By Hannah L. Robbins
BU News Service

Once I saw a bald eagle burst into flames. I was in Neah Bay, a town on the Makah Indian Reservation nestled in the northwestern tip of the Olympic Peninsula, Washington watching the bird swoop down over the marina, a two-foot-long flat fish dangling from its talons. As the bird abandoned the water and flew over the street, the flopping fish touched a live power line. A jolt of electricity traveled up the fish to the bird and stopped it mid–flight. Red flames instantly engulfed its body, and the bird dropped to the street below.

When I relayed the story to a local contact, his eyes grew wide and his expression somber. “This is a serious thing,” he said to me. “This bird has allowed you to witness its death. We need to get some drums, and some face paint. We must honor this moment with a ceremony.”

“Really?” I asked.

“Naw. I’m just messing with you. Those damn things are everywhere.”

By sheer numbers alone, bald eagles are taking over Washington’s seas and skies –– a trend facilitated by their federally protected status. Conservationists hail the bald eagle’s recovery as a success story for the Endangered Species Act. Yet some fear an ecological backlash. As bald eagle populations continue to grow, they threaten to disrupt the tenuous ecological balances that characterize sensitive communities.  There is little conservationists can do, however, because of the eagles’ protected status. The bald eagle conundrum exposes weaknesses in current policy and poses new challenges to conservationists.

The history of bald eagles on the Olympic Peninsula is well-known among Washingtonians. Since moving to the western edge of the peninsula in the early 1900s, logging companies have targeted old growth trees like Douglas fir and Sitka spruce. Bald eagles often make homes of these trees, where they can construct nests weighing more than 1,000 pounds in the strong, sturdy branches.

In addition to cutting down vital habitat, logging companies sprayed DDT throughout the forests to prevent insects from infesting the wood. The chemical blocks calcium absorption, making egg shells weak—too weak, in some cases, to support a developing embryo. The pesticide wreaked havoc on bald eagle populations throughout the US in the 1950s and 1960s. By 1963, only 417 breeding pairs of bald eagles remained in the lower 48 states.

In response to that destruction, the US Government took action, banning DDT in 1972, and protecting the eagle and its habitat as part of the 1973 Endangered Species Act (ESA). State governments took action as well and all but five of the contiguous US states put bald eagles on their state endangered species list. Washington listed the bald eagle as “threatened.” The ESA protects threatened species- those that are likely to become endangered-in the same way it protects endangered species. The bald eagle’s populations began to rise; and when its population neared 20,000 breeding birds in 2007, the US Department of Fish and Wildlife removed it from the endangered species list.

The rising number of bald eagles tugs hard on the Pacific Northwest’s ecological web. Having a greater number of apex predators creates additional stress for prey populations. Shorebirds like common murres, rhinoceros auklets, and cormorants are particularly vulnerable in the Pacific Northwest ecological web because their populations are already declining due to habitat loss, gill netting and pollution. Bald eagle predation adds one more weight to their already weakened thread.

Perhaps more troubling, is the devastation bald eagles do to nesting communities. Bald eagles have run rampant on Washington’s Protection Island, a National Wildlife Refuge set aside in 1982 specifically to protect seabirds. When bald eagles first arrived to the island, they flew over the cormorant colony, swooped down and took the young out of the nests. Sometimes they would even attack adults.

 

“They are like big bullies” said Dr. Jim Hayward of Andrews University, who studies seabirds on Protection Island. Hayward noticed that over the years, bald eagles gradually took over cormorant nesting sites. Eventually the cormorants left the island. Now fifty to sixty abandoned nests remain, vestiges of a once vibrant seabird community.

On Tatoosh Island, just off the northwestern tip of Washington state, the sight of a bald eagle can induce panic among common murres, another local seabird. When bald eagles fly over nesting sites, the murres take to the air for safety, leaving their unguarded eggs vulnerable to other aerial predators like gulls and crows.

This threat is not unique to the Pacific Northwest. In Maine, which boasts the greatest density of bald eagles in the northeast, the birds prey on baby cormorants, gulls, loons, and great blue herons.

While the Endangered Species Act has brought back important species from the brink of extinction (grizzly bears, whooping crane, gray whale, and gray wolf to name a few), it has its weaknesses. Zeroing in on one species can have consequences that reverberate throughout the ecosystem. The other seabirds, for example, are collateral damage of conservation efforts that focus on meeting the environmental needs of one species, the bald eagle. As such, this approach may not be the best moving forward.

