Justin Gerlach
@jstgerlach.bsky.social
Biologist. Director of Studies at Peterhouse, University of Cambridge.
Interested in evolution, ecology, species discovery & conservation: particularly for the overlooked (especially snails etc)
islandbiodiversity.com/jg.htm
Interested in evolution, ecology, species discovery & conservation: particularly for the overlooked (especially snails etc)
islandbiodiversity.com/jg.htm
My latest paper has just been published in PeerJ; working on this one was a really fun puzzle to solve. We identify an extinct predator on Mauritius from the holes it left in shells of its prey.
Mauritian snail shells show evidence of extinct predators
peerj.com/articles/201...
@peerj.bsky.social
Mauritian snail shells show evidence of extinct predators
peerj.com/articles/201...
@peerj.bsky.social
October 2, 2025 at 8:53 AM
My latest paper has just been published in PeerJ; working on this one was a really fun puzzle to solve. We identify an extinct predator on Mauritius from the holes it left in shells of its prey.
Mauritian snail shells show evidence of extinct predators
peerj.com/articles/201...
@peerj.bsky.social
Mauritian snail shells show evidence of extinct predators
peerj.com/articles/201...
@peerj.bsky.social
As we approach the beginning of the new academic year this year's @peterhousecam.bsky.social Biology Newsletter is now out islandbiodiversity.com/petnewslette...
September 29, 2025 at 6:36 PM
As we approach the beginning of the new academic year this year's @peterhousecam.bsky.social Biology Newsletter is now out islandbiodiversity.com/petnewslette...
Partula reintroduction comes to an end for 2025 with a final monitoring in lovely Papehue valley on Tahiti. Nothing startling today but lots of newborn snails is encouraging. I really hope we can show success with Partula nodosa next year.
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September 25, 2025 at 2:32 AM
Partula reintroduction comes to an end for 2025 with a final monitoring in lovely Papehue valley on Tahiti. Nothing startling today but lots of newborn snails is encouraging. I really hope we can show success with Partula nodosa next year.
🌏🐌
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Final monitoring on Moorea, and what a day. A good start in the reserve at Fare Natura. Then we found wild-born adult Partula taeniata simulans. I was confident we could do that, so a pleasing find, but...
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September 24, 2025 at 4:10 AM
Final monitoring on Moorea, and what a day. A good start in the reserve at Fare Natura. Then we found wild-born adult Partula taeniata simulans. I was confident we could do that, so a pleasing find, but...
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Last field survey on Tahiti today: the southern point of Te Pari. Nothing unusual but good populations of Partula hyalina marmorata. The sort of patchy metapopulations we found are probably natural for this species (one of few partulids not to be Critically Endangered or Extinct)
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September 23, 2025 at 4:52 AM
Last field survey on Tahiti today: the southern point of Te Pari. Nothing unusual but good populations of Partula hyalina marmorata. The sort of patchy metapopulations we found are probably natural for this species (one of few partulids not to be Critically Endangered or Extinct)
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Today was a search for high altitude snails on Mt Aorai. Finding snails in this environment isn't easy. We did find some Critically endangered Samoana diaphana. The shell is extremely thin and translucent (hence 'diaphana'), the distinctive pattern is on the body inside the shell
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September 21, 2025 at 1:54 AM
Today was a search for high altitude snails on Mt Aorai. Finding snails in this environment isn't easy. We did find some Critically endangered Samoana diaphana. The shell is extremely thin and translucent (hence 'diaphana'), the distinctive pattern is on the body inside the shell
🌏🐌
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Some encouraging signs for Partula nodosa and affinis today; many released animals found again and many births. We also scouted out possible additional release sites for next year.
September 20, 2025 at 4:01 AM
Some encouraging signs for Partula nodosa and affinis today; many released animals found again and many births. We also scouted out possible additional release sites for next year.
Partula are always unexpected. Today we visited a relict population of Partula hyalina and Samoana attenuata. What we didn't expect was to find hyalina eating another snail species. There was a carnivorous Partula in the past, but we've never document predation by hyalina before.
