TY - JOUR
T1 - Identifying critical interactions in complex competition dynamics between bean beetles
AU - Kawatsu, Kazutaka
AU - Kishi, Shigeki
N1 - Funding Information:
Acknowledgements – We are very grateful to Yumiko Ishii for permission to use her data and for valuable comments. We also thank Michio Kondoh, Masayuki Ushio and Daisuke Kyogoku for valuable discussions. Funding – This research was supported by a Research Fellowship for Young Scientists from the Japan Society for the Promotion of Science (JSPS) and JSPS KAKENHI grant no. 16H04846 and 16K18625 to KK. Statement of authorship – K. Kawatsu and S. Kishi contributed equally to this study.
Publisher Copyright:
© 2017 The Authors
PY - 2018/4
Y1 - 2018/4
N2 - Identifying behavioural basis of competitive relationship is essential to understand outcome of interspecific competition. However, it remains difficult to investigate demographic effect of competitive behaviour, because various kinds of behaviours may co-occur in the competition and make the dynamics far complicated in nonlinear ways. We report that the behavioural basis of interspecific interaction can be identified, by focusing on the timescale difference from the occurrence of each behaviour to the appearance of its demographic effect. Between two bean beetles, Callosobruchus chinensis and C. maculatus, major interspecific interactions are resource competition (RC) at the larval stage and reproductive interference (RI) at the adult stage. RC has longer time lag than RI, because effect of RC appears in the adult number of the next generation through larval competition while effect of RI appears instantaneously in the adult number through early death of females. If we detect two effects with different time lags from the competition dynamics, an effect with intergenerational time lag and with no time lag would be considered as RC and RI, respectively. We applied empirical dynamic modelling approach, which is a nonlinear time series analysis for detecting causal interactions and the strength, to two published datasets of experimental competition between those beetles. Results showed the significant causality from the winner species to the loser one in both experiments, but the causality time lag differed between experiments: the causality had no time lag in the C. chinensis-win data, while intergenerational time lag in C. maculatus-win data. Furthermore, detection of the causality with intergenerational time lag from C. maculatus to C. chinensis in both experiments suggests interplay of constant RC and variable RI which can reverse the outcome. This study is the first successful case study that links behavioural-level interactions to demographic-level effects in interspecific competition.
AB - Identifying behavioural basis of competitive relationship is essential to understand outcome of interspecific competition. However, it remains difficult to investigate demographic effect of competitive behaviour, because various kinds of behaviours may co-occur in the competition and make the dynamics far complicated in nonlinear ways. We report that the behavioural basis of interspecific interaction can be identified, by focusing on the timescale difference from the occurrence of each behaviour to the appearance of its demographic effect. Between two bean beetles, Callosobruchus chinensis and C. maculatus, major interspecific interactions are resource competition (RC) at the larval stage and reproductive interference (RI) at the adult stage. RC has longer time lag than RI, because effect of RC appears in the adult number of the next generation through larval competition while effect of RI appears instantaneously in the adult number through early death of females. If we detect two effects with different time lags from the competition dynamics, an effect with intergenerational time lag and with no time lag would be considered as RC and RI, respectively. We applied empirical dynamic modelling approach, which is a nonlinear time series analysis for detecting causal interactions and the strength, to two published datasets of experimental competition between those beetles. Results showed the significant causality from the winner species to the loser one in both experiments, but the causality time lag differed between experiments: the causality had no time lag in the C. chinensis-win data, while intergenerational time lag in C. maculatus-win data. Furthermore, detection of the causality with intergenerational time lag from C. maculatus to C. chinensis in both experiments suggests interplay of constant RC and variable RI which can reverse the outcome. This study is the first successful case study that links behavioural-level interactions to demographic-level effects in interspecific competition.
UR - http://www.scopus.com/inward/record.url?scp=85034017713&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034017713&partnerID=8YFLogxK
U2 - 10.1111/oik.04103
DO - 10.1111/oik.04103
M3 - Article
AN - SCOPUS:85034017713
VL - 127
SP - 553
EP - 560
JO - Oikos
JF - Oikos
SN - 0030-1299
IS - 4
ER -