The Science of Birds - Saving Bird Species From the Brink of Extinction

Episode Date: October 9, 2023

This is Episode 84. Our topic today is the challenge of saving bird species that are very close to extinction. Species like the Spix’s Macaw, which have tiny global populations—whether in the wild, or in captivity.Other familiar examples are the California Condor and the Whooping Crane, whose populations bottomed out at 22 and 23, respectively. Rigorous conservation programs have since given these two North American species a fighting chance at long-term survival.This episode is about species that we almost lost forever, but with great effort we’ve kept them from disappearing. Many of these species, like the California Condor, aren’t out of the woods yet. They may be in better shape now than they were a couple of decades ago, but they still need lots of help.In this episode, we’re first going to look at some of the biggest challenges faced by conservationists as they try to save species on the brink.Second, we’ll talk about the tools and methods used to save birds.~~ Leave me a review using Podchaser ~~Link to this episode on the Science of Birds website Support the show

In northeastern Brazil, there's a vast expanse of semi-arid shrub land and thorn forest called the Kachinga. This unique ecoregion is home to thousands of animal and plant species. Many of them are found nowhere else on earth. One such species, endemic to the Kachinga, is the Spixis macaw, cyanopsida Spixii. It used to live in the gallery forests on the margins of seasonal cree. This species, referred to by some as the little blue macaw, is stunningly beautiful. It has a pale blue-gray head and its body and tail display feathers in hues ranging from azure to cerulean. The elegant tail is long and tapered. Spix's macaws depend on large, mature

caribaira trees, also known as yellow trumpet trees in English. The birds make their nests in naturally occurring holes in the trunks of trumpet trees. Several hundred years of deforestation that began with European colonization has wiped out most of the Spix's macaws habitat. The oldest, largest trumpet trees are mostly gone. As wild populations plummeted over the last century, wealthy collectors around the world coveted these birds more and more. These people convinced themselves they just had to possess their own rare and beautiful Spix's Macaw. You know, when I hear wealthy collector, I can't help but imagine a Bond villain, or some dude wearing a top hat, twirling his thin

black mustache and wringing his hands with perverse pleasure over some recently accomplished misdeed, like buying a macaw, for example. Because buying a Spix's Macaugh is definitely a misdeed. It became illegal to trap and export these birds from Brazil starting in 1967. But sadly, that didn't stop poachers or the illegal trade of these birds. The rarer the macaws became in the wild, the higher the price one could fetch on the black market. You might be familiar with the plight of the Spix's macaw. It's one of the world's most critically endangered bird species, after all. And back in 2011, there was that animated kids' movie called Rio.

Remember that one? The main character is a Spix's Macaw with a highly original name, Blue. Blue is the last known male of his species. He was smuggled out of Brazil and ended up in Minnesota. Blue then gets taken back to Brazil, where he's paired up with the last known female Spix's Macaw in a captive breeding program. As you might expect, hijinks ensue. As is so often the case, animated kids' movies like Rio

teach us most of what we need to know about animals and nature. I mean, how else would we learn important true facts, such as lions can survive on a diet of insects alone. Female Asian elephants have tusks? All animals love and perform in highly choreogynes. song and dance routines? No? But the movie Rio does touch on certain real-life issues when it comes to the Spix's Macaw.

The last time a Spix's Macaw was seen in the wild was a brief glimpse in 2016, although it was debatable whether that bird was truly wild or just an escapee from captivity. Before that, it had been 15 years since anyone had seen one of these birds in the world. wild. Habitat destruction and the illegal trade in live birds had all but wiped out the species by the year 2000. In 2019, the International Union for the Conservation of Nature, the IUCN, declared the Spix's Macaw extinct in the wild. But conservationists didn't give up. They've searched the world to find as many of the remaining captive Spix's macaws as they could. They worked with the Brazilian government, which ended up giving amnesty to anyone who owned an illegal pet macaw.

