Friday, August 27, 2010

Book Review--The Tourist Trail by John Yunker

Yunker, John. The Tourist Trail. Byte Level Books, 2010. Reviewed by Lin Kerns August 27, 2010.


______________________________________________________________________________



I feel privileged.

A while back, I became acquainted with one John Yunker through his online short story, "The Tourist Trail." I was impressed with his thoughtful prose, even then. When John told me that he was expanding the short story into a novel, I became excited. Finally--someone who can write and who knows their penguins. Truly a novel mix.

A couple weeks ago, John sent me a copy of his new novel and although I had other commitments at the time, I eyed the book, trailed my hand along the cover, peeked at John's autograph on the first page... I allowed the book to tease me with anticipation. At the first opportunity, I grabbed the book, made a pot of coffee, put the computer on "sleep," and then settled in on the couch to indulge in, what I hoped, was a good read.

Consensus: I couldn't put the book down; I devoured it in two days.

The plot: The story is populated by 4 major characters--Angela, Aeneas, Robert/Jake, and Ethan. Angela studies, counts, and tags Magellanic Penguins at the Punte Verde Preserve; although she loves her profession, she doesn't realize the vastness of the void in her life until she meets a raft-wrecked Aeneas. She follows Aeneas back to his ship and learns the largest lesson of her life. Robert/Jake works for the FBI and he is hot on the trail of Aeneas, who roves the seas in order to cause havoc and mayhem to would be whalers. Robert has a past, which becomes significant as the story moves towards a convergence of all the characters. Ethan is the young man who searches for meaning and purpose in his life; what he discovers will alter his life irrevocably.


Of course, the backdrop of the main storyline is inhabited by penguins and whales. Be prepared for a lump in your throat and a tear in your eye as your read how horrible the conditions are when these creatures meet their end at the hands of fishermen and whalers.John's perspective is a personal one and you are right there with him to see it all.



Overall, The Tourist Trail is a testament to how humans and the inhabitants of the sea interact and affect one another. As the characters learn and adapt, so does the reader. I promise that you will finish the book with a different perspective regarding our responsibility to life in the sea. John's prose is effective, succinct, and definitive. You will know these characters he has created and you will live their lives until the final page.


Let us hope that John Yunker will continue to write and gift us with his thoughtful insight; he is decidedly an author to watch. I also hope that The Tourist Trail will garner the eye of a Hollywood producer. I eagerly anticipate this novel converted to the big screen. Indeed, the book would be perfect for a big budget flick and the message within would touch so many more lives.


If that happens, I'll buy the popcorn.





PS

(You can purchase this book HERE)

Wednesday, August 18, 2010

Prehistoric Penguins

Waimanu, the first penguin


How long have penguins been around?  I suspect that most people would respond that they seem relatively young, in the grand scheme of things.  Penguins are so unique, and they seem particularly modern because of their constant presence in ads and movies.  There is also that constant mental association with icy environments that makes it hard to picture them along a steamy Paleocene coastline.

Waimanu is currently the oldest known penguin, and it is an ancient taxon indeed.  The rocks containing the Waimanu manneringi holotype skeleton are an astounding 61.6 million years old, far and away the oldest to produce penguin bones. A close relative, the smaller Waimanu tuatahi is found in rocks 58-60 million years old. To put this in perspective, these penguins lived just 4-5 million years after the mass extinction that killed off the dinosaurs (except for birds of course).
The first fossils of this taxon were collected almost 20 years ago by Al Mannering, in whose honor the first species is named.  Both come from the Waipara Greensand, a unit of sedimentary rocks laid down in nearshore waters during the Paleocene in present down North Canterbury.  During the Paleocene, this area of the South Island of New Zealand was submerged, and penguins, plankton and shellfish often became entombed in the dark sandy sediments upon death. Millions of years later, these rocks and their trove of fossils were exposed as tectonic forces lifted the ancient seafloor up to the sun and the Waipara River cut away the overlying layers.

These early penguins inherited a world in which a reset button had been firmly pressed. It was warm, rather homogenous in temperature across most of the latitudinal gradient, and most importantly, nearly every major niche was hung generously with “help wanted” signs.  For much of the Mesozoic, dinosaurs dominated terrestrial ecosystems and large marine reptiles occupied the aquatic tetrapod predator niche.  Mosasaurs, plesiosaurs and pliosaurs swam the seas worldwide.  But at the end of the Cretaceous, an asteroid impact wiped out all of these groups.  Even sharks were decimated, though of course some survived to re-supply our oceans and imaginations with toothed nightmares.

