We tell the story of how genetics and conservation came together to save the Mauritian Echo Parakeet on the island of Mauritius.
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00:00 [Music]
00:11 The Echo parakeet in Mauritius is the sole survivor of the parrot species
00:25 that were once found in the Mascareen Islands in the Indian Ocean.
00:29 Habitat loss, invasive species, cyclones and infectious disease are just some of the reasons
00:34 the Echo was once named the world's rarest parrot.
00:37 The species has been on a journey of survival and recovery for decades.
00:42 It began with a case trial some 40 years ago which was at the brink of extinction.
00:47 In Mauritius we have lost so many species which were unique to the island.
00:51 The famous Dedu is one example.
00:53 So the government of Mauritius, we started to have collaboration with international partners
00:58 I'm one of those partners and have been researching the conservation genetics behind the survival of the species at DICE,
01:04 the Durrell Institute of Conservation and Ecology which is part of the University of Kent.
01:08 I've been interested in disease and how the Echo parakeets breed with the aim of increasing the population.
01:13 Decades of collaborative conservation and genetics research later,
01:17 there are now around 800 Echoes flourishing across the island.
01:21 But saving the Echo parakeet didn't start with my work, it began a couple of decades earlier
01:26 and Professor Carl Jones was one of the first international researchers to work on the project.
01:31 I came to Mauritius in the late 1970s to work on some of the world's rarest birds.
01:36 The Mauritius kestrel, the Echo parakeet and the pink pigeon.
01:40 We came up here in 1979 going through the forest looking for parakeets and we could only find a handful.
01:48 Restoring a species is something that happens over many many decades.
01:52 We established a population but we also started working with local biologists, training people.
01:59 We established our own organisation, the Mauritian Wildlife Foundation.
02:02 We worked with government and helped form the National Parks and Conservation Service.
02:07 That whole journey was not just about restoring the parrot,
02:10 it was about using the parrot to actually develop the conservation movement in Mauritius.
02:16 Fast forward from the 1970s to the early 2000s and we thought that the Echo parakeet was well on the way to recovery.
02:22 But we were wrong.
02:23 In 2005, my first PhD student at Dice, Claire Raisin and I, had started our genetic research
02:28 only to discover that the Echoes were threatened with extinction once again by cytosine beacon feather disease.
02:34 They were already a very inbred species so to then encounter a highly transmissible virus,
02:40 it's not surprising that people felt quite worried about it.
02:44 I think that was at the point when a lot of the intensive conservation management, all of that had to stop overnight, was that right?
02:49 Yeah, exactly.
02:50 First thing we needed to do was to minimise the contact.
02:52 We no longer took any birds from the wild into captivity.
02:55 We stopped all captive breeding and hand rearing.
02:58 We were wearing full, almost like hazmat suits.
03:01 All of our equipment was being disinfected between each site.
03:04 You were the first person to do genetic work on the Echo parakeet.
03:07 I was, yeah.
03:08 We had a couple of hundred blood samples stored away in a freezer.
03:11 One of the first things that I did was to develop a set of genetic markers.
03:14 To know the genealogy and the pedigree of a wild population is so valuable and your work started that process
03:20 so we could then map the offspring to find out how related they were.
03:23 But we can't conduct our research without the field teams who manage the parakeet population and the virus on the ground,
03:29 or more accurately, up in the trees.
03:31 There was two chicks and the female was in the tree opposite to the nest box tree.
03:37 Echoes are really intelligent, so they have their own personalities.
03:42 So having worked with them for a long time, I can tell from their behaviour who they are,
03:48 especially all-emotion, you know, that's like part of our heritage, you know.
03:54 And the ringing is going to let us follow these individuals throughout their life.
03:58 So one, it gives us an idea of how many individuals exist within the population.
04:03 But then two, it allows us to have these life histories.
04:08 The main disease affecting the echoes is the cytosine beacon feather disease.
04:13 It's going to present itself as yellow feathers and if it's a severe infection,
04:17 they're going to lose so many feathers that they won't be able to fly anymore.
04:20 And then if they can't fly, they won't be able to feed and they won't be able to get away from predators and it can be lethal.
04:26 With this data being recorded, we can keep track of how the echoes are breeding and relate this to their genetics.
04:32 We found that, yeah, the population at Bel Arm versus the population here in the Gorges had become genetically distinct.
04:39 Species need to have genetic diversity within their population to allow them to adapt and evolve to future challenges.
04:46 When populations become very, very small and rare, rare alleles in the population are the first alleles to be lost
04:52 through what we call random genetic drift, which is the process where rare alleles are lost just through random chance
04:58 because certain breeding pairs won't breed in a certain season and therefore won't transmit their genes into the next generation.
05:04 Hushna is a scientific officer with the National Parks and Conservation Service
05:08 who works to involve local communities in conservation and raises awareness around the diverse range of species in Mauritius.
05:14 Those ecoparaqui birds, they are surviving very well in the wild and even we have had a reintroduction of birds
05:23 from the founder population, Black River Gorges National Park, to other parts of the island, the Bamboo Mountain Range,
05:30 which is in the eastern part of the island.
05:32 The study of the genetic structure, the genetic viability, the genetic stability of the ecoparaquid birds
05:40 being studied by the University of Kent is of utmost importance if we want to ensure their survivorship.
05:47 Back in the forest, we take blood samples from all of the birds.