The single-species conservation approach is a relic of 1960s science. Back then, science giants like Robert T. Paine studied the effect one species would have on an entire ecosystem. Paine, for example, plucked sea stars from rocks, tossed them to the ocean, and watched biodiversity decline in areas where the sea stars were absent- from this study Paine coined the term “keystone species.” Such was the scientific mindset around the time when congress enacted the Endangered Species Act, originally the Endangered Species Preservation Act of 1966, (consequently, 1966 was the year Paine published his findings from his sea star experiment). Yet, science has evolved.

“There was a growing understanding in the science community that the species by species approach is ultimately insufficient and not terribly efficient,” explained Joni Ward, North American Director of Conservation Science for The Nature Conservancy.

Nowadays, ecologists recognize the complex network of interactions not only between many species, but between species and their environments. This, in turn, has influenced how some organizations approach conservation. Rather than focus on one species, they focus on conserving an area or landscape. The Nature Conservancy, for example, has been using this landscape-based approach for 15-20 years. They look at a given region and use science to understand what is there, what should be there, and how that landscape might reasonably change over a given time period. The Nature Conservancy defines its conservation goals within a given area based on that data.

This approach is becoming so widespread that government agencies have moved toward landscape-based models. In the marine world, the National Oceanic and Atmospheric Administration calls this approach ecosystem-based management.  “The idea of ecosystem-based management is definitely a guiding principle,” said Ed Bowlby, Science Coordinator for Olympic Coast National Marine Sanctuary. “All agencies, both state and federal, have totally accepted that, or adopted that, or are going to adopt it.”

The Olympic Coast National Marine Sanctuary (OCNMS), which encompasses over 3,000 square miles of ocean off the northwestern coast of Washington state, including the seaward hunting grounds of bald eagles uses this new approach to conservation. It protects the ecosystems that the eagles rely on. By protecting the ocean ecosystem, OCNMS indirectly protects all seabirds.

While the ideology behind ecosystem-based management is strong, enforcing policy based on it is extremely difficult. The sanctuary is large, about the size as Puerto Rico, and policing the waters would require a fleet of ships that would be both a financial and logistical nightmare. The system is complicated, and Bowlby reiterates the maxim: “There is no easy solution.”

Perhaps that is why we cling to a single-species approach. It is easy to grasp, and people can actually track “success.”

Legislation, like ecosystems, is made up of its own threads. Cultural, ecological and even economic values intertwine in a tapestry of legislative framework. As species like the bald eagle start to have a greater and more devastating impact on their ecosystems, scientists and lawmakers must think of new ways to weave these threads together. For now, their challenge is to untangle the thread without unraveling the entire system.

By Matthew Hardcastle
BU News Service

The character of the movie monster likely has its origins in our collective psyche, but in bringing their personal visions of horror to life, filmmakers often root themselves in  the world of biological possibility. Here are three monsters whose terror derives in part from their parallels in the real animal kingdom.

 

Crawlers – The Descent

The Descent (2005) stars a group of women alone in the dark, lost in an uncharted cave system inhabited by subterranean humanoids called Crawlers. These creatures seem to be an undiscovered branch of humans perfectly adapted to living in the pitch black. Exclusively cave-dwelling animals are called troglofauna, and although no known mammals have become troglofauna, the Crawlers share some of the commonest adaptations for a life of perpetual spelunking.

Lack of pigment – pale or translucent skin is a common adaptation for troglofauna, who require no protection from the sun’s rays.

Blindness – when it comes to evolution, it’s often “use it or lose it.” Without a speck of light to see, Crawlers are better off not wasting scarce cave resources developing eye sight.

Reduced metabolism – although the Crawlers seem to have quite an appetite for human flesh, they can probably go a long time between meals.

Acute Hearing – Sound is a lot more important than sight in a cave environment, and Crawlers have adapted bat-like external ears for increased reception.

Heightened sense of smell – This trait is a bit more problematic. Although cave dwellers tend to develop their non-visual systems, no primate or human species has ever hunted by scent.

 

Xenomorphs – Alien series

The seminal sci-fi masterpiece Alien (1979) introduced the world to xenomorphs, and subsequent films in the franchise have expanded on their life cycle and biology. Although they are totally alien life forms, their anatomy does have some counterparts on Earth. Some eels possess a secondary set of jaws within their mouths and some insects can spray acid. Xenomorphs most resemble arthropods, which once grew to fantastic sizes back when the Earth’s atmosphere had more oxygen — not unlike the oxygenated environment of a spaceship.

