[Note: this post replaces the preliminary, typo-ridden and imageless draft that subscribers may have received, for which I stupidly pressed the 'publish' button rather than 'save draft'... Not the 1st time, either... Sorry]
Scientist Caroline Stahala has spent 10 years researching the Abaco population of the Bahama parrot. Her aim is to develop understanding of their behaviour so that conservation and management strategies for this rare sub-species can be optimised. Particular protection problems arise because Abaco parrots, uniquely, nest underground. Their main vulnerability is to predation by feral cats, racoons and rodents which kill adults, chicks and fledglings in the nest
Predator monitoring and control programs have been in place for several years, removing surprising numbers of feral cats prior to and during the breeding season. Prevention techniques have been refined as predation data has accumulated. In 2011 for the first time motion-sensitive cameras were used, positioned near the openings of vulnerable active nests (shallow or with large openings), monitored 24/7 with infra-red night-time flash. Constant technical adjustments were needed to determine optimum filming distance and memory card size, and to avoid ‘false triggers’ (eg wind)
A great deal of vital data was collected, particularly at night when predation can’t otherwise be effectively monitored. Feral cats were the most frequent visitors, followed by rodents. No racoons were recorded, so these may be less of a threat than expected. One northern mockingbird (above) was caught on film up to no good. It it seems that the camera flash itself may act as a deterrent, something that bears further study. There is also new evidence that some predators approach a nest and ‘case the joint’ for later use. All this data will make it possible to target predator control preventatively, rather than in the sad aftermath of predation – a great step forward.
Overall, during the 2011 breeding season none of 55 nests monitored was lost due to predation. In previous years, the attrition rates have been around 25%. The use of cameras avoids any disturbance of the parrots and chicks and provides round-the-clock monitoring. If the cameras / flash are in themselves deterrents, that is a simple method of predation control. The new banding project means that it is now possible to be certain whether same parrot (or pair) is using the same nest cavity each year – and of course individuals can more readily be identified
Finally, Caroline confirms that the parrots weathered Hurricane Irene well. She was still monitoring the breeding territory then, and when she returned to check active nests after the storm, she found the chicks and fledglings safe in their nest cavities