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Public Lecture: Flight from Extinction: Helping Whooping Cranes Survive

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MODERATOR: Well, good evening everybody. Thank you for joining us this evening. Despite the weather, we've still got a fairly decent crowd and I see a number of familiar faces; I'm glad you're able to join us.

For those of you that are new, this is part of our public lecture series that we do here. It gives us an opportunity to showcase some of the science that's being conducted here at the USGS across the country.

Tonight we have with us Dr. John French. Dr. French is a program manager and a researcher at Patuxent Wildlife Center in Patuxent, Maryland. For those of you who are not familiar with it, it's a short - less than one hour - drive from here. And if you have not been there, I would encourage you to visit the research center. It's jointly managed by the USGS and the Fish and Wildlife Service. They have some wonderful exhibits about wildlife and they have some interesting tours. So I'd encourage you, if you have the chance, to go visit them. [0:01:03.4]

John, in his early years, got to learn a little bit about birds from a publication called the “Birds of North America" by Chan Robbins. And in that book, Chan noted that the whooping cranes are a rare bird; in fact, when that book was initially published, there were no more than 50 pairs of whooping cranes back then.

When John joined the USGS, he had a couple of things that he really wanted to accomplish; one was to have a chance to work with some of the whooping crane and to get an opportunity to meet Chan Robbins. Chan, as you see, is one of our scientists - or was one of our scientists at the research center in Patuxent. Chan has had over 60 years of service, both with the Fish and Wildlife Service and USGS. And some of you may know Chan; he is considered to be the father of the bird-banding program. He's a real legend in the wildlife program and we are fortunate to have him serve as an emeritus scientist for us at Patuxent.

So when John got a chance to serve as a scientist, he got an opportunity to work with the whooping crane. He never thought he'd have a chance to see whooping crane because they were an endangered species and were dwindling at that time. But lo and behold, his career found him an opportunity not only to see some whooping crane but actually to work on their recovery; and at the same time, he also got a chance to work with Chan Robbins, a living legend. [0:02:39.8]

So without any further ado, let me introduce Dr. John French.

(applause)

DR. JOHN FRENCH: Thank you, Bob, for that nice introduction.

It is indeed an honor to work with Chan at the Patuxent Wildlife Research Center and it's a real thrill to work with whooping cranes, too; they're a magnificent bird.

Can you hear me alright in the back? Good? Thank you.

Today we're going to tell you a little bit about the natural history of whooping cranes, a little bit about the historical causes for their decline and quite a bit about some of the details of our most active restoration project at the moment; that is the project where we're trying to reintroduce a migratory flock of whooping cranes in the eastern part of the United States. And I'll tell you also a little bit about some of the research that underlies the operations for restoring those cranes; the research, a lot of which has been done at the Patuxent Wildlife Research Center. [0:03:48.8]

Whooping cranes are an absolutely magnificent bird. They stand over five feet tall when they're fully grown. As you can see here, they're bright white; they have a beautiful red cap. That red cap is bare skin and the skin can be puffed up or change color and does so when the bird is upset or aggressive and certainly becomes brighter and more evident during the breeding season as well.

They also have black primaries, which are striking when you see the bird with his wing unfolded. And I have a wing for you to look at here. This is a wing, actually, of an almost full-grown, juvenile bird. You can see some of the brown, juvenile plumage yet remaining on this wing.

Actually, Patuxent oversees some of the work that's done at the Natural History Museum down at the Smithsonian. And the group that I oversee down there curates the North America collection of birds; so I was able to steal this from them for this talk. [0:04:59.0]

Cranes are in the order Gruiformes, along with limpkins and rails and other species. There are only 15 species of cranes worldwide, however, and almost all of them are endangered and almost all of them are endangered for roughly the same reasons that whooping cranes are: they live in habitats that humans like - coastal habitats; and they're great, big birds that often get hunted for their meat.

Oftentimes, cranes are mistaken for herons and the ornithologists among you will well know that cranes are not herons. They look like them. They are inhabiting the same wetland habitats and they have long legs and long beaks and long necks just like herons. It's certainly a case of convergent evolution but they're certainly not herons. They have that rather - that animal in the middle here displays that kind of very distinctive crane profile with that sloping back and long beak. They really are magnificent animals. These are three cranes along the shore of the Gulf Coast down in Texas. [0:06:11.0]

A little bit about the ecology of whooping cranes - it's very interesting. Among all whooping cranes, there was both a sedentary and migratory habit in different populations of birds. This is something you don't often see. One population of the species would migrate north and south - north during the springtime to breed and then come back south for the winter time. Another part of the population would spend its entire year on the Gulf Coast, breed there, not migrate. And the birds would mingle during the wintertime but that one migratory group would go back and forth.

This has some really interesting opportunities for us when we try and restore these animals; for instance, it's much easier to restore a sedentary population than a migratory population. But I'm going to tell you a little bit later about how we've been able to restore the migratory habit in some of these birds that we produce at Patuxent.