Some of those wealthy collectors came forward as a result, admitting that they owned pet macaws. Now, I couldn't find exact numbers, but by the year 2022, there were about 175 known spixas macaws in captivity. Many of these birds are in captive breeding programs, under the supervision of multiple conservation organizations. The beautiful cyanopsida Spixii, Spix's macaw, has been pulled back from the brink of extinction, just barely. Will we be able to save it in the long run? Is it possible? Have we been able to save any bird species that has come so dangerously close to being lost forever? Hello and welcome. This is the Science of Birds.

I am your host, Ivan Philipson. The Science of Birds podcast is a lighthearted exploration of bird biology for lifelong learners. This is episode 84. Our topic today is the challenge of saving bird species that are very close to extinction. Species like our poster child. the Spix's macaw, which have tiny global populations, whether in the wild or in captivity. Other familiar examples are the California Condor and the Whooping Crane, whose populations bottomed out at 22 and 23, respectively.

Rigorous conservation programs have since given these two North American species a fighting chance at long-term survival. Around the world, there are roughly 225 bird species in the critically endangered category on the IUCN's red list. To qualify as critically endangered, a species has to meet just one of several conditions. Most of the conditions have to do with small population size and dramatic rates of population decline. Examples of species in this category include red-headed vulture, Philippine eagle, mangrove finch, and spoon-billed sandpiper. What's worse than being critically endangered?

I'm inclined to say the answer is being socially awkward, speaking from personal experience. It's pretty bad, especially at parties. Oh, and weddings. Weddings are the worst. But no, I mean, what's worse than being critically endangered on the IUCA? end's red list. The next category on the red list in the not good direction is extinct in the wild. Every single individual of these species lives in captivity. Currently, there are five bird species that are extinct in the wild. The Alagoas Curacao, Socorro dove, Guam Kingfisher, Hawaiian

Crow, and, until very recently, Spix's Macaw. Now, I'll come back. later to what I mean by, until very recently for the macaw. This episode is about species that we almost lost forever, but with great effort we've kept them from disappearing. Many of these species, like the California Condor, aren't out of the woods yet. They may be in better shape now than they were a couple of decades ago, but they still need lots of help. In this episode, we're first going to look at some of the biggest challenges faced by conservationists as they try to save species on the brink. Second, we'll talk about the tools and methods used to save birds.

Honestly, the stories of all these birds are a little weak in the humor department. This is serious stuff after all. But just to keep us all from crying ourselves to sleep tonight, I'll try to bring a wee bit of levity into the discussion, because, hey, it's me. Okay, let us proceed. One of the world's most famous extinct birds, and I mean extinct extinct, not just extinct in the wild, is the dodo. Good old Raffus Cuculatus. The dodo lived on the small island of Mauritius, east of Madagascar in the Indian Ocean. I'm not sure anyone knows what

kind of vocal sounds the dodo made, but it probably sound something like this. I mean, who can say, right? But we do know the sound of another famous endemic bird species on the island of Mauritius. The Mauritius Kestrel, Falco Pontatus, is still with us. It sounds like this. This small member of the falcon family is rusty brown on the back, wings and tail, with lots of black bars and spots. The pale underside is also spotted. The natural habitat of the Mauritius Kestrel is tropical evergreen forest in the mountains. But these days, less than 2% of the island's natural forest remains. There were probably

never more than 500 breeding pairs of these birds, but habitat loss, the pesticide DDT, and introduced predators like mongooses drove the Mauritius Kestrel to near extinction by the 1970s. By 1974, there were just four of them. That's right, four. It was at the time the rarest bird in the world. Conservationists, in a desperate attempt to save the species, collected some eggs from kestrel nests and started a captive breeding program. Captive breeding and conservation of Mauritius kestrels in the wild increased the population to about 800 adult birds by 2005. From four to 800. That's amazing. Against the odds, people have kept this bird from going extinct. The recovery of the Mauritius Kestrel is often applauded as one of the world's greatest conservation

