FLAG EXPEDITION REPORT
PHOTOGRAPHIC IDENTIFICATION SURVEY – HUMPBACK WHALES,
NORTH WEST CAPE – AUSTRALIA (21° S, 114° E)
LEADER: WAYNE OSBORN, FI 04
FLAG ASSIGNED: #150
SEPTEMBER 2009
RESULTS
The expedition spent 13 days on the water between September 10 and 28, 2009.
We travelled 462 Nautical Miles in a 6.3 metre rigid inflatable boat, encountered
169 pods, including 417 humpback whales (Megaptera novaeangliae). We
photographed 378 individuals including 92 females with newborn calves. This
was a pleasing result. During a similar expedition in 2008 we photographed 325
whales.
EXPEDITION BACKGROUND
The waters around North West Cape and the adjacent Exmouth Gulf on the remote
Western Australian coastline are an important resting area for the southbound
migration of humpback whales. Most birthing activity takes place 700 nautical miles
to the northeast in sheltered bays along the Kimberley coastline. The new season’s
calves are cautiously chaperoned down the coast under mother’s watchful eye. They
have reached the grand age of around 4 weeks by the time they reach North West
Cape.
Rugged limestone outcrops form the narrow spine of the Cape Range. Arid coastal
plains fringe this outstretched finger of land which terminates at the North West Cape.
Exmouth Gulf nestles against the eastern shore and whales following the coastline on
their southern migration are swept into the gulf. These sheltered shallow waters
provide a safe haven and resting ground. It is an opportunity for the new season
calves to build additional blubber reserves and strength for the colder waters further
south. Water temperature in the gulf is already 5 degrees C lower from that in the
birthing grounds.
Since commercial hunting of humpbacks ceased in 1963, there has been an
encouraging recovery from the brink of extinction. It is estimated that only 3.5-5% of
the pre-whaling global population remained at that time. The Western Australian
population is known as Group D and is now thought to number around 20,000. At
this it stage appears to be recovering well from not so recent dark age of whaling.
Apart from some vessel activity due to the port at Exmouth, the area is isolated
providing a broad expanse of relatively sheltered water where females can rest their
calves before continuing the migration to feeding grounds in Antarctica. Pioneering
work on this population has been undertaken since 1990 by Curt & Mich Jenner,
founders of the Centre for Whale Research WA (CWR) and has demonstrated the
critical nature of resting grounds such as this in the breeding cycle and population
recovery.
Accumulation of sound scientific data is important to inform government policy and
decision-making. There is pressure for further development of this area to support
offshore oil and gas exploration/development and increasing levels of tourism.
The photo-identification database established by CWR underpins the current level of
knowledge and provides the authoritative reference for this whale population. Whilst
Curt and Mich continually add to the database, the task is enormous, expensive and
time consuming.
Private expeditions such as this can play a part in augmenting the database if the work
is undertaken in a structured and disciplined manner. For my wife, Pam and myself,
it is a rare opportunity to make a modest contribution to a very worthy cause. Our
objective was to capture as much field data in the form of photographic images
suitable for the database as we could in the time available.
We work under CWR’s research permit which allows for a closer approach to the
whales than normally permitted.
FIELD METHODOLOGY
The ideal photographic record includes:
The underside of the flukes and as much of the tailstock as possible.
A left lateral profile of the body including the dorsal.
A right lateral profile of the body including the dorsal.
An underside or ventral view showing the genital area (allows determination of
gender).
The photographs should be taken as square on to the body surface as possible.
The ideal is rarely achievable in the field and is highly dependent on animal
behavior and sea conditions. We endeavor to capture as much information as
we can from each animal against this objective.
Through experience we have found that a combination of Canon’s EOS 1D MkIII
body and a Canon L Series 100-400mm image stabilized lens is our preferred
workhouse for whale photography. The MkIII’s firing rate of 10 frames per
second is excellent for capturing rapid action such a breaches. At f4.5-5.6, the
lens is a little slow but we are usually working in bright light, the zoom range
gives good flexibility and very good image quality (beyond what may be
reasonably expected for such an extreme zoom).
