{"id":244260,"date":"2017-07-26T11:25:52","date_gmt":"2017-07-25T23:25:52","guid":{"rendered":"https:\/\/sciblogs.co.nz\/?p=244260"},"modified":"2022-08-17T04:53:59","modified_gmt":"2022-08-17T04:53:59","slug":"introducing-pouwa-new-zealands-unique-ill-fated-black-swan","status":"publish","type":"post","link":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/2017\/07\/26\/introducing-pouwa-new-zealands-unique-ill-fated-black-swan\/","title":{"rendered":"Introducing the Po\u016bwa: New Zealand\u2019s unique and ill-fated black swan\u00a0"},"content":{"rendered":"

Step inside\u00a0a\u00a0TARDIS and travel to\u00a0prehistoric\u00a0New Zealand\u00a0and the\u00a0landscape\u00a0looked\u00a0very different.<\/strong><\/p>\n

Moa<\/a> roamed the\u00a0forests, Haast\u2019s\u00a0Eagle<\/a>\u00a0soared in the sky and you would have\u00a0met\u00a0a very tall, heavy and potentially\u00a0grumpy\u00a0swan. This is the Po\u016bwa\u00a0\u2013\u00a0New\u00a0Zealand\u2019s newest\u00a0species discovered by my team\u00a0(published today in Proceedings B<\/em><\/a>)\u00a0including collaborators from the Otago Palaeogenetics Laboratory\u00a0(University of Otago), Canterbury Museum<\/a> and the Museum of New Zealand Te Papa Tongarewa<\/a>. But how did we get to this point?<\/p>\n

\"\"<\/a>
Po\u016bwa skeleton.<\/figcaption><\/figure>\n

We know\u00a0a lot\u00a0about\u00a0how\u00a0prehistoric human impacts on megafauna\u00a0have dramatically reshaped ecosystems worldwide. However, we know comparatively little about the\u00a0impact\u00a0of human exploitation on smaller species. Anatids (ducks, geese and swans) are one such example. This diverse group\u00a0of birds\u00a0(150 species\u00a0in\u00a040 genera), featured in medieval carvings and Roman mosaics,\u00a0has\u00a0a long history of human exploitation, with\u00a0their\u00a0bones\u00a0found in archaeological\u00a0middens (rubbish dumps)\u00a0worldwide<\/p>\n

New\u00a0Zealand\u00a0represents the ideal location to test for the human impacts\u00a0on Anatids.\u00a0These\u00a0islands were\u00a0settled\u00a0very late in human history, around the\u00a0late 13th<\/span>\u00a0Century AD,\u00a0during\u00a0a period of relatively stable\u00a0climate.<\/p>\n

The Black Swan<\/h3>\n

The black swan\u00a0(Cygnus atratus<\/i><\/a>)\u00a0is\u00a0an iconic Australasian bird.\u00a018th<\/span>\u00a0Century\u00a0European explorers were\u00a0amazed\u00a0to discover\u00a0this species\u00a0as,\u00a0until their first voyages to Australia, all\u00a0swans were\u00a0assumed to be\u00a0white, almost by definition.\u00a0By contrast, when Europeans arrived in\u00a0New\u00a0Zealand\u00a0there were no black swans.\u00a0By the 1860s, naturalisation societies had introduced\u00a0Australian\u00a0black swans\u00a0from Victoria into New Zealand. Today, black swans are found throughout New Zealand and the Chatham Islands, with a population size of around 50,000.<\/p>\n

At the same time as these introductions, black swan bones were being found in\u00a0New Zealand\u2019s\u00a0fossil and archaeological deposits,\u00a0leading scientists to\u00a0conclude\u00a0that\u00a0the Australian\u00a0black swan\u00a0formerly\u00a0inhabited New Zealand\u00a0but\u00a0had been hunted to extinction shortly after the arrival of humans \u2013 indeed, until recently, this was still the prevailing view. However, as we know from ancient DNA research\u00a0conducted\u00a0by our group on penguins and sea lions, the story is not so simple.<\/p>\n

Hunting for the remains<\/h3>\n

We scoured\u00a0New\u00a0Zealand\u00a0museum collections for prehistoric\u00a0black swan\u00a0remains\u00a0from mainland New\u00a0Zealand\u00a0and the Chatham Islands, and\u00a0modern\u00a0black swans from across Australasia. Our genetic analyses showed that prehistoric swans from\u00a0New\u00a0Zealand\u00a0and the Chatham Islands\u00a0formed one lineage,\u00a0while\u00a0modern black swans from\u00a0throughout Australasia\u00a0were a different lineage.\u00a0We had seen this genetic pattern before with our research on biological turnover events in penguins and sea lions.\u00a0Our data showed that a unique lineage of black swan in New\u00a0Zealand\u00a0and the Chatham Islands was hunted to extinction and replaced by the Australian lineage. The genetic divergence between the Australian and New\u00a0Zealand\u00a0lineages suggested a separation of around one to two\u00a0million years. Could these different lineages be different species\u00a0given the divergence time?<\/p>\n

