KEY TO THE IDENTIFICATION OF STRANDED CETACEANS OF THE WESTERN NORTH ATLANTIC
- 1. a. Double blowhole; no teeth present in either jaw; baleen plates in upper jaws.
- (Baleen whale) Go to 2
- b. Single blowhole; teeth present (sometimes concealed beneath the gums); no baleen plates in upper jaw.
- (Toothed whale) Go to 9
- 2. a. Ventral grooves present; dorsal fin present; viewed in profile, upper jaw relatively flat and broad.
- (Balaenopterine whale) Go to 3
- b. Ventral grooves absent; dorsal fin absent; viewed in profile, upper jaw and lower lips strongly arched; upper jaw very narrow.
- (Right whale) Go to 8
- 3. a. Ventral grooves end before navel.[18]
- Go to 4
- b. Ventral grooves extend to or beyond navel
- Go to 5
- 4. a. 50-70 ventral grooves, longest often ending between flippers; baleen less than 8 inches (20.3 cm), mostly white or yellowish white (some posterior plates may be dark) with 15-25 white bristles per centimeter; 300-325 plates per side.
- Minke whale, p. [63]
- b. 38-56 ventral grooves, longest ending well short of navel; baleen less than 31 inches (78.7 cm), black (some anteriormost plates may be white) and with 35-60 fine silky white bristles per centimeter; 318-340 plates per side.
- Sei whale, p. [32]
- 5. a. Flippers one-fourth to one-third length of the body length and knobbed on leading edge; less than 22 broad and conspicuous ventral grooves, longest extending at least to navel; head covered with numerous knobs; baleen less than 24 inches (61 cm), ash black to olive brown (sometimes whitish) with 10-35 grayish white bristles per centimeter; 270-400 plates per side.
- Humpback whale, p. [40]
- b. Flippers less than one-fifth body length; no knobs; from 40 to 100 fine ventral grooves, longest extending at least to navel; head lacks knobs
- Go to 6
- 6. a. Three ridges on head, one from blowholes, forward towards tip of snout, one auxiliary groove along each side of main ridge; 40-50 ventral grooves; 250-300 slate-gray baleen plates with 15-35 dirty gray bristles per centimeter.
- Bryde's whale, p. [37]
- b. Only one prominent ridge on head,[19] from just in front of blowholes forward towards tip of snout; 55-100 ventral grooves
- Go to 7
- 7. a. Head broad and U-shaped; dorsal fin less than 13 inches (33 cm) and very far back on tail stock; baleen all black with 10-30 black bristles per centimeter; plates extremely broad relative to length.
- Blue whale, p. [19]
- b. Head broad at gape but sharply pointed on tip; dorsal fin to 24 inches (61 cm) and slightly more than one-third forward from tail; right front one-fifth to one-third of baleen ivory white to yellowish white, remainder dark gray to bluish gray streaked with yellowish white; plates have 10-35 gray or white bristles per centimeter and are narrow relative to length.
- Fin whale, p. [26]
- 8. a. Top of snout not covered with callosities; 325-360 baleen plates per side, longest reaching 14 feet (4.3 m); plates black with black bristles (anterior portion of some plates may be whitish).
- Bowhead whale, p. [49]
- b. Top of snout covered with callosities, often including lice and/or barnacles; 250-390 baleen plates per side, longest reaching 7.2 feet (2.2 m); plates dirty or yellowish gray (some anterior plates all or part white and some posterior plates brown or black) with 35-70 bristles per centimeter.
- Right whale, p. [52]
- 9. a. Upper part of head extending appreciably past tip of lower jaw; lower jaw markedly undershot and considerably narrower than upper jaw
- Go to 10
- b. Upper part of head not extending appreciably past tip of lower jaw; lower jaw approximately same width as upper jaw
- Go to 12
- 10. a. Body more than 13 feet (4.0 m); head massive, to one-third of body length; blowhole located far forward of eyes and to left front of head; dorsal fin low, triangular or rounded followed by series of knuckles or crenulations; 18-25 teeth in each lower jaw fit into sockets in upper jaw (10-16 upper teeth rarely emerge).
- Sperm whale, p. [57]
- b. Body less than 13 feet (4.0 m); head considerably less than one-third body length; blowhole located approximately even with eyes on top of head, slightly displaced to left but not on left front of head; conspicuous dorsal fin present; 8-16 teeth in each lower jaw fitting into sockets in upper jaw
- Go to 11
- 11. a. No creases on throat; dorsal fin small and located in latter third of back; 12-16 teeth (rarely 10-11) in each lower jaw.
