Journal of Ethology

Esteve, Manu

doi: 10.1007/s10164-026-00890-ypmid: N/A

A foraging-related behavior potentially allowing killer whales (Orcinus orca) to identify fishing lines with hooked Atlantic bluefin tuna (Thunnus thynnus) is described from the Strait of Gibraltar. On two days, four whales were video-recorded swimming repeatedly along the fishline, intermittently interacting with it by placing it on their backs or pressing, holding, or pushing it with the fins, snout, melon or belly. These interactions are consistent with assessing line tension or weight to detect the presence of a hooked fish at depth. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo260512oo01a and at http://www.momo-p.com/showdetail-e.php?movieid=momo260512oo02a.

Egami, Rena; Harada, Natsu; Kuriwada, Takashi

doi: 10.1007/s10164-026-00891-xpmid: N/A

Urban environments exhibit a range of differences from natural environments in terms of various ecological and environmental factors. These environmental disparities will influence or modify the direction and/or intensity of sexual selection. Given the challenging survival conditions and thus low population density in urban environments in many species, selection may favor traits that enhance mating success during rare encounters. Although the impact of urban environments on acoustic signalling has received the most attention in crickets, chemical cues are also crucial for successful mating. We examined whether the chemical cues of urban males were more attractive to females than those of rural males in the ground cricket Dianemobius nigrofasciatus. Using a common garden experiment, we conducted a behavioral assay with filter papers bearing male chemical cues and quantified female response as the difference in time spent on treatment and control blank filter papers. Rural females showed a strong preference for the chemical cues of urban males, whereas urban females did not show a substantial preference for chemical cues of urban males. Our results suggest that chemical cues may alleviate some of the negative impacts of urban environments on acoustic communication. These findings highlight how urbanization can reshape sexual communication systems across sensory modalities.