Indirect effects of climate change altered the cannibalistic behaviour of shell-drilling gastropods in Antarctica during the Eocene

The fossil record from Seymour Island, Antarctic Peninsula, provides a record of biotic response to the onset of global climatic cooling during the Eocene. Using drilling traces—small, round holes preserved on prey shells—we examined the effect of a cooling pulse 41 Ma on the cannibalistic behaviour...

Full description

Bibliographic Details
Published in:Royal Society Open Science
Main Authors: Dietl, Gregory P., Nagel-Myers, Judith, Aronson, Richard B.
Other Authors: National Science Foundation
Format: Article in Journal/Newspaper
Language:English
Published: The Royal Society 2018
Subjects:
Online Access:http://dx.doi.org/10.1098/rsos.181446
https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.181446
https://royalsocietypublishing.org/doi/full-xml/10.1098/rsos.181446
Description
Summary:The fossil record from Seymour Island, Antarctic Peninsula, provides a record of biotic response to the onset of global climatic cooling during the Eocene. Using drilling traces—small, round holes preserved on prey shells—we examined the effect of a cooling pulse 41 Ma on the cannibalistic behaviour of predatory naticid gastropods. We predicted that cannibalistic attacks would decline in response to the cooling climate, reflecting reduced activity levels, energy requirements and constraints on the chemically aided drilling process of the naticids. Surprisingly, however, cannibalism frequencies did not change. This counterintuitive result is best explained by a sharp reduction in durophagous (shell-crushing) predation in shallow-benthic communities in Antarctica that also occurred as the climate cooled. Reduced durophagous predation may have created a less-risky environment for foraging naticids, stimulating cannibalistic behaviour. The change in the top-down control exerted by shell-crushing predators on naticids may have counteracted the direct, negative effects of declining temperatures on the predatory performance of naticids. Our results suggest that the long-term consequences of climate change cannot be predicted solely from its direct effects on predation, because the temperature can have large indirect effects on consumer–resource interactions, especially where risk-effects dominate.