Getting up at 1.30 am for work is not normally my idea of a fun night out but a dawn bat activity survey we carried out this week proved to be a winner. We saw the Black Isle BIG 5 as one of our bat surveyor’s Luka Coutts called the sightings. En route to the building to be surveyed badger, pine marten, roe deer and brown hare were all spotted from the car.
As if that wasn’t enough excitement for one night, at the bat survey which lasted from 2.00 am to 4.30 am 12 Pipistrelle roosts were observed and 20 brown long-eared bats seen entering a maternity roost. What a night.
This is not always the case when we survey for roosts at developments, as our last 2 bat surveys drew a blank, a result which always pleases the client but doesn’t offer much excitement for the surveyors.
You just can’t tell when or where you’ll see mammals. Bats are the exception to this general rule. I can’t think of any other mammals where you can turn up at a specific time and place and see them at a roost or in good foraging habitat in the north. During the summer months they will leave their roost often in a building, bridge or tree, to feed and return before sunrise. Pipistrelles leave the roosts earlier than the other native bats often near dusk. Whereas Myotis species such as Daubenton’s and Natterer’s bats as well, as Brown long-eared bats (Plecotus sp), tend to leave the roosts later and return much earlier. This strategy works for these species as they tend to eat much larger prey, so don’t need so much time echo-locating and catching food. Pipistrelles home in on small prey such as midges and spend much more time foraging as a consequence.
If you want guaranteed mammal sightings bats are the best bet. Pick a still warm evening and wander along the edge of woodlands or waterway and you’ll undoubtedly see these nocturnal flying mammals out on the hunt.