Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean

1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of ≥ 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic (‘true’) subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales.

Online Dictionary of Invertebrate Zoology: T

tabula tabular tachyauxesis tachyblastic tachygen tachygenesis tachytelic tactic tactile tactoreceptors taenia taeniate taenidium taenioglossate tagma tagmata tagmosis tail tailfan Takakura's talon talus tandem tangent tangoreceptor tanylobous tapetal tapetum tapinoma-odor Tardigrada tardigrades tarsal tarsation tarsite tarsomere tarsungulus tarsus taste tautonomy tautonym taxa taxes taxis taxis taxodont taxometrics taxon taxonomic taxonomist taxonomy tectiform tectostracum tectum teeth teges tegillum tegmen tegmentum tegula tegular tegulum tegumen tegument tegumentary tela telaform telamon telegonic teleiochrysalis telenchium teleoconch teleodont teleology teleotrocha telepod telescope telescopic teletrophic telioderma teliophan telmophage telocentric telodendria telofemur telogonic telolecithal telomitic telophase telophragma telopod telopodite telorhabdions telosonic telostome telosynapsis telosyndesis telotarsus telotaxis telotroch telson template temporal tenacipeds tenaculum tenent teneral tensor tentacle tentacular tentaculocyst tentaculozooid tentilla tentorial tentorium tenuous teratocyte teratogen teratogenesis teratogyne teratology terebella terebra terebrant terebrate teres terete terga tergal tergite tergolateral tergopleural tergopore tergum tergum termen terminal terminalia termitarium termitophile terranes terrestrial terricolous territory tertiary tertibrach tertibrachial tessellate test testaceology testaceous test-cross testes testis testisac testudinate tetanus tetany tetractinal tetractine tetrad tetradelphic tetramerous tetramorphic tetraploid tetrapod tetrapterous tetrasomic tetrathyridial tetrathyridium tetraxon tetraxonid thalassophilous thallus thamnophilous thanatocoenosis thanatosis theca thecae thecal thecate thelycum thelygenesis thelygenous thelyotokous thelyotoky theory thermocline thermophile thermophobe thermoreceptor thermotaxis thickness thigmotactic thigmotaxis thigmotropism third-form thoraces thoracic thoracomere thoracopod(ite) thorax thoraxes thread thylacium thylacogen thyridial thyridium thyroid thysanuriform tibia tibial tibiotarsal tibiotarsus Tiedemann's tiled timbal tinctorial tine tissue tissue titilla titillae titillator tocopherol tocospermal tocospermia tocostome tokostome tomentose tomentum Tomosvary tone tonic tonofibrillae tonus topochemical topogamodeme topomorph topomorphic toponym topotype tori torma tormogen tornote tornus torose torpid torqueate torsion tortuose torulose torus totipotent totomount toxa toxicognath toxicology toxin toxinosis toxoglossate toxoid trabecula trabeculate trabeculated trachea tracheae tracheal tracheate tracheoblast tracheolar tracheoles trachychromatic tract Tragardh's tragus transad transcoxa transcurrent transect transection transformation transient transitional translocation translucent transmission transposed transscutal transstadial transtilla transverse trapeziform trapezium trapezoid trema tremata Trematoda trenchant trepan triact triactinal triad triaene triage triangle triangular triangulate triaulic triaxial triaxon tribe tribocytic trichite trichobothrium trichobranchia trichobranchiate trichocerous trichodes trichodeum trichodragmata trichogen trichoid trichomes trichophore trichopore trichosors trichostichal trichotomous trichroism tricolumella tricomes tricostate tricrepid tricuspid tricuspidate tridactyl trident tridentate trifid trifurcate triglycerides trignathan trigonal trigoneutism trilabiate trilateral trilobate trilocular trimorphic trimorphism Trinominal triordinal tripartite tripectinate triplet triploblastic triploid triquetral triquetrous triradiate triradiates tritocerebral tritocerebrum tritocerebrum tritonymph tritosternum triturate triungulin triungulinid trivial trivium trivoltine trixenic troch trochal trochalopodous trochantellus trochanter trochanteral trochantin trochi trochiform trochlea trocholophous trochophore trochosphere trochus troglobiont troglodytic troglophile trogloxene tropeic trophal trophallactic trophallaxis trophamnion trophi trophic trophidium trophobiont trophobiont trophobiosis trophobiotic trophocytes trophodisc trophogeny trophoporic trophorhinium trophosome trophotaxis trophothylax trophozooid trophus tropis tropism tropotaxis trumpet truncate truncation trunk trypsin tryptic tryptophan tryptophane T-tubule tube tube-feet tubercle tubercula tuberculate tuberculose tuberiferous tubicolous tubifacient tubule tubulus tubus tuft Tullgren tumefaction tumescence tumid tumulus tunic tunica tunicary tunicate turbinate turgid turreted turriculate tychoparthenogenesis tylasters tylenchoid tyli tyloid tyloides tylosis tylostyle tylote tylus tymbal tympanal tympanal tympanic tympanum Tyndall type typhlosole typologist typolysis typostasis