Biological Adaptations
Taylah Rich 11MKL
Short-Beaked Echidna
Environment
The short-beaked echidna is found throughout Australia, including Tasmania. It is Australia’s most widely distributed mammal. This species of echidna can live in forests, woodlands, heath, grasslands and arid environments. Their only requirements for their environment are a sufficient supply of small vertebrates such as ants and termites.
As the echidna has no particular habitat requirements they are able to survive in all climates, temperature ranges and regions with different rainfall patterns. Echidnas found in temperate climates are often seen during the early morning and the late afternoon, as they tend to avoid temperature extremes whereas echidnas found in arid regions may forage during the night and take shelter during the hotter parts of the day.
As echidnas are widely distributed across Australia, there are variations in temperature, water availability and rainfall. The further south the echidna lives the colder the conditions. The south of Australia usually experiences four seasons throughout the year with contrasting weather conditions. However, the north of Australia experiences higher temperatures and only two seasons; wet and dry. Throughout the wet season the temperature remains warm however there is a higher level of rainfall.
Figure 3: Echidna Disbribution in Australia
Challenges Faced
The predators of the echidna include goannas, dingoes, foxes, feral cats, dogs, eagles and Tasmanian devils and snakes. Generally these predators are only harmful to the echidna when they are young as predators such as snakes will enter the echidna’s burrows and prey on the young and spineless puggles. Once an adult the echidna uses its spines to protect themselves from these predators.
Another challenge faced by the echidna is being injured as a result of being hit by a car. When a car hits an echidna it often results in the echidna getting a broken snout. This can suffocate the echidna as well as prevent it from being able to feed as the receptors in its snout may become damaged and the echidna will no longer be able to locate food.
Adaptations
Physiological:
The core body temperature of an echidna ranges between approximately 31 degrees celsius-34 degrees celsius which is lower than most other mammals. Echidnas are also able to drop their body temperature to ambient levels, which means they are able to adjust their body temperature to the levels of their environment.
In colder areas echidnas hibernate for periods of time as short as 6 weeks and as long as 28 weeks depending of the conditions of their environment. During hibernation the echidna regularly rewarms itself as temperatures decrease to as low as 5 degrees celsius. This is because echidnas rarely face temperatures below 15 degrees celsius.
To maintain a balanced temperature of around 32 degrees celsius the echidna relies on the circulatory system. To prevent or encourage heat loss, the echidna’s blood vessels are able to dilate or constrict accordingly, in a process called vasoconstriction/vasodilation.
Benefits:
The echidna being able to adjust its body temperature through vasoconstriction and vasodilation allows the species to obtain air and warmth as well as cope with the physical conditions of its environment including temperture.
Behavioural:
In order for echidnas to keep cool in hot climates they find shelter. They use fallen wood, bushes, rocks, small caves and burrows to take cover from the heat. In warmer areas of Australia such as Queensland and the Northern Territory echidnas often feed at night rather than during the day to keep out of the hot weather. In temperate areas echidnas usually feed at dawn and dusk.
Benefits:
The echidna finding shelter in hot climates allows the species to cope with the physical conditions of its habitat including extremes in temperature. The echidna adjusting its feeding times throughout different seasons and in different climates allows the species to secure food, water and nutrients all year round.
Structural:
A structural adaptation of the echidna is the spines that cover its back area. These spines are used for protection against predators. Echidnas have a long snout and tongue, which are another structural adaptation that allows the species to reach deep into ant and termite hills to find food. The echidna also has backwards facing claws that allow it to dig and protect its stomach.
Benefits:
The spines on an echidna allow the species to defend and protect themselves from predators as well as protect their offspring from predators. The long snout and backwards facing claws of an echidna allow them to secure food sources.
Figure 4: Vasoconstriction and Vasodilation
Figure 5: Echidna Footprints
Rhythmic Patterns
Short-beaked echidnas are typically active hunting for food during the day, however they aren’t equipped to deal with extreme heat as they do not have any sweat glands and do not pant. Therefore during warm seasons including summer as well as in warm weather they change their feeding patterns becoming crepuscular or nocturnal. Echidnas also hibernate during the winter as well as if they live in cold climates.
The purpose of these rhythmic patterns is to allow the echidna to survive in all types of climates as they live all around Australia.
Interesting Fact
Echidnas are mammals without nipples. Like all other mammals, echidnas feed their young milk. Instead of feeding their young milk with their nipples, the female echidna has special glands inside their pouch that secrete milk to their young puggles.