{"id":35812,"date":"2026-09-02T06:50:00","date_gmt":"2026-09-02T10:50:00","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=35812"},"modified":"2026-09-02T06:50:00","modified_gmt":"2026-09-02T10:50:00","slug":"wolf-bones-baltic-island-cave-marine-diet-isotopes","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/wolf-bones-baltic-island-cave-marine-diet-isotopes\/35812\/","title":{"rendered":"Wolf bones from 2 animals in a cave on a Baltic island under a square mile carry the same seal and fish chemistry as the people who camped there, on ground with no land mammals"},"content":{"rendered":"<p>There is a rock in the Baltic with sheer sides and a cave near the shore.<\/p>\n<p>Nothing lives on it that walks. No deer, no hare, no fox, no&nbsp;<strong>land mammal at all<\/strong>.<\/p>\n<p>Seabirds nest on the cliffs and seals haul out below, and that is the whole menu.<\/p>\n<p>Then somebody put two old canid bones from that cave through a mass spectrometer.<\/p>\n<p>The chemistry came back reading of the sea.<\/p>\n<p>So how does a bone&nbsp;<strong>remember a diet<\/strong>?<\/p>\n<h2>Why the sea leaves a mark that meat cannot fake<\/h2>\n<p>Bone is not inert. The collagen inside it is rebuilt continuously from the protein an animal eats.<\/p>\n<p>Carbon and nitrogen both come in more than one weight, and the ratios differ between a forest and an ocean.<\/p>\n<p>Marine food chains are longer and start from a different carbon pool, so anything living off them carries&nbsp;<strong>heavier values<\/strong>&nbsp;in both elements.<\/p>\n<p>A wolf eating elk in a Swedish forest signs itself one way. A wolf eating seal signs itself another, and the two cannot be confused.<\/p>\n<p>The reading is also slow.<\/p>\n<p>Collagen turns over across years, so what comes out of the machine is an average of a life rather than a last meal.<\/p>\n<p>Which makes the awkward part unavoidable. On a rock with nothing to hunt, a wolf with a marine signature was either&nbsp;<strong>catching seals<\/strong>&nbsp;or being handed food.<\/p>\n<h2>The rock and the hole in it<\/h2>\n<p>Stora Karls\u00f6 is roughly a mile long and half a mile wide, just under a square mile in total.<\/p>\n<p>It sits about&nbsp;<strong>4 miles<\/strong>&nbsp;off the west coast of Gotland, and Gotland itself is some 47 miles from the Swedish mainland.<\/p>\n<p>The cave is called Stora F\u00f6rvar, and it opens close to the water.<\/p>\n<p>Inside it, people left a deposit more than&nbsp;<strong>13 feet deep<\/strong>, built up from the Mesolithic through to the Iron Age.<\/p>\n<p>This was a working station rather than a village: a place seal hunters and fishers came back to, season after season, for thousands of years.<\/p>\n<p>Everything in that deposit had to arrive by boat.<\/p>\n<p>The stone, the tools, the people and, it turns out, the canids.<\/p>\n<h2>What the two bones actually said<\/h2>\n<p>DNA identified both animals as gray wolves, with&nbsp;<strong>no dog ancestry<\/strong>&nbsp;anywhere in the genome.<\/p>\n<p>Radiocarbon put them between roughly 5,000 and 3,000 years old, one of them Bronze Age.<\/p>\n<p>Their carbon and nitrogen values sat in marine territory and lined up with the humans from the same site.<\/p>\n<p>Set against the 72 ancient wolf genomes published in 2022, the better covered of the two had the lowest genetic diversity of any ancient wolf yet sequenced.<\/p>\n<p>One animal carried something else: severe damage to a limb bone that it survived, an injury that should have ended a wild hunter&#8217;s ability to run down prey.<\/p>\n<p>The work was published in a national academy journal in November of 2025 by teams in Sweden, England and Scotland.<\/p>\n<p>The authors describe wolves living alongside people, eating what those people ate, in a place reachable&nbsp;<strong>only by boat<\/strong>.<\/p>\n<h2>Four things two bones cannot settle<\/h2>\n<p>It is two animals, and two animals are an observation rather than a population.<\/p>\n<p>The cave was dug out in the eighteen nineties in flat 12 inch spits across a sloping floor, so depth in that deposit is not a reliable clock. Every date here comes from the bone itself, not from the layer it sat in.