This extinction spelled opportunity for many groups.  Mammals radiated into the void left by dinosaurs, and some dinosaurs got a new opportunity.  The volant (flying) ancestors of penguins had a window in which the seas were free of largely free of competitors and low on predators.  This was a perfect time to drop flight altogether.  By 60million years ago, Waimanu manneringi and Waimanu tuatahi, two closely related species, had reached this critical stage in penguin evolution.

A reconstruction of Waimanu tuatahi from Slack et al. (2006).

Waimanu is both amazingly penguin-like and amazingly primitive.  Waimanu manneringi was a healthy size, about halfway between a King Penguin and an Emperor Penguin in standing height, while Waimanu tuatahi was a bit smaller, about 2 1/2 feet (80cm) tall. Waimanu manneringi is only known from a single hindlimb and pelvis, while specimens of Waimanu tuatahi is much more complete – multiple specimens together combine to give us almost the entire skeleton.  From head to toe, the skeleton of Waimanu combines primitive and derived characters.  The skull exhibits the long, narrow beak seen in other early fossil penguins rather than a stubbier modern penguin beak.  The flipper is much shorter than the wing of a flighted bird, but significantly longer relative to the body than in living penguins (indicating it would have a lower wing load).  The bones are also more flattened than flighted birds but less flattened than living penguins, which have highly compressed bones to form a more knife-like wing profile.  In the hindlimb, Waimanu is very close to modern penguins.  The shape of the limb bones indicate an upright posture like modern penguins employ, and the feet are short and stubby.  So Waimanu walked like a penguin on land, swam like a less-efficient penguin in the water, and probably ate the same basic foods (perhaps a little fish heavy).  There is a lot more to say about these fascinating species, but I will await some upcoming work by the Waimanu team to cover that story.

In closing, I should point out that the title of this post is actually a bit inaccurate. Waimanu manneringi is in fact the oldest penguin we know of. But, it is highly unlikely it was actually the first penguin.  The rock record is incomplete, and there is a roughly 10 million year gap between Waimanu tuatahi and the next oldest penguin fossil, showing we are missing big pieces of penguin history – probably on both sides of the 60 million year mark.

The closest relatives of penguins that are alive today are the Procellariiformes, the group that includes albatrosses and petrels.  These birds are commonly called tubenoses because their nostrils take the form of short tubes instead of flat openings. Most likely, the penguin lineage and the tubenose lineage split off from one another and started on their own evolutionary paths deeper in time, perhaps even during the Cretaceous Period. At this deep split, the birds heading off along the evolutionary trajectories to modern penguins and modern petrel probably looked a lot more like a petrel than a penguin – certainly volant (capable of flight) and probably with a similar ecology to some modern tubenose birds.  Whether we would call the bird on the penguin side of the split a “penguin” is debatable – it would probably be very hard for us to recognize a fossil penguin in the rock record until, like Waimanu, they evolved  a flightless lifestyle.  So, pending the discovery of a mind-bending fossil of a flying penguin, we’ll let Waimanu revel in its place in the sun.

References: Slack, K.E., C.M. Jones, T. Ando, G.L. Harrison, R.E. Fordyce, U. Arnason, and D. Penny. 2006. Early Penguin Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution. Molecular Biology and Evolution 23: 1144-1155.

Source


Fossil Penguins

Waimanu - 60-million year old penguins from New Zealand

R Ewan Fordyce

An online article recently published in the journal Molecular Biology and Evolution (March 2006) recognises a new genus of ancient penguin (Waimanu) from New Zealand rocks some 60-62 million years old. The ancient penguins lived in shallow seas off eastern New Zealand in Paleocene times, only a few million years after the extinction of dinosaurs. These "proto" penguins were about the size of living yellow-eyed penguins. They probably looked a bit like shags (cormorants), but had compressed and dense wing bones, allowing wings to be used to swim underwater. It is most unlikely that the Waimanu penguins could fly in air. These fossils are a little older than archaic penguins from Tierra del Fuego, documented by Dr Julia Clarke and coauthors (2003), and are the oldest fossil penguins reported from New Zealand.

