158 Hybrid Giant Tortoises Released on Floreana, Beginning Two‑Century Restoration
Updated (2 articles)
Historic Release Marks Return After Nearly Two Centuries On 20 February 2026, park officials set free 158 captive‑bred juvenile tortoises on Floreana Island, the first giant tortoises seen there since the 1840s [1][2]. The release was timed with the season’s first winter rains to improve survival odds. The effort is led by the Galápagos National Park Directorate as part of the Floreana Ecological Restoration Project.
Hybrid Tortoises Carry Significant Ancestral DNA The juveniles are hybrids retaining roughly 40 %–80 % of the extinct Chelonoidis niger genome, traced to lineage from Wolf Volcano on Isabela Island [2]. Scientists launched a back‑breeding program in 2017 after a 2008 DNA analysis revealed surviving tortoise DNA on Isabela [1]. Selective breeding has produced over 600 hatchlings, many now large enough for release.
Long‑Term Goal Targets Seven Hundred Reintroduced Individuals The 158 released turtles constitute the first cohort of a planned 700 individuals to be introduced gradually over the coming years [2]. By 2025, more than 600 juveniles had been produced in captivity on Santa Cruz, with several hundred deemed release‑ready [1]. Researchers view the tortoises as “ecosystem engineers” whose grazing and seed dispersal will help restore degraded habitats.
Invasive Species and Human Presence Pose Ongoing Threats Floreana’s ~200 human residents and invasive fauna—including rats, cats, pigs, donkeys, and invasive plants such as blackberry and guava—challenge the tortoises’ survival [2]. Conservation plans must address these pressures while re‑establishing a viable tortoise population. The project underscores the broader significance of the Galápagos as a UNESCO World Heritage Site since 1978 [2].
Sources
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1.
BBC: Giant Tortoises Reintroduced to Floreana After 180‑Year Absence – Highlights the milestone of releasing 158 juveniles, the back‑breeding program sparked by a 2008 genetic discovery, and the tortoises’ role as ecosystem engineers.
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2.
AP: Giant Tortoises Return to Floreana After 150‑Year Absence – Focuses on hybrid DNA percentages, the target of 700 total releases, and the challenges posed by invasive species and the island’s human population.
Timeline
1840s – The native Floreana giant tortoise (Chelonoidis niger niger) goes extinct after sailors over‑harvest thousands for ship provisions, ending a population that once numbered about 20,000 individuals on the island. [2]
1978 – UNESCO designates the Galápagos Islands a World Heritage Site, highlighting the archipelago’s unique terrestrial and marine biodiversity and providing an international framework for future conservation actions. [2]
2008 – DNA analysis of tortoises on Isabela’s Wolf Volcano uncovers individuals carrying Floreana ancestry, revealing a hidden genetic reservoir that could be used to resurrect the lost species. [1]
2017 – Scientists launch a back‑breeding program, selectively breeding hybrid tortoises that retain 40‑80 % of the extinct Floreana genome, to create a viable stock for future reintroduction. [2]
2025 – Captive breeding on Santa Cruz produces more than 600 hatchlings, with several hundred reaching a size suitable for survival in the wild; the program notes “600+ hatchlings produced by 2025, many now release‑ready.” [1]
Feb 20, 2026 – 158 captive‑bred juvenile hybrid tortoises, aged 8‑13 cm, are released on Floreana Island timed with the season’s first winter rains, marking the first presence of giant tortoises there in 150‑180 years: “158 hatchlings … set free on the island.” [2][1]
Feb 21, 2026 – The Galápagos National Park Directorate confirms the release is part of the Floreana Ecological Restoration Project, emphasizing that the tortoises act as “ecosystem engineers” whose grazing and seed‑dispersal will help restore native habitats. [1]
2026 – future – The reintroduction plan calls for a total of 700 tortoises to be introduced gradually, with ongoing monitoring to mitigate threats from invasive rats, cats, pigs, donkeys, and invasive plants such as blackberry and guava. [2]
2026 – future – Researchers expect the restored tortoise population to dramatically reshape degraded ecosystems, noting that “their grazing and seed‑dispersal activities dramatically reshape and restore degraded ecosystems.” [1]