These birds are territorial both on the breeding grounds - which almost every bird is - but interestingly, also on the wintering grounds, which fewer species are. They're a big bird; they use a lot of territory. And so one of the reasons why they're endangered is because they need a lot of territory in the wintertime and they are territorial; so their density is rather low on the landscape. [0:07:40.0]

These birds are omnivorous. They'll eat almost anything: snakes; frogs; plant material; crawfish; peanuts - they like to forage in peanut fields in the south; grain - waste grain; and just about anything. In fact, there's kind of a funny story where in Central Wisconsin, where we have this migratory flock that is breeding up there now, there is an energy plant that uses corn for fuel. And these great big boxcars come into the siding and dump their corn into the furnaces - or however they do this thing - but they spill a little bit along the way. Some of these really clever whooping cranes that we've restored have found out that there are piles of - little piles, according to the plant but big piles for a crane - piles of grain along the rail tracks and they go find these little piles of grain. And actually, it's been kind of a difficult situation because there are still trains running along the track there, too; so we've had to remove those birds. So, the point is, they'll eat just about anything if there's a food source out there. [0:08:50.8]

As you probably have known, if you've seen anything about whooping cranes, they have very distinctive courtship behavior. A very graceful bird, to begin with, but they have this dancing behavior where the male and the female face each other and throw their heads back and leap up three and four feet in the air flapping their wings. It's really quite beautiful.

And they also have a unison call, which accounts - it's very loud - which accounts for the name of this species, the whooping crane. The unison call is extremely loud and it sounds like one bird calling but, in fact, it's a duet. As part of the mating ritual, these birds coordinate their calling in such a way that the male and the female time their call so that, really, you can't tell the difference; it does sound like one call. [0:09:45.0]

Another distinctive aspect of crane biology is this very loud call, as I mentioned, and we think that the reason they can generate such a loud call is because of the interesting anatomy of the trachea. I have here - on loan from the museum again - a sternum of a bird. Now, all birds have a sternum which is, of course, the breast bone; and the sternum has a - and birds have a keel that sticks out straight like this and that keel is for the attachment of the very powerful flight muscles that pull the forelimbs together when birds are flapping. In cranes - this is the keel we're looking at here. In cranes, that keel is hollow and the trachea is very, very long and is coiled and is invested within the keel of the sternum. And I invite you to come up and take a look at this after the lecture if you'd like.

Basically, what we have here is a French horn - the long, long pipe and the coiled pipes of a French horn - which allows this very, very loud call for whooping cranes. I don't think I know of another bird that has this particular kind of anatomy; it's really pretty interesting. So definitely come up and take a look at this afterwards. [0:11:00.9]

Whooping cranes, because they're large and because they're a spectacular bird, have always elicited a lot of interest in the ornithological community. And people have known, throughout the century, that the populations were declining and that this was a conservation task that needed to be taken on. Well, in 1952, there was a monograph written by a fellow named Robert Porter Allen. It was commissioned by the National Audubon Society. Robert Porter Allen gathered together all of that was known about whooping cranes at that time - from published papers, from museum records, from explorer's records, from records of hunters - and really galvanized the ornithological community toward conservation action for these birds. A lot of the information that we use now today still comes from that monograph. It really was extremely extensive and gathers together all the best information about whooping cranes. And I'd just like to point out a couple of things to you. [0:12:09.7]

This map that you see there is from his monograph and there really is a lot of information there. First of all, you can see they're very widespread across North America; that is, they inhabit a wide range of latitudes. There is this sedentary population down along the Gulf Coast here. You can see the little word that says “nesting" there; that's where the sedentary population lived. If you look over here, there's a wintering population right in our area here: Chesapeake Bay; Northern Virginia; maybe up into the Long Island Sound. So 150, 200 years ago, you could go out in our area here and perhaps see a wintering whooping crane. We don't see them here now but it's kind of interesting to note that.

Another very interesting aspect of their geography depicted here is this very large wintering area in Central Mexico. This is in the high plains of Mexico and you don't usually think of those high plains as being a very wet habitat; in fact, it's not a very wet habitat. But there are wetlands throughout this area sort of perched in these high plains, and an awful lot of our North American sandhill cranes spend the winter down there, too. [0:13:26.9]

Now, I visited that area a couple of years ago. We were looking for more habitat to expand for the Aransas-Wood Buffalo population to expand into. And while there is a lot of habitat there, it's very agricultural right up to the edges of wetland. So, at this point, we don't think that those habitats are probably going to be the most secure for introducing an endangered species like cranes. But it's really interesting to note that they are able to thrive in what looks like very arid habitat.

