Only hardier species can adapt to global warming
Story submitted by Eric Worrall
Another claim that its worse than we thought – this time warmer temperatures are killing the bees.
According to Scott Groom, PhD student at Flinders University, mathematical modelling has connected changes in bee populations over the past 20,000 years across the South Pacific region, and exceptionally large declines in bee populations, with changes in temperature.
Groom says that prior to the ice age when temperatures rose, many bee species migrated to cooler areas, with only one hardy species able to adapt to the warmer temperature.
“They’re almost canaries in the coal mine, you can see that they’re going to be the first sort of species to be impacted by changes in climate,” Groom said.
The study, “Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific” can be found at the link below.
The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops.
I don’t have access to the full text, so I don’t know whether other possible causes of population crashes, such as bee killing Varroa mites, were considered.
Varroa mites were originally discovered in Asia, but have since spread worldwide. Some bees are resistant to Varroa mites, because they have evolved hygiene behaviour, which removes and kills the mites.