Waimanu Paleocene_penguin
The reconstruction shown here, by Chris Gaskin, is © Geology Museum, University of Otago.
Waimanu humerus
Ewan Fordyce shows the position of the humerus, or upper wing bone, on a reconstruction of Waimanu tuatahi.
Photo by R Ewan Fordyce; reconstruction ©Geology Musuem, University of Otago.
Waimanu reconstruction
Reconstruction by G. Gaskin, showing 3 individuals of Waimanu tuatahi on a New Zealand beach in Paleocene times, 58-60 million years ago. Reconstruction ©Geology Museum, University of Otago.

Because the Waimanu penguins are well dated in terms of geological age, it is possible to use that known age to calibrate a new molecular phylogeny - or pattern of relationships - for living birds. The phylogeny shows a branching pattern of bird relationships based on study of genetic material from a range of living birds such as storks, albatrossses, ducks and moas. By using the dates from the fossil Waimanu penguins as a calibration point, we can then predict how far back in time the other groups of living birds originated. If early penguins lived in southern seas not long after the extinction of dinosaurs, then other bird groups more distantly related to penguins must have been established even earlier.

The study suggests that many groups of living birds originated well back in Cretaceous times, when dinosaurs were thriving - thus, many modern lineages had ancient origins. Such a notion conflicts with an idea suggested by Professor Alan Feduccia (1995, 2003), who suggested that many living bird groups are geologically young, and mostly represent groups that arose after dinosaurs went extinct.

Feduccia argued that most birds from Cretaceous times - from the age of dinosaurs - were ancient lineages not related to living forms. He suggested that those ancient bird groups disappeared, along with dinosaurs, in a turnover at the catastrophic "KT boundary" extinction 65 million years ago. Feduccia also suggested that there was a complete new evolutionary radiation of "modern" birds following the KT extinction.

Now, the new study which combines fossils and molecular approaches, predicts that "modern" birds thrived in the age of dinosaurs. We expect that the fossil record will continue to produce the hard evidence of those birds.

Details of title and authorship

Early Penguin Fossils, plus Mitochondrial Genomes, Calibrate Avian Evolution Kerryn E. Slack1 , Craig M. Jones2 , Tatsuro Ando3 , G. L. (Abby) Harrison4, R. Ewan Fordyce3, Ulfur Arnason5, and David Penny4
  1. Allan Wilson Center for Molecular Ecology and Evolution Institute of Molecular BioSciences Massey University Palmerston North New Zealand; Division of Evolutionary Molecular Systematics Department of Cell and Organism Biology University of Lund Solvegatan 29 S-223 62 Lund Sweden
  2. Institute of Geological and Nuclear Sciences Lower Hutt New Zealand
  3. Department of Geology, University of Otago Dunedin New Zealand
  4. Allan Wilson Center for Molecular Ecology and Evolution Institute of Molecular BioSciences Massey University Palmerston North New Zealand
  5. Division of Evolutionary Molecular Systematics Department of Cell and Organism Biology University of Lund Solvegatan 29 S-223 62 Lund Sweden
Abstract
PDF
The first specimen of Waimanu was found in the 1980s, by Brad Field (then of NZ Geological Survey), and was passed to Ewan Fordyce for study. Craig Jones prepared the specimen - now curated in the Geology Museum of University of Otago - while working for Fordyce as a technician. Fordyce and Jones (1990) later published some details of the first fossil. Subsequently, Al Mannering (of Christchurch, affiliated with Canterbury Museum) discovered more Paleocene penguins (Jones and Mannering 1997) which Mannering prepared; those fossils are curated in Canterbury Museum, Christchurch. Most recently, the Waimanu fossils have been studied in detail by Geology graduate student Tatsuro Ando, as part of his PhD studies at University of Otago. Al Mannering's sterling efforts of collecting and preparation are honoured in the name of one of the species, Waimanu manneringi.
For details of molecular studies, contact Professor David Penny of Massey University.

References

Clarke, J. A., Olivero, E. B., and Puerta, P. 2003. Description of the earliest fossil penguin from South America and first Paleogene vertebrate locality of Tierra del Fuego, Argentina. American Museum Novitates (3423): 1-18.
Feduccia, A. 1995. Explosive evolution in Tertiary birds and mammals. Science 267 (5198): 637-8.
Feduccia, A. 2003. 'Big bang' for tertiary birds? Trends in Ecology & Evolution 18 (4): 172-176.
Fordyce, R. E. and Jones, C. M. 1990. The history of penguins, and new fossil penguin material from New Zealand. Pages 419-446 in Davis, L. S. and Darby, J. D. (editors), Penguin biology. Academic Press, San Diego. 467 p.
Jones, C. M. and Mannering, A. 1997. New Paleocene fossil bird material from the Waipara Greensand, North Canterbury, New Zealand. Geological Society of New Zealand miscellaneous publication 95a: 88.
Simpson, G. G. 1971. A review of the pre-Pliocene penguins of New Zealand. Bulletin of the American Museum of Natural History 144: 321-378.