A mounted Po\u016bwa skeleton.<\/p>\n

Po\u016bwa<\/h3>\n

Weeks of measuring of modern and prehistoric black swan skeletons to capture the shape of the\u00a0skeleton,\u00a0months of statistical analysis,\u00a0and New\u00a0Zealand\u00a0has\u00a0its\u00a0own unique species of black swan\u00a0(Cygnus sumnerensis<\/i>) \u2013 named after Sumner in Christchurch, where\u00a0the first\u00a0remains of this species\u00a0were discovered. We\u2019ve called our new species Po\u016bwa, based on a Chatham Island Moriori legend about a large bird that inhabited the lagoon and whose bones were common in\u00a0the surrounding\u00a0sand dunes.\u00a0As in all good trans-Tasman rivalries, we\u2019ve claimed one\u00a0species\u00a0back from the Australians.\u00a0Sadly, the Po\u016bwa did not survive the arrival of humans.<\/p>\n

The Po\u016bwa\u00a0was\u00a0truly\u00a0unique. It was larger and heavier than its Australian cousin \u2013\u00a0more like an\u00a0All Blacks\u00a0rugby player\u00a0than a\u00a0soccer player. Po\u016bwa weighed up to 10 kg\u00a0(as opposed to\u00a0the\u00a06 kg\u00a0Australian black swan),\u00a0had\u00a0very elongated legs, and proportionally shorter wings.\u00a0Such proportional\u00a0anomalies\u00a0are\u00a0common in birds\u00a0from\u00a0island\u00a0ecosystems\u00a0lacking\u00a0terrestrial mammals.\u00a0Prior to human arrival,\u00a0New Zealand\u00a0lacked\u00a0predatory\u00a0mammals,\u00a0being\u00a0truly\u00a0the\u00a0land of the birds.\u00a0The\u00a0Po\u016bwa\u00a0thus was\u00a0probably\u00a0on the evolutionary pathway to flightlessness\u00a0–\u00a0a\u00a0very tall\u00a0and\u00a0heavy\u00a0bird\u00a0indeed.<\/p>\n

The\u00a0extinct\u00a0Po\u016bwa\u00a0may\u00a0also\u00a0raise\u00a0interesting\u00a0questions\u00a0for conservation\u00a0and\u00a0ecological restoration\u00a0efforts.\u00a0The Australian swan is not really a \u2018replicate\u2019 of the original Po\u016bwa,\u00a0so is this Aussie newcomer\u00a0a pest, or something to be protected?\u00a0Perhaps, one day, de-extinction science will allow us to bring back New Zealand\u2019s unique Po\u016bwa.<\/p>\n

Image:\u00a0A black swan (not<\/em>\u00a0Po\u016bwa)\u00a0floats on Lake Rotoiti.<\/p>\n","protected":false},"excerpt":{"rendered":"

Step inside\u00a0a\u00a0TARDIS and travel to\u00a0prehistoric\u00a0New Zealand\u00a0and the\u00a0landscape\u00a0looked\u00a0very different. Moa roamed the\u00a0forests, Haast\u2019s\u00a0Eagle\u00a0soared in the sky and you would have\u00a0met\u00a0a very tall, heavy and potentially\u00a0grumpy\u00a0swan. This is the Po\u016bwa\u00a0\u2013\u00a0New\u00a0Zealand\u2019s newest\u00a0species discovered by my team\u00a0(published today in Proceedings B)\u00a0including collaborators from the Otago Palaeogenetics Laboratory\u00a0(University of Otago), Canterbury Museum and the Museum of New Zealand Te Papa … Continue reading “Introducing the Po\u016bwa: New Zealand\u2019s unique and ill-fated black swan\u00a0“<\/span><\/a><\/p>\n","protected":false},"author":40066,"featured_media":280658,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[87395],"tags":[71154,87454,62,87546],"class_list":["post-244260","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-environment-and-ecology","tag-black-swan","tag-extinction","tag-new-zealand","tag-pouwa"],"_links":{"self":[{"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/posts\/244260","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/users\/40066"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/comments?post=244260"}],"version-history":[{"count":0,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/posts\/244260\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/media\/280658"}],"wp:attachment":[{"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/media?parent=244260"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/categories?post=244260"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.otago.ac.nz\/lost-worlds\/wp-json\/wp\/v2\/tags?post=244260"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}