The 2019/2020 Australian bushfires caused the destruction of 10 million hectares of wildlife habitat, affecting 1.25 billion animals . An estimated 30% of the global koala population has been affected, placing the species under new levels of threat (Gonzalez-Astudillo et al., 2019; World Wide Fund for Nature, 2020). While bushfires have recently become a massive threat to the species, the koala population has been in decline since the 18th century, since Europeans settled Australia. This population decline can be partly attributed to several introduced threats against which the population is anatomically ill-equipped. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get an original essay Due to their diet, koalas are arboreal animals, meaning that much of their locomotion involves climbing and to move between the branches of trees. The functional anatomy associated with climbing in the Koala is best described in comparison to its closest terrestrial relative, the Wombat. Koalas and wombats are both marsupials (Louys et al., 2009) and have many similarities, including molecular data, dentition, a backward-facing marsupium, and a vestigial tail that indicate their close relationship ( Grand and Barboza, 2001). However, due to their relative environment and diet – trees and eucalyptus foliage for koalas, burrows and grasses for wombats – they possess many derived traits. The sedentary position of koalas when climbing and feeding has led to mid-facing soles and palms, allowing them to grip the trunk or branches of trees, while the Wombat has palms and soles plantigrades allowing stability and pressure distribution during loading (Fig.1)(Young, 1881). Supination of the Koala's forelimb is facilitated by the deeply curved radius while the Wombat's compact radius restricts supination (Fig.2)(Grand and Barboza, 2001). Although this skeletal orientation facilitates climbing, it hinders koalas' ability to move between habitats in search of quality food sources and mates. Yet terrestrial locomotion is becoming increasingly important as human interference leads to increasing fragmentation of eucalyptus habitat (Grand and Barboza, 2001; Narayan). and Williams, 2016). Compared to wombats, koalas also have an elongated humerus and diminished olecranon (Fig. 2), which allows them to fully extend their forelimbs, thereby increasing the length of their strides (Grand and Barboza, 2001). Increasing stride length is common in arboreal species and is hypothesized to reduce destabilizing peak forces when crossing narrow branches. This morphology further prevents excessive terrestrial locomotion because the slender humerus is not designed to support weight on solid surfaces with greater resistance. The absence of a notable olecranon also reduces stability against hyperextension of the elbow joint during weight-bearing (Gaschk, Frère, & Clemente, 2019). In addition to the medial rotation of their limbs, Koalas also have an opposable hallux on each foot and two opposable halluxes. digits on each hand to give them extra grip strength. All of their toes have large, curved claws that further enable them to secure their position in a tree and hold on to the bark (Young, 1882; Grand and Barboza, 2001; Gaschk, Frère, and Clemente, 2019).However, these also hinder ground movements because they force the hands and feet to be spread apart and the fingers to be hyperextended when in contact with the ground, resulting in significant lateral displacement when the limbs are swung forward; this is very inefficient when considering speed versus energy consumption (Grand and Barboza, 2001; Shipley, Forbey, and Moore, 2009). These claws reduce the speed of terrestrial locomotion because they increase the stance phase required due to an increased reliance on precise finger placement in order to correctly apply pressure for propulsion (Gaschk, Frère, & Clemente, 2019). Similar to the forelimbs, adaptations in the musculature of the hindlimb mean that it is also inverted. The absence of an iliac attachment for the external gluteus, the absence of soleus and a single origin of the biceps femoris as well as the occasional attachment of the gracilis to the marsupial bone all encourage medial rotation of the hind limb (Young, 1882) . These muscular arrangements also result in reduced mobility of the hip joint, which contributes significantly to the biomechanical inefficiency of land movements (Grand and Barboza, 2001). Due to their slow land speed and antisocial behavior, which causes most koalas to travel individually rather than in packs - Koalas are particularly vulnerable on the ground as they are exposed to road kills and predator attacks , particularly from dogs (Lassau et al., 2008; Gentle et al., 2019). However, recent climate change and evolving human settlements mean that eucalyptus habitat is increasingly fragmented (Narayan and Williams, 2016). Therefore, the Koala is forced to spend extended periods of time moving on land between suitable habitats in