Fig 1.
Survey effort and sighting locations of bottlenose dolphin group encounters.
The black lines indicate survey effort in the two research areas off northwest Ireland, Mayo and Connemara. Sighting locations of bottlenose dolphin groups in inshore waters are indicated by red circles, encounters in offshore waters are indicated by green circles. The geological map of Ireland has been reproduced under an open-access license from the DECRN, and the Intellectual Property Right and Copyright of the Geological Service Ireland. The bathymetry is reproduced from GEBCO, and extracted from the GEBCO Digital Atlas published by the British Oceanographic Data Centre on behalf of the IOC and IHO, 2003.
Fig 2.
Grades of severity of dorsal fin scarification.
Examples of the mark severity grades of dorsal fin scarification as applied in this study. (A) Permanently marked, (B) Temporarily marked, (C) Superficially marked, (D1-3) Permanently marked with damage to the tip of the dorsal fin. Pictures represent images cropped using Irfanview software.
Table 1.
Survey effort and photo identification analysis.
Fig 3.
The number of sightings of individuals comprising network A and network B-E.
Table 2.
Statistic descriptive of mark severity, dorsal tip damage and sighting record for network A and network B-E.
Fig 4.
Social network analysis: sociogram of permanently marked individuals.
Five social clusters (A-E), as identified by the social network analysis of associations of permanently marked bottlenose dolphins. Each symbol represents one individual, with the size of the symbols corresponding to the number of sightings of each individual (range: 1–18 sightings per individual). Blue squares represent individuals with typical scarring to the tip of the dorsal fin. Individuals without dorsal fin tip damage are represented by red squares. Black lines represent associations between individuals. The network composition has been manually adjusted to enhance the visualization of the separate clusters.
Table 3.
Chi square pair-wise comparison of the proportion of permanently marked individuals for social networks A-E.
Fig 5.
The distance from shore for bottlenose dolphin groups that comprised network A (left) and networks B-E (right). The boxplot displays the mean and the 1st and 3rd quartile of the distance from shore. Whiskers indicate one standard deviation from the mean. Note the logarithmic scale of the Y-axis.