success stories. And it really is an incredible accomplishment. However, this hard-won success could easily collapse. It wouldn't take much for the Mauritius Kestrel population to plummet again. It's still very much an endangered species. And this is true for pretty much every bird species I'll be talking about today. It's not like any of them went from being on the verge of disappearing forever to now being as cheerfully ubiquitous as the house sparrow, self-sustaining and seemingly invulnerable to the threat of extinction. Let's talk now about the many challenges faced by conservationists

as they do their best to save imperiled bird species like the Mauritius Kestrel from extinction. Perhaps the most obvious challenge is fixing whatever caused a species to almost go extinct in the first place. We're talking about things like habitat destruction, pollution, hunting, invasive predators like cats and rats, and so on. If we don't address the primary threats faced by a species, it likely won't matter how great our captive breeding program is. We can toss hundreds or thousands of captive-reared birds out into the wild, patting ourselves on the back for saving them, only to watch them die because those original threats are still there. Take the California Condor, for example. Conservation action has taken this species population from just 22 birds in 1987 to over 500 today.

One thing that nearly wiped out the California Condor was lead poisoning. These massive scavenging birds often eat mammal carcasses left behind by hunters. Unfortunately, those dead animals are often riddled with the fragments of lead bullets. Powerful acids in condor's stomachs dissolve the lead, which gets into the bird's blood, and tissues, and the result is lead poisoning. Today, the number one cause of death for wild California condors is, you guessed it, lead poisoning. If we don't remove this threat, our condors could slide towards extinction again.

So there are these original problems, these root causes, that need to be addressed. But there's also a whole new set of challenges that arises once a bird species has been reduced to just a handful of individuals. For example, say you've got a small number of birds and they represent the last of their kind. Let's say they all happen to live on one small island, or they're all being cared for in the same captive facility. Such a species is vulnerable to random events. All it would take is one natural disaster or accident to kill those birds and obliterate the species. The critically endangered Puerto Rican parrot, for example, has suffered major losses from multiple hurricanes over the last few decades. In 2017,

Hurricane Maria slammed into the island and wiped out many of the wild parrots. In the aftermath, food supplies were severely reduced for the surviving birds. So, random events like hurricanes, volcanic eruptions, wildfires, and floods can be especially dangerous to bird species that have only a small number of individuals living in more or less the same place. Small populations are also at risk for biological reasons, for genetic reasons. These two cause headaches for conservationists. The Mauritius Kestrel was down to just four individual birds, right? Well, That is what biologists would call a population bottleneck. In this case, an extreme bottleneck.

A bottleneck has consequences for the genetics of the population. The more severe the bottleneck, the more dramatic its consequences. When a population goes through a bottleneck, it loses a lot of genetic variation. Its gene pool is greatly reduced. Like, it used to be an Olympic-sized gene pool, filled with tons of genetic diversity, But after a bottleneck, it's more like one of those six-inch-deep plastic kitty pools your parents put out in the backyard on hot summer days, the one that was fun to play in for exactly five minutes. If your population is just four birds, only the genes of those individuals are available to be

passed down to the generations that follow. Populations with such small gene pools aren't all that great at evolving by natural selection. Selection works best when there's some actual variation to select from. So compared to a large genetically diverse population, a small population isn't as good at adapting to environmental changes. And related to that, there's the problem of genetic drift that occurs in small populations. Now, I know what you're thinking, kids. Genetic drift sounds like something cool, like that 2006 film The Fast and the Furious, Colon, Tokyo Drift, a film which, I feel it is my civic duty to tell you, has an approval rating of only 38% on rotten tomatoes. No, genetic drift isn't quite as cool as cars going vroom vroom. At least it's not cool for small

populations of endangered birds. Genetic drift in very simplistic terms is the change in a population's gene pool from one generation to the next because of random chance alone. Random is the key word there. We're talking about random genetic changes as opposed to the ones caused by natural selection. A fancy word scientists sometimes use instead of random is stochastic, St-O-C-H-A-S-T-I-C, stochastic, just FYI. We think of natural selection making incremental improvements to a population from one generation to the next. Selection allows a population to adapt to changing conditions. When genetic changes are occurring all willy-nilly, randomly, stochastically through genetic drift,

well, who knows what the outcome will be? But more often than not, random changes are harmful to the population, rather than helpful. And the smaller the population, the stronger the genetic drift. Then we have inbreeding. The definition of inbreeding is the production of offspring from the mating of individuals that are closely related. As in siblings mating with siblings, or parents mating with their offspring, that sort of thing. Why is in-reading a bad thing for endangered birds? To answer that, we first need to remember that a gene often has variance or alternate forms.

