Tab. 2. Ethogram of snorkeling (S) and cliff-top (C) observed behaviours of Negaprion brevirostris in Fernando de Noronha Archipelago, Brazil (see Fig. 1 for location of sites).

Behaviour category	Size class, sites observed	No., type and duration of observations	Behaviour description	Habitat type/ Depth
Substrate inspection	Juveniles and subadults less than 2 m TL, sites 1 and 2	89 (S), mean duration 8.5 seg (4-15 seg)	A shark approached a hole or crevice poking the substrate with its rostrum. The shark inclined the body forward and introduced its head and/or anterior part of the body in the hole performing abrupt lateral undulations to adjust the anterior part of the body to the hole and keep the body in position.	Reef flat and front reef, 0.5 to 1.5 m
Sardine blitz	Juveniles and subadults less than 2 m TL, sites 1 and 2	47 (S, C), mean duration 15.1 seg (4-30 seg)	One or more sharks approached the sardine schools exhibiting usual “patrolling behaviour” and when at a distance of less than 2 m, suddenly stroked the fishes with short bursts of speed towards a small part of the school.	Reef and rocky flats, sandy bottom with sparse reefs and rocks, 0.5 to 1.5 m
Sand hunting	Subadults larger than 2 TL and adults, sites 3 and 4	12 (C), mean duration 37.7min (17-38min)	Sharks larger than 2 m TL were initially observed performing “patrolling behaviour” at the deeper near-shore section of the beach (~ 1.5 m depth), immediately beyond the surf zone. Similar to the “sardine blitz” described above, but sharks only attacked the schools of sardines in the swash zone (0.3-1 m depth) immediately after the waves have broken.	Sandy beach, 0.3 to 1.5 m