Source

The first fossil penguin – Palaeeudyptes antarcticus Huxley 1859, from Kakanui, North Otago

By R.Ewan Fordyce

The first fossil penguin recognised to science was an incomplete but dramatically large ankle bone from Kakanui, in coastal Otago. The bone was acquired by Government Agent Walter Mantell during his travel along the Otago coast in late 1848, and was sent to Britain where it was studied by the pre-eminent paleontologist T.H. Huxley. Huxley announced the find in the Quarterly Journal of the Geological Society in March 1859. There he identified the bone as from a new genus and species of penguin which he named Palaeeudyptes antarcticus – literally, ancient winged diver of the south. The ankle bone or tarsometatarsus is perhaps the single most distinctive bone in penguins and, had he been presented with some other bone, Huxley might have found it more difficult to convince people that the fossil was from a penguin.

Huxley woodcut 1859
Huxley's original illustration of the ankle bone is reproduced here. The left figure shows a front view; the right figure, the back view. One trochlea, or projection for a toe, is missing – from the right side of the front view.

penguin bones
Illustrations of penguin bones produced for James Hector's 1872 article on fossil penguins.
Within a few decades, other fossil penguin bones were reported from New Zealand, both from North Otago and from Westland. Again, the bones clearly represented species larger than those of today. Because of their size, the fossils were thought to represent more individuals of Huxley's new species, Palaeeudyptes antarcticus. However, no ankle bones were known amongst the new specimens, and it could not be confirmed that all the fossils really did represent the one species. Indeed, despite 150 years of field work, no more material of Huxley's species has been found – the species Palaeeudyptes antarcticus is indeed known from one incomplete bone. So, the name can be used confidently only for the one fossil which resides in a drawer in the Natural History Museum, London. Finally, we aren’t even sure of the age of the fossil; it is probably from the soft white Ototara Limestone which, at Kakanui, spans the Eocene/Oligocene boundary – in the range 32-34 M years. However, the bone could be from the harder and younger Otekaike Limestone, with an age of perhaps 23-24 M years.

The lack of complete specimens was not going to spoil a good story. The early finds quickly led to speculation that ancient penguins were giants, with body heights perhaps reaching "eight feet" (about 2.4 m). In 1975, renowned fossil penguin expert G.G. Simpson reviewed penguin body size, and concluded that even the most massive New Zealand penguin, Pachydyptes ponderosus, was much smaller - at 1.43-1.62 m.

Other new discoveries from the Waitaki Valley region show that there was quite a range of body size represented amongst penguins – not all were giants. Species of Platydyptes, for example, probably stood a little taller than a living yellow-eyed penguin (Megadyptes antipodes), and several fossils of tiny penguins – the size of little blues (Eudyptula minor) are known.

Our collections of penguin fossils are under study by PhD student Tatsuro Ando, as part of his research on the origin of penguin flight.

Remarkably complete skeletons of Palaeeudyptes-like penguins are sometimes on display in the Geology Museum, University of Otago. (The Geology Museum is open to the public 9am – 5 pm weekdays; access is via the Quadrangle.) Less complete but equally large specimens also may be seen at Otago Museum.

There are significant displays in North Otago that relate to fossil penguins. A poster reviewing these birds is in the Blue Penguin Visitor Centre in Oamaru. Interpretive graphics, casts and original fossils are displayed in the Vanished World Centre, Duntroon.


Tatsuro Ando studying fossil and modern penguin skulls.

Cast of Mantell's original ankle bone on the left; original fossil of a Palaeeudyptes-like penguin on the right. Both specimens from Geology Museum, University of Otago.

