Some say “necessity is the mother of invention.”
A clear necessity and the World Parrot Trust’s objective for the critically endangered Blue-throated Macaw (Ara glaucogularis) is to maximize the reproductive output of wild pairs. Our recovery plan is quite straightforward as well – to identify the species’ limiting factors and respond to each with solutions. During the past breeding season (2009/10) we believe we have reached our maximum level of both manipulation and monitoring.
One of the first limitations identified for Blue-throats was a lack of suitable nesting cavities. We responded by introducing nest-boxes. After several attempts, we finally identified different nest-box models that the birds would accept. We have tried vertical and horizontal boxes; wooden and PVC; with large entrance holes and small ones. Macaws showed interest in almost all models, but they laid eggs mostly in wooden, vertical boxes with large entrance holes. Since 2007, 4 pairs have used nest-boxes in seven different attempts. Now we have set up boxes in all the areas where Blue-throats are breeding.
Nest-boxes are safer than natural nests as they don’t flood and experience lower predation rates. We still have problems with bees, but we have found that bees abandon the nest-boxes, especially those made of PVC, after a short period of 2-3 months. The causes of nest failure have included flooding, predation and botflies. We have almost solved the flooding problem by identifying the most risky nests and using drainage holes at the bottom of the cavity. In some nests we have installed roofs to keep water out of the cavity. No nests have flooded since 2008.
Predation has historically been the main cause of nest failure. It has also been historically hard to deal with because of the difficulty in positively identifying the predators. During the last breeding season we installed anti-predator defences in every nest. Those defenses included installing metal flashing around tree trunks and pruning back nearby branches. Thanks to the volunteer’s efforts, we also maintained a high level of daily monitoring. In order to identify the visitors and potential predators during the night, this season we installed surveillance and trap cameras. In some nests, we used surveillance cameras inside the nests. Those cameras revealed intense activity of other animals at Blue-throated Macaw cavities. The most common neighbours are cockroaches, frogs and bats.
Part 2: Breeding Problems
In order to maximize the parent’s ability to defend their nests we also sought to reduce the time they needed to be foraging far from the nest. We did this by offering bunches of motacú palm nuts near some of the active nests. This was the first year in the history of Blue-throat nest monitoring with zero predated nests. Botflies are still a problem. The only nest we lost this year was because the two chicks were infested early by botflies. Fortunately we had a veterinary volunteer with us and she was able to conduct necropsies. She found botfly larvae inside the body cavity of the two dead chicks which died very young – five days after hatching. We saw botflies in 2007, but they attacked the chicks at 45 days old. Because the chicks were older and larger, it was possible to remove the larva without hurting the chicks. Unfortunately in this case, the damage was faster and more serious due to the chick’s small size.
Another important cause of low reproductive output is brood reduction. Brood reduction occurs when weaker, later hatching chicks die because they are out competed by the first chick. It is a common consequence of hatching asynchrony in parrot species. Unfortunately, to raise only one chick per clutch is not really helping the recovery of the Blue-throated Macaw. Since 2007, and thanks to our manipulation, no chicks have died because of brood reduction and we have increased the average number of fledglings per nest from one to two. As a result of daily monitoring, we now identify those chicks that are not growing normally and help them by hand feeding. In some cases we need to hand raise chicks for one week. During the last three years, 20 new Blue-throated Macaws have successfully fledged. We are still seeing most of the fledglings from the 2007/08 season. In half those cases the young are still with their parents, and those parent birds have not yet returned to breeding.
Unico, the lone surviving chick from 2008/09, is in captivity due to a wing deformity and is still waiting for a companion. He has some injuries on his breast because of his flight difficulties. He has problems landing and continues to receive extra help and training. Our veterinary volunteer takes care of Unico and has been focusing on improving his diet by offering motacú fruits. All of these actions are making a difference for the Blue-throated Macaw. In the last two breeding seasons we have lost only one nest per season. We will continue to use these techniques to maximize fledgling success in the future. With management actions in wild nests working well, now is the time to incorporate more conservation actions. During the last two years we have been intensively working on the repatriation of some individual Blue-throats from the US to Bolivia. We are still working through the paperwork to obtain final authorization and we are hoping to move the first birds before the end of the year.
