Throughout evolutionary history animals have been affected by environmental factors, with some species dying out and others adapting to the changes and becoming stronger.
By Leigh Kemp
Extinction and Adaptation of Animals
Throughout history there have been major climatic and geographic changes that have occurred on Earth, causing the inhabitants of affected areas to adapt or die. It is now known that there have also been cataclysmic cosmic events, such as comets striking the Earth that have played a role in changing the course of living things on Earth.
But why whole groups of species such as the Dinosaurs have gone extinct is still the source of debate. Consensus is, however, moving toward a geomorphic change such as a major earthquake or a massive flood.
Climatic change such as an Ice Age explains the extinction of other species. What happens after these major events is that species would need to adapt to the new environment. Those that survive do so by adapting to the new challenges.
Climatic and geomorphic changes are also happening today, subtly changing the conditions on Earth, with man adding to the change phenomenon - and forcing animals to adapt.
Volcanoes and Fertile Plains
The nutritious southern plains of the Serengeti in Tanzania are the result of lava deposits from volcanic eruptions of the once-high Ngorongoro peak and surrounding volcanoes. Rich soils were then deposited on the lava which in turn provided nutrients to shallow rooted plants such as grasses which are now the birthing grounds of the great migration.
Aerial photographs of northern Botswana show how the Okavango Delta has changed over time. The fossil floodplains indicate a once larger body of water and a shift in the location of the Delta over time. The incidents of termite mounds in areas of the permanent Delta today indicate that at times the Delta has experienced exceptionally dry periods. These factors will all have had an effect on the behaviour of animals at the time.
The Savute River
The Savuti River system in Botswana is an example of recent geomorphic change. Once part of the greater lake system that included the Okavango Delta and Makgadikgadi Pans the Savuti has experienced a great deal of recent change. The system today is flowing after being dry for almost thirty years.
In the past 200 years it has flowed and stopped four times for varying periods. It last dried up in 1981, before starting to flow again in 2008. When the channel flows it provides a lifeline for animals in the dry season and vast herds gather on the nutrient plains of the Savuti Marsh in the wet season. This is an example of a recent geomorphic change that animals have had to adapt to.
Chance or Ancient Knowledge
We have our ideas as to how animals should behave but often exceptional behaviour occurs. Is this behaviour chance or a hidden trait from the past that has not been observed before by biologists? Is it a trait that arose under extreme climatic occurrences and then settled when conditions improved?
In the aforementioned Savuti there is a pride of lions that has adapted to killing adult Elephants, behaviour that had never before been recorded. There were records of Lions killing young and ill Elephants but to specialize in killing adults was unheard of.
Was this a chance development or a long-hidden ancestral trait that has surfaced? Could it be simply that the lions developed a liking for elephant meat from feeding on a carcass or killing a young one and developed their kill strategy over the seasons to eventually be confident enough to kill adult elephants?
Read more on the Human Impact on Animal Behaviour