silhouette plot to identify possible groupings of the variables (B).

Figure 2

Mean (±SE) values of the tested behavioral measures grouped together in the exploratory dimension of C. convexus’ personality by agglomerative cluster analysis: square visits (A), covered distance (B), motion time (C), inner square visits (D), and wall time (E). Different letters indicate significant differences based on the LSD test (p < 0.05).

Figure 3

Mean (± SE) values of the tested behavioral measures grouped together in the risk-taking dimension of C. convexus’ personality by agglomerative cluster analysis, flight duration (A) and flight distance (B). Different letters indicate significant differences based on the LSD test (p < 0.05).