References for further reading

  • Fordyce, R.E. and Jones, C.M. 1990. The history of penguins…. Pages 419-446 in Davis, L.S. and Darby, J.D. (editors), Penguin biology. Academic Press, San Diego. 467 p.
  • Gaskin, C. and Peat, N. 1991. The world of penguins. Hodder and Stoughton, Auckland. 48 p. (Non-technical.)
  • Hector, J. 1872. On the remains of a gigantic penguin (Palaeeudyptes antarcticus, Huxley) from the Tertiary rocks on the west coast of Nelson. Transactions and proceedings of the New Zealand Institute 4: 341-346.
  • Huxley, T.H. 1859. On a fossil bird and a fossil cetacean from New Zealand. Quarterly journal of the Geological Society of London 15: 670-677.
  • Marples, B.J. 1952. Early Tertiary penguins of New Zealand. New Zealand Geological Survey paleontology bulletin 20: 66 p.
  • Peat, N. 1992. Penguins from the past. Forest and bird 23 (1, February): 32-34. (Non-technical.)
  • Simpson, G.G. 1975. Fossil penguins. Pages 19-41 in Stonehouse, B. (editor), The biology of penguins. MacMillan, London. 555 p.
  • Simpson, G.G. 1976. Penguins past and present, here and there. Yale University Press, New Haven. 150 p. (This is an excellent introductory text.)
Source

Researchers follow Adélie penguin winter migration for the first time

Two penguins on a rock nest.
Photo Credit: Viola Toniolo
Two Adélie penguins, with the one in the foreground sporting a satellite tag used to track its migration from its southern breeding grounds at Ross Island to the north in the winter and back again.

On the move

Researchers follow Adélie penguin winter migration for the first time

Adélie penguins living at the far southern extreme of their geographic range migrate an average of about 13,000 kilometers during the year as they follow the sun from their breeding colonies to winter foraging grounds and back again.
“They’re definitely making a longer distance migration than we thought,” said Grant Ballard External Non-U.S. government site, lead author of a study recently published in the journal Ecology that examined the birds’ past and present migration patterns, and how changes in climate and sea ice extent might affect migration patterns in the future.
The researchers tracked penguins from two colonies on Ross Island using geolocation sensor tags between 2003 and 2005. The birds came from Cape Royds, a small colony of about 2,500 breeding pairs and the farthest south congregation of penguins in the world, and Cape Crozier, a much larger colony of 150,000 breeding pairs.
Project Web site
Ballard and his colleagues, including long-time polar research and co-author David Ainley with H.T. Harvey and Associates External Non-U.S. government site, already knew the Adélies ventured north during the winter because they need light and some amount of open water to forage in the ocean.
But the tags revealed many surprises about where the birds went and how quickly they moved. Data collected by the tags also showed that while Adélies need light for navigation and fishing for food, they can operate under extremely low light conditions.
“This is the first time we know where the Adélies go and the environmental conditions they encounter during the winter,” said Ballard, a staff scientist at PRBO Conservation Science External Non-U.S. government site, a California-based wildlife conservation and research non-profit organization.
And while the birds venture far north in the winter, following the setting sun and the twilight conditions they need to survive, they stop about 500 kilometers from the edge of the ice and the open ocean.
“We assumed that they went all the way out to the ice edge. They actually stay fairly well inside,” Ballard said.
The scientists believe the flightless birds save energy on their northbound trip by moving with the ice floes, which follow ocean currents in a clockwise gyre around the Ross Sea. The return trip to their breeding colonies, where they need ice-free land to make nests and breed, is not as leisurely. Ballard said the penguins double-time it back to Ross Island in the spring.
Scientist working outside of tent.
Photo Credit: Emily Stone/Antarctic Photo Library
Scientist David Ainley at Cape Royds.
Penguins floating on an iceberg
Photo Credit: Nate Biletnikoff/Antarctic Photo Library
Adélie penguins float on an iceberg near Cape Crozier.
Penguins
Photo Credit: Emily Stone/Antarctic Photo Library
A penguin preens its feathers at Cape Royds.
“They’re coming back as early as they can,” he said. “They probably need the sun for navigation. We think that’s the main way they navigate. The study strongly suggests that is what is going on.”
The distances covered by the Ross Island penguins, with the longest trek of 17,600 kilometers, represent the longest migration of the species, according to the Ecology paper. In comparison, the most well-traveled seabird in the world, the Arctic Tern, makes a pole-to-pole return journey of 44,000 kilometers.
The ability to migrate over long distances may be an ongoing adaptation in the evolution of the species, the authors suggest.
During the Last Glacial Maximum (LGM) about 20,000 years ago, the West Antarctic Ice Sheet covered almost the entire Ross Sea, meaning most of today’s colonies didn’t exist. However, the authors speculate that one colony might have persisted through the LGM at northerly Cape Adare, which historically has been ice-free during previous glaciations.
Over the last 12,000 years, the ice sheet has retreated, and the Adélies have penetrated farther south to their current location, developing a strategy to move to and fro between summer breeding colonies and winter foraging areas.
However, the authors warn that as climate change finally hits the Ross Sea region in the coming decades, as predicted by some climate models, the Adélies of Ross Island will face difficult challenges.
In such a scenario, winter sea ice — a habitat for the Adélies, as well as key prey like krill and silverfish — will retreat south, as it has in the already-warming Antarctic Peninsula. At some point, the edge of the ice could peel back far enough south that the penguins won’t be within reach of twilight in the winter.
Ballard said it’s possible the Adélies could go extinct locally. The species is notoriously “hard-wired” by its biology, and individuals rarely abandon their birth colony.
However, in a different paper published in June 2010 in the journal Proceedings of the National Academy of Sciences by some of the same scientists, researchers reported that Adélie penguins can indeed move when conditions for raising young deteriorate.
That study was based on a natural experiment that occurred when giant icebergs that calved off the Ross Ice Shelf in 2000 locked in hundreds of additional square kilometers of sea ice for several years. That meant a long, long trek for the Cape Royds penguins to reach open water to forage food for their chicks each summer.
Some birds eventually moved to new nesting sites, choosing colonies that had access to better feeding sites, regardless of the size of the colony. 
The same instinct for survival could come into play in the future. After all, the Adélies have survived the ebb and flow of ice ages for hundreds of thousands of years. The question is whether they can adapt in time.
“We still don’t understand all of the dynamics of the Adélies and the ice, but we’re getting closer,” Ballard said.
NSF-funded research in this story: Grant Ballard, PRBO Conservation Science, Award No. 0439759 External U.S. government site; and David Ainely, H.T. Harvey and Associates, Award No. 0440643 External U.S. government site. Other co-authors on the Ecology paper include Viola Toniolo, Stanford University; Claire L. Parkinson, NASA/Goddard Space Flight Center; Kevin R. Arrigo, Stanford University; and Phil N. Trathan, British Antarctic Survey.

