Arctic Tern's Remarkable Migration Journey

Summary of Key Facts and Data on Biomass Movement and Migration

Migration Patterns

• Arctic Tern:
  • Medium-sized grey bird, weighs 100 g.
  • Travels annually between the Arctic and Antarctica, covering 90,000 km.
  • Total biomass for Arctic terns during migration is 0.016 gigatonnes (gt) per km per year.

Other Species Migration Data

• Grey Wolf:

  • Reported biomass movement of around 0.03 gt/km/yr.

• Serengeti Migration:

  • Migration of blue wildebeest, gazelles, and zebras results in an annual biomass movement 20 times larger than that of grey wolves.

Human Mobility

• Human biomass movement is 4,000 gt/km/yr, significantly higher compared to wild land mammals, arthropods, and birds combined:
  • Over 40 times greater than the biomass movement of all wild land mammals.
  • Over six times greater than the upper estimates of all land animals combined.

Patterns of Human Movement

• Average distance moved by humans is approximately 30 km per day, largely facilitated by motorized transport:

  • 65% in cars and motorcycles.
  • 10% in airplanes.
  • 5% in trains and subways.

• Economic Disparity:

  • Two-thirds of all motorized mobility is found in high-income and upper-middle-income countries.

Impact on Ecosystems

• Movement of both humans and animals influences ecosystems:
  • By transporting nutrients and organisms.
  • By inducing trophic effects and physical ecosystem engineering.

Declines in Marine Animal Movement

• Biomass movement of marine animals, considered the largest in the living world, has halved since 1850 due to industrial fishing and whaling activities during the Anthropocene epoch.

Domestic Animals

• Biomass movement of domesticated animals is comparable to that of humans, primarily driven by non-dairy cattle locomotion.

Wild Land Mammals Data

• Combined biomass movement of all wild land mammals (excluding bats) is estimated at 30 gt/km/yr.
• Large-bodied animals, which typically migrate longer distances, have seen the most significant declines in biomass movement.

This information underscores the vast differences in mobility and ecosystem impacts between species and highlights the significant role human activities play in shaping biodiversity and ecosystem dynamics.