September 10 2007
The Blue-throated Macaw (BTM) 2007 field season is well underway. I’ve just finished orientating our new coordinator for the project. After four field seasons here in Bolivia I felt it was time to move on to other things.
My replacement is an Argentine, Igor Berkunsky (of Ukrainian descent if you’re wondering about his name). He did his PhD studying Blue-fronted Amazons in the Argentine Chaco for five years and is ideally suited to take the reins of the BTM project. He’s worked with over 130 nests and the field conditions of the Chaco should making working in the Llanos de Moxos (where Blue-throats are found) a cake walk. Temperatures in the Chaco can get up to 45 ºC (125 ºF) at midday and water is so scarce, field workers have to use second hand bath water to wash dishes.
I should apologize for neglecting this blog for so long. I made a much needed trip back to Canada (the first in almost four years). I’ll make up for the abstinence by including a lot of photos in this entry. Eye candy for your enjoyment.
The past month has been a whirlwind tour of showing Igor as many Blue-throats and nest trees as possible in the field while introducing him to important contacts and dealing with the bureaucratic side of things in town. August is usually one of the driest months of the year in terms of field conditions though 2007 has proved to be an exception. This year will go down as an El Niño year which in this part of Bolivia means rainfall was heavier than normal. The main river in our study area, the Mamoré, flooded extensively in March causing humanitarian crises in many populated areas and killing thousands of livestock, the main economic activity in the region. Even in August some areas were still flooded, necessitating the use of horses to get around, something we don’t normally do until November.
It’s hard to say how the flooding will effect this breeding season. On the one hand, increased rainfall should translate into more fruit production and thus more food resources available to Blue-throat breeding pairs. On the other, things appear to be more out of whack compared to previous years. For example, in August it’s not unusual to find large Barn Owl chicks Tyto abla in nest cavities also occupied by macaws later on in the year. This past month we found two Blue-throat nests occupied by Barn Owls but the females had only recently begun incubating.
Also, a larger proportion of nest cavities had been taken over by Africanized bees compared to past nesting seasons. This complicates our work as one of the goals of our project is to provide as many nest cavities as possible to prospective Blue-throat nesting pairs. It’s difficult to say if the increase in bees and delay in Barn Owl breeding are a result of the increased rainfall or due to other factors but they may result in fewer nesting attempts by Blue-throats this year (unless we ‘clean out’ the bees like we did with one successful nest last year). On the bright side of all of these concerns for the effects of El Niño is that we already have an active nest. This nest began incubating the first week of August, the earliest active nest I’ve seen in five field seasons.
It was also interesting to inspect the numerous nest boxes we put up last season. Many of them were occupied by bees (the bane of my existence last month!) but a few were full of Black-bellied Whistling Duck chicks Dendrocygna autumnalis. One of them plummeted to the ground the first time I opened the side door to the box to see who was inside. Was it hurt in the fall? Not a chance. These ducklings are anatomically designed to weather such a fall as they are still incapable of flight by the time the exit the nest. Hence the origin of the term ‘rubber duckies’.
Even though only two seasons exist in the tropics, namely the wet and dry, the end of the dry season in August still feels like spring in a way. Many trees are in flower including these Tajibo trees which reminds me of Japanese cherry blossoms, a riot of pink everywhere but an ephemeral beauty. There one day and absent the next.
Numerous parrot species are attracted to the nectar of the flowers which add to the colour spectacle, throwing irridescent greens, blues and yellows into the mix. A Dusky-headed Parrot Aratinga wedelli gracefully illustrates the phenomenon below.
Numerous bird species are preparing their nests for the coming breeding season and males sing and display throughout the day, including the Crested Oropendula Psarocolius decumanus whom I caught in mid-display as he tried to lure females nearer to his nest. Yes, they display upsidedown.