We call these alternate forms alleles. Allel is spelled A-L-E-E. Every bird in a population will have two copies for each gene in its genome, one allele from its mom and one allele from dad. Some alleles are dominant and some are recessive. You've heard these terms. If a bird has one dominant allele and one recessive allele for a particular gene, only the dominant allele will get expressed.

The recessive allele is hidden or masked by the dominant allele. It's sort of like every time the recessive allele is about to say something at a dinner party, its partner, the dominant allele, which has had way too much. to drink, rudely interrupts and starts talking loudly about itself. A recessive allele can only be expressed when a bird has two copies of the recessive allele for a particular gene. Sometimes recessive alleles have harmful effects when they get expressed. They might, for example, cause developmental problems or low fertility. In large, randomly mating populations where inbreeding is rare, recessive alleles tend to stay hidden because they get paired up with dominant

alleles most of the time. We don't see the effects of recessive alleles very often in such populations. But small populations are another story. Birds in a small population are much more likely to mate with one of their close relatives. Their options are limited, after all. Inbreeding goes through the roof in small populations. Recessive alleles with whatever harmful effects they might have get expressed much more often in small inbred populations. When that happens, the genetic health, the biological fitness of the population, goes down. Fitness decreases. Inbred populations often have all sorts of genetic problems that result in lower chances of survival and lower rates of reproduction. We call this phenomenon, inbreeding depression. That's inbreeding depression,

not to be confused with chip-eating depression. Chip-eating depression is when I get sad after I just ate the last potato chip in the bag. I'm sad because I wish there were like a thousand more of those salty, greasy chips for me to scarf down. But I'm also sad because I'm ashamed of myself for eating an entire family-sized bag of cheddar jalapeno chips. My understanding is that potato chips are bad for you. But oh man, that sounds good though, doesn't it? Maybe after I record this episode, I'll go get some cheddar jalapeno potato chips. I'll treat myself to a little reward. Treat yourself. But first, let's return to the example of the Spix's Macaw. Every one of these blue beauties alive today can trace its pedigree back to a population of less than

15 individuals, and even those founding individuals might have already been close relatives. So there's a long history of inbreeding in the captive Spix's Macaw population. As a result, these birds have been plagued by low fertility, a high rate of deformities in their chicks, and delayed maturity. Sounds like inbreeding depression to me. So to review the challenges faced by conservationists managing small endangered bird populations, they have to deal with the threat of random events like natural disasters, the loss of genetic diversity in small populations, which is made worse by genetic drift,

and inbreeding depression. Let's say you're a conservation biologist, and your job is to save a bird species from going extinct. The pressure is on. One of your most important tasks might be to perform a, population viability analysis. Wikipedia offers this definition. A population viability analysis is, quote,

a marriage of ecology and statistics that brings together species characteristics and environmental variability to forecast population health and extinction risk. End quote. Lots of data and computer number crunching is involved in performing a population. population viability analysis. One outcome might be an estimate of the probability that a species

will go extinct within X number of years. Like, based on all the input data, this bird species has a 17.2% chance of going extinct in the next 20 years. To calculate probabilities like that, conservationists often turn to a mathematical model called an extinction vortex. Vortex is a cool word, I know, but something with the word vortex in its name is probably never a good thing. Add in the word extinction and it only gets worse. So I feel like we need to say it like this. The extinction vortex. Scientists could just as easily have named it the vortex of doom or the circling the drain model or the downward spiral. An extinction vortex model attempts to combine, using math, all the factors that affect the

