Day, David

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April1994 NOTICIAS DE GALÁPAGOS
LIST OF CETACEANS SEEN IN GALÁPAGOS
By: David Day
This listis mainly basedon personal observations,
records from other qualified observers, and from
collected specimens preserved in the islands. Only
fairly recently ( 10- 15 years) has there been more than
a casual interest in observations of whales ; thus, there
are anomalies in previous records, e.g. formerly the
larger baleen whales were nearly always identified as
fin whales (B alaenopter a phy s alus),butrecently these
are conectly identifred as Bryde's (8. edeni), or oc-
casionally Sei (8. borealis) whales. Tui de Roy, a
Galápagos resident and very experienced naturalist,
was uncertain of their identification for many years,
until she observed fin whales in Baja Califomia' She
has since corrected many previous identifications.
Another dilemma is with the common (Delphinus
delphis) and stenellid dolphins (Stenella spp.); in all
my years here I have never seen a spinner (Stenella
longirostris), but some people report them regularly.
When the other species leap, and gyrate their tails, as
the striped (5. coeruleoalba) does, it looks like they
are spinning. Spinners certainly are present in the
waters around the Islands. To differentiate between
these species at distance can be very difficult.
Two other species that are almost impossible to
tell apart are the melon he aded (P ep o no c ep hal a e I e c -
tra) andthe pygmy killer whale (Feresa attenuata).
The mesoplodont beaked whales are almost impossi-
ble to tell apart as well; for many species there is very
little data, and new species have been described in the
last few years.
A demonstration of our limited knowledge at sea
of these creatures is that theF¡aser's dolphin(Lagen-
odelp his hos ei), arelativ ely common tropical species,
was not described to science until 1956. The most
recent case is that of the blue whale (Balaenoptera
musculus), a species common to other a¡eas of the
eastern ropical and south Pacific. It was never re-
ported for the Galápagos until 1993 when they were
sighted on four different occasions in western and
southem Isabela and Fernandina Islands, within a
few miles from the coast. The southem bottlenose
whale (Hyperoodon planifrons) could be a potential
candidate, as there are records from along the equa-
tor.
The following list of 24 species should be regard-
ed as a minimum numberrather than a complete list.
My taxonomic organization follows Leatherwood and
Reeves (1983). Abundance is classified as frequent
(F), present (P), occasional (O), rare (R). Range is
described as outer, normally in waters deeper than
1000 fathoms (O), mid, waters between 1000 and
100 fathoms deep (M), inner, waters less than 100
fathoms (I), all areas (A).
Note: This describes the normalrangefrompresent
knowledge, anddoes not mean that some species from
deep water will not make incursions into shallower
water, especially where deeper water is close to the
coast.
Other classification ma¡ks are: ? = lack of data,
owing to the animals being shy or rare, or because of
identification difficulties and ( ) = in range category
that they are occasionally seen there; in abundance
category that they are probably more common than
sightings suggest. * = probable sighting just off NE
coast of SanTaCruz Island. ** = skull and skeleton
remains found in 1964 by members of the Galapagos
International Scientifrc Project expedition, buried in
sand along the beach at Tortuga Bay, Santa Cruz Is-
land. The skull is deposited in the collection of the
Califo¡nia Academy of Sciences (Orr 1965).
NOTICIAS DE GALÁPAGOS No.53
LIST OF CETACEANS SEEN IN GALÁPAGOS.
SCIENTIFIC NAME COMMON NAME ABUNDANCE
A. Suborder Mysticeti
1. Balaenoptera musculus Blue whale
2. Balaenoptera borealis Sei whale
3. Balaenoptera edeni Bryde's whale
4. Balaenoptera acutorostata Minke whale
5. Megaptera novaeangliae Humpback whale
B. Suborder Odontoceti
6. Physeter macrocephalus Sperm whale
R
R,?
F
R
o
RANGE
M,O
M,O
A
?
r, M (o)
o, (M)
o, (M)
A
M,O
M,O
o, (D
o
I, M, (O)
A
A, (M, O)
o
M,O
I, M, (O)
M,O
o
o
o
72. Peponocephala electa Melon headed whale
7. Kogia breviceps
8. Kogia simus
9. Berardius sp.
I0. Ziphíus cavirostris
lI. Mesoplodon spp.
13. Feresa ettenuata
14. Pseudorca crassidens
15. Orcinus orca
17. Steno bredanensis
18. Lagenodelphis hosei
19. Delphinus delphis
20. Tursiops truncatus
21. Grampus griseus
22. Stenella attenuata
23. Stenella coeruleoalba
24. Stenella longirostris
Pygmy sperm whale
Dwa¡f Sperm whale
Beaked whales*
Cuvier's beaked whale
Beaked whales
Pyg-y killer whale
False killer whale
Killer whale
Rough-toothed dolphin**
Fraser's dolphin
Common dolphin
Bottlenose dolphin
Risso's dolphin
Panrropical spotted dolphin
Srriped dolphin
Spinner dolphin
F
R,?
o,?
P
o
R
R
P
P
P
*, t"l
F
F
P
P,R,?
P
,)
16. Globicephala mauorhynchus Short finned pilot whale
ACKNOWLEDGMENTS
I gratefully acknowledges the help of many peo-
ple, particularly Jaqueline Schonenwald, Steve
Leatherwood, Godfrey Merlin, Hal Whitehead, re-
search group members of the 'Siben' and 'Odyssey'
expeditions from Dr. Roger Payne's Whale Conser-
vation Institute, in particular Daniel palacios, and
finally Howa¡d Snell.
LITERATURE CITED
Leatherwood, S., and R. Reeves. 1983. The Sierra
Club Handbook of Whales andDolphins. Siera
Club Books. San Francisco.
Orr, R.T. 1965. The rough-toothed dolphin in the
Galápagos Archipelago. Journal of Mammalogy
46(1):101.
David Day, PuertoAyora,Isla Santa Cruz, Galápa-
gos, Ecuador.


List of cetaceans seen in Galápagos

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List of cetaceans seen in Galápagos

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