- Pygmy sperm whale, p. [144]
- b. Inconspicuous creases on throat; dorsal fin tall and falcate, resembling that of the Atlantic bottlenosed dolphin, and located near middle of back; 8-11 (rarely 13) extremely sharp teeth in each lower jaw; rarely 1-3 teeth in each upper jaw.
- Dwarf sperm whale, p. [148]
- 12. a. Two conspicuous grooves on outer surface of throat forming V-shape pointed forward; notch absent or inconspicuous in flukes.
- (Beaked whale) Go to 13
- b. No conspicuous grooves on outer surface of throat; deep median notch on rear margin of tail flukes
- Go to 18
- 13. a. A pair of teeth located at the tip of the lower jaw (erupted only in adult males, concealed in females and immature animals)
- Go to 14
- b. No teeth at the tip of the lower jaw
- Go to 16
NOTE: Immature individuals of the species covered in paragraphs 14 and 15 may not be readily identifiable without museum preparation and examination.
- 14. a. Two well-developed teeth, erupted or hidden beneath the gum, are compressed so they appear elliptical in cross section; body to 16 feet (4.9 m); united portion of the lower jaws[20] more than one-fourth the length of the entire lower jaw.
- True's beaked whale, p. [77]
- b. Two well-developed teeth substantially less flattened so that they appear more nearly rounded in cross section
- Go to 15
- 15. a. Distinct elongated beak; pronounced bulge to forehead; blowhole located in lateral crease behind bulge; body to 32 feet (9.8 m); sometimes second pair of teeth behind first in lower jaw.
- Northern bottlenosed whale, p. [67]
- b. No distinct beak; forehead slightly concave in front of blowhole, increasing in concavity with increasing size; body to 23 feet (7.0 m); united portion of lower jaw less than one-fourth the length of the entire lower jaw; head of adult males all white.
- Goosebeaked whale, p. [70]
- 16. a. A single pair of teeth in the united portion of the lower jaw, at the suture of the mandible (about one-third of the way from the tip of the snout to the gape); length to 22 feet (6.7 m); flukes less than one-fifth the body length.
- Antillean beaked whale, p. [78]
- b. A single pair of teeth back of united portion of lower jaw; body less than 17 feet (5.2 m)
- Go to 17
- 17. a. Teeth not exceptionally large and located immediately back of united portion of lower jaw, about half way from the tip of the snout to the gape.
- North Sea beaked whale, p. [82]
- b. Teeth exceptionally large, located on bony prominences near the corner of the mouth, and oriented backwards; corners of mouth, particularly in adult males, have high-arching contour; flukes to one-sixth or one-fifth of the body length.
- Dense-beaked whale, p. [80]
- 18. a. Rostrum, if present, not sharply demarcated from forehead
- Go to 19
- b. Head has a distinct, though sometimes short rostrum separated from the forehead by a distinct crease angle
- Go to 30
- 19. a. Teeth spade-shaped, laterally compressed and relatively small; body to only about 5 feet (1.5 m); 22-28 teeth in each upper and lower jaw.
- Harbor porpoise, p. [150]
- b. Teeth conical and sharply pointed (in cross section circular, or slightly flattened anteroposteriorly)
- Go to 20
- 20. a. No distinct dorsal fin; back marked instead with small dorsal ridge near midpoint of back.
- Go to 21
- b. Distinct dorsal fin, in middle or forward third of the back
- Go to 22
- 21. a. 8-11 teeth in each upper jaw, 8-9 in each lower jaw; body of young slate gray or brownish, adults white; short broad rostrum.
- Beluga, p. [99]
- b. No visible teeth (or two teeth) in upper jaw of adults only; in males and sometimes females one or both of these may grow up to 9-foot (2.7 m) tusk in left-hand (sinestral) spiral; no rostrum.
- Narwhal, p. [102]
- 22. a. Head long and conical
- Go to 23
- b. Head blunt
- Go to 24
- 23. a. 20-27 teeth in each upper and lower jaw; crowns of teeth often marked with many fine vertical wrinkles; body to about 8 feet (2.4 m).
- Rough-toothed dolphin, p. [135]
- b. 26-35 teeth in each upper and lower jaw; teeth smooth; body to about 5.6 feet (1.7 m); distribution restricted to northern coast of South America, in the Guianas, and adjacent eastward territory of Venezuela.
- Guiana dolphin, p. [132]
- 24. a. Teeth usually at front end of lower jaw only, 2-7 pairs (rarely teeth in upper jaw); all teeth may have fallen out of the lower jaw of older specimens or may be extensively worn; forehead with median crease; dorsal fin tall and distinct to 15 inches (38.1 cm); body to 13 feet (4.0 m).