We use 16 GB cards which offer over 1000 images without the need to change
cards. Rule 1 of whale photography is that the most interesting behavior occurs
when the memory card is being changed. We have found that an ISO setting of
400 and a shutter speed of 1/1600 works well for most situations including
breaches. Contrary to many wildlife photographers, we use time value or shutter
priority for this work as freezing action is more critical than managing depth of
field.
Single point autofocus is also important. Multiple point autofocus is too easily
distracted by sea conditions. We also let the auto focus track the subject. The 1D
MkIII will usually pull focus on the second frame of a breach if it misses the first.
We also use a Nikon D3 with a 70-200mm f2.8 VR lens for closer work and late
light. We started out using a prime 300 mm f2.8 VR Lens on Nikon bodies but it
has failed us twice now whilst far from home on whale expeditions. Sorry Mr
Nikon but it has been an expensive exercise and my manual focus skills are just
not up to the job any more.
A number of underwater images were also taken to supplement the topside
work. For this I used a Canon EOS 5D MkII with a 16-35mm Lens in a Nexus
housing. This proved to be useful in providing additional images on occasions
when whales came close to or under the boat.
A hand held GPS is used to record the day’s track plus waypoints. It is set to
record a track point every 30 seconds. The track files are later used to load the
GPS coordinates into each image. A waypoint is struck each time a pod is
encountered.
My wife Pam does most of the photography. I drive the boat, write the field
notes and operate the hydrophone and the second camera when I get a chance.
When working with multiple whales, it is important to note which whale flukes
at what times so we can tie each image back to a particular animal. This is not
always easy and we tend to take a lot of images to capture each animal before
and during a dive sequence. A typical days shooting is north of 2000 images and
can be up to 3000. All images are taken in RAW to allow flexibility in processing.
Over 200 GB of images were taken on this expedition.
We find that it is not worth working once the wind is over 15 knots (over 12 is
marginal). The RIB is low to the sea and the ability to track a subject with a
telephoto lens is challenging. In addition, the whales are more difficult to
approach and less body is out of the water reducing the value of the images.
Approach techniques are particularly important. As this is resting ground for
cow and calves, minimizing disturbance to resting and feeding is paramount. We
approach slowly and from the side. Whales are more tolerant to a vessel running
alongside but crossing closely ahead and behind them creates anxiety.
Once we are in range, we switch off the engine and in many cases the pod will
approach us.
BEHAVIORS OBSERVED
Our expedition was timed to coincide with the peak of the Southern migration to
North West Cape and Exmouth Gulf. Many of the younger males and females
were further south, heading for Antarctica and anxious to end their winter fast.
Cows and calves are often found resting or asleep. During this time they are at
particular risk of ship strike, as they lie low in the water with only about 300 mm
of dorsal profile showing. It is also not an ideal time for photography with little
above surface body as a target. The calves will sometimes lie across their
mother’s head to rest.
We observed one ship strike victim. A new season’s calf had a deep one-metre
laceration along one flank. On prior visit we have observed whales with dorsals
sheared off and a number of other disfigurements.
At other times cows and calves are quite surface active. The mother may breach
and the calf will follow suit. Calves can be observed repeatedly breaching and
vigorously tail-slapping. Both behaviors are useful for getting photographs of
the genital area to determine the calf’s sex.
On three occasions we observed double cow and calf pairs and in each case there
was a lot of surface activity taking place. This level of socialization is thought not
to be that common however we have also observed this behavior on prior visits.
An escort (or two) may take up with the cow and calf in the hope of a future
relationship (the female will not usually mate again until the calf is weaned at
around 12 months of age). The escorts are usually keen to prove their value and
genetic pedigree with protective behavior, breaching, pectoral slapping and lobtailing. They may also sing and can be distinctly heard through the boat’s hull if
you are close. We recorded several hours of whale song during the expedition
and will make this available to researchers.
