(A) Albatross data and the model with destructive scenario. Green circles: accumulated distribution
of flight lengths between successive detected prey of the model forager with perception radius
r = 0.001 following a Lévy process with
µ = 1.5 (from 20 simulations of 75 captures each). The foraging ground is represented by a square of area unity and contained 5000 prey. Continuous line: exponential fit. Red triangles:
of the Bird Island albatross takeoff/landing data . Blue triangles:
of the Crozet Islands albatross prey capture data , converted into flight durations assuming a constant flight velocity
m/s. Inset: same curves represented in semi-log to better emphasize the non exponential nature of the observed albatross data versus the exponential form of the model forager detections. (B) Albatross data and model with non-destructive scenario. Violet circles: accumulated distribution
for the model forager performing a Lévy process with
µ = 2. Continuous line: exponential fit. Prey number: 3000;
r = 0.0003. In A) and B), the lengths in the model with foraging arena of area unity are converted in hours (
t) by using
with the scaling factor
v = 0.12. Inset: same curves represented in semi-log to better emphasize the non exponential nature of the observed albatross data versus the exponential form of the model forager detections. (C) Murre data and model with destructive scenario. Green circles: accumulated distribution
of flight lengths between prey of the model forager with perception radius
r = 0.001 following a Lévy process with
µ = 1.5 (from 20 simulations of 75 captures each). Continuous line: exponential fit. Brown dots are the murre flight durations from . Inset: same data represented in semi-log in order to better emphasize the exponential nature of both the observed murres data and the model forager. (D) Murre data and model with non-destructive scenario. Violet circles: accumulated distribution
for a forager performing a Lévy process with
µ = 2. Continuous line: exponential fit. Prey number: 3000;
r = 0.0003. Inset: same curves represented in semi-log. Similar close-to-exponential detections are obtained in all simulations with
, in both destructive and non-destructive scenarii.