Biomass Movement

The World’s Longest Animal Migration:

• The Arctic tern, a medium-sized grey seabird weighing about 100 grams, undertakes the longest migration on Earth, travelling 90,000 km round-trip each year from the Arctic to Antarctica and back.
• Around two million Arctic terns complete this annual journey, making it one of the most remarkable feats of endurance in the animal kingdom.

Biomass Movement of the Arctic Tern:

• Despite its incredible journey, the total biomass movement of Arctic terns is relatively small due to their light weight — just 0.016 gigatonnes per kilometre per year (gt/km/yr).
• Biomass movement is defined as the total biomass of a species multiplied by the distance it travels annually.

Comparison with Other Animal Migrations:

• The grey wolf, one of the most mobile land mammals, has a biomass movement of about 0.03 gt/km/yr.
• The annual migration of over a million blue wildebeest, gazelles, and zebras in the Serengeti is around 20 times higher than that of the grey wolf.
• This large-scale migration is comparable, in biomass movement terms, to international human gatherings such as the FIFA World Cup, according to the study.

Human Biomass Movement — A Massive Scale:

• The study, published in Nature Ecology & Evolution, found that human biomass movement is approximately 4,000 gt/km/yr.
• This is over 40 times greater than the combined biomass movement of all wild land mammals, arthropods, and birds, and six times greater than that of all land animals combined.

How Humans Move:

• On average, humans travel about 30 km per day, most of it using motorised transport:
  • ~65% by cars and motorcycles
  • ~10% by airplanes
  • ~5% by trains and subways
• This extensive mobility, powered by fossil fuels, underscores humanity’s disproportionate ecological and energetic footprint compared to natural animal migrations.

Source: TH