- Grampus, p. [96]
- b. Teeth in both upper and lower jaws, 7 or more pairs, forehead with no median crease
- Go to 25
- 25. a. Flippers large and paddle-shaped, ovate, and rounded on the distal end; dorsal fin tall and erect to 6 feet (1.8 m) in males and 3 feet (0.9 m) in females; 10-12 teeth in each jaw; teeth to 1 inch (2.5 cm) in diameter.
- Killer whale, p. [84]
- b. Flippers long and pointed
- Go to 26
- 26. a. Dorsal fin located in forward one-third of body, very broad at the base; head bulbous.
- (Pilot whale) Go to 27
- b. Dorsal fin located near midpoint of back; head long
- Go to 28
- 27. a. Flippers one-fifth of body length, or more.
- Atlantic pilot whale, p. [91]
- b. Flippers one-sixth of body length, or less.
- Short-finned pilot whale, p. [94]
- 28. a. Flipper has distinctive hump on forward margin; 8-11 prominent teeth curved backwards and inwards, in each upper and lower jaw.
- False killer whale, p. [88]
- b. Flipper lacks distinctive hump on forward margin; 10-25 teeth in each upper and lower jaw
- Go to 29
- 29. a. 8-13 teeth in each jaw.
- Pygmy killer whale, p. [138]
- b. 20-25 teeth in each upper jaw, 21-24 teeth in each lower jaw.
- Many-toothed blackfish, p. [142]
- 30. a. Beak short, usually less than about 1 inch (2.5 cm)
- Go to 31
- b. Beak more than 1 inch (2.5 cm)
- Go to 33
- 31. a. Flippers very short; dorsal fin small and triangular; 38-44 teeth in each jaw; body to at least 8 feet (2.4 m); distinct black stripe from beak to area of anus; in profile beak shows very little separation from forehead.
- Fraser's dolphin, p. [120]
- b. Flippers long relative to body length; dorsal fin tall and distinctly falcate; 22-40 teeth in each jaw; in profile, beak shows distinct separation from forehead.
- (Lagenorhynchus sp.) Go to 32
- 32. a. 22-28 teeth in each jaw; dorsal fin all black; body to about 10 feet (3.1 m).
- White-beaked dolphin, p. [126]
- b. 30-40 teeth in each jaw (some animals have greater number in upper than in lower jaw); dorsal fin part gray, part black; body to about 9 feet (2.7 m).
- Atlantic white-sided dolphin, p. [123]
- 33. a. 20-26 teeth in the upper jaws; 18-24 in the lower jaws; body to 12 feet (3.7 m); teeth may be extensively worn.
- Atlantic bottlenosed dolphin, p. [128]
- b. 26 or more teeth in both upper and lower jaws
- Go to 34
- 34. a. 29-36 teeth in each upper jaw; 28-36 in each lower jaw.
- (Spotted dolphins) Go to 35
- b. More than 40 teeth in each upper and lower jaw
- Go to 36
NOTE: Characters in paragraph 35 are usable only on fresh specimens. Spotted dolphins in advanced stages of decomposition can be distinguished only with museum preparation and examination.
- 35. a. Bridle present (dark lines from eye to rostrum and from flippers to corner of mouth); cape on head distinct; no spinal blaze.
- Bridled dolphin, p. [108]
- b. Bridle absent though there is a light line from the flipper to the eye; cape indistinct; spinal blaze.
- Atlantic spotted dolphin, p. [104]
- 36. a. From 46-65 small, sharply pointed teeth; body dark gray on back, tan to light gray on sides, white on belly; beak dark gray or black above, white below, and often black-tipped; body to about 7 feet (2.1 m).
- Spinner dolphin, p. [110]
- b. From 40 to 50 teeth in each upper and lower jaw
- Go to 37
- 37. a. Body to 9 feet (2.7 m); black to dark gray on back, gray on sides, white on belly; distinctive black stripes from eye to anus, eye to flipper, and dark dorsal coloration to side above flipper.
- Striped dolphin, p. [113]
- b. Body to 8.5 feet (2.6 m) but usually less than 7.5 feet (2.3 m); body dark on back with light thoracic patch and crisscross or hourglass pattern on side; black stripe from middle of lower jaw to origin of flipper.
- Saddleback dolphin, p. [116]
[18] Counts of ventral grooves are made between the flippers and do not include shorter grooves often found on the side of the head and on the side above the flippers.
[19] Blue whale has faint lateral ridges.
[20] By feeling between the lower jaws on the ventral surface and moving the finger forward towards the tip of the snout, one can feel the point at which the two lower jaws become united (called the symphysis). This location is an important reference point in distinguishing among the species separated in paragraphs 14, 15, and 16.
