1

Craig Matkin

Lance Barrett Lennard

David Ellifrit

Ecotypic Variation and Predatory Ecotypic Variation and Predatory Behavior of Killer Whales in the Eastern Behavior of Killer Whales in the Eastern AleutiansAleutians

ASLCNPUMMRC

AcknowledgementsAcknowledgements

SSteller SSea LLion RResearch IInitiative

Field Assistance: Mike Brittain Damian Power, Peter Nilsson, Buck Laukitis Flip Nicklin (photographs)

NPUMMRC

Alaska Sea Life Center

Southeastern Alaska

Northern Gulf of AlaskaEastern Aleutians

Bering Sea

Regional focal areas and “hotspots” as a Complement to NMFS/NMML cruises

MethodsMethods

Summer

Spring

Research vessels: 32-42 ‘ Research vessels: 32-42 ‘ aluminum fishing boatsaluminum fishing boats

PHOTOIDENTIFICATION OF INDIVIDUALSover a period of years from small vesselsin killer whale “hot spots”

High speed Black and whiteWith digitalbackup

GENETICS, CONTAMINANTS,LIPID/FATTY ACID,STABLE ISOTOPES

Using an air powered rifle toto collect skin andblubber biopsies

Lightweight biopsy darts take a 30mm x 5mm sample from saddle patch region

Biopsy darts with samples

ACOUSTICS

Classification of Discrete Calls to Determine Lineage

FEEDING HABITSDirect evidence required to determine predation

1) Sample of prey 2) Prey observed in mouth

Separation of Lineages by Genetics, Separation of Lineages by Genetics, Acoustics and AssociationAcoustics and Association

• All groups of whales from 281 killer whale encounters from 2001 to 2005 could be classified to lineages by acoustic or genetic sampling or association with previously sampled animals

• Three lineages were determined:• RESIDENTS RESIDENTS (900+),• TRANSIENTSTRANSIENTS (192) • OFFSHORESOFFSHORES (54+) only one encounter

• RESIDENTSRESIDENTS 31 calls identified, 23 call types. Seven showed 31 calls identified, 23 call types. Seven showed

no similarity with residents in other areas, 16 shared some no similarity with residents in other areas, 16 shared some structural similarity with residents from GOAstructural similarity with residents from GOA

• TRANSIENTSTRANSIENTS No calls shared with residents. Identified 24 calls No calls shared with residents. Identified 24 calls and 14 call types. Seven showed no similarity to transients in and 14 call types. Seven showed no similarity to transients in other areasother areas

• OFFSHORESOFFSHORES No shared calls with transients/residents No shared calls with transients/residents Recordings from only one encounter, but very similar to calls Recordings from only one encounter, but very similar to calls recorded in offshore encounters elsewhere recorded in offshore encounters elsewhere

• There is with residents and transients evidence for finer scale There is with residents and transients evidence for finer scale population separations, but not with offshorespopulation separations, but not with offshores

Acoustic SeparationsAcoustic Separations

Genetic mtDNA Separations

• RESIDENTS RESIDENTS Single haplotype =NR (central Aleutians = SR (NMML data) northern Gulf of AK = NR/SR mix)

• TRANSIENTSTRANSIENTS False Pass (spring) mixed haplotypes = GAT1, GAT2, AT1 Unimak Pass/Umnak I. (summer)= Single haplotype = GAT1

• OFFSHORESOFFSHORES = Single Haplotype = OFF

Ecotypic SeparationEcotypic Separation

• Research results thus far indicate Eastern Aleutian resident lineages and transient lineages comprise separate ecotypes… residents preying on fish and transients on marine mammals

• Data is insufficient to classify offshore lineages by ecotype

Resident Killer Whale TracklinesResident Killer Whale Tracklines2001-20042001-2004

Tracks tend to follow 200m depth contour

1150

534

745

903

10231110

0

200

400

600

800

1000

1200

1400

2002 2003 2004 2005 2006 2007

Year

Nu

mb

er o

f w

hal

esDiscovery Curve for Eastern Aleutian Discovery Curve for Eastern Aleutian

Resident Killer WhalesResident Killer Whales

657 135

False Pass Spring 2003-2005

EA Summer 2001-5

Number of Transients Identified Number of Transients Identified in Eastern Aleutiansin Eastern Aleutians

157

84

114

135149

23

41

6357

0

20

40

60

80

100

120

140

160

180

2002 2003 2004 2005 2006 2007

Year

Nu

mb

er

of

wh

ale

s Spring False Pass

Summer Eastern Aleutians

Discovery Curves for Spring False Pass and Summer Eastern Aleutians Transients

Summer 2005: short season

Eastern Aleutian Transient PredationEastern Aleutian Transient Predation

Marine Mammal Kills by Transient Whales Unimak Pass-Umnak Is. Summer

2001--2005 n= 9Steller Sea

Lion11%

Northern Fur Seal

67%

Minke whale22%

From Barrett-Lennard and Matkin in review

Also harassment:2 northern fur seals3 Dalls porpoise1 Humpback whale

Marine Mammal Kills by Transient Whales False Pass/Unimak/I.

