Data from: Hierarchical influences of prey distribution on patterns of prey capture by a marine predator

1. Prey distribution acts at multiple spatial scales to influence foraging
success by predators. The overall distribution of prey may shape foraging
ranges, the distance between patches may influence the ability of
predators to detect and move between profitable areas, and individual
patch characteristics may affect prey capture efficiency. 2. In this
study, we assessed relationship between spatially-explicit patterns of
prey capture by a central place forager, the little penguin (using GPS
tracking and accelerometry), and the distribution of aggregations of
potential forage fish prey (using boat-based active acoustics) in eastern
Australia. We used complementary resource selection functions to estimate
the distribution of both prey captures and aggregations across the study
area, based on a suite of habitat characteristics. 3. We found that 99 %
of prey captures by penguins occurred in the top 20 m of the water column.
The estimated distribution of prey captures across the study area was
similar to the distribution of aggregations above 20 m depth, indicating
that penguins effectively matched the local distribution of their prey. 4.
The distances between consecutive prey captures followed a bimodal
distribution, with means of 8.1 ± 2.2 m and 57.4 ± 1.7 m. Based on the
length of aggregations and the distances separating aggregations along
survey transects, this implies that foraging behaviour occurs on multiple
spatial scales corresponding to within-patch and between-patch movements
respectively. 5. Morphological characteristics of aggregations above 20 m
depth were important for explaining variance in the number of prey caught
by penguins in an area, with penguins catching more prey where
aggregations were relatively dense, compact and shallow. 6. These results
reveal spatially explicit patterns of prey capture, and provide a
framework for understanding how features of prey distribution influence
prey intake by predators in patchy environments.