survival of an endangered population, the environmental factors, the genetic factors, and the demographic factors. A population viability analysis for the Spix's Macaw was recently published in the journal Bird Conservation International. The researchers and conservationists who did the analysis came to this conclusion. Quote, we found that the minimum viable population for reintroduction of the species is 20 individuals. However, considering the impact of disease, drought, hunting, and illegal trafficking, this population can only persist if the release of individuals from captivity occurs annually over the next 20 years, combined with the reforestation of natural habitat to support population growth. End quote. So this population

viability analysis provided some information that should be helpful in the fight to save the spix's macaw. A population viability analysis is just one tool in the toolbox of the conservation biologist. Let's move on now to look at some more of the tools and methods used to help critically endangered birds. Depending on the species, it might be necessary to work with birds in the wild, in captivity, or both. Each context has unique challenges. Also, keep in mind that there are conservation approaches for dealing with short-term crises and others that are meant to help birds survive for the long haul so that their populations are self-sustaining. First, let's look at

captive breeding. This is a complex topic, so I should probably devote an entire episode to it at some point. But the basic idea is pretty straightforward. You've got a population of captive birds, you want them to fall in love and pair up, and you want them to crank out babies like a bird-making factory. Your ultimate goal should be to release them into the wild so that they establish a new population or at least reinforce an existing population. Easier said than done. Each bird species has its own quirks when it comes to keeping them alive and happy in captivity. Getting them to breed can be very difficult and keeping the chicks alive can be a struggle. Your captive population is almost certainly going to be small and perhaps

inbred to some extent. It wouldn't be wise to let these birds pair up however they like, since that would probably increase the level of inbreeding. Instead, those in charge of captive breeding programs do their best to pair birds with mates who are as distantly related as possible. enter the stud book a stud book is a registry of all the animals in a captive breeding program it's a record of things like birth death and geographic origin of each individual who it has made it with who its parents were who its offspring are etc among other things a stud book provides a detailed pedigree of the captive population Now I picture a stud book as a heavy leather-bound tome with dusty yellowing pages. The records are all written in calligraphy with a quill pen. Maybe once upon a time, but these days it's more likely to be a computer database that lives on a server and gets accessed via the cloud.

Using a stud book, one can make the best choices for pairing up birds so that they aren't too closely related. There are many other challenges with captive breeding, besides the need to minimize in-breeding. For instance, just because you can make informed decisions about which two birds to pair up, that doesn't mean the birds will cooperate. Putting them together in a cage does not guarantee they'll find each other attractive enough to make some babies. Maybe one of the birds chews with his mouth open, and that's a total turnoff to his cagemate. Or he can't stand her because she always finishes his sentences for him. Or the two of them just can't see eye to eye on several hot-button political issues.

Who knows? If a pair of birds aren't interested in making the magic happen on their own, assisted reproduction using artificial insemination may be an option. This method, not surprisingly, has plenty of challenges. But artificial insemination has been a useful tool, in helping some species, like the Philippine Eagle and the Kakapo of New Zealand, both of which are critically endangered. Around 2013, a new method of artificial insemination was developed and applied to Spix's Macaws. As far as I can tell, this has been a successful approach for increasing

the captive macaw population. You know, when I was researching this stuff about the Spix's Macaw, I stumbled onto this web page that was in Portuguese, because, you know, these birds are native to Brazil. Well, Google decided to translate the page into English automatically. Thanks, Google. And that's when I discovered that the Portuguese word for chicks, which is Filocis, translates as puppies in English, at least according to Google. Yes, we're talking about parrot puppies, folks. How great is that? But I guess the word filoches is sort of a catch-all that can also mean cubs, babies, chicks, and so on. Oh, well, providing bird puppies and their parents with enough food and food of the right kind isn't always easy.