The highlight from the field last month was in the 7 Islas areas. This was our most successful area from last season with three chicks fledging in late December. Of course I was interested to see how many of those chicks had survived thus far. Early one morning Carmen Silva, a volunteer from last year who is a now a paid field assistant this season, and myself were walking down to the end of a forest island and when were stopped dead in our tracks by the sight of several Blue-throats in a tree ahead of us. It was comical how we both started counting out loud to ourselves, “Four. No! Six! No! Seven! There’s seven here!!!”. We’d already seen four other Blue-throats in other areas that morning so there were at least 11 birds around. A small miracle given how rare Blue-throats are. Examining facial feather line patterns, which are unique for each Blue-throated Macaw, I recognized two birds as the pair which had fledged two chicks around last season. Sure enough there were two chicks perched above them. I was so happy. They’d both made it this far.
It’s a bit hard to put into words how I felt when I saw those chicks. In essence they represent what our project is all about, hope for the future for this species in the wild. At the same time because I’ve spent four field seasons working with Blue-throats, many memories, good and bad, drifted over me as I watched them that morning play and clown around with one another.
Since I’m leaving the project it is perhaps expected that I reflect on whether or not I’ve made a difference with my time here in Bolivia. Having a morning like that one in 7 Islas is reassuring on many levels. In my opinion we are a long way from having Blue-throats fully recovered but during my time with this project I feel we’ve identified many aspects of their breeding ecology we can manage more successfully to help get more chicks into the wild each season. I’ve communicated as much of this knowledge as possible to Igor during our month together and now where our project succeeds or fails lies with him. From what I’ve seen from our time together, the future of Blue-throats is in good hands. That’s him below checking out a potential BTM nest.
So what’s next for me? Later this month I’ll be heading over to Peru to look for Blue-headed Macaws Primolius couloni. I did my thesis work in the Peruvian rainforest in 1999 and 2000 and truth be told, I have never seen jungle as rich in wildlife as there since. It’s going to be a welcome home coming of sorts.
Blue-headed Macaws are the least studied macaw, and incidentally the only species of macaw I’ve yet to see in the wild. There’s a pressing need to get a better sense of where the species is distributed as well as basic elements of their natural history; what they feed on, their nesting habits, etc. I read recently that due to their rarity, they fetch almost $USD 3500 each on the black market in Peru, so I’m also curious to learn about trapping pressures, if at all possible. I don’t expect to answer all of these questions with the relatively short time I’ll have to study them but given how little is known about these birds, any information I can collect for them will help. The photo below was taken of Blue-headed Macaws at a clay lick in Peru by a colleague of mine, Luis Claudio Marigo. God willing I could take pictures like his!
February 21 2007
Things are winding down for the 2006/2007 field season. Our last nest fledged two chicks a couple of days ago, bringing this season's total to six chicks, from four nests. Unfortunately the nest that began incubating in late December was predated when it had two small nestlings. I'm guessing either Toco Toucans or Crane Hawks were responsible. Both these species frequent the island where this nest is found. With the loss of this nest we can see that predation remains the main cause of nest failure for Blue-throated Macaw (BTM) nests. Of the seven active nests we found this season, three were lost to predation. I strongly believe that the habitat where BTMs are found, forest islands scattered amongst natural grasslands, favors nest predation. Macaw nests are concentrated in forest islands and are thus more easily located by predators than would be the case in a continuous forest setting, like the Amazon rainforest for example. All of the main nest predator species have large distributions and are not threatened. Consequently I think it's time to seriously consider controlling nest predators around BTM nests. This may involve trapping and relocating predators away from BTM nesting areas or even shooting persistent individuals. This type of management will no doubt draw criticism from bird lovers but given the state of BTMs in the wild, we simply can't allow common species to feed on critically endangered ones.