Source 

Friday, August 13, 2010

More on Mapping Penguin Colonies


Mapping penguin colonies from space


2 August 2010

A QuickBird satellite image of islands in the study area with bright areas of guano highlighted in red, green and yellow.
A QuickBird satellite image of islands in the study area with bright areas of guano highlighted in red, green and yellow.
Photo: QuickBird/AADC
Penguin poo, or 'guano', can provide scientists with a wealth of information, especially when viewed from space. For example, using high resolution satellite images, the spatial extent of a penguin colony – which could extend for kilometres – can be discerned by the guano's distribution. For biologists such as the Australian Antarctic Division's Dr Colin Southwell, this offers a way of developing maps of habitat occupied by penguin colonies. Such maps, used in combination with an estimate of penguin numbers within smaller parts of the habitat, could enable accurate estimates of penguin numbers across very broad regions; such as the whole of East Antarctica.
'Currently, penguin populations can be surveyed in relatively accessible areas using traditional methods, but the most remote regions remain difficult and costly to access,' Dr Southwell says.
'If we can develop accurate habitat maps using satellite imagery of guano deposits, we could design truly large scale surveys that could be applied consistently across very broad regions.'
The feasibility of using satellite images to map penguin habitat over broad scales was recently explored in a pilot study by remote sensing analyst, Angela Bender, of the Australian Antarctic Data Centre.
Angela used QuickBird satellite images covering islands along the Mawson coast, some of which were surveyed for Adélie penguin colonies in 2007 and 2009. The QuickBird satellite has a spatial resolution of 60 cm and collects 'multispectral' imagery by detecting different wavelengths of light, including visible and near infra-red, reflected by different land cover, such as rocks and vegetation (it also collects black and white images). Guano appears as bright areas in multispectral images, due to its high near-infrared reflectance.
Map of the Rookery Islands study area. The area within the green box is covered by one satellite image.
Photo: AADC
 
Map showing the location of Rookery Islands off the Mawson coast.
Location of Rookery Islands off the Mawson coast.
Photo: AADC
 

'Rookery Island and Giganteus Island, two of the larger islands within the Rookery Islands Group, were used to test the feasibility of using satellite images,' Angela says.
'We used these islands because the bright areas in the satellite images, which are assumed to be guano and are clearly discernable from the surrounding rocks and ice, also fall within the colony boundaries that were surveyed using a handheld GPS in 2007.'
Definiens Developer 7 software was used to extract and analyse the guano using 'object-based image analysis' (OBIA). This technique aims to simulate the way humans visually analyse imagery. It uses the spectral reflectance, shape, size, texture and contextual properties of objects, such as rocks, vegetation, or areas of guano, to classify them as such. This allowed Angela to separate and gradually refine areas of guano, from other objects. She was also able to classify areas of guano into 'dense, thin and sparse'.
The dense and thin areas of guano extracted using OBIA aligned well with a guano map of the area that had been manually digitised from the satellite images. However, the 'sparse' guano was not visibly discernable in the manual mapping.