For example, there's the blue-eyed ground dove, columbina cyanopsis, also from Brazil. This critically endangered species has only about 16 individuals left in the wild. There's now a captive breeding program for the blue-eyed ground dove. But hand-raising pigeon and dove chicks is especially difficult. Because newly hatched birds in the family Columbody, as you might remember from the episode I did on this family, need to feed on crop milk. This is a nutritious semi-solid secretion. made in an adult dove's esophagus. Crop milk is rich in protein, fat, and antioxidants. Well, good news for the blue-eyed ground dove, several conservation organizations worked together

to invent an artificial crop milk. It's baby formula for pigeons and doves. And then there's the whole issue with captive-raised birds needing to learn the correct behaviors to survive and successfully raised chicks in the wild. This is so, so complex, and the details vary from species to species, of course. For example, cranes have to learn their migration routes. Maybe you remember those captive-raised whooping cranes that learned their migration route by following human pilots in small aircraft, called ultralights. On the other hand, caretakers raising birds often do their best to prevent young birds from imprinting on humans. California condor and Hawaiian crow chicks, for example, are fed by humans wearing hand puppets that look like adult birds. The person's

face and body are hidden behind a screen. This way, the youngsters don't learn to associate humans with food handouts. That's great, but I have a couple of concerns about this whole puppet thing. First off, Puppets are creepy. That's just a fact. Second, this makes me question my entire reality. If someone can trick baby birds using puppets, maybe that's what happened to me. I mean, what if my parents were puppets? Were they made from the same stuff as Cookie Monster and Kermit the Frog? How would I know for sure? People these days keep asking, what if we all live in a simulation like the Matrix? I say the real question should be, what if everyone except me is a puppet?

I'll have to investigate this. So far, we've considered some tools and techniques used for birds in captivity. What things do conservation biologists do to help populations of critically endangered species out there in the wild? Time and time again you've heard me point out how habitat laws, is, for most bird species, the number one conservation issue. If we hope to move a species from the brink of extinction to being self-sustaining long-term, we have to make sure it has enough of its natural habitat. Habitat restoration, for example, is an essential part of the plan to bring back wild populations of the Spix's macaw to the Kachinga ecosystem in Brazil. To prepare

For this species reintroduction, patches of habitat have been protected and restoration efforts are, I believe, underway. Controlling goats and cattle in the area will be a necessary part of that work, because these critters have grazed the Kachinga ecosystem into the dust. The recently protected area set aside for the Spix's macaw is about 463 square miles in area. But the successful habitat restoration of Kachinga habitat for the macaw will take decades of hard work. For bird species that need some extra help to survive in the wild, another tool conservationists have is supplementary feeding. Species that have benefited from

some additional food calories provided by humans include the white-rumped vulture, Seychelles magpie robin, crested ibis, and whooping crane. And supplementary feeding stations were crucial for saving those Puerto Rican parrots that survived Hurricane Maria in 2017. Now let's assume your small endangered population of wild birds has enough habitat and plenty of food. There may be other problems to deal with. One of the biggest problems for many species is being eaten by non-native predators. Conservationists have gone to great lengths to reduce or eliminate introduced predators that prey on endangered birds. There are many examples of predator control from locations around the world. One example involves Zeno's Petrol, Terodroma, Madeira. This seabird

lays its eggs in burrows high in the mountains on the island of Madeira, which is in the Atlantic ocean west of Morocco. Zeno's Petrol is Europe's most endangered seabird, with fewer than 200 individuals left. But back in 1969, when the breeding grounds for this species were first discovered, there were only about 14 of these birds. One of the big problems for Zeno's Petrol has been black rats and feral cats, both of which are introduced predators. Conservationists have been using predator control for decades, and that's helped to keep Zeno's Petrel from going extinct. But remember earlier when I talked about the danger of natural disasters or accidents wiping out the last individuals of a species? Well, that almost happened to Zeno's Petrel.

In the summer of 2010, there was an enormous, devastating wildfire on Madeira. It swept over the bird's breeding grounds in the mountains. Three adult petrels and 25 chicks were found dead after the fire. This loss represented 65% of the chicks born in the colony that season. It seems reasonable to me that we should eradicate introduced predators that threaten endangered birds. After all, humans are the ones who brought in the ravenous rats, cats, mongooses, and other critters of that sort. The least we can do to help the birds is round up the not. non-native predators and haul them away, or often they're just exterminated.