Overall, the status of the whooping crane, the numbers of the whooping crane were reduced by hunting and by agricultural conversion of wetland habitats. And this resulted, finally, in a very low population number and they were listed as an endangered species in 1967 which, if you know your history of the Endangered Species Act, was the year the act was written and was one of the first species, the initial species, to be listed as endangered by the act. [0:14:40.2]

I mentioned briefly, just a minute ago, the Aransas-Wood Buffalo flock. This is the flock, the one wild flock, of whooping cranes that remains. It spends its winters at the Aransas National Wildlife Refuge and the surrounding wetlands in the estuaries on the coast of Texas and migrates all the way north to the Northwest Territories of Canada to breed. It's very interesting that when, in 1942 - make sure I get this right - there were 16 birds in this flock. And we estimate, based on kind of the population structure that we see in whooping cranes now, there were really only three or four breeding females in that flock. That is essentially extinct.

The fact that these birds were able to come back from such very low numbers is really remarkable. But they did and their growth rate has been pretty steady since then and now there are over 200 birds in that flock. Again, that's the one wild flock and the recovery team has set, as its very first goal, to preserve that flock; not to harm it in any way. So far, we've done a pretty good job of that; although, there are some threats to the winter habitat in that flock that I'll tell you about in a minute. [0:16:02.8]

This is a picture of the habitat in the northwest territories of Canada where the whooping cranes breed and I took this photograph from an airplane. And this is how we count the birds up there; from an airplane. The habitat is impossible to get through otherwise. I kind of tilted the thing so the horizon was level for you because the pilot is circling over these nests, we're trying to count them and I'm getting a little bit wheezy and I'm trying to take pictures; so it didn't come out quite even there. But one thing that is very important about this flock is that all the captive birds are now extant in North America and there are a number of them, number of flocks. Patuxent has the biggest captive flocks. All of the extant birds in captivity came from birds or eggs collected from this flock.

The very first bird in the captive flocks was Cans (ph) and he was collected as an injured juvenile in the very first summer of his life. Apparently, he had a broken wing. When the surveys were going on in 1965, I believe it was, the biologists who were doing the surveys noticed that this bird had a broken wing and wasn't going to survive. There was a great interest in starting to captive flock for propagation to establish, reestablish other flocks of whooping cranes and they felt this was an opportunity to start a captive flock. So they landed the plane, picked up this bird. This bird subsequently came to Patuxent about a year-and-a-half later and was the very first bird that started our captive flock at Patuxent; named Cans (ph) for the great cooperation under way then between Canada and the U.S. Little cheesy but OK; worked out OK. [0:17:58.4]

So what do we have now? I mentioned there were only 16 birds in the flock in 1942. Now there are over 550 birds or roughly 550 birds; and I say “roughly" because counting these birds in these different flocks is a variable kind of thing. We count them at different times of the year and you have to use different methods; so we think there's, at this point, about 550 birds in the flock. The Aransas-Wood Buffalo flock has grown very well, up to over 260 birds. That includes chicks of the year that have migrated down from the Northwest Territories to the Aransas National Wildlife refuge.

There are 25 birds in a non-migratory flock. This was one of our early attempts to restore whooping cranes and, as I mentioned earlier, it's quite a lot easier to restore a non-migratory group of animals than to establish a migratory habit. And we attempted to do that over the last 10 or 12 years and - although the introduction had some problems; there's quite a bit of predation that goes on down there in these habitats in Florida and they're not breeding very well either. So we've stopped putting birds into that flock but there are still quite a number of birds there and, in fact, of course as soon as we stopped doing it they bred really well last year; so we're all feeling a little bit, “Well, maybe we should have kept going." So we'll see what happens. We certainly hope that they make it and start increasing on their own without our help. [0:19:33.6]

There are now 105 birds in the eastern migratory flock and that's the flock that I'm going to tell you a little bit about in a minute. And there are 150 birds or so in various captive flocks across the country. Those captive flocks are there for two reasons: one, to preserve as much of the genetic diversity in whooping cranes as possible, in captivity; and secondly, to breed and produce chicks that can be part of a restoration or different restoration programs for whooping cranes across the country.

So I had mentioned we had started this non-migratory flock which was down on the Kissimmee Prairie in Florida; right down in here. And the recovery team thought it would be a good - the recovery team has a plan, endorsed plan - plan endorsed both by Canada and the U.S. - to establish two restored flocks of whooping cranes. And as most of the cranes are migratory, we wondered if it would be possible to establish a migratory habit in a group of restored whooping cranes. [0:20:47.6]

Well, as some people were experimenting with leading birds behind trucks that had all sorts of flags on them and behind ultralight aircrafts, we - and perhaps you've heard about the movie Fly Away Home, a story about a goose, a couple of geese that got off-course. Anyway, it was a big hit and some of our biologists saw this movie and they thought, “You know, I bet we could use that technique to teach whooping cranes how to migrate." And it was a pretty farfetched idea but we contacted the folks that were working on this thing and they were all excited about trying to do something like this.

