Giant squid eyes are huge, farsighted, and well-adapted to detecting predators (flickr | Jonathan Lampron)

Now, though, we know a little more.

According to a study published in Current Biology, the giant squid (and ‘colossal squid‘)’s huge eyes—which, aside from being the largest eyes of any known animal, are proportionally larger than those of other squid—have evolved for a special purpose:

…such giant eyes are unlikely to evolve for detecting mates or prey at long distance but are instead uniquely suited for detecting very large predators, such as sperm whales. [...] we predict that, below 600 m depth, (the eye) would allow detection of sperm whales at distances exceeding 120 m [...] we hypothesize that a well-prepared and powerful evasive response to hunting sperm whales may have driven the evolution of huge dimensions in both eyes and bodies of giant and colossal squid.

Lead author Dan-Eric Nilsson, a marine vision expert at the University of Lund in Sweden, and his team determined that giant squid are lousy at seeing things up close—they’re farsighted—and good at seeing big things off in the distance. This offers a unique and much-needed advantage when your primary day-to-day threat to life and limb (and limb, and limb, and limb…ha!) is a 60-ton predator with nature’s most powerful sonar system.

Duke Today:

But the boost in being able to sense contrast, which large eyes provide, is critical for detecting the low light differences of large, distant objects, the most important one being the bioluminescence stimulated by large animals such as approaching sperm whales, [report contributor and Duke biologist Sonke Johnsen] said.

Giant squid washed ashore in Norway, 1954 (flickr | NTNU-Vitenskapsmuseet)

The team realized that sperm whales dive and swim continuously while emitting sonar to ping the squid. The cephalopods are deaf to the sonar, but the whale’s wake triggers small organisms like plankton to produce light. Based on the design of the squid’s eye, the animal could see this light, though contrast is low, over “freakishly long distances,” about 120 meters — the length of an American football field, Johnsen said.

We all know that Duke basketball is evil and lame, but Duke biology is evidently quite useful.

The giant squid’s massive eyes are (presumably) the latest stage in an epic arms race against sperm whales—a specific, complex adaptation that justifies their tremendous metabolic expenditure. The big eyes allow squid to spot sperm whales by their glowing wake from about 390 feet away, through murky expanses of deep ocean water, and escape—despite the predator’s sonar and speed.

For more on ocean creatures, see Kevin Coyle’s post from last year about animals’ various methods of swimming or my post about the Top 5 Real Sea Serpents (including the giant squid). You can also check out an article about sperm whales and the threat posed to them after the oil spill in the Gulf of Mexico.

Birds dropped out of the sky, dead fish covered miles of the surface of rivers and bays, the media started digging up any reference to mass animal deaths they could find, and the public voiced a growing concern about what it all meant.

These kinds of die-offs are unusual but not unheard of in the nature, and so the good news is that while alarming, they don’t mean the world is ending and probably won’t have too much impact on the overall survival of the species that have experienced them.

While most wildlife experts see little cause for significant concern with these events, there are some mass wildlife deaths that we really should be worrying about.

5. Colony Collapse Disorder

Colony Collapse Disorder (CCD) causes honey bees to mysteriously abandon their hives and die. First reported in the United States in 2006, scientists are still trying to figure out the exact causes. While not native to North America, honey bees are critically important for the pollination of over 100 crops that both people and our livestock rely on for food. Eighty percent of all crop pollination service in the U.S. is provided by honey bees, which means that one-third of all the food we eat is directly the result of these insects. Honey bees also play an important role pollinating wild plants that wildlife depend on for survival. This mass die-off of honey bees could have significant economic and ecological repercussions.

Theories for the cause of CCD include infestation by exotic mites, viruses, a fungus, pesticides or other chemical pollutants, global warming, stress on hives from industrial beekeeping practices, or a combination of these factors that is suddenly pushing millions of honey bee hives over their tipping point and ultimately to death. While native pollinators can help fill in the gap caused by honey bee CCD, unexplained mass die-offs in several native bumble bee species are now also being reported.