Rats on Madeira, for example, are controlled with poison. Now, let's say you release some birds into the wild from a captive breeding program. Everything seems to be going hunky-dory, but then your precious endangered birds start to get knocked off, one by one, like teenagers in a horror movie. There's a fierce predator out there, lurking around at the release of, sight. Is it a feral cat? Is it a mongoose? A demonic goat with a thirst for blood? Nope. It turns out to be a native predator, one that belongs in the habitat. Not only that, but this predator that's taking out your birds is itself an endangered bird species.

This is exactly what happened in Hawaii. The Al-Lah, otherwise known as the Hawaiian Crow, Corvus-Hawaii, has been extinct in the wild since about 2002. It's the most endangered species in the family Corvody. Al-A have been bred in captivity for decades. In 2016, the first of several attempts to reintroduce them failed. That was, in part, because the crows were attacked by a predatory bird species. The Eo, or Hawaiian hawk, Vuteo Solitarious. The EO has been, until very recently, on the endangered species list.

So this is quite a dilemma. Conservationists trying to re-establish a wild population of Al-Lah can't remove or kill the EO because the hawks are legally protected just like the crows. To be fair, there are multiple reasons why reintroductions of the crows have failed so far. But predation by the hawks has definitely been one wrench in the geese. years of conservation. Sometimes it's not practical or even possible to remove predators from a habitat. In that situation, conservation workers might instead choose to relocate the endangered birds themselves. Translocation is another conservation tool. Some of the best and most dramatic

examples of translocation come from New Zealand. The main islands of New Zealand have been overrun by introduced mammalian predators for centuries. To save a number of imperiled native birds, people have moved them onto small offshore islands. It's much easier to control or eradicate introduced predators on these small islands. The Kakapo, that flightless, moss-colored, nocturnal parrot of New Zealand, is a perfect example. As the critically endangered Kakapo was spiraling deeper into an extinction vortex, conservationists decided that saving this species in its natural habitat wasn't practical. From the mid-1970s to the early 90s, 65 Kakapo were translocated to four small islands offshore. Since then, the Kakapo recovery program has been successful.

Today, there are about 250 of these birds. And very recently, some of them have been reintroduced to mainland of New Zealand for the first time in about 30 years. Translocations can also be used to help beef up the local genetic diversity of an endangered bird population. In theory, you can scoop up some birds from one population and toss them into another population, and the result is that diversity in the gene pool of the second population will increase. Genetic evolutionary fitness in that population should improve due to the increase in genetic diversity

and due to the reduction of inbreeding depression. Translocations like this mimic the natural process of migration. They introduce new blood into a population. The name for this conservation technique is genetic rescue. It's used for small genetically depopurate population. on the verge of extinction. One famous example of genetic rescue is the Greater Prairie Chicken, Timpanukas Kupido.

This North American bird, which is actually a type of grouse, was once widespread on the Great Plains. But habitat loss has severely reduced or eliminated its populations in many places. In the state of Illinois, just 46 greater prairie chickens were left by 1992. Conservationists turned to translocations and genetic rescue. Prairie chickens from larger populations in Minnesota, Nebraska, and Kansas were introduced to the Illinois population in the 1990s.

The operation was a success, inbreeding was reduced, produced, and there was a major increase in genetic diversity. Let's take a brief look at a conservation case study, that of the Lord Howe Rail, Gallerales Sylvesteris. Lord Howe Island in the Tasman Sea between Australia and New Zealand is where this rail lives. The species is flightless. Males and females are grayish-brown. You can guess what forces drove this rail to near extinction. Yes, it was habitat destruction and predation by introduced mammals. For centuries after Europeans discovered Lord Howe Island, the place has been sworn to

with non-native rats. But interestingly, research revealed that introduced pigs were actually the worst offenders. Pigs were eating young rails. Only three breeding pairs of Lord Howe rails were left by 1980. They were taken into a captive breeding program. Thankfully, the captive population grew and the program was a success.

