Arboreal trail camera network
The Problem
Fatu Hiva Monarch (Pomarea whitneyi) is the most endangered bird of French Polynesia and one of the most CR birds in the world. Endemic to Fatu Hiva, in Marquesas Archipelago and previously common all around the island, its population suffered a catastrophic decline in the 90s to less than 30 birds in 2017 with only 4 active breeding pairs, all restricted into one valley. Their decline shows a rate of 97-99% over 3 generations and it’s mainly caused by two introduced invasive species, the black rat (Rattus rattus) and the feral cat. Invasive species management implemented since 2007 (rat control) and 2010 (cat control) has been progressively extended to 150 ha for manual rat baiting and 600 ha for cat control. Even though the decline has been reversed within the managed population, the birds are still at such precariously low numbers that they remain vulnerable to catastrophic events, disease or inbreeding depression. Despite the high nesting success between 2008 and 2016, the recruitment rate has not been sufficient to increase the population. The new Species Action Plan concludes that increasing the survival rate of post-fledging juveniles is the highest priority to save the species. Juvenile survival rate the first two months after fledgling is high but after that period emancipated juveniles disappear from the managed area. Their research of new territories remains unknown or lethal. This critical key question needs to be answered to improve the recovery of the species.
Our Proposal
Test an innovative non-invasive monitoring method by deploying a network of trail cameras placed in branches and other specific spots next to appealing objects (shiny objects, feathers, suspended doorbells, artificial water points, etc.) to draw attention of curious juveniles for a better understanding of Fatu Hiva Monarch young dispersal movements. This will be coupled with the deployment of acoustic recorders. The juveniles that usually leave the parental territory in between 2-6 months after they fledged disappear from the core area that is already well monitored. We suspect that they explore other territories and then come back to the core area several months or years after to find a partner and breed, but we ignore where they go in the meanwhile. The steepness and difficulty of the fieldwork combined with the lack of funding and human power limit the prospecting area and efforts. This new non-invasive method will allow expanding at the same time the surveillance area and its duration so it will maximize the chances of detecting new breeding pairs but mainly erratic birds and newly fledged birds elsewhere than in the core area. If it works, we will expand the invasive species trapping system to protect the dispersal areas as well as the core area. At the same time we will conduct several walking explorations to nearby areas and historical monarch territories to increase the chances to detect birds.
We Assume that...
- Young individual’s dispersal zones are outside the monitored area
- Juveniles come back to the core area several months or years after to find a partner and breed or find new territories outside the monitored area
- Juveniles are extremely curious and approach colorful/shiny objects and strange noises
- If we place that kind of appealing objects in front of trail cameras, young Fatu Hiva monarchs will be attracted by them and come closer enough to be captured by the trail cameras
- We have already capture birds in trail cameras and even obtain an individual recognition of banded juvenile’s perched facing a camera trap.
- The lack of funding and human power limit the prospecting area and effort
Constraints to Overcome
Obtaining fine information of the fate of every single bird is crucial to adapt the conservation management and avoid the extinction of the species and our fieldwork technicians are not able to perform it. More observation effort needs to be done to improve the monitoring of post-fledging juveniles and enlarge prospecting areas to look for its dispersal areas. The steepness and difficulty of the fieldwork combined with the lack of funding and human power limit the prospecting area and effort by fieldwork technicians. More human power or a new methodology is needed to enlarge the surface of new prospecting areas to look for non-fixed juveniles and other birds. The conservation challenge of this project is to improve the knowledge of juvenile’s dispersal areas with the deployment of a trail camera network to expand the monitoring surface and duration and maximize the probability of monitoring post-fledging juveniles in these unknown and frequented areas.
Current Work
To ensure that our methodology will be adapted to the local context, we will test different cameras trap settings and lures in order to find out the best configuration. We will use different lures and combine its physical parameters as sounds, forms and colors to find out the ones preferred by the birds and we will trial different configurations in order to discover the best distance and position between the trail cameras and the appealing objects. We will run the trial within the core area to be sure that birds can visit the trail cameras, but avoiding the breeding territories and focusing on the most visited spots by juveniles. After that we will deploy the network of trail cameras in our pre-selected areas and let them run for 6 months, with periodical verifications. Once the network will be running, several walking prospecting explorations will be conducted in surrounding areas and historical territories not surveyed by our network in order to increase the chances to detect birds