On the whole I believe this season has been a success. For the first time we've observed nests with multiple nestlings. We've also seen that many of these nestlings die in the early developmental stages either to starvation (due to parental neglect) or predation. I'll be recommending to the Bolivian government the need to captive raise nestlings likely to die if left in the nest. Ideally we can release these birds into the wild taking maximum precautions to minimize the transmission of disease to other birds. Captive raised birds have their work cut out for them in terms of learning to locate food resources and avoid predation but I'd rather give them that chance at survival instead of leaving them for dead in the nest. This type of undertaking will of course be complicated and require more funding and expertise. I'd like to ask everyone who has enjoyed reading these blogs to consider making a donation to our Blue-throated Macaw project. We still have a long way to go before this species is fully recovered and as I've mentioned previously, we need to raise more money to be more effective in our efforts to save the species from extinction in the wild. Every type of donation, large or small, helps. Thanks for reading about our activities this season. May the 2007/2008 season be even more successful!
January 12 2007
More good news, another 3 chicks have fledged for the season, this time all from the 7 islas area. I flew in on New Year's Eve to relieve some of our field team of duties. One guy had a bad ear infection that required immediate medical attention and some others were simply burnt out from being in the field for over two months. One nest (nest 27, see September 28th entry) had fledged a single chick two days previous but there still remained a nest with two nestlings that was important for me see through to fledging. I saw at least one chick in the nest on January 1st and none the next day. Either they fledged on the afternoon of the first or the early morning of the 2nd. Right after these chicks fledged there was a curious Green-winged Macaw inspecting the cavity. It's a good nest. No surprise it's in demand.
The 7 islas area is one of the success stories for our project. When we first visited the area in October 2004, there were two BTM pairs there. They each fledged a single chick that season. In 2005 another nesting pair showed up (the vaca muerta pair) though none of the pairs nested that year. This season a total of three chicks fledged there bringing the total of birds up to nine. On the surface not a big increase but to have the population more than double is a testimony to what we can do when we invest the time managing nesting attempts. Hopefully with an influx of more funding and field staff when can replicate the success we've had here in other regions.
After the chicks fledged at 7 islas, I headed over to check on the last nest we have with chicks, the 'bee hive' nest. Both the chicks were in good health (decent weight, no ectoparasites, and good energy) and look in good shape to fledge in less than a month's time.
Of all the nests we worked with this season, this is the one I'm most proud of. After enduring all those bee stings getting the hive out of there in early September, it was gratifying to see the nest become active in mid-October; more so to have chicks fledge from it this year when it failed in 2005. With a bit of gumption we can have a positive effect on this species' recovery.
About three km (2 miles) north of the bee hive nest, another BTM nesting pair began incubating in late December. Sadly its discovery comes at the tail end of this current field season when project funds have dried up. We'll have a local check on this nest periodically but we can't afford it the full protection we've given to other nests. I've always wondered if there's a second wave of BTM nesting attempts later on in the breeding season, more in tune with the nesting of other macaw species. Ideally we could have enough money to work year round in order to adequately look after all nesting attempts and getting a better sense of what is happening to chicks once they fledge. The reality is that conservation work in general is always short on cash, so we have to make due with what we funds we do have. In the case of our study that means we can start working in August until early February.
Based on photos I took of the facial feather lines on this pair I was able to determine that the pair from the new nest tried unsuccessfully to nest in a motacu snag that collapsed due to strong winds in 2005. That nest was about 10km away from the nest they're using in 2006/2007, suggesting that pairs will move around in search of adequate nesting sites. In fact the more I analyze facial photos, the more it seems like a game of 'musical chairs' is occurring with BTM nesting trees. Nesting pairs at specific nests change from year to year, rather than having the same pair each breeding season. This is good news from the perspective of a high quality nests, as different pairs will have a chance at using them instead of having certain pairs dominate them year after year.
I also had the chance to check on our nest boxes in the area. Alas two of the boxes were being occupied by Blue and Gold Macaws (BGMs), both of which had small nestlings. In other words, the metal plates we placed over the entrances do no exclude the larger, BGMs. As I've mentioned before, we don't want to encourage the already larger BGM population from growing due to our boxes. Although only two of the 15 boxes we put up were used by BGMs we'll have to replace all the entrance plates early next breeding season with something smaller to prevent BGMs from using them. Back to the drawing board with the nest boxes!