4. White-Nosed Syndrome

North American bats are dropping like flies as a result of this mysterious ailment, which is characterized by the growth of a white fungus on the face of bats that hibernate in colonies in caves during the winter. The bats repeatedly wake up from their hibernation and fly about despite the cold temperatures and lack of insect food. In doing so, the bats burn off critical calories and ultimately die. Some bat hibernation caves have experienced mortality rates as high as 99 percent and since 2006 millions of bats have succumbed.

Scientists don’t know if the fungus is the cause of the odd behavior and killing bats directly, or if it is simply a secondary symptom of some other problem. One thing is certain, White-Nosed Syndrome has spread rapidly across the country, adding additional threat to endangered species such as the Indiana bat and drastically reducing once-common species like the little brown bat. Scientists are still searching for a clue as to the cause of these devastating mass bat deaths.

3. Global Amphibian Decline

Amphibians are often considered to be ecological “canaries in the coal mine” because their sensitive skin allows for the exchange of gas and liquids, making them particularly vulnerable to pollution and other disturbances to their habitat. As a result, amphibians are often the first group of animals to die out in disturbed or polluted environments. Dying out is exactly what amphibians are doing all around the world, and scientists don’t know why.

As with Colony Collapse Disorder, any number of causes could be at work either by themselves or in concert, including air and water pollution, global warming, habitat destruction, invasive species and most notably the type of chytrid fungus known as Batrachochytrium dendrobatidis or “Bd” for short. This fungus was discovered in 1999 and has been rapidly spreading and killing mass numbers of amphibians on several continents, including both North and South America, Europe and Australia. As with White-Nose Syndrome in bats, it’s not known whether this chytrid fungus is a new, random pathogen or if it has always been present and is only now spreading because of other, as-yet-unknown reasons. The statistics are frightening: thirty percent of amphibian species on the planet are listed as either threatened or endangered and another six percent are listed as near threatened. Scientists don’t know the status of another twenty-five percent.

2. Gulf Oil Disaster

The official wildlife body count of the Gulf Oil Disaster is 5,686 dead birds, 546 dead sea turtles, and 96 dead dolphins and whales. And that’s just the animals that rescue workers were able to recover in the vast area of the Gulf of Mexico affected by the millions of gallons of oil that gushed into the Gulf’s waters and coastal wetlands when BP’s Deepwater Horizon rig exploded. It’s doubtless that the wildlife death toll is more likely in the millions when you factor in open ocean species such as sperm whales or whale sharks that sink when dead or that might not immediately die but eventually succumb to slow poisoning as they eat contaminated food, as well as the fish and marine invertebrates that have also died but for which no one has a count. Even worse, judging from previous oil disasters such as the Exxon Valdez in Alaska, we can expect wildlife will continue to die for months, years or even decades as a result of this disaster.

1. Global Warming

The scale of the impact that global warming is predicted to have on wildlife across the planet can’t be understated.

We are already experiencing the rapid melting of glaciers, more severe storms, an increase in droughts, wildfires and flooding events, the spread of invasive species, and the record decline in Arctic sea ice making the long-term survival of species such as ringed seals and polar bears uncertain.

Countless other wildlife species around the globe will be negatively affected as global warming destabilizes ecosystems unless we act quickly to change the root causes.

From an environmental standpoint, the BP blowout could not have occurred in a worse place. The warm currents of the Gulf make it one of the most productive ecosystems on the planet, home to 1,200 species of fish, five species of endangered sea turtles, scores of mammals like bottlenose dolphins and millions of migratory birds. Even worse, the spill took place in “biological spring,” the moment when the entire Gulf comes to life – the migratory birds returning to nest, the sperm whales nudging along the edge of the continental shelf, the bluefin tuna laying their eggs, the pelican eggs cracking open in the rookeries. In the first three months alone, the spill has killed 1,978 birds, 463 sea turtles and 59 marine mammals – and that’s just the official tally.

“No list can ever do justice to what’s happening in the Gulf,” says Doug Inkley, a senior scientist for the National Wildlife Federation. “The birds that get sick and die in the wetlands will never be found. And there are so many things we are not counting. Who is out there counting the mortality among deepwater squid, which are important to the survival of sperm whales? Who is out there counting the impact on plankton, which are key to the Gulf’s food chain?”

We’ll have much more from Doug’s latest trip to the Gulf as the week goes on.

For all the latest news on how the oil spill is impacting the Gulf Coast’s wildlife & to learn how you can help, visit NWF.org/OilSpill.

