Winter Migration of Magellanic Penguins From the Southernmost Distributional Range

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Winter Migration of Magellanic Penguins From the
Southernmost Distributional Range

• Mollie Ryan
• BI257 Winter Ecology

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General Info The Subjects

• 22 magellanic penguins (Spheniscus magellanicus)
  from Isla Martillo in the Beagle Channel,
  Argentina

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General Info The Study

• Winter migration after molt
• Satellite tracked a total of 22 penguins for
  three years
• In 2004, seven penguins
• In 2005, seven penguins
• In 2006, eight penguins

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General Info Top Predator

• One of the top predators in the Patagonian Shelf
  (the southernmost part of Argentina)
• Breeding distribution is restricted to coastal
  locations between Cape Horn (southern tip of
  Chile) and 42S (about halfway point of
  Argentina) and sites on Falkland Islands

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General Info Population

• Total world population 1 million breeding pairs
• An additional 100,000 breeding pairs on Falkland
  Islands
• Numbers have decreased at many breeding sites
  over the last part of the twentieth century

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General Info Population (contd)

• Largest colony is found on Punta Tombo, Argentina
• An important breeding colony is Isla Martillo in
  the Beagle Channel, Argentina
• It is located at the boundary between the
  Atlantic and Pacific oceans
• One of the southernmost colonies

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General Info Population (contd)

• Annual variability in breeding success related to
  changes in quality and quantity of diet and/or to
  weather conditions
• Populations impacted by human-related factors
• Commercial fishing
• Oil pollution
• Disturbance due to tourism

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Purpose of Study

• Investigate winter migration patterns of these
  penguins originating from the southern range of
  their breeding distribution
• Identify distribution of penguins
• Identify potential conflicts with human activities

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Materials and Methods

• Fieldwork conducted at the magellanic penguin
  breeding colony on Isla Martillo
• Comprised of about 2,000 breeding pairs
• 22 adults (10 females, 12 males) were randomly
  selected and attached with satellite transmitters
• 23 March 2004 7 penguins
• 22 March 2005 7 penguins
• 17 March 2006 8 penguins

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Materials and Methods

• Transmitters attached on the mid-line of the back
  using black tape and synthetic rubber glue
• To minimize hydrodynamic drag
• In 2004, devices were attached as far distally as
  possible without impairing preen gland
• In 2005 and 2006, devices were attached to the
  middle of the back to not compromise the
  penguins balance
• Devices were then covered with a layer of quick
  epoxy

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Materials and Methods

• The KiwiSat 101 satellite transmitter had maximum
  dimensions of 130 x 35 x 20 mm
• hydrodynamically-shaped
• Powered by 2 AA lithium cells
• Weighed about 100 g
• Equivalent to 2.7 of mean penguin body mass of
  3.7 0.5 kg

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Materials and Methods

• To reduce further hydrodynamic drag, a flexible
  antenna protruded at an angle of 60 from the
  rear of the device
• 170 mm long and 3 mm in diameter
• In 2006, along with five KiwiSat 101, three
  KiwiSat 202 were used
• Each had maximum dimensions of 60 x 35 x 22 mm
• Weighed about 60g
• Equivalent to about 2 of the mean penguin body
  mass of 3.0 0.4 kg

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• Various KiwiSat 101 transmitters

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• KiwiSat 202 transmitter for a penguin or small
  sea turtle

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Materials and Methods

• Devices were programmed to transmit on a cycle of
  6 hr on / 18 hr off with a repetition period of
  60 s
• Equipped with a saltwater switch that prevented
  transmission while under water to conserve
  battery life
• The KiwiSat 101 recorded and transmitted time
  penguins spent at the surface
• Transmitter life 84 days with 2 AA batteries

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Results

• A total of 1,340 daily positions were obtained
  from the 22 magellanic penguins
• The mean minimum distance traveled by all
  penguins was 1,440 685 km
• The mean distance covered per day was 23.2 6.6
  km

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Results

• Penguins spent 52.8 6.3 of their time at sea
  submerged
• Sex-related differences were not found with
  regard to transmission duration and migratory
  parameters

