How Did Ice Age Animals Adapt to Limited Resources?

Woolly mammoths, helmeted muskox, and giant short-faced bears were iconic Ice Age animals that once roamed Alaska’s forests. Yet at the end of this Ice Age, these iconic species became extinct – what happened?

The answer lies within their environment. Read on to gain more insight into how these large mammals and other cold-blooded creatures managed to make it through the Ice Age.

Size and Insulation

During the Ice Age, much of Earth was covered with thick icy sheets that reduced temperatures drastically and altered landscapes by glaciers, creating steppes or dry grassy plains inhospitable to animals – mammoths and ground sloths were particularly adept at adapting to such an inhospitable climate thanks to their large sizes giving them an advantage in such harsh climates.

As the ice melted, it created new habitats and seasons with distinct boundaries, forcing animals to adapt their feeding sources and strategies to survive in new environments.

Scientists have long been baffled as to how life survived the most severe ice age ever to occur on Earth in its four billion-year history. Previous research had pointed to oxygen-dependent organisms living only at surface-level meltwater puddles as being resilient, yet new research offers another explanation: the existence of underground ecosystems.

Cope’s Rule

The Ice Age was marked by cold, snowy conditions that blanketed much of Earth, creating vast grasslands and tundra habitats that provided abundant food sources for herbivorous animals to feed on – leading them to expand in size as their resources increased; this phenomenon became known as Cope’s Rule.

• But, what about non-herbivorous species?
• The fossil record reveals some animals who lived during the Ice Age were much smaller than their predecessors; why is this happening?

Bergmann’s Rule may provide insight. When temperatures dropped, large bodies retained more heat than smaller bodies; as the planet cooled off, natural selection favored larger animals as natural selection took hold and made way for evolution to progress; when conditions warmed back up again however, these larger creatures lost out and went extinct as competition increased with smaller ones.

Bergmann’s Rule

Bergmann’s Rule has been an influential concept for more than 170 years and falls into what people in Germany refer to as “Lieschen Muller knowledge”, or just-so stories that have been passed from generation to generation without any academic learning or scientific research being involved. Bergmann’s Rule describes latitudinal clines in body size and shape (the other being Allen’s Rule regarding length of limbs).

Bergmann’s rule states that larger animals lose proportionally less heat due to having lower surface areas, thus contributing to more efficient energy conservation. Large animals thus tend to possess thick fur or scales to retain body heat more effectively in cold environments as well as slower metabolic rates and fewer heartbeats per minute that help conserve energy reserves.

Seasons

Ice Age seasons were vital to animal species as they allowed them to eat and expand during warmer months while resting and hibernating during colder ones. Furthermore, this helped ensure food was easily accessible for animals during all four seasons of the year.

Researchers are gaining a good understanding of what life was like during the Ice Ages through studying fossils and rocks preserved by ice, fossilized vegetation, tree rings as a good indication of temperature changes over time, fossilized fossils found within ancient artifacts found within glaciers, as well as through scientific modeling of climate models.

Geologists now recognize that ice ages follow predictable cycles linked to fluctuations in sunlight reaching different parts of the world due to wobbling Earth axis motion known as Milankovitch cycles. A new Ice Age could disrupt agriculture by leading to crop failures and food shortages leading to mass starvation across the planet, in addition to extreme cold, avalanches, or damage to roads and infrastructure as potential effects.