It is the first dead whale spotted since BP’s rig exploded on April 20.

The whale was not found in oiled waters, but scientists can’t yet say where or how it died. [...]

[Sperm whales] live at depth in areas where subsurface dispersants and oil are present, and feed on deepwater squid, which may also be impacted by the oil and dispersants.

Learn more about how the BP oil disaster threatens the Gulf’s sperm whales.

I write this from Venice, Louisiana, a few days after the explosion at British Petroleum’s (BP) Deepwater Horizon oil rig set off a massive oil spill in the Gulf. Looking at the scale of the ecological disaster, I am frustrated, saddened and angry. BP has been long on promises and short on responses. Though two decades have passed since the Exxon Valdez spill occurred in Alaska, the oil industry and the various governmental enforcement agencies don’t seem to have learned much.

With a huge volume of oil flowing in the Gulf of Mexico unabated, we clearly have an epic catastrophe unfolding. The greatest coastal wetland system in America is at the height of spring wildlife nesting season. It now faces what may be the largest oil spill in the nation’s history. It is hard to imagine a more dire situation.

BP and the other oil giants have at various times testified before congressional committees that deep, offshore oil could be developed without harming the environment. But the reality I am experiencing here on the ground in Louisiana is revealing their rhetoric as little more than spin.

As of this writing, there are no reliable predictions when the flow of crude will be stopped or where the oil slick is headed next.

What will happen to this oil? Some of the lighter constituents will volatize into the air where, in combination with other pollutants, it will increase haze and ground-level ozone. When my colleagues and I flew through that haze over the oil slick, the air burned our eyes and throats. And scientists are warning that pollutants could linger for generations in the Gulf Coast’s soil and water.

Last summer, on the 20th anniversary of the Exxon spill, I traveled to Cordova, Alaska, a once-peaceful fishing village that became ground zero for the 1989 disaster when the supertanker ran aground on Bligh Reef, spilling more than 11 million gallons of crude into Prince William Sound. On that trip, I met with scientists who were part of a team that took 9,000 samples from holes dug along the impacted shoreline. They found oil in half of them, and they told me that crude oil and its breakdown products will continue to enter the food chain for years to come.

Of the 31 impacted species of wildlife studied there, only a third is fully recovered. And the once-plentiful pigeon guillemots and Pacific herring remain absent from the Sound. What does the future hold for Gulf Coast wildlife?

Coastal Louisiana produces 40 percent of the nation’s oysters. Oysters are filter feeders that are known to ingest and concentrate pollutants in their systems at levels 1,000 times higher than those found in ambient waters. Oil-impacted oyster beds may be off-limits for years to come, and there are long-term ramifications of low-level contamination on such species as bluefin tuna, bottlenose dolphins, sperm whales and manatees, as well as on humans who consume tainted fish and shellfish.

Unlike the formerly pristine Prince William Sound, coastal Louisiana has seen its share of environmental insults. Canals dredged by the oil industry have carved up the once-vast coastal wetland system. The canals accelerate saltwater intrusion, destroying the protective cypress forests and replacing brackish and freshwater wetlands with degraded salt marshes. Withdrawing oil and natural gas has further deflated the region, causing millions of acres of marshes to subside. Coupled with sea-level rise caused by global warming, Louisiana is losing the equivalent of about two football fields of land every hour.

For those of us who care about the viability of the ocean and of our world, this is our “Avatar moment.” We must challenge those who continue to pollute and destroy our world before it passes a point of no return.

We support President Obama’s freeze on new coastal drilling, because it is time to reassess America’s energy priorities. This is not just about making oil platforms safer—this is about moving to an entirely new energy platform.

Oil companies have deployed 700 lobbyists in Washington and spent tens of millions of dollars on advertising to persuade us that their drilling operations are completely safe. They have successfully stalled congressional action on clean energy alternatives and persuaded politicians to put oil company profits ahead of real energy reform. Now the bill is coming due. The hidden costs of our oil dependency are no longer invisible.

Helping Gulf Coast Wildlife: For information about the wildlife species threatened by the oil spill and updates on National Wildlife Federation activities relating to the region, please visit www.nwf.org/oilspill.