Great success. Meanwhile, every single pig was erratic. on the island. And as we've learned, predator control like this is very important. Within just a few years, the rails were reintroduced to the wild, and the population has been fairly stable ever since, at about 250 individuals. That may not sound like much, but scientists think it's as many rails as the small island can naturally support. Goats were eventually eliminated, too, and there has been a lot of work to get rid of other interesting. harmful species. As a result, the subtropical forests required by the Lord Howe Rail have recovered

significantly. This habitat supports not just this one endangered bird, but many other native animals and plants, too. The work done on Lord Howe Island is considered a model of conservation success. To quickly review, there are several major challenges to saving birds from the brink of extinction, including random disasters, low genetic diversity, and inbreeding. Tools and techniques for dealing with those challenges include population viability analysis, captive breeding, supplementary feeding, translocations, and genetic rescue. But if the root causes that endanger birds aren't dealt with, many of these techniques might amount to rearranging the deck chairs on the

Titanic. Threats like habitat loss and introduced predators need to be dealt with to keep our birds from being sucked into the extinction vortex, past the point of no return. Now, I've told you a few success stories today, but can we get a bigger picture of how conservation has saved endangered birds? Yes, we can. to a 2020 study published in the journal Conservation Letters. The researchers in this study gathered a bunch of expert opinion data on which bird species were saved from extinction between 1993 and 2020. They concluded that conservation efforts saved at least 21 bird species from going extinct

since 1993, and perhaps as many as 32 were saved. Sadly, 10 bird species did go extinct in that time span. That is a terrible tragedy. But if we take a hopeful view, we see that without conservation action, three times as many birds could have disappeared forever in the last 30 years or so. I say we should applaud the many people around the world who have given so much of their time and effort to saving these birds. They're rock stars in my book.

They didn't give up on bird species that other people might have seen as lost causes. I'll leave you today with some good news. Well, it was news about a year ago anyway. In 2022, 20 Spix's macaws were released into the wild. Remember that in the population viability analysis for this species, the magic number was 20 individuals? Well, 20 macaws have been released so far, and as I understand it, the goal is to release 20 into the wild per year going forward. This is more than just good news for the macaw, because this bird is a flagship species

for the Ka Chinga ecosystem. By protecting and restoring large tracts of habitat for the Spix's macaw, we also help to protect countless other species, birds, mammals, reptiles, amphibians, invertebrates, and plants. As far as I know, the little blue macaws released in 2022 are doing fine out there, squawking and flying around together in the wilds of Brazil, where they belong. I hope you found this episode interesting and perhaps inspiring. Not all conservation actions with birds are successful. There are so many challenges.

But it sure is nice to hear about the stories with happy endings. Of course, there aren't usually endings since any of these birds could be in trouble again if we aren't careful. In any case, thanks for listening. It's great to know that you care about birds. Thank you to my wonderful supporters on Patreon for making episodes like this possible.

You too are rock stars in my book, my heavy leather-bound book with its dusty yellowing pages. Next to each of my patrons' names in said book I have written, in elegant calligraphy, mind you, the word rock star. My newest patrons are Amy H., Jonathan, Skyler, Belwood, Francis Toller, and Emily C. Welcome and thank you very much for the support. If you, my friend, would like to support the podcast and get your name in my book, you can check out my Patreon page over at patreon.com slash science of birds. You could also click the support the show link in your podcast app, way down at the bottom of the show notes for this episode. Please shoot me an email if you have any deep thoughts or feelings about the podcast. Or maybe you just want to tell me which potato chip flavor is your favorite.

That's fine too. Teter Halapeno is objectively the best, and sea salt and vinegar is a close second, in my opinion. In any case, my email address is Ivan at Scienceofbirds.com. This is episode 84. You can check out the show notes for this episode, along with some curated photos of species I talked about today, on the Science of Birds website, science of birds.com. I've also got a shop on the website where you can get yourself some fun Science of Birds merch, like t-shirts, posters, and stickers. This is Ivan Philipson.

I wish you a great rest of your day. Peace.