The 2007 field season was a busy one! This was for good reason and the efforts we put in have certainly been worthwhile. Good data has been collected and those precious numbers are revealing patterns that mean this or that, but more about them in a moment. First a recap of the season... Before even the most shagadelic parrot was getting in the mood preparations were being made to discover the most secretive nests across Bonaire. For 2007 the parrot team would initially be ten strong. Rowan Martin (fellow PhD research student) and I were going to need help if we were to survey more ground than we had in the previous year.
Exploiting every offer of free lodgings we scattered these dedicated nest finding volunteers across the island while we ourselves remained at Parrot HQ (aka The Palace!). It was with a heavy shock that we realised what a mammoth task it was to organise all 10 people and get them into the field before dawn, every day. The fact this involved at least three houses, three cars, one motorbike, a fear of heights, a fear of cacti and several requests to "get to watch something interesting today, please!", only made the logistics even more interesting. But everyone's efforts paid off and we soon had found nearly 40 active lora nests, more than double what we knew of in 2006.
And so the time-demanding job of nest inspections began in earnest and the invaluable Sophie and Tom (Our season-long volunteers) soon learnt their way around the island. After complaints of poor wages (none) Sophie decided to feign illness so she could finally have some time off. So dedicated was she in her efforts she visited the recompression chamber 3 times before we found she didn't even have the bends! Sadly she was to return to the UK and leave us boys to it. As the season progressed we started to lose chicks. Competitors, rats and then dirty rats (poachers) were to blame. We knew of 23 chicks that fledged so the other 10 that were poached were a serious disappointment. Being able to follow a larger number of nests has given us a better perspective of lora reproductive efforts and success and we must again thank the nest finders for their efforts.
As the season drew to a close the three weary lads returned to grey skies and the UK. It seems the transition to office life is never easy but maybe it was quicker this year. As the nights drew in (or is it that the days appear less?) we launched into statistical analysis. We'll each tell you more about that in just a mo (I’m going to include Rowan’s piece so you can hear more about his side of the Bonaire parrot research), but a bit on Parrotwatch first.
Setting up Parrotwatch.org was a challenge but a worthwhile one. Over $4000 was raised through online sponsorship and personal donations, this has almost entirely covered the cost (subsistence- excluding rum) of both the short term and the long-term field assistants. There will be more details of this on the site soon. It has certainly put Bonaire on the map, in fact the only continent where the site itself has not been viewed, is Antarctica! A host of PW articles were generously printed by The Reporter (Bonaire’s English language newspaper) and these were well received. We also ran an “Ask Olivia” column where people could write in and ask Olivia a question such as “How man chicks do you have?”. Olivia is of course the star of parrotwatch with whom you are already familiar, right?!
Anyway, Olivia's column was even translated into Papiamento, and printed in the local newspapers too, though she chose to do it under an alias! It will be necessary to secure more advertising on the site to cover the costs of the enterprise (not paid for from online sponsorship) so if you know any business that might be interested, then please put them in touch! There will be a few tweaks before the 2008 season and we hope to renew interest as the season begins, watch this space...
Now here’s a bit more info about our research from me and then Rowan
Limiting factors - Sam
The year got off to a good start with a solid count generating an estimate of 650 parrots. But this is confusing because even if the recruitment of fledglings was incredible over the last 3 years we could still expect maybe 400 of these to be adults. In that case there would be 200 breeding pairs yet we only know of 40 active nests and we've covered the main areas. Sure we haven't got every pair and there may be another 40 nests, but certainly not 160 more! So what is going on?
All the evidence suggests the parrots are limited by the number of available nest sites. This is a major limit for population growth and will also influence the genetic structure of the population. The lora needs nest cavities and they do not make their own. Poachers have chain-sawed holes into almost every nest tree on the island, making them unsuitable for future use, and there are surprisingly few suitable cavities in the cliffs. I repaired some damaged tree nests and they were used within a few months - a clear sign of desperation! This is something I'll be investigating further in 2008, but what about those that did try to breed?
We were able to access and monitor 30 nests. Those pairs produced 92 eggs, 59 of which hatched, and 23 of those chicks fledged. So despite following 13 more nests than in 2006 there were virtually the same number of fledglings. The bigger sample of nests gave us a better perspective and now we must ask whether this rate of productivity will sustain the population. After another year of data collection I'll be putting all this data into a population model and it'll just tell us the answer. It's really that simple, and I can't wait to do the analysis, honest.
Different pairs have better reproductive success than others and I've been trying to find out why. Rowan will tell you it's down to the pair's behaviour but I say it's the environment. I've looked at a number of variables and there are some interesting patterns. For example, the proximity to food hot spots like Dos Pos and Fontein, has a significant effect on offspring survival and independent of that the proximity of other pairs has a positive effect too. It's early days for this analysis but it is very satisfying to be finding patterns that will help us manage these amazing parrots.
Parrot Parenting - Rowan
This year saw a continuation of intense observations of parrot parenting behaviour. The aim of all this is to figure out exactly how pairs care for their offspring and to identify the roles of males and females in parenting. Who does what? How do they share out the workload? How does this affect their success at being parents? The answers to these questions aren't just relevant to conservation but also shine light on how the unusually strong monogamous pair bond of parrots evolved.
Having so many volunteers meant that nesting parrots could be identified early and I was able to collect data on how pairs behave right at the start of breeding. At this time they are still checking out potential nest holes and trying to keep rivals away from the good ones. There seems to be a lot of variation between pairs in how they interact with each other at this stage, which probably determines their success later on. Pairs that nest earlier fledge more chicks so getting on with breeding quickly seems to be a good idea.
Once they get down to business the female does all the brooding of the chicks and during this time she's completely dependent on the male for food. From this year's observations it seems that males aren't particularly flexible in the amount of food they'll bring to the nest - either the female can't communicate when she needs more or the male is just unwilling to work harder. This may mean that as the chicks demand more food the female is torn between the need to brood the chicks and the need to feed them. Or could it be that she's just being lazy and letting the male do all the work and only pitching in when things get really tight? Either way, how the pair negotiates over chick care during this period could prove critical to determining whether or not they are successful parents.
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It seems impossible that we are already planning our third field season and there is talk of 'writing up' - a phase in the PhD process that neither of us are particularly relishing. For now there's a great deal to be getting on with, not least surviving the sub-zero temperatures currently gripping England. The good news for me is that I hope to be getting back to Bonaire at the end of January in order to assist in the annual parrot count. Then between that and the breeding season I hope to spend my time radio tracking some of the chicks from 2007 to investigate patterns of habitat use and activity budgets. I can’t wait!!!
Thanks to all those who have supported our project in 2007 either through donations through the World Parrot Trust or through parrotwatch.org
Best wishes for 2008
Sam
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