Editing Kangaroo (section)

=== Locomotion ===
Kangaroos are the only large mammals to use [[Jumping|hopping]] on two legs as their primary means of [[Animal locomotion|locomotion]].<ref>{{cite news |last1=Briggs |first1=Helen |title=When did the kangaroo hop? Scientists have the answer |url=https://www.bbc.co.uk/news/science-environment-47130734 |access-date=5 February 2023 |work=BBC News |date=6 February 2019 |quote=Living kangaroos are the only large mammal to use hopping on two legs as their main form of locomotion.}}</ref> The comfortable hopping speed for a red kangaroo is about {{convert|20–25|kph|abbr=on}}, but speeds of up to {{convert|70|kph|abbr=on}} can be attained over short distances, while it can sustain a speed of {{convert|40|kph|abbr=on}} for nearly {{convert|2|km|abbr=on}}.<ref name="secret">{{cite book | last = Penny | first = Malcolm | title = The Secret World of Kangaroos | publisher = Raintree Steck-Vaughn | year = 2002 | location = Austin TX | isbn = 978-0-7398-4986-6 | url = https://books.google.com/books?id=NNLpLfdP5GwC&q=%2270+km%22 | access-date = 8 May 2020 | archive-date = 16 August 2021 | archive-url = https://web.archive.org/web/20210816140648/https://books.google.com/books?id=NNLpLfdP5GwC&q=%2270+km%22 | url-status = live }}</ref> During a hop, the powerful [[gastrocnemius muscle]]s lift the body off the ground while the smaller [[plantaris muscle]], which attaches near the large fourth toe, is used for push-off. Seventy percent of potential energy is stored in the elastic tendons.<ref>{{cite book |last1=Jackson |first1=S |last2=Vernes |first2=K |year=2010|title=Kangaroo: Portrait of an Extraordinary Marsupial|publisher=Allen and Unwin|pages=139–140|isbn=9781741759037}}</ref> At slow speeds, it employs pentapedal locomotion, using its tail to form a tripod with its two [[forelimb]]s while bringing its hind feet forward. Both pentapedal walking and fast hopping are energetically costly. Hopping at moderate speeds is the most energy efficient, and a kangaroo moving above {{convert|15|kph|abbr=on}} maintains energy consistency more than similarly sized animals running at the same speed.<ref name="Dawson 1995"/>