Vision in echolocating bats - Fladdermus.net

General observations
RESULTS
When released in the flight room, the bats typically flew across the feeding area
a few times before deciding from which dish to feed. They usually hovered just
above one of the dishes (10 – 15 cm) for a short period and then landed next to it.
The bats then crawled into the dish to feed. On a few occasions, bats crawled
around the feeding area on the floor to investigate the different dishes. After
capture of a mealworm, the bats consumed it while hanging on one of the walls
in the flight room. Bats moving around consistently emitted detectable
echolocation calls.
Experiment 1
The number of feeding attempts and estimates of preference at the different
dishes are presented in table 1. We found no significant differences between bat
individuals in their probability of feeding at a certain dish (? 2 9 = 7.94, p>0.05).
This means that we do not gain any statistically significant information by
treating the individuals separately, and we therefore pooled the results.
When comparing the number of feeding attempts between each
of the four foraging situations (data and statistics in tab. 1 and 2), we found that
in lit situations, it made no difference if sonar cues were added or not. However,
there were more feeding attempts when sonar cues and visual cues were present,
compared to when only sonar cues were available. This suggests that the bats
predominantly used vision when they searched for prey.
When comparing the frequency of foraging attempts at situations
providing visual or sonar cues only, the bats scored better at the visual cues, and
when comparing sonar cues only to the no cue situation, we found no significant
difference. This analysis too suggests that the bats predominantly relied on
vision and it also suggests that they could not find prey items using sonar alone.
Experiment 2
There were significantly more feeding attempts at lit petri dishes containing
mealworms than at lit empty ones (? 2 1 = 7.7, p