Preliminary field inspection and searching for burrows.
During the field inspection, we searched the valley for marmot burrows
and recorded their location using a GPS device. We treated every
entrance as a separate burrow unless several entrance corridors were
clearly merging into one corridor. We noted the presence or absence of
plants on the mound. A common method to check the activity status of a
burrow is checking for the presence of fresh faeces (Karels et al.,
2004). We suspected, that due to the type of environment fresh faeces
dry out very quickly, but then remain intact for a long time. Therefore,
we counted all burrows which had any faeces on them. Burrows without
faeces were abandoned and usually damaged and we did not record them.
The area we searched was 17.18 km2 (Fig. 1A).