order to search for food, water and mates (Gaschk, Frère, & Clemente, 2019). Because koalas have very few natural predators, they lack the adaptations necessary to escape or defend themselves when threatened. Around peri-urban areas, wildlife habitats have been replaced by an area of ​​intense human activity and fraught with threats in which koalas are unable to thrive. Aside from their anatomical adaptations to an arboreal lifestyle, the other major components of koala anatomy that place them The adaptations that have arisen as a result of their diet are at a significant disadvantage in today's environment. As a hindgut fermenter, the Koala is one of the few species capable of digesting the highly fibrous eucalyptus leaf and extracting its limited nutrition and energy. To enable the koala to extract maximum nutrition, the species has a huge caecum relative to its body size (Grand and Barboza, 2001; Shipley, Forbey and Moore, 2009). Koalas are considered one of the most specialized mammals. folivores (Shipley, Forbey and Moore, 2009). With more than 93% of their diet made up of 120 species of trees of the Eucalyptus genus, they are the most avid consumers of Eucalyptus (Grand and Barboza, 2001). It is assumed that koalas have adapted to eating the eucalyptus leaf due to the lack of competition for the food source, as it is highly toxic to many other species (Moore and Foley, 2000). The koala's eucalyptus diet is notoriously low in energy and difficult to digest. With a diet high in indigestible waxes, toxic terpenoids and fiber mass, but low in calories, the Koala requires 19 to 22 hours/day of food and sleep just to meet its needs.basic energy and finance an average of 4 minutes per day of active movement (Grand and Barboza, 2001; Johnson et al., 2018). They are unable to spare the energy needed to move or socialize excessively, leading them to lead sedentary and antisocial lives. The low energy available to the Koala means that it must have a basal metabolic rate significantly lower than the average for other mammals of similar size (Grand and Barboza, 2001). This has caused them to be metabolic preservatives in every way possible. To minimize the energy spent regulating body temperature, koalas have highly insulating skin that keeps them warm in the windy treetop environment (Degabriele and Dawson, 1979). . When trying to stay cool, koalas rely on the shade provided by the eucalyptus canopy and an area of ​​thin skin on their sternum that they press against cool areas of the ground or bark to reduce body temperature (Smith, 1979). However, although these reduce basic energy cost, their highly insulating skin led to exploitation of the species through the skin trade in the 19th and 20th centuries, resulting in millions of deaths (Johnson et al., 2018).If climate change intensifies, causing more extreme weather, and their habitat continues to fragment, it is unlikely that the species will be able to maintain a healthy body temperature using these methods alone. The increasingly elusive nature of shade and cool surfaces poses a particular threat; High temperatures and low water availability can cause many koalas to die due to dehydration or overheating. 91% of the energy that can be used by koalas from eucalyptus comes from digesting cellular contents rather than the cell wall (Lanyon and Sanson, 1986), so it is important that the cellulose walls are broken down as much as possible. as possible to expose maximum amounts of content. This is done during chewing in Koalas, the grinding motion of the jaw breaks down cell walls and maximizes surface area to promote subsequent fermentation. Given the importance given to the exposure of cellular contents, the dentition of the species has adapted to maximize this (Lanyon and Sanson, 1986). Koalas use lateral crushing mandibular movements to crush leaves into pulp before swallowing them. They also have an oral cavity disproportionate to the size of their skull, allowing more food to be chewed at any given time. As a result, a decrease in brain size can be seen in the fossil record as more emphasis was placed on the chewing process, leading to an increase in the size of the masticatory muscles and their attachment sites (Large and Barboza, 2001; ). Grand and Barboza (2001) described the skull of a modern koala as "a chewing machine housing a small brain." Smith (1979) hypothesized that koala brain size, which is one of the smallest brains relative to body size, observed in koalas. any mammal, may be responsible for Koalas' lack of adaptability and social skills. Smith suggested that because they are not opportunistic animals, like primates or carnivores, they are able to simply analyze whether what is placed in front of them is a palatable food source or not, based on appearance, odor and moisture content, without the need to do so. to assess their environment in detail. These results are supported by Moore and Foley (2000) and Ellis et al. (2010). This lack of capacity to manage..