Search for India’s lost Namdapha Flying Squirrel

Methods

Summary

Namdapha is accessible for survey only in the months from October to March/April, because during the rest of the year it is rainy and the forest undergrowth is thick. This project will conduct field surveys over two field seasons of six months each.

The original specimen was collected from Naharbhadi, which is on the left bank of River Noa Dihing. This suggests that we should first survey for the Namdapha Flying Squirrel on the southern bank of the Noa Dihing as it is a fast-flowing wide river which may have restricted this species distribution. We will ideally carry out the surveys in small blocks of (app 10sq km) starting around Naharbhadi, and then progressively expand by 10 square kilometers every phase of the work as it progresses. This species is likely restricted by big rivers and more likely to be found in southern Namdapha continuing into Myanmar.

Spotlighting: The primary method we will use to survey the species will be to walk with spotlights across transects of suitable forest habitat. This will begin at dusk, with the field team scanning the canopy with red lights at a walking speed of 10m per minute. We will use two spotlights and night vision binoculars to observe the animals. We will photograph and film the animals to identify the species and potentially enable the acquisition of additional data. Based on the surveys, we will estimate encounter rates for each species, number of gliding squirrels sighted per km of trail traveled per species.

Arboreal Camera Trapping:  20 motion sensor camera traps will be placed at suitable arboreal locations of trees that are visited by flying squirrels, for example, they visit Mesua ferrea with ripen seeds, fig trees while fruiting as well as arboreal bait stations using expertise of our local team and past encounters, to deduce their final location when in the field. Camera’s will be active at bait stations for the duration of the study period to increase our chance of capturing the target species. We will also set up arboreal bait stations based on observation of movement pattern of the flying squirrels in study area.

Tree Hole Scoping: We will scope Identified tree holes during day time using a digital burrow scope when nocturnal squirrels are at rest. Colour photograph of the animal will be taken and examined to identify the species. When we find a flying squirrel, the same hole will be monitored regularly to examine occupancy by the same or multiple species. However, scoping holes on trees will be limited by heights and access.

Fur Trapping: We will use fur trapping at suitable arboreal locations. This will be done alongside the other methods to potentially gather more information about the target species and the wider small mammal community

Challenges

One of the greatest challenges is that we know so little about the species and due to its presumed ecology of being an arboreal species that is most active at dusk, this means it is going to be difficult to survey.

With this sort of project there is the possibility of course that the species may have gone extinct. If this does turn out to be the case, then we would ensure that the work was not done in vain. There are two avenues for making the most of any information that will be gathered. Firstly, the surveys  will collect information about a suite of other species, particularly of small mammals for which there is generally a lack of information. Any new distribution and abundance information will feed directly into the IUCN Red List of Threatened Species. Secondly, trialing alternative methods and techniques for surveying and monitoring will be relevant and transferable for conserving other threatened squirrels. For example, it could help in the plight of the extremely poor known similar species, the Laotian giant flying squirrel (Biswamoyopterus laoensis), in Lao PDR. This species has a bizarre story, having been discovered only recently at a bushmeat market. Scientists have no idea where it is found across the region.

Pre Analysis Plan

It will be good to gather some more information about this species, especially around the circumstances of its discovery, which its largely known through field notes, this can be achieved through interviewing team members present during the survey. Exact field information is vital to the rediscovery of such a poorly known species. We will survey nearby villages and interview hunters: villages nearby Namdapha NP shall be surveyed for skin and trophies of flying squirrels and when found details of the specimen will be recorded for taxonomic purpose. When possible animals collected will be used for further study along with samples for DNA barcoding. Known hunters will be interviewed for their specific knowledge on flying squirrels in particular.

We will also Interview a team member of the specimen collection team of Zoological Survey of India (to gather more specific information about the circumstance of collection of the original specimen). The publication did not specify exactly where in Naharbadi the individual came from. Namdapha has wide distribution of Mesua ferrea trees, where from it was collected.