Photographs of seal-feeding killer whales KI-03, KI-05 and KI-06.

<p>Individuals in upper photographs, observed off central coast of Norway in 1988, match individuals visible on the lower row of photographs, taken off Andenes in June 2015.</p

Plots of lagged association rates.

<p>The blue plot represents our real data set while the red plot shows the expected lagged association rates if individuals associated at random.</p

Sociogram of seal-feeding killer whales observed in at least four sampling periods.

<p>Occurrence and thickness of links show association patterns between pairs of individuals, revealing the two assemblages KI and K.</p

Important prey areas and observations of seal-feeding killer whale groups.

<p>The left panel (A) shows seasonal herring grounds since 1990 while the middle panel (B) shows areas of abundance of coastal seals since 1990 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180099#pone.0180099.ref032" target="_blank">32</a>]. The right panel (C) shows locations of K and KI whales sightings since 1988. (The map was made in ESRI ArcGIS software [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180099#pone.0180099.ref033" target="_blank">33</a>] using public domain map data @ <a href="http://naturalearthdata.com" target="_blank">naturalearthdata.com</a>).</p

Sighting histories of KI and K whales.

<p>Sighting histories of KI and K whales.</p

Summary of recorded predation events on seals where involved individual killer whales could be identified.

<p>Summary of recorded predation events on seals where involved individual killer whales could be identified.</p

Photograph of KI-03 preying upon a harbor seal pup in June 2015.

<p>The photograph (A) illustrates the predation observation and the inset (B) confirms effective prey consumption.</p

Data from: First longitudinal study of seal-feeding killer whales (Orcinus orca) in Norwegian coastal waters

The file set contains photographic identification and group size data for seal-feeding killer whales observed in Norwegian coastal waters. All records of observations and/or predation events for these killer whales are available. Additionnal records of predation on seal prey by unidentified killer whale individuals are also reported