Climate Change
Most species are well-adapted to short-term variation in climate or weather, but not to long-term shifts in climate and increased frequency or intensity of extreme events.
Short-term extremes in weather, like intense storms and high temperatures can affect birds directly. Fat and heavily feathered, the hoiho is perfectly insulated for foraging in the depths of the cold ocean. But ashore, in this warm temperate climate, the insulation becomes a liability. The birds cannot remove their ‘wetsuits’, but need shady undergrowth to avoid overheating. Shade also prevents their eggs from getting too hot. Storms can stir up the ocean reducing visibility for hoiho which swim to the seabed to capture fish.
Global warming may also impact oceanic processes and alter the food webs on which hoiho depend. Fluctuation in the numbers of breeding pairs of hoiho from year to year are at least in part linked to climate change, in particular changes in sea surface temperature (SST) and rainfall. Adult survival was low in periods with warmer than normal SST and conversely was high with cooler than normal SST.