Mature males were also well represented and keen to mate if the opportunity
presented. We observed them in pods of 4 to 8 animals. They we never hard to
find as there was always a lot of surface activity where the boys would gather as
they raced around at 6-8 knots. Lunging forward on each other, pectoral
slapping and breaching were common. Things must get quite physical as the top
surfaces of their tubercles (raised protuberances on the head) were often raw
and bleeding. We were treated to a number of mock charges and also continued
breaching close to our boat. High levels of testosterone obviously have similar
behavioral impacts across many species.
A number of whales bore the tell-tale scars of killer whale (Orincus orca) attack.
Orca’s are a natural predator and work in concert to wear down and drown
humpbacks by gripping flukes and pectoral fins. One mother had significant
body scarring but had recovered sufficiently to nurse a healthy new season calf.
In the most extreme example, the entire dorsal fin of one whale had been
amputated.
IMAGE PROCESSING AND COLLATING
Unfortunately for every hour in the field, there are many more to be spent in
front of the keyboard (one small advantage of bad weather).
A folder is created for every pod photographed (e.g. Pod 17 September 21). Each
animal is identified according to a code and the type of photograph. This data
entered into a master spreadsheet against the photograph file number.
The best indicative images are cropped and converted to black and white, then
stored as jpegs. Black and white images are easier to assess when looking to
match features, skin textures, scars and pigmentation.
Where the pod is comprised of a cow and calf or a cow, calf and escort, the task of
assigning images to a particular animal is relatively straightforward. If the pod is
larger and, if there has been a significant amount of fluking activity, life gets
more interesting. Details need to be examined to almost a forensic level. Small
scars and unique body features are invaluable aids. Of course, if one side of the
animal was photographed with the light, the other side will be shot against the
light. These images need to be worked hard to get acceptable detail.
A check is made to detect and identify obvious re-sights.
This task is now thankfully completed and the files containing 1,469 images are
ready for presentation to the Centre for Whale Research’s Humpback Database.
CWR will use research assistants to digitally classify from the images the
following information:
Dorsal – match against 11 profiles.
Body Pigmentation – match against 4 types.
Fluke Pattern – match against 32 types.
Left/Right laterals – divide into 5 sectors and assign against marking and
pigmentation guide.
Fluke – divide into 14 sectors and assign against marking and pigmentation
guide.
THANKS
To the Explorers Club: It was a delight and privilege to carry flag # 150 into the
Australian outback. It has now been well exposed to down-under sunshine,
filtered a bit of our ubiquitous red dust, absorbed a sprinkling of the Indian
Ocean and inhaled the occasional spray of humpback whale breath.
To Curt and Mich Jenner of CWR: Thank you for the privilege of working under
your permit and the opportunity to contribute to the database.
To Pam Osborn: My partner and chief photographer. She has a very good eye
and has the camera in hand ready to go every minute we are on the water.
To Denis & Una Glennon: Fellow photographic fetishists who assisted and joined
us for part of the trip.
To Wade Hughes: My EC sponsor and lifetime friend.
Wayne Osborn FI 04, October 15 2009
wayneosborn@mac.com www.wayneosborn.com.au 61-417 012 625
APPENDICES
Appendix 1 Images prepared for database, Spreadsheet examples (Ap1EX.pptx)
Appendix 2 Maps, Waypoints and Tracklogs (Ap2EX.pptx).
Appendix 3 Expedition Images (Sent as a series of emails)
3775: Hydrophone deployed as a whale passes by.
3788: CWR vessel Whalesong II arrived in Exmouth during the expedition. Flag
150 on the upper deck.
0598: Closer shot of flag 150. Curt and Mich Jenner with their daughter Tasmin
and Wayne Osborn (left).
0923: Scarred Fluke from Orca attack. This was the whale with the missing
dorsal.
0163: Flag 150 and Shutterbug (a 6.3 metre Gemini RIB).
0511: A calf rests by lying across mum’s head
0972: An escort breaches next to a calf in the day’s last light.
0119: Flag 150 on the stern of Shutterbug. Hydrophone gear on the left.
Injured Calf: A ship strike victim – new season’s calf.