The colour of the environment is changing – becoming bluer – apparently due to climate change, says a new study that finds that environment and animal populations are fluctuating more rapidly over time.
The change that could have important implications for animals' risk of becoming extinct, ecologists have found.
Researchers examined how quickly or slowly animal populations and their environment change over time, something ecologists describe using spectral colour.
Ecologists have investigated the link between fluctuations in the environment and those of animal populations for the past 30 years. They describe fluctuations as a colour spectrum, where red signifies an environment or population that fluctuates more slowly over time (such as ocean temperature) and blue signifies more rapid fluctuations (such as changes in air temperature).
The researchers said the study not only confirmed that the colour of changes in the environment map onto the colour of changes in animal populations, but found that our environment is becoming bluer, in other words fluctuating more rapidly over time.
According to Daniel Reuman of Imperial College London: We showed using field data for the first time that the colour of changes in the environment maps onto the colour of changes in populations: redder environments mean redder populations, and bluer environments mean bluer populations.
Researchers said the results are important because previous studies show that the spectral colour of a population affects its extinction risk. Some simple models show that bluer populations – those that fluctuate more rapidly over time – are at less risk of extinction. This is because adverse conditions are more likely to be followed by better conditions when the environment is fluctuating more rapidly.
According to Reuman: Since it was previously known that the colour of changes in populations is related to extinction risk of the populations, our results show a way that climate change should impact the extinction risk of populations by affecting the colour of populations.
While the study seems to provide some good news for species facing extinction, the researchers warn that this is offset by other pressures. This apparent good news is tempered by the fact that habitat loss, overexploitation and other factors are likely more important drivers of extinction risk than the colour of temperature fluctuations, Reuman said.
The researchers used the Global Population Dynamics Database, from which they extracted data on changes in population for 147 species of bird, mammal, insect, fish and crustacean over the past 30 years.