Stranding of a Sperm Whale Physeter Macrocephalus (Linnaeus 1758) on the Chennai Coast

2007·1.2 MB·

by  K Venkataraman

MISCELLANEOUS NOTES
theextremitiesofbranchletstolickthelatexfromeverymature The latex probably provides nutrition to squirrels; it
leaf. A gentle gnawing and/or licking at the vein furcating seems thatthe squirrels procure water, minerals andorganic
point of the leaf initiates the flow of latex. Once the latex nutritionfromthelatex.
beginsto How, thesquirrelslickitandgotoanotherleafand
this action is then repeated. A scar oT dried latex could be ACKNOWLEDGEMENTS
seen on the underside ofevery licked leaf. The fresh scars
are whitish, while old dried scars are dirty white or black. Iamgrateful toMr. Jagdeesh Rao,ExecutiveDirector,
Presenceofalatex-scarontheundersideofaleafisindicative FoundationforEcologicalSecurity(FES),Anand;Mr. Dinesh
of it having been tapped by a squirrel. This behaviour of Reddy, Dr. Subba Rao and members of FES-Chintamani,
squirrels is commonly seen in various parts ofthe country MadanapalleandUdaipurforextendinghelpduringthefield
(Table 1). studies.
Balasubramanian, P. (1989): Nectar feeding by Three-striped Palm sp. J. BombayNat. Hist. Soc. 93(1): 84.
Squirrel Funambulus palmarum at Point Calimere Wildlife Mathew, K.L. &C.Lukose(1995): Five-stripedSquirrel Funambulus
Sanctuary,Tamil Nadu. J. BombayNat. Hist. Soc. 86: 437. pennanti(Wroughton)feedingonfledglingHouseSparrowPasser
Balasubramanian, P. (1995): Some notes on the fruits, seeds and domesticus. J. Bombay Nat. Hist. Soc. 92(2): 256.
nectar consumed by Three-striped Palm Squirrel Funambulus Prater. S.H. (1980): The Book of Indian Animals. Bombay Natural
palmarum at Point Calimere Wildlife Sanctuary. Tamil Nadu. History Society and Oxford University Press. Mumbai. Pp. 1-
J. Bombay Nat. Hist. Soc. 95(2): 256-258. 324.
Barnett,S.A.& I.Prakash(1975):RodentsofEconomicImportance Sadakathulla,S.&A.A. Kareem(1995):CannibalisminsouthIndian
in India.Arnold-Heinemann,NewDelhi andLondon. Pp. 1-175. Palm Squirrel Funambuluspalmarum. J. BombayNat. Hist. Soc.
Gupta, P.D. & V.C. Agarwal (1968): Cannibalism in Five-striped 92(1): I 13-114.
Squirrel Funambuluspennanti. Sci. Cult. 34: 185. Tiwari, J. (1990): Five-striped Squirrel Funambulus pennanti
Harit,D.N.(1996):UnusualfeedingbehaviourofsquirrelsFunambulus (Wroughton) killing birds. J. BombayNat. Hist. Soc. 87: 137.
2. STRANDING OF A SPERM WHALE PHYSETER MACROCEPHALUS (LINNAEUS 1758)
ON THE CHENNAI COAST
1
K. Venkataraman2-3, M.C. John Milton2 4and K.P. Raghuram2-5
'Accepted March 07, 2005
-Marine Biological Station, Zoological Survey of India, 130, Santhome High Road, Chennai 600 028, Tamil Nadu, India.
’Email: [email protected]
''Email: [email protected]
"Email: [email protected]
WhalesarethemostdominantmarinemammalsofOrder onthepresenceofteethorbaleenplates,whalesareclassified
Cetacea. They are mostly denizens of temperate and polar astoothed(Odontoceti)orbaleenwhales(Mysticeti).Toothed
oceanic waters, but they do migrate to tropical waters for whales mostly feedonfishes andcephalopods, while baleen
breedingand/orescapingextremeclimaticconditionsduring whales mostly feed on plankton such as euphausids, by a
certainseasons(CorbettandHill 1992).However,notallwhales filter-feeding mechanism, and sometimes pelagic fishes and
thataredenizensoftemperateandpolaroceanicwatersmigrate cephalopods(Bensam andMenon 1996).
to tropical waters, e.g. the Bowhead Whale Balaena
mysticetus Bryde’s WhaleBalaenoptera edeni are believed StrandingofaSpermWhaleontheChennaiCoast
,
toliveprimarily intropicalandsubtropicalwatersalltheyear A Sperm Whale Physeter macrocephalus Linn, was
round. There is no evidence of their migration away from stranded on the Chennai coast, behind Napier’s Bridge
these regions. The body ofthe whale is protected by a thick (13°06'N,80°18'E),intheearlyhoursofJanuary21,2002. It
layer of oil rich blubber beneath the skin, which acts as a wasamale,measuringabout995cm long,andweighingabout
thermal insulator, a store ofenergy forlong migrations, and 3tons.Theanimalhadinjuriesthroughoutthecaudal region,
