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Ability to efficiently localize productive foraging habitat is crucial for nesting success of insectivorous birds. Some bird species can use olfaction to identify caterpillar-infested trees by detection of herbivore induced plant volatiles (HIPVs), but these cues probably need to be learned. So far, we know very little about the process of olfactory learning in birds, whether insectivorous species have a predisposition for detecting and learning HIPVs, due to the high ecological significance of these odors, and how olfaction is integrated with vision in making foraging decisions. In a standardized setup, we tested whether 35 wild-caught great tits (Parus major) show any preference for widely abundant HIPVs compared to neutral (non-induced) plant odors, how fast they learn to associate olfactory, visual and multimodal foraging cues with food, and whether the olfactory preferences and learning speed were influenced by bird sex or habitat (urban or rural). We also tested how fast birds switch to a new cue of the same modality. Great tits showed no initial preference for HIPVs compared to neutral odors, and they learned all olfactory cues at a similar pace, except for methyl salicylate (MeSA), which they learned more slowly. We also found no differences in learning speeds between visual, olfactory and multimodal foraging cues, but birds learned the second cue they were offered faster than the first one. Bird sex or habitat had no effect on learning speed or olfactory preference, but urban birds tended to learn visual cues more slowly. We conclude that insectivorous birds utilize olfactory and visual cues with similar efficiency in foraging, and that they probably don't have any special predisposition toward the tested HIPVs. These results confirm that great tits are flexible foragers with good learning abilities.

The ladybird beetle Coccinella septempunctata (L.) is an important biocontrol agent of pests such as various aphid species. Despite being one of the most studied coccinellid species, many aspects of its foraging behavior are still not completely understood. This study focuses on the diel foraging behavior of C. septempunctata, investigating their olfactory orientation toward aphid-infested plants, walking activity on plants and on the soil, and feeding rates. In the scotophase the ladybird beetles were significantly more attracted to the odor of aphid-infested plants, on which they also showed considerably higher walking activity then on uninfested controls. Females were more prone to utilize olfactory cues when searching for prey and fed at higher rates than males; this shows that they are better adapted to nocturnal activity, as they require higher food intake. Coccinella septempunctata have the same feeding rate during the scotophase as in the photophase. Our study shows that C. septempunctata has the potential to forage in the scotophase if prey is abundant. The results support the hypothesis that volatiles of aphid-infested plants can attract or arrest foraging adult ladybird beetles, even in the darkness, which makes a considerable contribution to efficient prey search and enhances feeding capacity.