To Record and Report Information

As discussed in the preface, though learning to identify the whales, dolphins, and porpoises one sees may be exciting in itself, many persons may want to participate in the accumulation of data on these interesting animals by routinely reporting their observations to scientists who are actively studying them and who can make immediate use of the information. The following may help these persons:

Suggestions for making and recording observations of cetaceans at sea and sample data forms are included in [Appendix C]. Similar suggestions for taking and recording data on stranded cetaceans are included in [Appendix D]. For both types of data, blank data forms located after the appendices may be photocopied in bulk for use in the field.

Completed data forms and all associated information for sightings at sea should be forwarded to the Platforms of Opportunity Program, National Marine Fisheries Service, Tiburon, CA 94920, or to one of the authors of this guide. From there, they will be made available to scientists actively studying the cetaceans of a given species or geographical area.

Completed data forms and all associated information for observations of stranded cetaceans should be forwarded to the Division of Mammals, U.S. National Museum, Washington, DC 20560, to one of the authors of this guide, or to one of the regional laboratories listed in [Appendix E]. These persons have, in turn, been encouraged to keep a free flow of information among them.

Table 1. Ranges in Numbers of Teeth in Each Upper and Lower Jaw of Western North Atlantic Odontocetes.

Species common name	Species scientific name	Page of species account	Ranges in tooth counts		Remarks
Species common name	Species scientific name	Page of species account	Upper	Lower	Remarks
Sperm whale	Physeter catodon	[57]	0	18-25	Ten to sixteen upper teeth rarely emerge; lower teeth fit into sockets in upper jaw.
Northern bottlenosed whale	Hyperoodon ampullatus	[67]	0	2(2)[A]	At tip of lower jaw; sometimes second pair behind first.
Goosebeaked whale	Ziphius cavirostris	[70]	0	2[A]	At tip of lower jaw.[B]
True's beaked whale	Mesoplodon mirus	[77]	0	2[A]	At tip of lower jaw.[B]
Antillean beaked whale	Mesoplodon europaeus	[78]	0	2[A]	At suture of mandible. One-third of way from tip of snout to gape.[B]
Dense-beaked whale	Mesoplodon densirostris	[80]	0	2[A]	On prominences near corner of mouth; oriented backwards.[B]
North Sea beaked whale	Mesoplodon bidens	[82]	0	2[A]	About halfway from tip of snout to gape.[B]
Killer whale	Orcinus orca	[84]	10-12	10-12	Prominent; curved and oriented backwards and inwards; pointed.
False killer whale	Pseudorca crassidens	[88]	8-11	8-11	Prominent; pointed and curved.
Atlantic pilot whale	Globicephala melaena	[91]	8-10	8-10	— —
Short-finned pilot whale	Globicephala macrorhyncha	[94]	7-9	7-9	— —
Grampus	Grampus griseus	[96]	0	0-7	Near front of jaw; may have fallen out in older specimens; sometimes teeth in upper jaw.
Beluga	Delphinapterus leucas	[99]	8-11	8-9	— —
Narwhal	Monodon monoceros	[102]	2	0[A]	One (rarely both) grows up to 9 ft (2.5 m) tusk which has left-hand (sinestral) spiral.
Spotted dolphin	Stenella plagiodon	[104]	30-36	28-35	— —
Bridled dolphin	Stenella frontalis	[108]	29-34	33-36	— —
Spinner dolphin	Stenella longirostris	[110]	46-65	46-65	— —
Striped dolphin	Stenella coeruleoalba	[113]	43-50	43-50	— —
Saddleback dolphin	Delphinus delphis	[116]	40-50	40-50	— —
Fraser's dolphin	Lagenodelphis hosei	[120]	38-44	38-44	— —
Atlantic white-sided dolphin	Lagenorhynchus acutus	[123]	30-40	30-40	Some specimens have more teeth in upper than in lower jaw.
White-beaked dolphin	Lagenorhynchus albirostris	[126]	22-28	22-28	— —
Atlantic bottlenosed dolphin	Tursiops truncatus	[128]	20-26	18-24	— —
Guiana dolphin	Sotalia guianensis	[132]	26-35	26-35	— —
Rough-toothed dolphin	Steno bredanensis	[135]	20-27	20-27	Crown is sometimes marked with many fine vertical wrinkles.
Pygmy killer whale	Feresa attenuata	[138]	8-13	10-13	Many specimens have fewer teeth on right than on left side.
Many-toothed blackfish	Peponocephala electra	[142]	22-25	21-24	— —
Pygmy sperm whale	Kogia breviceps	[144]	0	12-16	Rarely 10 or 11; curved back and inwards; fit into sockets in upper jaw.
Dwarf sperm whale	Kogia simus	[148]	0-3	8-11	Rarely 13; curved back and in; sharply pointed; fit into sockets in upper jaw. Rarely has 1-3 upper teeth as well.
Harbor porpoise	Phocoena phocoena	[150]	22-28	22-28	Spade shaped, laterally compressed, and relatively small.