Finally the two hardwood nest trees I repaired in August (see August 20th entry) are currently active with Chestnut-fronted Macaws. While they are not a target species for our project it's good to know these nests are being used again and in theory will be available to BTMs for the next breeding season.
December 15 2006
Looking over the past few things I've posted I'm wondering if I'm depressing readers; nests failing, adults hemorrhaging, etc. It's a nice change then to write about the first nest of the season to fledge young. I flew out to the area to verify it myself. Part of me was secretly hoping to actually see the chick fledge, something I've never seen in over six field seasons of watching macaw nests. For me it would be particularly rewarding to see it happen with a Blue-throat nest as this is the species I've spent the most time with and every chick that fledges into the wild is so valuable.
The chick from this nest was quite the tease with respect to witnessing its first flight. The top of this nest had broken off so I had a good view of the nestling as it would climb up to the top and exercise its wings. It reminded me a bit of a kid taking his first dive off the high diving board. The chick would teeter at the edge of the nest entrance leaning forward and spreading its wings, all the while receiving light caws of encouragement from its parents who were perched nearby.
When it reached that critical point where it would either fly or fall over, it would pull back, aborting its exit from the nest at the last moment. The batteries on my camera eventually died from filming this ritual of 'almost fledging' over the course of five days. On the morning of the sixth day I arrived at the nest tree to find no macaws around, adults or chick. And so the first flight of the macaw remains this elusive, mysterious event for me.
The fledging of this particular nest was significant on several levels. Occurring in mid-December, it's the earliest fledging event we've seen so far. To do so, this pair started incubating in mid-August. For whatever reasons, most of the nests this season started earlier compared to past years. This is also the first time we've seen a motacu palm snag nest fledge successfully. Over the past three seasons all the past examples of this nest type have failed, most to predation, some to flooding, one even fell over. It's good to know that these nests do work on occasion but we've seen that we really need to pro-actively management motacu nests to improve the probability of fledging success.
Something else happened during my visit to this area worth mentioning. One nest tree there has been occupied every year since we first started visiting in 2002. One pair has been periodically guarding it this season since mid-August. There have been periods where we thought it was active, as the female was spending long periods inside the nest but by mid-December still no eggs. This particular nest isn't deep enough for my liking. It's only about 15cm (6 in) deep, so when the female sits inside it, her tail feathers jut out of the entrance. In order to make the nest more difficult to predate, I decided to climb it to deepen the cavity. The strangest thing happened while I was up in the ropes at the nest entrance. The pair that was guarding the nest flew into the area, circled the tree once and perched in another tree nearby. I've learned in the past that staring directly at wild animals usually frightens them off, so I ignored the pair and went on with my work, chiseling away pieces of wood from the base of the nest cavity. To my shock one of the pair flew to a perch in the nest tree, less than 2m (7ft) from my position. I tried to continue ignoring the bird but to be this close to a wild Blue-throat adult was too tempting. As I sneaked a glance over my shoulder the bird started to hang upside down in order to get a better look at what I was up to. Where was my camera at this spectacular moment? On the ground of course, eight meters below. After what seemed like an eternity, the macaw flew off to join its mate leaving me breathless. Blue-throats are usually so wary of human beings. I didn't get the feeling this particular bird was trying to protect its nest. It would have been making lots of noise if that was the case. I got the feeling that it was merely curious and felt sufficiently safe to get that close to me. As I mentioned before, we've been visiting this area for five years now, so maybe the birds recognize us and know we represent no threat to them. As much I'd like to have all the birds habituated to our presence around their nests, it's preferable they all retain their fear of, and distance from, humans. As long as there are beautiful birds in this world there will always be people who will try to trap or shoot them.