<\/p>\n<p>Low genetic diversity has&nbsp;<strong>two readings<\/strong>&nbsp;and the data cannot separate them: a small isolated island population inbreeds, and so does a kept lineage.<\/p>\n<p>A marine diet is&nbsp;<strong>not proof<\/strong>&nbsp;of a feeding hand either, because dead seals wash ashore and a wolf will take one.<\/p>\n<p>Transport by people is the best available explanation and not a demonstrated fact, since the Baltic freezes and canids swim, as other&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/fox-lost-wild-home-solar-panels\/24938\/\" target=\"_blank\" rel=\"noopener\">wild canids living<\/a>&nbsp;at the edge of human space keep showing.<\/p>\n<p>What is not in doubt is that the crossing happened somehow, on a sea people had been&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/2-000-years-sailors-called-sea\/28581\/\" target=\"_blank\" rel=\"noopener\">working for millennia<\/a>.<\/p>\n<h2>The experiment that did not take<\/h2>\n<p>The instinct is to read this as an early stage of dog domestication, and the genome forecloses it.<\/p>\n<p>These were wolves at the end, not dogs at the beginning, and they left no descendants in any dog alive.<\/p>\n<p>That makes the find more interesting rather than less.<\/p>\n<p>Dogs were already common across Europe by the time these two were living on that island, so this was not a first attempt at anything.<\/p>\n<p>It was people who already had dogs, keeping wolves anyway, and getting nowhere with it, as&nbsp;<a href=\"https:\/\/www.pnas.org\/doi\/10.1073\/pnas.2421759122\" target=\"_blank\" rel=\"noopener\">the published paper<\/a>&nbsp;lays out.<\/p>\n<p>Domestication reads in textbooks like a single event with a single outcome, and it looks more like a thing tried repeatedly in different places, as&nbsp;<a href=\"https:\/\/www.crick.ac.uk\/news\/2025-11-25_ancient-wolves-on-remote-baltic-sea-island-reveal-link-to-prehistoric-humans\" rel=\"nofollow noopener\" target=\"_blank\">the research institute<\/a>&nbsp;puts it.<\/p>\n<p>Most of those attempts&nbsp;<strong>went nowhere<\/strong>.<\/p>\n<p>These two&nbsp;<strong>wolf bones<\/strong>&nbsp;are one of them, kept by accident in a cave.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>There is a rock in the Baltic with sheer sides and a cave near the shore. Nothing lives on it that walks. No deer, no hare, no fox, no&nbsp;land mammal at all. Seabirds nest on the cliffs and seals haul out below, and that is the whole menu. Then somebody put two old canid bones &#8230; <a title=\"Wolf bones from 2 animals in a cave on a Baltic island under a square mile carry the same seal and fish chemistry as the people who camped there, on ground with no land mammals\" class=\"read-more\" href=\"https:\/\/www.ecoportal.net\/en\/wolf-bones-baltic-island-cave-marine-diet-isotopes\/35812\/\" aria-label=\"Read more about Wolf bones from 2 animals in a cave on a Baltic island under a square mile carry the same seal and fish chemistry as the people who camped there, on ground with no land mammals\">Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":35845,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"1 square mile","rank_math_title":"Wolf bones from 2 animals in a cave on a Baltic island under a square mile carry the same seal and fish chemistry as the people who camped there, on ground with no land mammals","rank_math_description":"Two gray wolf skeletons found in a Swedish island cave reveal ancient humans transported wild wolves by boat and fed them fish and seals 5,000 years ago.","footnotes":""},"categories":[83],"tags":[],"class_list":["post-35812","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=35812"}],"version-history":[{"count":5,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35812\/revisions"}],"predecessor-version":[{"id":35846,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/35812\/revisions\/35846"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/35845"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=35812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=35812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=35812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}