[A] Usually erupted from gums only in adult [MALES].

[B] May have toothpick size vestigial teeth in either jaw.

Table 2. Body Size; Numbers, Maximum Dimensions and Descriptions of Baleen Plates; and Numbers and Relative Lengths of Ventral Grooves of W. N. Atlantic Mysticetes.

Species common name	Species scientific name	Page of species account	Maximum body size [C] ft(m)	Number of baleen plates/side	Maximum dimensions of plates				Color of baleen	Mean No. of bristles /cm.	Numbers of ventral grooves	Relative lengths of ventral grooves
					Length		Width base
					ft/in.	cm	ft/in.	cm
Blue whale	Balaenoptera musculus	[19]	85 (26.0)	270-395	33"	84	12"	30	All black with black bristles.	10-30	55-88	At least to navel.
Fin whale	Balaenoptera physalus	[26]	79 (24.0)	262-473	29"	72	12"	30	Dark gray to bluish gray; one-fifth to one-third of right front is whitish.	10-35	56-100	At least to navel.
Sei whale	Balaenoptera borealis	[32]	62 (19.0)	318-340	31"	78	15"	39	Ash black with blue tinge and fine, light bristles; some near front may be light.	35-60	38-56	End far short of navel.
Bryde's whale	Balaenoptera edeni	[37]	46 (14.0)	250-300?	17"	42	10"	24	Slate gray with dark bristles.	15-35	40-50	At least to navel.
Humpback whale	Megaptera novaeangliae	[40]	53 (16.0)	270-400	24"	60	5"	13	Ash black to olive brown; sometimes whitish; bristles grayish white.	10-35	14-22	At least to navel.
Bowhead whale	Balaena mysticetus	[49]	65 (19.8)	325-360	14'	414	14"	36	Black; anterior side of some is whitish; bristles black.	?	None present.	XX
Right whale	Eubalaena glacialis	[52]	53 (16.0)	250-390	7.3'	223	12"	30	Dirty or yellowish gray; some anterior plates all or part white.	35-70	None present.	XX
Minke whale	Balaenoptera acutorostrata	[63]	31 (10.0)	300-325	8"	21	4"	10	White to yellowish white. Posterior plates may be brown or black.	15-25	50-70	End short of navel; often just behind flippers.

[C] As stated in the Index to the species, these figures represent maximum sizes recorded for the W. N. Atlantic. For all species exploited by whaling industries' current maximum sizes will be substantially smaller than these figures (see species accounts).

DIRECTORY TO SPECIES ACCOUNTS

LARGE WHALES
(40-85 feet [12-26 m] maximum overall length)

With a Dorsal Fin

All five species of large whales with a dorsal fin belong to the same major baleen whale group, the balaenopterid whales or rorquals. All are characterized by the presence of a series of ventral grooves, usually visible on stranded specimens and the length and number of which are diagnostic to species. In addition, all species, with the exception of the humpback whale, have at least one distinctive (though often not prominent) ridge along the head from just in front of the blowhole to near the tip of the snout. (The humpback whale, on the other hand, is distinguished by numerous knobs, some of which are located along the line of the head ridge, with others scattered on the top of the head.) In Bryde's whale, the single head ridge characteristic of the other rorquals is supplemented by two auxiliary ridges, one on each side of the main ridge.

At sea, these whales often appear very similar and must be examined carefully before they can be reliably identified.