05:50 Having access to this allows us to screen for disease and we can also analyse their genetic diversity and levels of inbreeding.
05:57 So that sample gets stored at minus 80 degrees for long-term storage.
06:01 We take the samples back to DICE at the University of Kent, extract the DNA and then we'll sequence the virus.
06:07 So if this individual is actually infected, then we'll isolate DNA of the virus from the blood sample
06:14 and we can sequence the DNA and see what viral genotype or viral haplotype this particular individual has
06:22 and then compare it to all of the other individuals that we know to be infected
06:27 and we can see patterns in how the virus is mutating.
06:30 I then met Professor Kok van Oosterhout from the University of East Anglia.
06:34 We are now working together to sequence the genomes of the ecoparaquids.
06:38 We have now access to data sets that were unthinkable in the past.
06:42 So we can really look not only at genetic variation but also at the mutational load.
06:47 They have come through this bottleneck and then all these mutations, or some of them,
06:51 can become in high frequency in the population and that's unnatural.
06:55 And so the conservation genomic work that we're doing today, which is cutting edge,
06:59 is to try and remove and reduce the frequency of those bad mutations
07:04 to try and return the genetic composition of the population to a state that it was in
07:08 before the population became very, very rare.
07:11 And in some of the parts of the genome you have these ultra-conserved elements
07:15 that are DNA sequences that have not changed for millions and millions of years.
07:19 If there is a mutation or a change in that particular sequence, it's probably going to be deleterious.
07:25 For me, sequencing the whole genomes of these species allows us for the first time
07:29 to try and quantify the effects of these bad mutations
07:33 in something we've never really been able to do before.
07:35 And it's exciting that we can begin to understand what is putting different species at risk.
07:40 And it's also vital to help the eco-population survive on its own.
07:43 The native forest in Mauritius is also crucial.
07:46 It's tall and dense, the perfect place for parakeets to nest and find food,
07:50 but there's only a few percent of it there.
07:52 So around 25% of Mauritius is considered a forest cover.
07:57 Native forest, much of it is degraded by invasive alien species.
08:01 However, not all of it is native forest. Much of it is planted forest.
08:06 These alien species, like invasive guava, pose a real threat to the native forests
08:11 and therefore the eco's too.
08:13 But in the south of Mauritius, Ebony Forest is on a mission to restore the native ecosystem.
08:17 Not only are they replanting trees alongside the work of the National Parks and Conservation Service,
08:22 they're reintroducing parakeets to help disperse seeds, helping the forest grow.
08:27 Using the screening that is done at DICE, we're able to see which pair we can collect from.
08:33 Because at the start we want to bring birds that are going to be healthy,
08:36 because there's going to be a stress being moved from their boxes from the National Park to Ebony Forest.
08:40 They are going to be fed until they fledge and wean.
08:43 And once they can fly well and feed by themselves, then they will be released.
08:47 And we hope they will just set up in the area, start making babies and spreading the seeds around.
08:54 What we're trying to do now is to learn the role that diet plays in the breeding performance and productivity of echid parakeets.
09:02 So as we've seen already, the echid parakeets benefit from supplementary feeding.
09:06 They will lay more eggs and there's a greater chance that their chicks will fledge successfully.
09:10 But we can't do that forever.
09:12 The native forests that are behind me and which are being conserved by all of these organisations collaboratively,
09:18 they are going to be the long-term future for the echid parakeets.
09:21 And so we're using DNA metabar coding. For each individual bird we'll have a menu of what they've eaten.
09:26 We then sequence all of the DNA that's found in the foetal samples of the echid parakeet fledgings
09:31 and we can then relate that information to the extent to which the native habitat is contributing to the fitness of individuals.
09:39 And the future looks bright with collaboration.
09:42 Getting them back to what we have now is some 800 species, which seems to be a huge success,
09:49 because what we are doing at the National Parks is to ensure that this species survives for future generations.
09:56 Restoring the ecosystem which has been degraded for a long time is a long and difficult process.
10:04 That's why we are trying to get the bird to cover the whole island,
10:08 which obviously is going to increase and to help us in keeping this biodiversity.
10:14 With much still to do to maintain the future of this island's ecosystem, we're not stopping at Mauritius.
10:20 I think the echid parakeet is a great symbol for what we should be doing on Mauritius,
10:26 what we can do elsewhere in the world.
10:28 And there are so many parrots out there that are threatened, that are declining,
10:33 and I'd like us to be an example of what can be done through science, through fieldwork, through planning, through vision.
10:43 We are not stopping here. I think we are going to go to Réunion next,
10:47 restoring the birds to a place where they've gone extinct.
10:50 It would be one of the world's first or unique example where we are trying to,
10:56 especially in the south, in the global south, where such types of translocations are being undertaken.
11:02 And we have Mauritius to thank for unlocking new potential.
11:06 Islands have really informed the way we think about the world.
11:10 The first time we realised a species had become extinct was on an island with the dodo.
11:14 We're not trying to turn the clock back and recreate systems as they once were,
11:19 but we're looking forward and thinking, how can we mitigate the effects of climate change?
11:25 How can we actually adapt to a world which is changing very rapidly?
11:30 The answer is the work we're doing here in Mauritius, which can be applied worldwide.
11:35 And now the echoparakeet has become an icon of successful species restoration.
11:40 [Music plays]