Antarctic Bestiary

Terrestrial Animals

Living on the ground of the Antarctic Peninsula presents some extreme challenges to organisms, including:

  • Highly variable, extreme temperatures, from -30°F to 50°F air temperature, with summer surface temperatures of rocks and moss reaching 70°F.

  • Extremely high winds.

  • A very short growing season (period when temperatures allow plant growth).

  • Wide swings in pH, from 3 (very acidic) to 12 (very basic), partly caused by...

  • Immersion in penguin guano (waste) from nesting Adélie penguin colonies in the summer.

  • Immersion in both freshwater (from melting glaciers and snow and rain) and saltwater (from waves splashing on the land).

  • Dehydration from exposure to very dry air in the winter.

  • Exposure to intense UV rays. The protective ozone layer is naturally thinner here, and there is a hole in it (probably caused by human pollution) that opens up in the winter.

  • Lack of oxygen, due to being encased in ice for long periods, as well as being immersed in penguin guano filled with oxygen-using microbes.

Visit our Study Sites page to learn more about the terrestrial habitats of the Antarctic Peninsula.

 

Here are some of the terrestrial animals we’ve encountered on the Antarctic Peninsula:

Belgica antarctica —

The focus of most of our research here, this wingless midge (a type of fly) is the only true insect found on Antarctica, and is considered the continent’s largest terrestrial animal (it’s only 2-6 mm long!). Belgica undergoes complete metamorphosis (like many insects), meaning it has a larval and an adult form that are quite different. This insect is amazingly resistant to all kinds of stresses in both its life stages. Among its adaptations:



Belgica larva:


  • Survives freezing of its body fluids

  • Clusters together during dry conditions to avoid water loss

  • Survives dehydration to 35% of its original body weight

  • Tolerates wide swings in salinity and pH

  • Can survive lack of oxygen for 2-4 weeks

  • Deep purplish black coloration to absorb heat and possibly block harmfully intense ultraviolet radiation

  • Lives for two years, giving it two growing seasons in which to accumulate the energy to reproduce.

 

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Belgica adult:


  • Wingless, to avoid being blown off islands

  • Tolerates relatively high temperatures

  • Lives 10 days, enabling it to mate and lay eggs quickly during the highly variable summer months

 


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Cryptopygus antarcticus —

A species of Collembola, or springtail (closely related to, but not quite considered a true insect). They do not change much as they develop (unlike Belgica’s metamorphosis from larva to adult), and are also well adapted to their environment. Some adaptations:


  • Very dark coloration, absorbs heat

  • Lives for three or more years, accumulating enough nutrients to reproduce

  • Floats on water due to a hydrophobic exoskeleton and the tendency to form rafts, or clusters

  • Supercools (cools extensively without freezing) to -22°F in the winter

 


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Ixodes uriae —

A parasitic tick (an Arachnid, in the same class as spiders and mites). It feeds on the blood of Antarctic and Arctic seabirds, including penguins, petrels, and Arctic and Antarctic terns. These ticks are found at high latitudes in both hemispheres. Adaptations:


  • Tolerates temperatures from -22°F to 104°F! (104°F is the temperature of the blood of some birds)

  • Tolerates starvation for approximately 11 months, only feeding once per year

  • Forms tightly-packed clusters under cool, moist rocks to prevent water loss

  • Three year lifespan

 


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Alaskozetes antarcticus —

A species of non-parasitic mite, which lives under the rocks found all over the Antarctic Peninsula. Adaptations:


  • Very dark coloration
  • Supercools to below-zero temperatures without freezing

  • 5-7 year development period


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- Luke Sandro and Juanita Constible