So we worked with them over several years and then developed some protocols to do it and the plan was then we would establish this migratory route in the eastern part of the U.S., far enough away from the migration route of the Aransas-Wood Buffalo flock that they would not interact. And the idea there was you don't want to allow any potential interaction that would bring diseases from one flock into the other and that kind of thing. [0:21:56.0]

And so what we were going to do is produce and train the chicks at Patuxent and then we'd ship them up to Central Wisconsin where they would learn how to fly and then we would take them down to - behind an ultralight aircraft all the way down through the eastern part of the United States and release them in Florida. People thought we were a little crazy and we probably were, but that's OK. The idea, initially, was a little crazy but I will say that there was an awful lot of good planning and good research on different aspects of crane natural history and biology that went into establishing protocols to make this a success.

One thing we did do was we tried it first in sandhill cranes. Sandhill crane is a very abundant and very closely-related crane species in North America. Actually, sandhills and whoopers are the only two crane species in North America. But this is a standard method for endangered species biology: find a very closely-related species and do all your experimental work on that species; make all your mistakes in the very common species and then, when you have things worked out, then go to the - use it on the endangered species. So we did that.

We formed a whooping crane eastern partnership in the year 2000 and included a number of different people, a number of different organizations: international recovery team; Fish and Wildlife Service; Patuxent and the National Wildlife Health Center, another one of our USGS labs - was very instrumental in helping us in all sorts of different ways on this project; couple of NGOs we work with - this group called Operation Migration, they're the ones that get to fly the ultralight aircraft. We also work with a number of different state agencies, too, and some funders that have helped us out greatly. [0:23:49.4]

So I guess the point here is it has really been a partnership and a very important partnership. There is an awful lot to do on a big project like this and, really, it couldn't be done by one organization but the partnership aspect of it has been very good.

So what do we do at Patuxent? Well, we have a flock of about 60 whooping cranes that fluctuates through the years - the number fluctuates through the year, depending on how many birds have bred. We have somewhere between 10 and 15 pairs that are productive in any given year and we produce something like 35 or 40 eggs from those birds.

The normal clutch size for a whooping crane is two. You guys are all pretty good mathematicians; you can tell that 35 eggs don't come from 10 pairs producing only two eggs. So what do we do? When the eggs are laid, we take them out from underneath the bird and we put one of these dummy eggs underneath the female. So she keeps laying another egg and we pull that egg out and we pull another egg out and we stick them in the incubator here. So we can get a number of eggs from a single female. I think we've gotten up to eight eggs from one female. Those later eggs, the shells are getting a little thin, the female is looking a little peaked and the eggs are getting smaller and smaller and they don't hatch quite as well. So we don't like to take that many. But usually we can get three or four, sometimes five eggs from a single productive pair. [0:25:22.9]

The reason we do that is because these birds don't really breed in captivity all that well. As I say, we have 60 birds but we've only got, really in any given year, maybe 10 pairs producing eggs. And one of our research goals is to try and figure out what it is about the captive habitat or the food or the mates that we've put together that might cause more of them to become reproductive in captivity.

We also have undertaken a program of artificial insemination for these cranes - that's AI right here. And you can see Jane and Brian here collecting a semen sample from one of the males. This is one of the more hilarious aspects of the work we do. Jane or Brian, they go into the pens of a male in a reproductive pair and you can't really tell from this picture that Jane is rubbing the thighs of the male and it gets him all excited (audience chuckles) and then he produces a little bit of semen that Brian is collecting in a tiny, tiny little thimble. I mean it really is pretty amusing to see but it really works well. [0:26:36.5]

And we, through this whole process, are able to increase the fertility of these birds quite a bit. We are able to form reproductive matches that are different from the behavioral pairs; that is, we can collect semen from a male that's in a good behavioral pair and inseminate another female not the mate of that male, which allows us to do a little genetic maintenance of the captive population, which is really very important.

So then we get all these eggs, right? And they're all in the incubator. Actually, they're not in the incubator to begin with. We put them under sandhill crane incubators to start with. In fact, it's very clear, from our data, that the longer we leave a whooping crane egg under a live, female bird - and the male birds do some incubating, too - the longer we leave them under live birds, the better their hatching success is.

Now, we have done extensive research using this little beauty right here, which is a telemetered egg. It's got a temperature sensor, a humidity sensor and a motion sensor and sends out radio signals to our receiver and we can tell, within very close limits, what those physical parameters are that the egg experiences in the nest and we set our incubators by this. But somehow we don't have a sensor in here that measures crane motherhood very well. Something about those cranes that incubate eggs improves the hatchability and the survivorship of the embryo within the egg; something that we can't measure. Don't know what it is. The long and short of it is we maintain a large sandhill crane population at our center in order to incubate these whooping crane eggs so we get them to hatch better. [0:28:29.9]

OK. So now we - but we do bring them into the lab to hatch; so the last week or so of their life, they're in an artificial incubator like this.