In general, though the characteristics of behavior may vary from one encounter to the next, based on the activities in which the animal is engaged, whales in this group may be distinguished from each other on the basis of differences in 1) the size, shape, and position of the dorsal fin and the timing of its appearance on the surface relative to the animal's blow (in general, the larger the whale, the smaller the dorsal fin—the further back its position and the later its appearance on the surface after the animal's blow); 2) the height of body in the area of the dorsal fin, relative to the size of the dorsal fin, which is exposed as the animal sounds; 3) sometimes the blow rate and movement patterns; and 4) the shape and color of the head.

Despite variability in behavior by members of the same species from one encounter to the next, an observer can greatly increase the reliability of his identification by forming the habit of working systematically through a set of characteristics for the species rather than depending on any single characteristic.

Blue whale
Balaenoptera musculus
p. [19]

Body very large, up to 85 feet (25.9 m) long.[7]
Body basically bluish with mottlings of grayish white.
Baleen all black.
Head broad and nearly U-shaped, viewed from above.
Head flat in front of blowhole, viewed from side.
Dorsal fin small (to 13 inches [33 cm]), triangular to moderately falcate, in the last one-third of back.
Distribution primarily from temperate seas to pack ice; rare in tropics.
Distribution more northerly during summer.
Flukes occasionally raised slightly on long dive.

[7] These figures are all near maximum sizes recorded for the North Atlantic. For all species which have historically been exploited by whale fisheries present maximum sizes may be significantly less than these figures.

It should also be noted that differences in methods of measurements often account for discrepancies in reported lengths.

Fin whale
Balaenoptera physalus
p. [26]

Body large, up to 79 feet (24 m) long.
Body mostly dark gray or brownish gray; undersides of flukes and flippers and belly white; grayish-white chevron frequently on back behind head.
Right lower lip white; right upper lip sometimes white; left lip dark.
Head V-shaped, viewed from above.
Right front one-third to one-fifth of baleen plates, yellowish white.
Other baleen bluish gray with yellowish-white stripes.
Dorsal fin to 24 inches (61 cm), slightly more than one-third forward from tail; forms angle of less than 40° with back.
Distribution extensive but not very common near pack ice and in tropics.
Distribution more northerly during summer.
Flukes not raised on dive.

Sei whale
Balaenoptera borealis
p. [32]

Body up to 62 feet (19 m) long.
Body appears shiny; dark gray on back, often with ovoid grayish-white scars; white on front of belly; undersides of flippers and flukes dark.
Baleen grayish or ash black with fine, light-gray bristles.
Dorsal fin to 24 inches (61 cm), strongly falcate, well more than one-third forward from tail; forms angle of more than 40° with back.
Distribution extensive; are not very common in cold waters and may have a greater tendency than fin whales to enter tropical waters.
Distribution more northerly in summer.
Flukes not raised on dive.

Bryde's whale
Balaenoptera edeni
p. [37]

Body up to 46 feet (14 m) long.
Body dark gray overall.
Head has series of three ridges from area of blowhole to snout.
Baleen slate gray with coarse dark bristles.
Dorsal fin to 18 inches (45.7 cm), falcate, well more than one-third forward from tail, often irregularly worn on rear margin.
Distribution primarily tropical and southern temperate.
Flukes not raised on dive.

Humpback whale
Megaptera novaeangliae
p. [40]

Body up to 53 feet (16.2 m) long.
Body dark gray with irregular white area on belly; flippers white; underside of flukes often has varying amounts of white.
Head in front of blowhole flat and covered with knobs.
Baleen dark gray to black with olive-black bristles.
Dorsal fin small, quite variable in shape, usually hooked, located on a step or hump, in last one-third of back.
Flippers very long (to nearly one-third of body length), white, and scalloped on leading edge.
Distribution at least New England to Iceland and Greenland during summer.
Distribution to shallow tropical banks, winter and spring.
Flukes often scalloped on trailing edges and sometimes raised on dive.

NOTE: Because of its small adult size, usually less than 30 feet (9.1 m), another member of the rorqual family, the minke whale, is included with the medium-sized whales in this guide. Features by which it may be distinguished from all other rorquals are discussed in the species account.

Further, inasmuch as the dorsal fin of the humpback whale is highly variable in shape, positive identification may require reference to the sperm whale (p. [57]), which, though the sperm whale has been classified with species without dorsal fin, has a rather distinct dorsal hump, particularly noticeable when the animal arches the back and tail to begin a long dive.