Spring 2002--2005 n=28

Gray whale100%

From Barrett-Lennard and Matkin in prep

UnID Marine

Mammal21% Harbor

seal37%

Dalls Porpoise

34%

Steller Sea Lion0%

Harbor porpoise

5%

Northern Fur Seal

3%

Steller sea lion15%

Harbor seal27%Unid. marine

mammal26%

Pacific white-sided dolphin

1%

Dall's porpoise17%

Harbor porpoise13%

Minke whale1%

AT 1AT 1 n=38n=38

PWS and KF SEA SEA n =90n =90

Transient Feeding Summary Transient Feeding Summary (Kills Only observed by (Kills Only observed by researchers only)researchers only)

Steller Sea Lion11%

Northern Fur Seal

67%

Minke whale22%

EAT EAT summersummer

N=9N=9Also see John Also see John

Maniscalco et al Maniscalco et al posterposter

Northern Fur Seal

Gray Whale

In May-June, 75+ individuals In May-June, 75+ individuals from a total “population” of from a total “population” of 141+ transient killer whales 141+ transient killer whales focus on grey whales in focus on grey whales in False Pass/UnimakFalse Pass/Unimak Island Island area area

In summer, 20+ individuals In summer, 20+ individuals of a total “population” of of a total “population” of

63+ transient killer whales 63+ transient killer whales feed primarily on Northern feed primarily on Northern

fur seals from Unimak fur seals from Unimak Pass to Umnak IslandPass to Umnak Island

ConclusionsConclusions• Only transient type whales are significant marine Only transient type whales are significant marine

mammal predators in the Eastern Aleutiansmammal predators in the Eastern Aleutians• Prey and predatory behavior of killer whales Prey and predatory behavior of killer whales

varies by location and season in EA. Across varies by location and season in EA. Across Alaska there is a wide variation in predatory Alaska there is a wide variation in predatory behaviorbehavior

• Fur seals are preferred summer prey. Impact on Fur seals are preferred summer prey. Impact on this locally increasing population?this locally increasing population?

• If SSL predation was at similar levels in the past, If SSL predation was at similar levels in the past, it is unlikely that it drove the decline. it is unlikely that it drove the decline.

• But But fur seals were not as abundant in the past, fur seals were not as abundant in the past, SSL may have been more important in the diet. SSL may have been more important in the diet.

• Suprisingly, frequent predation on minke whales; Suprisingly, frequent predation on minke whales; however, little evidence of predation on HW however, little evidence of predation on HW even though they are much more abundanteven though they are much more abundant

Bogoslof IslandBogoslof Island

Steller Sea Lion RookerySteller Sea Lion Rookery

Pups Pups 1973 23281973 2328 2004 2782004 278

Northern Northern Fur Seal RookeryFur Seal Rookery

Pups Pups 1992 8981992 898 1999 50961999 5096 2005 12,6312005 12,631

Future WorkFuture Work• Examine predation in more detail in summer in Bogoslof Examine predation in more detail in summer in Bogoslof

Is / Bishop Point.(sea lion haulout) and continue spring Is / Bishop Point.(sea lion haulout) and continue spring work in False Pass/Unimak Island. work in False Pass/Unimak Island.

• Transient KW population dynamics in False PassTransient KW population dynamics in False Pass

• Radio/Satellite Tagging to increase follow times and Radio/Satellite Tagging to increase follow times and determine long term movements of KW in relation to determine long term movements of KW in relation to potential preypotential prey

• Nuclear DNA analysis/ further acoustic analysis to Nuclear DNA analysis/ further acoustic analysis to

determine killer whale fine population structure in EAdetermine killer whale fine population structure in EA

• Continue research into chemical methods of assessing Continue research into chemical methods of assessing predation jointly with NWFSC and NMMLpredation jointly with NWFSC and NMML