Warming oceans

Albatross divorce rate rises

No, we haven’t seen an albatross flying over the reserve but occasionally a story from beyond our particular corner of Southwick catches our eye.

Researchers have found that the warming ocean seems to be causing a rise in the divorce rate among the black browed albatross of New Island, a rocky outcrop of the Falkland Islands.

Black browed albatross are usually monogamous, forming partnerships that can last for decades, the pair meeting at the beginning of each breeding season and re-establishing their bond with ritual dances. But divorce is not unknown: a female will sometimes leave a partnership if it lacks breeding success and re-appear next season with a new male.

Rising sea surface temperatures are beginning to alter black browed albatross breeding success. A warmer ocean reduces the phytoplankton population right at the bottom of the food chain and this catastrophic depletion works its way up through the entire food chain. As a result, there are fewer fish in the surface water where the albatross hunt and they have to travel further and for longer to find enough food to keep their nestlings alive. As the nests fail, the divorce rate rises; the higher divorce rate means fewer successful partnerships and even fewer baby albatross, and the overall population falls

The researchers suggest that this previously unpredicted outcome of climate change may affect the population numbers, not only of black browed albatross, but of other monogamous birds, and possibly mammals, as well. Climate change is finally making us aware of the complexity of the relationships that hold our environment together: let’s hope it’s not too late for the black browed albatross.