Alright, we've got 35 or 40 eggs; they're in an incubator and then they hatch. Oh, my God; now you've got 35 or 40 crane chicks running around the building. Now what do you do with them? We don't have - their parents are out in the pens. That's where people like this come in. They're all in costume and here's a costume for you right here. I understand that Anna is going to model this for you a little bit later; looks really great. (audience chuckles) We have about eight or nine or ten crane handlers that wear these costumes all summer long to raise these chicks and it can get to be very hot work as the summer wears on. [0:29:25.1]

Here's a chick that has just hatched and we keep them inside these pens. And we're trying to teach this bird how to eat. Recall, it doesn't have a parent to teach him, so we've got somebody in this crane costume here who's holding a puppet head just like this; dips the puppet head into a little bit of water, dips the puppet head in the grain bowl and then offers it to the chick and the chick will, by instinct, come up and try to peck at the end of the beak of the puppet head and they learn pretty well how to eat. It takes three or four or five days and little animals, little humans, they've got to eat very frequently and it doesn't matter what time of day, they're hungry. So we've got people in costumes there from 4:00 in the morning til 10:00 at night trying to teach these little birds how to get them to eat; trying to make sure they're not starving to death. And it's really a great day when each one of those chicks learns that that food bowl is there so that he can go or she can go get food herself. We like that a lot; it lessens our workload. [0:30:30.1]

Other interesting aspects of the early chick-rearing include the fact that when they're in the incubator, we play tape-recorded sounds of what they might expect to hear when they're in a marsh habitat. We play frogs and red-winged blackbirds and crickets and other things that they would expect to hear. We do want these birds to be as wild as possible when we release them several months later, so we know they can hear that stuff while they're in the egg. In fact, we know that birds communicate with their parents. Late-term embryos cheep and peep a little bit and their parents answer them while they're in the egg. It's a form of bonding between the chick and the parent. So, for these birds, we play them both the contact call that a parent would give to a chick and we play them the sound of the ultralight aircraft so that when we finally put them with the aircraft, they're not completely freaked out about this big, buzzing propeller noise; and actually, we found - we didn't do that the first yet. We found it really did help quite a lot and we were able to get them to accept the aircraft quite a bit more quickly, so that's kind of an interesting aspect of the unusual upbringing these birds get at Patuxent. [0:31:52.1]

And one of the other important things we do is inside the pens we have an adult whooping crane in the pen right next to these birds so that they can see what they're supposed to be when they grow up. It sounds kind of silly but, actually, we know that's an important aspect of them learning to recognize other adult whooping cranes when they get to be older. We don't have them in the pens with them because if they're not their own offspring they get very aggressive and have killed some - actually, you may be able to see that there's Plexiglas in addition to the wire mesh between these two; between the adult and the chick.

It's very important that these birds get regular exercise and we run them around and we swim them in a swimming pool here. This is a very energy-intensive way for them to get exercise. We like to introduce them to wetland habitat and habitats that we put them in when they get older.

As they get older, we do introduce them to the ultralight aircraft and here's our what we call our circle pen. Here's the trike of the ultralight aircraft and here's the costume handler. Here's a very long version of this puppet head and you'll see - you'll notice a little bump in the neck of that puppet head; that's a little reservoir in which we put crickets and meal worms or something like that. And the way this works is the ultralight aircraft scoots around the pen a little bit, plays the contact call - and here's the loudspeaker through which the mp3 player is attached and they'll hear the contact call of the crane. Chicks come running along; the guy in the costume pulls a little trigger; the meal worm drops out in front of the long puppet head which we call the Robo-crane. The little meal worm drops out; the chicks get rewarded for following. You have classical conditioning and paradigm (ph). It works for all sorts of things in the animal world. [0:34:02.8]

So we do this for a couple of weeks and then they get imprinted on the aircraft. Actually, we think they get imprinted on the costume, the handler; and, as you can see, we do exercise them by running them around behind the costumed handlers as well. And when they get older, we run them through the fields a little bit faster. They're starting to exercise they're wings here. They're not quite ready to fly. There aren't any feathers on their wings but they're exercising their wings and building up those flight muscles.

Another interesting aspect about this, you see that they're on a rope here. In order to fly them behind the ultralight aircraft, we want them to become socialized together to actually be in a group and be able to interact with one another. This is highly unusual for whooping cranes. You know, as I mentioned, the clutch size of a whooping crane is two - sometimes one, usually two - and most often, it's only one egg, one chick per nest that fledges. On migration, by far the majority of the time, we have one chick flying with two adults. There are almost never two chicks - very rarely two chicks - and there's never more than two; they're never flying in migration in a group like this. So this is a highly unusual circumstance, social circumstance, for these birds to be in. And one thing I worry about a little bit, as we go through all this experimenting, trying to allow the ultralight to lead them on migration, is what this unusual early upbringing might mean for their later behavior. And I'll mention that again as we get into some of the other stuff that happens. [0:35:45.4]

Well, before they fledge, before they learn to fly, we pack them up in these crates and we put them in a real plane; we fly them to Wisconsin. Here you can see the ultralight aircraft with a couple of very much older birds flying - starting to take off behind the aircraft up in Wisconsin and you can see the wetland habitat that they use up there.

