Fig 1.
Mean 30-day catch per unit effort (CPUE) ± SD for each species on Isla Mocha (A) and Isla Robinson Crusoe (B), Chile. Mean 30-day CPUE was calculated as the mean hourly CPUE and multiplied by 720 (24 hours* 30 days). The x-axis is a square root scale. Species CPUE values are comparable within islands but not across islands because study methodology and duration differed on each island. Five breeding colonies were monitored from 2015–2020 on Isla Mocha and one breeding colony was monitored from 2019–2020 on Isla Robinson Crusoe.
Table 1.
Detections of animals from trail cameras at five pink-footed shearwater colonies on Isla Mocha, Chile, during 2015–2020.
Table 2.
Detections of vertebrate animals from four trail cameras at the Piedra Agujereada pink-footed shearwater colony on Isla Robinson Crusoe, Chile, during February 2019-February 2020.
Fig 2.
Pink-footed shearwater island-specific attendance from trail cameras on Isla Mocha and Isla Robinson Crusoe, Chile, and pink-footed shearwater breeding phenology.
Cameras were deployed on Isla Mocha (n = 1–4 per colony) at five colonies with deployment times ranging from mid-October to early June from 2015–2020. Cameras (n = 4) were deployed at on colony on Isla Robinson Crusoe from February 2019-February 2020. Bar length indicates the proportion of the island-specific maximum CPUE for each day on each island. Proportion of island-specific maximum CPUE was calculated by dividing the mean hourly pink-footed shearwater CPUE by the maximum recorded hourly CPUE on each island, and averaging the hourly results for each day. This relative seasonal and diel CPUE metric is a unitless proportion and the magnitude cannot be compared across islands because of differing maximum of CPUE values, but it emphasizes relative within-species attendance patterns. Red line indicates no data. Black line indicates effort without detections on that date. Breeding stage phenology is based on long-term breeding biology studies on both islands; breeding phenology is similar on both islands [10].
Fig 3.
Seasonal (A) and diel (B) island-specific attendance of pink-footed shearwaters on Isla Mocha (inside circle, blue; five colonies, 2015–2020) and Isla Robinson Crusoe (outside circle, orange; one colony, 2019–2020), Chile. Proportion of island-specific maximum CPUE was calculated by dividing each species’ hourly CPUE by the maximum recorded hourly CPUE for that species on each island, and averaging the hourly results for each day for the seasonal metric (A) and for each hour of the day for the diel metric (B). This unitless relative CPUE metric can be used to compare seasonal and diel attendance across islands, but does not reflect actual magnitude or relative abundance of species because the maximum CPUEs were species- and island-specific. Circle size (A) and bar length (B) indicate the proportion of the island-specific maximum CPUE for each day (A) or hour (B) on each island. The largest point and the longest bar for each species represent the highest CPUE for that species on that island. On panel A, red line indicates no data and black line indicates effort without detections on that date.
Fig 4.
Seasonal island-specific attendance of mammals in pink-footed shearwaters colonies on Isla Mocha (inside circle, blue; five colonies, 2015–2020) and Isla Robinson Crusoe (outside circle, orange; one colony, 2019–2020), Chile.
Proportion of island-specific maximum CPUE was calculated by dividing each species’ hourly CPUE by the maximum recorded hourly CPUE for that species on each island, and averaging the hourly results for each day. This unitless relative CPUE metric can be used to compare seasonal attendance across islands, but does not reflect actual magnitude or relative abundance of species because the maximum CPUEs were species- and island-specific. Circle size indicates the proportion of the island-specific maximum CPUE for each day on each island. The largest point represents the highest CPUE for that species on that island. Red line indicates no data. Black line indicates effort without detections on that date. Species with no colored data points were not observed on that island. All mammals shown were introduced with the exception of the pudú (Pudu pada), whose native status was uncertain.
Fig 5.
Diel island-specific attendance of mammals in pink-footed shearwaters colonies on Isla Mocha (inside circle, blue; five colonies, 2015–2020) and Isla Robinson Crusoe (outside circle, orange; one colony, 2019–2020), Chile.
Proportion of island-specific maximum CPUE was calculated by dividing each species’ hourly CPUE by the maximum recorded hourly CPUE for that species on each island, and averaging the results for each hour of the day. This unitless relative CPUE metric can be used to compare diel attendance across islands, but does not reflect actual magnitude or relative abundance of species because the maximum CPUEs were species- and island-specific. Bay size indicates the proportion of the island-specific maximum CPUE for each day on each island. The longest bar represents the highest CPUE for that species on that island. All mammals shown were introduced with the exception of the pudú (Pudu pada), whose native status was uncertain.
Fig 6.
Trail camera image of a cat near two pink-footed shearwaters on Isla Mocha.