plays an important role for maintaining its hydrostatic which could have been caused by the propeller of fishing
buoyancy. Whalesare usuallyfoundintheupperfew metres boats. Ingeneral,however,theanimalwasingoodcondition
ofthesea,butarecapableofextensivedeepdives.Depending withallspecificcharacteristicfeatures.
J. Bombay Nat. Hist. Soc., 104 (1), Jan-Apr 2007 83
MISCELLANEOUS NOTES
MorphologicalfeaturesofP.macrocephalusLinnaeus1758 could be stranded (Watson 1988).
Enormous truncate head, almost one-third the size of Inmostcases,theanimalsarestillalivewhentheyfirst
thebody,containingalargeorganfilledwithspermaceti. become stranded, usually on gently shelving beaches. Post-
Dorsalfur.Low,small,pointedandridge-like,followed mortem often reveals air injury, infection ordebility, which
by a series ofhumps up to the tail. probablycauseddiscomfort,makingitdifficultforthewhale
Pectoralflippers:Broad,paddle-like,small. tobehavenormallyindeepwater.Underthesecircumstances,
Tailfluke: Broadandnotchedinthemiddle;darkbelow. faced with the risk ofdrowning, it would be natural forthe
Teeth: Nofunctionalteethontheupperjaw; 18-27large cetacean to seek a place where itcould continue to breathe,
teeth onleftsideofthe lowerjaw. while marshalling its strength to deal with other problems
Blowhole:Anasymmetrical,S-Shapedblowholeonthe (Watson 1988).
leftsideoftheupperanteriorextremityoftheforehead. b. Navigational errors: Pollution and other extreme
Sexualdimorphism: Malesnearlyoneandahalftimes climatic conditionsofoceanic waters may interfere with the
larger than females; end of snout squarish in males and communicationsystemofthewhales,therebyreducingtheir
roundedinfemales(AgarwalandAlfred 1999;Muthiahetal. ability to perceive signals, resulting in navigational errors.
1988;Jamesetal. 1993). Manywhalesgettrappedinicebergswhilemigratingtotheir
feeding/breedinggrounds(Berzin 1972).
REASONSFORBEINGSTRANDED e. Pathogens: Likeallanimals,cetaceansarehoststoa
numberofinternalparasites,suchastapeworms,hookworms,
The plausible cause forbeing stranded is the inability roundwormsand flukes. When the ancestorsofthe modern
of the animals to determine and avoid shallow areas, as a whale left land to take up a new life in the sea, they simply
result ofparasitic infestations ofthe organs connected with carriedtheselodgerswiththem,astheirinternalenvironments
sonar wave perception. Hence, such whales get stranded on were largely unchanged. Accumulation of viruses and
gently sloping beaches, murky waters and tidal sites. bacteriain the body ofthe whales has been proved to be an
a. Interference with breathing: Despite many important reason for the mass stranding of pilot whales
impressiveadaptationsofwhalestoanaquaticenvironment, (Watson 1988).
they still breathe in air. Apart from those killed by man,
many die due to drowning. Illness, weakness and old age ACKNOWLEDGEMENTS
could lead to death, but the gravest danger faced by all
cetaceans is their inability to breathe. There are numerous We thank the Director, Zoological Survey of India,
reports of whales of all sizes coming to each other’s aid, for the facilities provided, and the All India Coordinated
assisting ill or injured group members to the surface where ProjectonMarineBiodiversity,MinistryofEnvironmentand
theycancontinuetorespire.Thisphenomenonoftenbecomes Forests, New Delhi for financial assistance. We also thank
areason for mass stranding in shallow waters (Bensam and Mr. P. Oppili, Senior Reporter, The Hindu for providing
Menon 1996). information about the stranding of the whale. I sincerely
AnalysesofstrandedwhalesontheBritishcoastreveal acknowledge the support by Dr. P. Krishnamoorthy,
that toothed and baleen whales, deep and shallow water Dr. Ch. Sathyanarayana, Mr. S. Saravanan, Mr. A. Gokul,
species,youngandold,maleandfemale,solitaryindividuals Mr.B.AshokKumar,Mr.M.NithyanandanandMr.C.Suresh
and social groups, apparently healthy but injured whales Kumar.
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