The other interesting thing is here's the cockpit of one of those little ultralight aircrafts. It's not very darn big and I'm not sure, no matter what the (inaudible at 0:36:23.4) say, that I want to go too high in that aircraft myself. But these guys from Operation Migration do a great job of doing the flying and working with those birds, so I'm happy to let them do it; they know what they're doing. [0:36:38.7]

One of the issues we've had up at Naceda is that some of the older birds come back to that same site; there are birds from years past come back and they really get in the way of training the chicks to fly behind the aircraft. They jump right into the flock; they start - and the chicks of the year start modeling this other bird and they're attacking them and they just absolutely destroy the training. It's kind of like an older brother or sister getting in the way of trying to teach your kid how to read or doing whatever. So an awful lot of time is spent by costume handlers chasing away older birds from the thing. And so this is our first - sometimes it gets a little brutal. [0:37:20.6]

This is our first stage of deterrent; we go yelling up at the bird and take your puppet head and make all these threatening gestures to the birds. If they don't - if they still are there, then we get a gray costume and then we get out of costume and we aggressively get a little bit more scary, we think, and eventually the birds do go away.

Finally, after all this work, migration begins and it's usually in late October; the date of the start of migration. This is really set by humans - I mean it's to our convenience; but it's about the right time of year - and it's really a great day. It's a beautiful sight to see these birds flying behind the ultralight aircraft and it's the culmination of an awful lot of hard work by folks at Patuxent, by folks in Operation Migration that have taught them how to fly. And we really like to see that happen.

There is a question, though. I mean does this work? Does all this effort to train these birds to fly behind an ultralight aircraft to teach them a migratory route or habit, does it actually work? Couple of slides here just to show you that indeed we think it does work very well and did work right from the beginning. [0:38:38.3]

What I've depicted here is the route on the left side of the slide here. This is the route north in the spring of 2003 that our first group - I should say our second group of cranes that were trained in the fall of 2002, this is the route north that they took. And you can see they spent the winter down here at Chassahowitzka National Wildlife Refuge and pretty well made their way straight back here to the Naceda National Wildlife Refuge. These two different lines are basically two different large groups of cranes that flew together.

But you notice that red line. That's a single bird that started out doing pretty well; flew north with the group and then kind of veered off to the east and puttered around in North Carolina, [got out of] (ph) West Virginia and finally settled down in Ohio. And we actually went out and picked up that bird and carried it back to Wisconsin. [0:39:40.0]

So why do I mention this? Well, it was very interesting. On the way down, this bird did not fly with these birds until right about the border of - what is that - Tennessee right there. And the reason it didn't fly was because it had a slightly injured leg and we weren't confident that it would be - it would withstand the rigors of flying and landing and all that, so we crated it; we had it in a crate and trucked it down, put it in the pen with the birds every night. And then, by about this time during migration, it looked like it was doing better so we let it fly the lower half of this thing.

So as you can see, it learned the migratory route when it was flying, but once it got as far north as it had been flying, it kind of got a little bit lost and headed off into the east. And so we took this as evidence that the flying part of the route was very important to teach them the migratory route and we know that to be true from other studies and other birds, that there is kind of a period of - a sensitive period where imprinting of the migratory route can occur and it occurs during that first, maybe the seven to nine months of age period of time. And it is true that if we try - and we can train adult birds to fly behind the aircraft but we cannot teach them a migratory route once they're adults; they don't seem to be able to learn it, which is kind of interesting. And then, on the right side of the graph, you can see what happened that following fall; they all made it back south very well. [0:41:13.4]

So running these birds north and south behind the aircraft does seem to do pretty well to teach them the migration route both north and south, which was gratifying to see. Well, here's a little bit more accurate depiction of where the birds are during the migration - and by the way, how do we know that? Well, they have satellite transmitters that we place on their legs and there's a transmitter here. You're welcome to come up and take a peek at this afterwards. And we get regular downloads from satellites and we can plot the data and we see where they're going.

It is interesting that our goal here is to have a group of birds that are all centered in Central Wisconsin so that the breeding can proceed properly and so that they have a choice of mates to breed with. If we had them run scattered all over North America, it really wouldn't be a very good thing; they wouldn't find each other very well.

So, some of the people that work with the birds are very concerned with this graph that I put up here because there are birds all over the place. By far, the majority of them are in Central Wisconsin but not all of them, obviously. Some of them are hanging out in Michigan. You can see that some of them even got over here into New York, up above the Finger Lakes here and up into Ontario. Actually, it's a very interesting story. These birds - this is one bird; actually, these dots up in Ontario. We went and picked up that bird three times and brought him over to Wisconsin. The next year he'd take off and go up to Ontario again. It was getting a little bit old, to tell you the truth. [0:42:50.3]

So, finally what we did was we put him in a pen with a female and they bonded and the female took him right back to Wisconsin and now he's just doing great in Wisconsin, so (audience laughs) - alright. So where was I here? So the question is, is this - is what we see here, is this scattering of birds across North America, is that poor training on our part or is this kind of natural dispersal that you'd expect to see in any species and I think it may be a little bit of both.

