The increasing aridity of the Australian continent over the past 20 million years has favoured organisms that could adapt to dry conditions. Marsupials have developed a variety of behavioural, physiological and morphological adaptations to survive in these arid conditions with little or no food and free water for extended periods of time.
Marsupials living in Australia’s hot arid environment must deal with exposure to extreme conditions such as high temperatures, solar radiation and limited food and water supply. More than 50% of the world’s marsupial species occur only in Australia (Steffen et al 2009), which indicates their ability to adapt to Australian conditions.
This essay will provide specific examples of the way Australian marsupials species have adapted to the arid Australian environment.
Marsupials have developed a variety of physiological adaptations to cope with arid Australian environments. Several examples of physiological adaptations are described below.
Torpor is a short-term state characterised by a reduction in the metabolic rate (MR) including a lower than normal body temperature (Tb) and heart and respiratory rate (Solomon et al, 2011).
Some Australian marsupials have evolved to utilise torpor as an effective survival strategy by reducing water loss and energy expenditure in the harsh arid zones in Australia where food and water are often in short supply (Geiser, 2004).
According to Geiser (2004), Dasyurids are one of the most effective small arid zone mammals due to their effective use of torpor, which is used to adapt to strong variations in food and water availability. As mentioned by Geiser (2004), Dasyurids utilise torpor during the night or early morning and utilise the sun’s warmth to rewarm from torpor, minimising energy expenditure.
Another species that utilises torpor to adapt to the arid
References: Armati, Patricia J.; Dickman, Chris R.; Hume, Ian D. 2006, Marsupials, e-book, accessed 26 April 2012, .