Manually digitised guano on Giganteus Island - bright areas assumed to be guano were hand-traced and appear here outlined in green.
Manually digitised guano on Giganteus Island - bright areas assumed to be guano were hand-traced and appear here outlined in green.
Photo: QuickBird/AADC
Areas of guano extracted by Object Based Image Analysis correlate well with the manually digitised map of guano on Giganteus Island.
Areas of guano extracted by Object Based Image Analysis correlate well with the manually digitised map of guano on Giganteus Island.
Photo: QuickBird/AADC
Angela says that the results of the pilot study showed that OBIA is a feasible method for separating and extracting environmental data from a small number of satellite images. However, broader scale mapping with many images would require significantly more computing power. On-the-ground measurements of actual guano (density and spectral reflectance) would also help to answer other questions raised by the study.
'The time limitations of the pilot study precluded some important questions being answered; for example, is guano more or less detectable with krill or fish diets; are new or small colonies less detectable because there's less guano; can old guano be mistaken for fresh guano; and does satellite imagery give consistently reliable results across these variations?' Angela says.

An Adélie penguin colony stained pink from eating krill.
This colony of Adélie penguins has been enjoying a diet rich in krill (pink staining).
Photo: Louise Emmerson
An aerial photograph of penguins, which have a visible 'texture', on Giganteus Island.
An aerial photograph of penguins, which have a visible 'texture', on Giganteus Island.
Photo: AADC
Angela hopes to incorporate spectral reflectance data from actual guano in the field ('ground-truth data') into future analyses. She is also keen to test the usefulness of satellite imagery and aerial photos to count individual penguins based on 'texture'.
'Texture based algorithms could potentially be used to identify the texture of penguin colonies when the birds are on their nests,' she says.

Source 

Thursday, August 12, 2010

Penguin poo gives clues from space

Penguin poo gives clues from space


A pink "carpet" of penguin poo is allowing Australian researchers to track the birds by satellite.
SATELLITES ARE USED to spy on many things on our planet, but now Australian scientists are using one to hone in on penguin poo. The images are being used to determine accurate population numbers of Antarctic Adélie penguins.
Although individual penguins can't be seen from space, the pink stains of their poo - coloured from the planktonic krill that they eat - are clearly visible.
"Because they congregate to breed in very dense populations it is like a [pink] carpet of poo - not just a bit here and a bit there," says biologist Colin Southwell from the Australian Antarctic Division (AAD) in Hobart.
Adélie penguins (Pygoscelis adeliae) are habitual, returning annually to the same rocks to breed. As a result, each year the poo - also called guano - builds up under a colony and remains visible for long periods of time. Colin says this makes it harder to spot guano from Adélie penguins, compared with other penguins whose breeding grounds are on the ice  - like emperor penguins which breed on ever-changing sea ice.

'Quickbird' technology

The AAD team aim to survey a much larger area of Antarctica than they have already have, including those regions difficult to reach by foot. "If we can develop accurate habitat maps using satellite imagery of guano deposits, we could design truly large-scale surveys that could be applied consistently across very broad regions," says Colin.
Satellite imaging was used in 2009 by researchers from the British Antarctic Survey to discover new colonies of emperor penguins from their guano. The Australian researchers, however, are using the latest "QuickBird satellite" technology, which is capable of taking higher resolution images of a smaller area. It offers better quality pictures, which can precisely target penguin guano, the researchers say (see image below).
Satellite imaging is a cheaper alternative method to track penguin numbers, something previously done with the aid of helicopters. "Only so much field work can be done due to the hostility and remoteness of the region," says ecologist Iain Field from Macquarie University in Sydney. "It's one more tool we can use to gather information about the broader scale of the distribution of penguins."
The team hope to use the satellite images over a number of years to monitor the effects of climate change on the penguins.

LINKSAdélie penguins

Below: A satellite image of the "pink carpet" of Adélie penguin poo seen from space (credit: Australian Antarctic Data Centre/DigitalGlobe).