One thing that's quite important to note is that these birds are selecting habitats that they find to be the best. We think we know, based on our studies, what they require for habitats but we don't always choose the best ones. So I think we need to let them choose some of these habitats and choose some of the locations and, hopefully, the population will grow as they spread across North America.

I think another point to be made here is that when we're raising these birds, the people that are working with the birds get to know birds individually. And they're very concerned if, you know, number 27 - who they know is a little bit - perhaps a little bit aggressive and doesn't get along well with all of the other birds - where they're concerned is this bird is off to the side. Well, this bird hasn't learned enough to get along with some of the others in the flock so we've got to go get him and socialize him better. Well, yeah, maybe that's the case. But if you step back a couple of steps and take a population perspective on this whole restoration project, I think you'd see things a little bit differently and I think that's the perspective that our population biologists at Patuxent can bring to this and some of the population modeling that we're doing I think is helping inculcate that perspective in some of the very dedicated bird handlers that work on this project. [0:44:43.2]

There's another aspect of recovery - a little more technical - that I want to mention to you and that is you can tell that when there are only 16 birds in a flock - 16 whooping cranes from which all live whooping cranes in North America have derived - that the gene pool is very, very restricted; this is a severe genetic bottleneck. And I think there's been a lot of very good population genetics work over the last, say, 15 years that has really helped endangered research understand how difficult that can be - how much of a risk that can be for a population and come up with methods to try and preserve that genetic diversity in the best way possible. And we do that in captivity where we can manipulate the pairing of these birds. We have a genetic management plan that's based on sound population genetics principles and we have a - we consult our studbook and we form pairs on that basis to preserve the genetic diversity. [0:45:46.8]

We kind of do the same sort of thing for the birds that we release in the wild. There are some very good - some pairs in captivity that produce very well. So naturally, to begin with, a lot of their offspring are the ones that we have available to put back into the wild. So after a few years, if you look at the genetic heritage of the birds in that restored population, half of them derive from this one genetic line that's a very good producer in captivity and only very few - very little contribution is made by other genetic lines in captivity. Well, a population geneticist would say this is a very bad thing because the risk of inbreeding among those birds in the wild is very high and we know that inbreeding allows recessive alleles to be expressed and they don't really do very well.

On the other side of that coin is the fact that we have a very small population and the risk of catastrophic events befalling a very small population is very high; especially if they're all in one place, which these birds are. So, to mitigate that risk, what you want to do is get all the birds out there you possibly can. [0:46:57.5]

The other risky part of equalizing the contribution of genetic lines to a population of restored birds is that you're leaving out of that population some of the best birds - some of the birds that reproduce the best - and that also can be a problem.

So what do we see in our population? Well, here, very briefly, we have annual survival along the Y axis and we have a measure of inbreeding among the birds that are in the wild. Inbreeding goes up along - in this direction. And we see that there is a decrease in survival with higher inbreeding, so the concerns of the population geneticist has some basis, some reflection on the data that we have.

And likewise, if you look at the survival of the chicks based on the number of chicks released per female, the survivor goes up; suggesting that those females that are productive produce higher-quality chicks and that's probably one reason why they're highly productive. So we have evidence for both of these demographic and genetic constraints happening in this population. Now, for those of you that are statistically-minded, you'll see that these (inaudible at 0:48:12.9) limits here are very high or very quality and there was no significant - statistical significance to these data but there are suggestions. And the reason those limits are so wide is because we only have very few data and we'll - as we accrue more data those conferences will come down. We may be able to say something a little more statistically sound in a few years.

And my final point here is that Patuxent is embarking on a modeling project that will look at the tradeoff between demographic risk and genetic risk and help us decide, thereby, what the best makeup of a group of birds to put into the wild may be. That's going to have great impact on the crane project but also is an extremely general result that will be useful to many, many other endangered species programs as well.

There's been an awful lot of research at Patuxent on all sorts of different aspects of crane biology that is underlying the work that we do. Some of the stuff in green is ongoing research and you can see we've got a number of different partners here: the Calgary Zoo; the Smithsonian Conservation Research Center in Front Royal is helping us with some work, too. [0:49:31.5]

I want to highlight a couple of things here. One is this line here. For the Florida non-migratory flock, there has been a concern for many years that this population wasn't thriving; should we still put more birds in there, should we not. Patuxent's folks put together a population model for this group and did a very nice job of using that model to, through a structured decision-making process, come to the decision that in fact it was not a good idea to put more birds in there. It was kind of wasteful of resources. These resources could be better used somewhere else. So we stopped putting birds out there and I think it was a really excellent example of how the structured decision-making paradigm can really, basically, save money. So now we can take our resources and put them into a program that's working a little bit better. So that's a really important result for us. [0:50:34.5]

The other thing I want to point out to you is a little more lighthearted. Migration training - you know, as I mentioned earlier, when we first started this project the whole idea of migration training was, frankly, a little bit nuts. People thought we were crazy. Alright, so it was a crazy idea at first. But you know, a lot of these ideas start out as crazy ideas. I mean here are a couple others of them that might sound a little crazy to you.

