{"id":243632,"date":"2017-07-27T15:41:02","date_gmt":"2017-07-27T18:41:02","guid":{"rendered":"http:\/\/revistapesquisa.fapesp.br\/?p=243632\/"},"modified":"2017-07-27T15:41:02","modified_gmt":"2017-07-27T18:41:02","slug":"amazonian-manatee-knows-just-when-to-migrate","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/amazonian-manatee-knows-just-when-to-migrate\/","title":{"rendered":"Amazonian manatee \u201cknows\u201d just when to migrate"},"content":{"rendered":"
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L\u00e9o Ramos Chaves \/ Photo taken at the S\u00e3o Paulo Aquarium <\/span><\/a> The manatee moves from Lake Mamirau\u00e1 to Lake Aman\u00e3 in the dry seasonL\u00e9o Ramos Chaves \/ Photo taken at the S\u00e3o Paulo Aquarium <\/span><\/p><\/div>\n

October through December is the dry season in the region of the middle Solim\u00f5es River, about 600 kilometers west of Manaus, and the waters in nearby Lake Mamirau\u00e1 drop so low that one of its most famous inhabitants, the Amazonian manatee (Trichechus inunguis)<\/em>, moves to another lake, called Aman\u00e3, to ensure its survival. Although Mamirau\u00e1 offers the aquatic mammal more food than Aman\u00e3, the risky trip \u2013 which can last three days and cover as much as 115 kilometers \u2013 is fully justified. Lake Mamirau\u00e1 sits in a v\u00e1rzea<\/em>, where waters alternately rise and recede, while Lake Aman\u00e3 lies in an area of perennial flooding. A recent study suggests that the Amazonian manatee possesses biological mechanisms for spatial localization that prompt it to start its forced migration at the best possible moment (Acta Amazonica<\/em>, January-March 2017). \u201cThey seem to have a cognitive map of the region that is updated as the waters drop,\u201d says ecologist Eduardo Moraes Arraut, a remote sensing specialist with Brazil\u2019s National Institute for Space Research (INPE) and author of the paper. According to Arraut, when the Mamirau\u00e1 starts shrinking, the manatee puts its move off as long as possible so it has more time to feed on local aquatic plants that are not found in Lake Aman\u00e3. Yet the animal usually manages to make the trip without getting stuck in shallower stretches along the way, known as migratory bottlenecks. \u201cMaybe he has some kind of sensor to monitor the chemical changes that occur in the water during the dry season,\u201d ventures Miriam Marmontel, oceanographer with the Mamirau\u00e1 Institute. The study tracked the movements of ten Amazonian manatees for up to four years, in addition to compiling 30 years\u2019 worth of satellite images of the region and 14 years\u2019 worth of information on the discharge of local rivers and lagoons. One worrisome discovery was a new migratory bottleneck along a stretch between Mamirau\u00e1 and Aman\u00e3, which formed in the last 15 years. The water there nearly vanishes during the dry season, hampering the animal\u2019s passage.<\/p>\n","protected":false},"excerpt":{"rendered":"Amazonian manatee \u201cknows\u201d just when to migrate","protected":false},"author":475,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[1651],"tags":[206,224],"coauthors":[785],"class_list":["post-243632","post","type-post","status-publish","format-standard","hentry","category-notes","tag-biodiversity","tag-ecology"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/243632","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/475"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=243632"}],"version-history":[{"count":0,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/243632\/revisions"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=243632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=243632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=243632"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=243632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}