We also need to better understand how this species is using the habitat. The Beni savannahs remain flooded for six months every year, making it impossible to follow the flocks during the non-breeding season. As a result, we have no information about bird movements. To know where the birds are during the rest of the year will help us to propose protected areas for Blue-throats. We hope to start a monitoring project to track the birds’ movements during the breeding and non-breeding season.
A special baby Blue-throated Macaw brightens a dim breeding season
There are few things more exciting and spectacular than seeing a macaw fly for the first time. Everything had been going well for this fledgling Blue-throated Macaw (Ara glaucogularis) – his parents selected a great nest site, his mother incubated his egg just so, and both parents fed him all the right seeds and fruits. But “Único,” as he came to be known, had one big problem. His right wing developed with a deformity and he couldn’t extend it properly to fly. For most wild parrots, the loss of one chick would not be a grave concern, but for Único (“oo-nee-koh” meaning “unique”), the situation was truly unique. He wasn’t just the only chick to make it out of his own nest this year, he was the only Blue-throated Macaw chick to “fledge” in all of 2008. None of the other known nesting pairs in the wild produced chicks, and most never even laid eggs! How could this be?
As we’ve reported many times over the past seven years, the World Parrot Trust has been working in Bolivia with this spectacular bird – the rarest wild macaw – to locate, protect, and help each nesting pair produce as many chicks as possible. We do this by deploying a number of conservation tools, many developed specifically for this project, such as upgrading existing nest sites, installing new nest boxes, protecting the nests and chicks from predators, and providing chicks with medical and nutritional support as needed. Just last season (2007), our years of work paid off with the strongest breeding performance on record, and ten chicks fledging. And, for the first time ever, we saw cases of three Blue-throat chicks fledgling successfully from a single nest.
On the heels of 3-chick nests, the dismal breeding in 2008 came as a shock. We had only seen a similar situation once before in the past, also when the species’ primary food source, the motacú palm simply failed to produce fruit. As it turns out, 2008 was one of the driest years on record, so it was not terribly surprising the palms made no attempt to flower and fruit. In fact, nearly all the other parakeets, amazons and macaws living in this region held off on breeding as well, presumably in hopes that more food would be available next year.
Unfortunately, the Blue-throats have no time to waste. As a critically endangered species, every chick and every breeding season is an important part of their hoped-for recovery. The remaining 15-20 wild pairs which attempt to breed in the good years are scattered over a vast seasonally flooded region, roughly the size of the country of Wales, or twice the size of the state ofConnecticut. For the population to grow and recover, these remaining adult pairs not only have to breed successfully year after year, but their youngsters must make it to adulthood, find other available Blue-throats of the right sex and age, and form a functional pair bond. In an area so vast with so few young birds produced each year, finding any Blue-throat is a considerable challenge. Finding just the right bird is an especially tall order. Even then, the difficulties aren’t over, as the new pair must find a suitable and available nest site, and get all the other details right before they can produce chicks of their own and help the population grow.
A special Blue-throated Macaw baby brightens a harsh breeding season
While we see the protection and support of the wild birds as our first conservation priority, it may be that a full recovery under current conditions just isn’t in the cards. They may have just too many challenges to face. More intensive nest work to reduce predation risk further still may be a viable solution. But in the end, it may be necessary for captive birds to assist their wild counterparts, filling some of the extensive areas now unoccupied in Bolivia, and eventually making it easier for these birds to find ideal mates, breed successfully and for the species to return once again to safe levels.
For Único, the story has just begun. He’s now being cared for in captivity and will hopefully become an education ambassador for his wild kin. Few Bolivians have ever heard of, much less seen, a Blue-throated Macaw. We’re hopeful Único will change all that, helping locals and international tourists alike understand how precious these birds are and how precarious their situation is today. We’re also working to find him a mate in hopes that he may one day raise chicks of his own to fly free over the savannahs and forests of Bolivia.
Our work to prevent the extinction of the Blue-throated Macaw has only been possible through the contributions of parrot enthusiasts around the world. With your generosity, we can put the researchers in the field to find and protect nests, install nest boxes, feed chicks and ensure they fledge successfully.
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