September 18, 2025 at 4:17 AM
Partula are always unexpected. Today we visited a relict population of Partula hyalina and Samoana attenuata. What we didn't expect was to find hyalina eating another snail species. There was a carnivorous Partula in the past, but we've never document predation by hyalina before.
Today was monitoring day on Huahine island and the last day for most of the team. What a day for a big find! Great results from the releases, but even better was finding this tiny one- the first wild-born Partula on Huahine for 31 years. Another great vindication of everyone's hard work
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September 17, 2025 at 2:41 AM
Today was monitoring day on Huahine island and the last day for most of the team. What a day for a big find! Great results from the releases, but even better was finding this tiny one- the first wild-born Partula on Huahine for 31 years. Another great vindication of everyone's hard work
🌏🐌
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Today was the last Partula snail reintroduction of the year: Huahine island with more varia and the first rosea to be released since 2019
September 16, 2025 at 2:40 AM
Today was the last Partula snail reintroduction of the year: Huahine island with more varia and the first rosea to be released since 2019
2nd day of monitoring on Moorea; still great progress with good dispersal and very little mortality despite us finding several of the predatory Euglandina. They may be invasive monsters but I still have a soft spot for their elegance (a picture of one instead of Partula for once)
September 14, 2025 at 4:57 AM
2nd day of monitoring on Moorea; still great progress with good dispersal and very little mortality despite us finding several of the predatory Euglandina. They may be invasive monsters but I still have a soft spot for their elegance (a picture of one instead of Partula for once)
First day of monitoring the released snails on Moorea. Exceptionally good results, for most species there was no mortality at all despite a night of unbelievably heavy rain - not what the zoo snails are used to at all. The snails in the reserve look fantastic
September 13, 2025 at 4:50 PM
First day of monitoring the released snails on Moorea. Exceptionally good results, for most species there was no mortality at all despite a night of unbelievably heavy rain - not what the zoo snails are used to at all. The snails in the reserve look fantastic
Yesterday was a busy day for Partula conservation. As well as a full day of releases of snails back into the forest on Moorea we had the opening and stocking of the new reserve at Fare Natura. Fantastic to see that go from my wild idea exactly two years ago to this
September 12, 2025 at 4:43 PM
Yesterday was a busy day for Partula conservation. As well as a full day of releases of snails back into the forest on Moorea we had the opening and stocking of the new reserve at Fare Natura. Fantastic to see that go from my wild idea exactly two years ago to this
On Raiatea today reintroducing Partula navigatoria descended from the last wild snails I collected in 1991. This was supposed to happen back in 2020. We also found an excellent site for Partula hebe next year (hopefully)
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September 11, 2025 at 7:07 AM
On Raiatea today reintroducing Partula navigatoria descended from the last wild snails I collected in 1991. This was supposed to happen back in 2020. We also found an excellent site for Partula hebe next year (hopefully)
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Partula releases today: we are trying a new monitoring technique with Partula nodosa using RFID tags. We also visited Tiapa valley to look for Partula incrassa but without success; that's often the way with Partula field research.
September 10, 2025 at 7:25 AM
Partula releases today: we are trying a new monitoring technique with Partula nodosa using RFID tags. We also visited Tiapa valley to look for Partula incrassa but without success; that's often the way with Partula field research.
It's back to the Pacific today: to Tahiti for this year's Partula tree snail reintroductions. We hope to build on least year's success. This year we have participation in the field from London Zoo, Disney's Animal Kingdom and Woodland Park Zoo
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September 8, 2025 at 8:18 AM
It's back to the Pacific today: to Tahiti for this year's Partula tree snail reintroductions. We hope to build on least year's success. This year we have participation in the field from London Zoo, Disney's Animal Kingdom and Woodland Park Zoo
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The collecting for surveying Cambridge college garden biodiversity is complete; now it's identifying the hundreds of insects etc that we've collected. A slight diversion from that work was this visiting sparrowhawk - our sparrows were less than delighted at its sudden appearance.