Tuesday, August 3, 2010

Penguin pics track Antarctic changes

Penguin pics track Antarctic changes

Updated Tue Aug 3, 2010 7:31pm AEST
An Adelie penguin on the ice in Antarctica
Australian scientists have developed a new camera to help them monitor Antarctica's Adelie penguins. (Australian Antarctic Division)
Tasmanian scientists have developed technology to help improve the monitoring of an important species of penguin in Antarctica.
For 20 years, scientists have studied the breeding habits of Adelie penguins on Bechervaise Island near Mawson Station.
They have been monitoring the impacts of fishing and climate change.
Colin Southwell from the Australian Antarctic Division in Hobart says the remote, extreme conditions have been a challenge.
"We send a two-person team down every summer but they work on an island that is isolated from the mainland," he said.
The high cost of sending scientists to remote areas had prevented the program being expanded.
Researchers wanted a cost-effective way to monitor more sites, so electronics engineer Kym Newbery developed a camera that could withstand the Antarctic elements.
"The winds are up to 200 kilometres an hour, they're very dry and cold," Mr Newbery said.
Colin Southwell says the new camera means researchers can now monitor multiple locations, without having to put researchers on-site.
"We're monitoring in the Davis region as well as the Mawson region, and this summer we plan to be monitoring by deploying more cameras in the Casey region as well.
"So what we're able to start doing now is to develop a network of monitoring sites, not a single monitoring site... and we're able to see how much variation there is from site to site.
"Hopefully this can extend right across east Antarctica," he said.

'International interest'

Kym Newbery says a number of countries including Japan, France and England are keen to use the camera in their own monitoring programs.
"If we make a method that other countries can adopt then it becomes a standard, almost a no-brainer, for everyone to use: the same mechanism, the same method, to monitor the same species at lots of different sites.
"Having common data recording techniques is really important to be able to compare what you're measuring."

Source

Five Penguins Win U.S. Endangered Species Act Protection





For Immediate Release, August 2, 2010
Contact:  Shaye Wolf, Center for Biological Diversity, (415) 632-5301

Five Penguins Win U.S. Endangered Species Act Protection

SAN FRANCISCO— Five penguin species will get U.S. Endangered Species Act protections after a 2006 petition by the Center for Biological Diversity and two lawsuits filed jointly with Turtle Island Restoration Network. Today’s Interior Department decision will list the Humboldt penguin of Chile and Peru and four New Zealand penguins, the yellow-eyed, white-flippered, Fiordland crested and erect-crested, as threatened.
“Protecting these penguins under the Endangered Species Act gives them a chance at survival,” said Center biologist Shaye Wolf. “Sadly, in today’s finding the Obama administration failed to acknowledge climate change as a threat. It won’t be able to help penguins survive the climate crisis if it doesn’t admit that it’s a problem.”

The penguins face serious threats from climate change, ocean acidification and commercial fishing. Today’s designation will raise awareness about the penguins’ plight, increase research and conservation funding, and provide additional oversight of activities approved by the U.S. government that could harm penguins and their habitat, including development projects and high seas fisheries. 

Warming oceans, melting sea ice and overfishing have depleted the penguins’ food supply of krill and fish. As sea ice melt has melted, krill has declined by up to 80 percent since the 1970s over large areas of the Southern Ocean where penguins forage. Ocean acidification is also inhibiting the growth of organisms at the base of the food web. What’s more, these penguins also drown in commercial fishing gear, die in oil spills and are killed by introduced predators at their breeding colonies.

“Finally the government is throwing penguins a lifeline to recovery by protecting them under the Endangered Species Act,” said Todd Steiner, executive director of Turtle Island Restoration Network. “Industrial fisheries and ocean warming are starving the penguins. Longlines and other destructive fishing gear entangle and drown them. Now they will have a fighting chance to survive.”

The Center filed a petition to list 12 penguin species under the Act in 2006. In December 2008, the Interior Department proposed listing seven penguins, including the five given official protection today. By court order, final decisions for the African and southern rockhopper penguins are due in September 2010 and January 2011. The Center and TIRN plan to file suit against Interior for denying listing to emperor and northern rockhopper penguins despite scientific evidence that they are jeopardized by climate change and commercial fisheries.

For more information on penguins, see: http://www.biologicaldiversity.org/species/birds/penguins/index.html.
The Center for Biological Diversity is a national, nonprofit conservation organization with more than 255,000 members and online activists dedicated to the protection of endangered species and wild places.