APPENDIX D
RECORDING AND REPORTING DATA ON STRANDED CETACEANS
So that measurements of cetaceans taken at different times and at widely divergent locations can be compared, the measurements and the methods of taking them have been standardized, although there is still some disagreement about which of the measurements are most important. The data form located at the end of this guide, usable on both baleen and toothed whales, includes all the measurements routinely taken by cetologists plus a few new ones the authors consider important. The form and the directions for taking measurements are synthesized from those currently in use by the Naval Undersea Center, San Diego; the Fisheries Research Board of Canada; the University of Rhode Island; the University of Florida; the U.S. National Museum, Washington, D.C.; and the National Marine Fisheries Service, La Jolla, Calif.
Data on stranded cetaceans should be collected by someone experienced in handling and measuring cetaceans. The legal problems associated with collection of a specimen are discussed in [Appendix C]. In addition to having a permit or knowing how to obtain permission to collect the specimen, persons active in cetacean research will usually have access to laboratory facilities where in-depth studies, including postmortem examinations and collection of tissues for specialized laboratory examinations, can be conducted. Furthermore, specialized equipment, and the number of steps required to do a complete job with the specimen, make the procedure prohibitive for most noncetologists. Diligent attempts should be made to contact one of the institutions listed in [Appendix E]. If no one is available and no permit or approval is obtainable, you are limited to photographing, sketching, and measuring the specimen without removing the carcass or any part of the carcass from the beach.
Any person taking data on stranded cetaceans should follow the instructions itemized below, being careful to take measurements in the manner prescribed and to record data in as much detail as possible.
1. Specimens should be preserved in 10% neutral Formalin, except for the stomach contents, which should be kept in 70% ethyl or 40% isopropyl alcohol, or be frozen. Commercial rubbing alcohol will suffice. As a minimum, the head, flippers, and reproductive tract should be preserved. If no other method of handling the specimen is available, and only as a last resort, it may be buried in the sand well above the high tide line and carefully marked so it can later be recovered. Burying usually results in the loss of some vital parts.
2. The carcass should be examined for external parasites particularly in such areas as the blowhole(s), the eyes, any wounds on the trailing edges of the dorsal fin, flippers, and flukes. Occasionally barnacles will be found on teeth or baleen plates. Like the stomach contents, parasites should be preserved in alcohol.
3. Photographs and sketches are a valuable part of data collection—views of the animal(s) from as many angles as possible, and detailed shots of such features as baleen plates, mouth and teeth, ventral grooves, flippers, flukes, and unusual scars or coloration should be included. Including a ruler for size reference may be helpful.
4. Although scientific data are usually expressed in metric units, measurements should be taken in whatever units are readily available. All measurements should be taken in a straight line, as shown in the diagram, unless otherwise noted. Measurements which refer to the rostrum are taken from the tip of the upper jaw. The external auditory meatus (ear) is a small inconspicuous opening located just below and behind the eye. To locate the ear the observer must sometimes scrape away some of the skin to expose the unpigmented ear canal beneath it.
5. Throat grooves are short grooves found on the throat of beaked whales, sperm whales, and dwarf sperm whales. Ventral grooves are long grooves found only on balaenopterine whales. Ventral grooves should be counted between the flippers.
It is difficult to overstress the importance of data from stranded cetaceans. For some species, the only data available have come from stranded individuals. By carefully gleaning from each specimen all the data that can be collected, you will make a valuable addition to the body of knowledge on these elusive animals.
APPENDIX E
LIST OF INSTITUTIONS TO CONTACT REGARDING STRANDED CETACEANS
The following list includes many of the institutions in the area covered by this guide, which are likely to respond to calls about stranded cetaceans. The institutions on the mainland are listed roughly in order from north to south, following the contour of the coast. Several island institutions and organizations are also listed.
These institutions are the ones that come to mind as having taken an active interest in cetacean strandings in the recent past. In addition to these, almost any university biology or zoology department, State or Federal conservation agency or marine laboratory, or local natural history museum or society can recommend an interested biologist if no staff member is interested. Such organizations are widely distributed on or near the coasts and are usually adequately listed in local telephone directories.
It should be obvious that organizations such as oceanaria are the most likely ones to be interested in live animals on an emergency basis. Even so, these organizations often cooperate with biologists with whom they are familiar and so will pick up dead animals for them as well. Conversely, museums and the like are most interested in the dead animals as they have no facilities for handling live ones. Nevertheless, they often cooperate with institutions equipped to handle live animals and will usually help in making arrangements for picking up the live ones. Therefore, rather than the finder's making a decision as to whether or not an institution should be called because the animal is alive or dead, we would urge that the nearest organization in the following list be contacted under any circumstances.
Space is provided at the end of the list for additions of contacts inadvertently overlooked in compiling this list, or of institutions which come into being after its publication.