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Results

• All 22 penguins left Beagle Channel in an
  easterly direction
• Most (except for three) penguins traveled around
  the southeasterly tip of South America into the
  Atlantic
• They headed north and migrated along the
  Argentine coast until transmission ceased
• Migratory behavior was decomposed into periods of
  rapid movement in a northerly direction,
  interspersed with periods, during which the birds
  remained for some time in a certain area

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Migration routes in 2004

• Fips red (filled square)
• Flo green (filled diamond)
• Fyjima yellow (plus symbol)
• Lu pink (filled circle)
• Miriam blue (filled triangle)
• Silvester brown (rectangle)
• WaRu black (filled inverted triangle)

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Migration routes in 2005

• Biggi black (filled circle)
• Egregrius red (rectangle)
• Eva brown (filled square)
• Jennifer pink (filled diamond)
• Jupp blue (filled triangle)
• Schroder green (filled inverted triangle)
• The Boss yellow (plus symbol)

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Migration routes in 2006

• Florian blue (filled circle)
• Gimmy light blue (open rectangle)
• Kira brown (filled diamond)
• Klaus green (filled triangle)
• NN1 pink (filled inverted triangle)
• NN2 black (open rectangle)
• NN3 red (plus symbol)
• Whitney yellow (filled square)

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Discussion Impact of Transmitter?

• The external attachment of devices is likely to
  have an impact on behavior
• Likely an increase in hydrodynamic drag, which
  negatively impacts on a great variety of foraging
  parameters
• This effect is more pronounced in transmitters
  equipped with an antenna, which increases
  hydrodynamic drag even more
• After 2005, the position of the transmitters was
  moved further to the body center

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Discussion Impact of Transmitter?

• All devices ceased transmission during migration
• A possible reason
• Penguins detached satellite transmitter by biting
  and breaking the feathers attached to it

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Discussion Migration Patterns

• Penguins originating from the Falkland Islands
  (51S) remained exclusively in the Atlantic
  Ocean, then migrated northwards
• One penguin migrated into the Pacific, but headed
  northwards as well
• A north-bound winter migration appears to be a
  general feature for magellanic penguins

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Discussion Migration Patterns (contd)

• Due to the temporal and spatial differences in
  their migration patterns, penguins experience
  qualitative and quantitative variations in food
  availability
• However, nothing is known of a magellanic penguin
  diet during winter months

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Discussion Migration Patterns (contd)

• Northbound migration can be related to decreasing
  sea temperatures, light levels and progressively
  impeding planktonic growth in more southerly
  regions as season progressed
• Migration is driven by formation and subsequent
  dissipation of areas with enhanced food
  availability

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Discussion Human Activity Interactions

• Magellanic penguins are increasingly exposed to
  human-related activities
• Prey of the penguins is commercially exploited
  and population crashes may happen due to the
  poorly-managed fisheries
• There are mortalities associated with the fishing
  itself
• Example in Puerto Quequen, Argentina, 100
  magellanic penguins die each year as bycatch in
  coastal fishing

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Discussion Human Activity Interactions (contd)

• Oil pollution is a much more obvious effect on
  penguin survival
• In 1991, about 15,000 magellanic penguins died as
  a consequence of one single oil incident
• Each year, more than 40,000 penguins die each
  along the Argentine coast of Chubut due to
  chronic oil pollution
• Magellanic penguin breeding population located in
  the northern distributional range has decreased a
  lot over the past decade which greatly indicates
  harmful interaction with human activities

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Conclusions

• Winter migration after molt was satellite tracked
  for three years
• Potential impact of transmitters on behavior
• Northward migration during winter is related to
  decreasing sea temperatures, light levels, and
  food availability
• Harmful human activity interactions include
  poorly-managed fisheries, fishing gear, and oil
  pollution
• These decrease breeding populations in the
  northern distributional range

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Thank you!Questions?
Putz, K., Schiavini, A., Rey, A.R., and B. Luthi.
2007. Winter migration of magellanic penguins
(Spheniscus magellanicus) from the southernmost
distributional range. Mar Biol 152 1227-1235.