Background: Burrowing by protected, subterranean European ground squirrels or Lesser
blind mole-rats increase landscape heterogeneity and improve the availability of resources
to other organisms of semi-arid grasslands of Central Europe. They are important in
such ecosystem functions as the improvement of soil quality or they are important
prey for raptors. Besides people often visit their colonies for outdoor recreation
or education. If they vanish the soils’ macrofauna diversity decreases, which is an
overall indicator of soil health. Consequently, they are keystone, flagship species
of grasslands and their monitoring is recommended. However, colonies go extinct due
to land use changes or unknown reasons. Our primary aim is to develop an automated,
non-invasive method to detect, count and map animal burrows and estimate population
size more accurately.
Problem: According to their monitoring actively used burrow entrances are counted
per hectare. Then this number is extended to the area occupied by the colony. Two
main systematic errors make the population estimation inaccurate and relative. First,
it considers the animals’ distribution even on the entire area, second, the estimated
ratio of burrow entrances per each individual is inaccurate.
Innovation: The method includes detection and counting of burrow entrances and mounds,
and then, determining the number of burrow systems per area. Each animal occupies
one burrow system. To fulfil our plan we use proximal surface sensing, such as UAV
(camera and DGPS): for automatic burrow entrance or mound recognition and counting.
We also apply proximal subsurface sensing, such as GPR (DGPS) up to a depth of 1.0
m: for burrow mapping. Finally, the surface and subsurface models of the burrow systems
are interconnected visually.
Impact: Accurate population estimation would give nature conservationists an early
warning system so that they can intervene when colonies begin to decline in time.