Ant circadian activity associated with brood care type.
In group-living animals, social interactions influence various traits including circadian activity. Maternal care, in particular, can have a strong effect on the circadian activity of parents or nurses across taxa. In social insects, nest-mates are known to have diverse activity rhythms; however, what kind of social environment is crucial in shaping an individual's rhythm is largely unknown. Here, we show that the focal brood types being taken care of (i.e. egg, larva and pupa) have significant effects on individual activity/rest rhythm, using the monomorphic ant Diacamma (putative species indicum). When isolated from a colony, nurses exhibited a clear circadian rhythm. However, when paired with eggs or larvae, they exhibited around-the-clock activity with no apparent rhythm. In contrast, a clear activity rhythm emerged when nurses were paired with a pupa, requiring little care. Such brood-type-specific changes in circadian activity are considered to arise from the difference in caretaking demands. Our finding may contribute to the understanding of the organization of a colony in the context of behavioural variability under different microenvironments.
Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan.
Haruna
H
Fujioka
Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan.|National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan.|JST, ERATO, Kawarabayashi Large Graph Project, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan.
Masato S
0000-0002-0468-1179
MS
Abe
Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto, Japan.
Taro
T
Fuchikawa
Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
Kazuki
K
Tsuji
Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan.
Masakazu
M
Shimada
Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan okayasukazu@gmail.com.
Yasukazu
0000-0003-4528-2980
Y
Okada
D000818:Animals; D001000:Ants / Q000254:growth & development / Q000502:physiology*; D001522:Behavior, Animal; D002940:Circadian Rhythm; D007814:Larva / Q000502:physiology; D008124:Locomotion; D010063:Ovum; D011679:Pupa / Q000502:physiology; D012919:Social Behavior
behavioural variability; circadian activity rhythm; social insect; social interaction