One of the things that hampers our migration training is that ultralights can only fly in very good weather. So maybe we should try something else. Maybe we should try a blimp; blimps can go anywhere at any time. They don't - you know, it doesn't bother - in fact, how would we - they go very slowly but how - [all the ideas] (ph) maybe we'd have a great big cage - you know, maybe a 20x20 cage that would hang from the blimp. You'd just stick the birds in there, take the blimp on the migration route at that time of their life when they're sensitive to learning and they learn it. Alright, maybe that would work; I don't know. We tried putting birds in a big cage and hauling them up the flag pole one time just to see if it was possible. It may be. They didn't freak out too badly. OK, so that's the first step.

Or here's another idea: maybe what we ought to do is fly the route ourselves, just the way a bird would; take a movie of it - take an IMAX movie of it; stick the birds in an IMAX theatre, play them the movie (audience laughs) and they learn migration. Who knows? It might work.

So the point is that we're laughing and it is kind of fun to think about these things. But I think part of the joy of working a project like this is that you can take ideas from anywhere but then you make them work; you test them out, you make them rigorous and you can see if it can be held. So I like to bring this point up whenever I talk to high school students or younger students, kind of motivating them that “Science isn't just all confidence limits and learning statistics. It's applying your imagination and your knowledge of biology in all sorts of different ways to all sorts of different situations. And I really hope that this is a small example of how that can work and hopefully we motivate others to come into the field.

So what have been our results so far? Well, the migration training has worked very well. We've got very low mortality in this group. We've got over 80 birds, actually; we've got over 100 birds in the population. Reproduction has been another story. There has been reproduction each year in the group that comes to Wisconsin and there's been more reproduction each year; that is, more pairs are nesting and more eggs are being laid.

However, only one bird has fledged out of all of those eggs, which is very distressing. And there are a number of different hypotheses about why this is happening and we are in the process of testing them out right now. One of the issues may be that they're being bothered by biting insects. Because what we do see is that they build nests very well and they lay eggs and they incubate, or they start to incubate, and then they abandon their nests with perfectly good eggs in them. So we're in the process of doing that. [0:53:50.8]

The state of Wisconsin has done a very nice job of developing a management plan for breeding birds and it's a good example that other states can use; hopefully other states will have the opportunity to use them when whooping cranes move into their states, so that's great. And indeed, this project has stimulated an awful lot of habitat conservation along the flyway. People have been really kind of engaged by this project and have used the fact of whooping cranes migrating behind ultralights through their states as a justification for more habitat conservation, which is great for the cranes but also has other benefits.

Whooping crane recovery, over all, is doing pretty well, too. We've done a good job getting started on these reintroductions. We really need to find a way to allow or encourage or whatever, better reproduction among these flocks. And I will say that for all of the restoration projects and the conservation projects in the Aransas-Wood Buffalo flocks, they've all been based on very good science and Patuxent has played a role in that and I feel pretty proud of that.

In fact, the WCEP group has worked out very well. The partnership itself got the 2003 DOI Secretary's Four C's Award, the first award given in that program. There are some challenges in the overall recovery. The breeding in Wisconsin is one I've mentioned. We're planning to start another flock, too. I was just on a conference call today with the Louisiana fish and game folks who are very excited about planning to take some birds back to Louisiana to reintroduce that non-migratory flock on the Gulf Coast, so we'll see how that goes.

This picture is a flock of migrating whooping cranes, both adults and juveniles. You can see the juvenile plumage right here. And indeed, after all this hard work, it really is a wonderful, gratifying sight to see this kind of a flock in the wild. It really - it's a wonderful thing because there's a lot of work that goes into this and a lot of good work. And when you see these birds out on the landscape, it's really the reward that you want to have.

Thank you very much for your time and I'd be happy to answer any questions you have.

(applause)

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Title: Public Lecture: Flight from Extinction: Helping Whooping Cranes Survive

Description:

  • Scientists and volunteers are working to restore the Eastern population of the federally listed whooping crane
  • The life history and migration of whooping cranes

Location: Reston, VA, USA

Date Recorded: 1/6/2010

Audio Producer: Kara Capelli , U.S. Geological Survey


Usage: This audio file is public domain/of free use unless otherwise stated. Please refer to the USGS Copyright section for how to credit this audio.
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