August 26, 2025 at 4:27 PM
The collecting for surveying Cambridge college garden biodiversity is complete; now it's identifying the hundreds of insects etc that we've collected. A slight diversion from that work was this visiting sparrowhawk - our sparrows were less than delighted at its sudden appearance.
Last major sampling of the Cambridge colleges biodiversity survey today: @selwyn1882.bsky.social. A pond teeming with life, and an overlooked find: Hesperomyces harmoniae fungus that lives only on the invasive harlequin ladybird (those are the little yellow tufts on the back of the beetle)
August 23, 2025 at 4:52 PM
Last major sampling of the Cambridge colleges biodiversity survey today: @selwyn1882.bsky.social. A pond teeming with life, and an overlooked find: Hesperomyces harmoniae fungus that lives only on the invasive harlequin ladybird (those are the little yellow tufts on the back of the beetle)
Another day studying biodiversity in Cambridge colleges. A rosy tiger moth at Trinity, woodland @queens.cam.ac.uk and I was hoping for the Cambridge endemic 'Backs goldilocks buttercup' @kingscollege.bsky.social but I can't find out how to identify it, so this photo might be any old buttercup.
August 22, 2025 at 8:54 PM
Another day studying biodiversity in Cambridge colleges. A rosy tiger moth at Trinity, woodland @queens.cam.ac.uk and I was hoping for the Cambridge endemic 'Backs goldilocks buttercup' @kingscollege.bsky.social but I can't find out how to identify it, so this photo might be any old buttercup.
Top find of today's biodiversity survey of Cambridge colleges was a wasp spider at Trinity College, also wonderful flowers Clare College despite the dry
August 21, 2025 at 3:08 PM
Top find of today's biodiversity survey of Cambridge colleges was a wasp spider at Trinity College, also wonderful flowers Clare College despite the dry
Today its been biodiversity assessments in what looks like very interesting long grass habitat in @churchillcol.bsky.social and @trinityhallcamb.bsky.social
August 19, 2025 at 7:13 PM
Today its been biodiversity assessments in what looks like very interesting long grass habitat in @churchillcol.bsky.social and @trinityhallcamb.bsky.social
Another week, another set of Cambridge colleges to study. Yesterday we surveyed the biodiversity of Murray Edwards and @fitzwilliamcollege.bsky.social. Two more to do today.
August 19, 2025 at 7:49 AM
Another week, another set of Cambridge colleges to study. Yesterday we surveyed the biodiversity of Murray Edwards and @fitzwilliamcollege.bsky.social. Two more to do today.
And today we sampled habitats in @caiuscollege.bsky.social and @darwincollegecam.bsky.social . A very hot day for hunting insects.
August 13, 2025 at 5:48 PM
And today we sampled habitats in @caiuscollege.bsky.social and @darwincollegecam.bsky.social . A very hot day for hunting insects.
This week my Cambridge colleges' biodiversity project has so far surveyed Wolfson, @corpuscambridge.bsky.social , @robinsoncollege.bsky.social and @newnhamcollege.bsky.social. With yesterday's heat comparing the colleges' range of water bodies was particularly welcome
August 13, 2025 at 7:59 AM
This week my Cambridge colleges' biodiversity project has so far surveyed Wolfson, @corpuscambridge.bsky.social , @robinsoncollege.bsky.social and @newnhamcollege.bsky.social. With yesterday's heat comparing the colleges' range of water bodies was particularly welcome
Our paper on the extinct Chilonopsis land snails of St Helena has just been published in @ejtaxonomy.bsky.social. We review all the old material, including what we could find of Charles Darwin's collection, and describe a new species from ongoing palaeontological work
doi.org/10.5852/ejt....
doi.org/10.5852/ejt....
August 13, 2025 at 7:17 AM
Our paper on the extinct Chilonopsis land snails of St Helena has just been published in @ejtaxonomy.bsky.social. We review all the old material, including what we could find of Charles Darwin's collection, and describe a new species from ongoing palaeontological work
doi.org/10.5852/ejt....
doi.org/10.5852/ejt....