气候变化领域集成服务门户

Our study confirmed that changes in these environmental data were linked to the decline in calving rates. The probability of observing mother-calf pairs was related to favourable environmental conditions in the previous year, especially with the abundance of herring, one of their main prey. These results suggest that environmental changes in the Gulf of St Lawrence have resulted in declines in herring abundance, and this is negatively affecting the breeding success of the humpback whales.

We believe this decline could – at least in part – be the result of females being unable to build up the energy reserves needed to sustain pregnancy and meet the energetic demands of nourishing their young in years of poorer feeding availability.

It was previously thought that baleen whales could show some resilience to climate change because of their ability to change their migratory patterns, or switch prey species, for example, if the location, timing or abundance of their main prey changed. However, our research shows that their ability to respond in these ways may not be enough to prevent their breeding success from being impacted by environmental change.

Continued monitoring of this humpback population in the Gulf of St Lawrence is required to assess how the observed decline in calving rates will affect population growth and viability.