The xenomorph lifecycle also has terrestrial parallels. Their colonies are eusocial like an ant colony, with one fertile queen and physically-differentiated castes. They have a complex life cycle, involving an endoparasitic phase. Facehuggers hatch from eggs laid by a queen and act as mobile ovipositors, traumatically inserting larvae into a host, much like a parasitic wasp laying its eggs inside of a living caterpillar. Unlike most earthly endoparasites, facehuggers don’t seem picky about their hosts, and their larvae can adopt genes from their temporary incubators. After incubation, the developed larvae fatally escapes its host and rapidly grows into a warrior, shedding its outer shell as needed, much like many arthropods.

 

Dren – Splice

Splice (2009) is a surreal film about the possibilities of genetic engineering. Because the modern day Dr. Frankensteins are working with a mystery grab bag of human and animal genes, a healthy suspension of disbelief makes any combination of traits plausible. As an adult, Dren is definitively mammalian (possessing breasts) so we’ll try to stick close to that Order as much as possible.

Newborn – Mammals like humans, cats, and dogs give birth to young that are altricial, meaning they still possess some fetal traits. Young Dren possesses a dramatic form of this in her cleft face and undeveloped arms. However she also is extremely mobile, like the precocial newborns of horses and cows.

Adult – As an adult, Dren’s most prominent feature is her tail and long hind limbs. Besides this, she is more or less externally human. Her tail is counterbalancing like a kangaroos and prehensile like a monkeys. It also has a stringer. Though this is perhaps meant to be insectoid, male platypuses do possess poisonous barbs on their hind limbs.

Other traits – without getting into too many spoilers, Dren develops more exotic traits through the course of the film. She eventually sprouts feathers on her arms and uses them like wings. This is largely for dramatic effect, resting on shaky biological ground. Dren’s species also exhibits sequential hermaphroditism, changing from one sex to another. Although in Splice this plays out more like a Greek tragedy, many fish and gastropod species are capable of swapping sexes during their lifetime.

By Matthew Hardcastle
BU News Service

The maned wolf (Chrysocyon brachyurus) is often described as a red fox on stilts, but it is neither a wolf nor a fox. It is part of a distinct lineage of South American canids, many of whom also bare misleading common names like the bush dog and crab-eating fox. Maned wolves can be found in the grasslands of southern Brazil and neighboring countries.

Unlike more familiar canids, maned wolves do not form packs and are instead largely solitary. They also have an omnivorous diet, feeding on small game as well as fruits and vegetables. As a plant-eater, the maned wolf enters into a strange symbiotic relationship with leafcutter ants.

First the maned wolf eats the fruits of the Loberia plant. Then it likes to deposit its pungent feces (it also goes by the name “skunk wolf”) onto elevated ground to mark out its territory, so the mounds of leafcutter ant nests make good targets. The leafcutter ants don’t mind having their home defecated on because they use the feces to fertilize their underground fungus gardens. Meanwhile, the undigested seeds of the Loberia plant get discarded by the ants, increasing their dispersal rates. It’s a win for wolf, ant, and plant.

The maned wolf is listed as near threatened by the IUCN and the Brazilian government considers it vulnerable. Populations have dropped in some areas due to habitat loss and culling by farmers who falsely considered them a threat to sheep and cattle. Though maned wolves are occasional chicken thieves, they are too shy to bother humans or large livestock. Some of the maned wolf’s body parts, like their eyes, are also sought after for their purported magical properties.

By Matthew Hardcastle
BU News Service

The tuatara (Māori for “peaks on the back”) looks to the uneducated eye like an iguana, but it is in fact nothing of the kind. It’s true that its closest living relatives are lizards and snakes, but in the same sense that birds are the closest relative of crocodiles. The two living species of Sphenodon are in fact the sole survivors of their entire order.

The tuatara’s order Rhynchocephalia thrived 200 million years ago. As such it is sometimes called a “living fossil,” although in truth tuataras have spent as much time evolving as any other modern species. Even so, tuataras can give scientists a window into early saurian life forms.

The tuatara has white spikes along its back, loose gray skin, and a sprawling stance. It also has more exotic features including an exceptional well-formed pineal eye. This third eye is present as a light sensitive spot or scale in some other reptiles and fishes, but the tuatara’s has a small lens and retina, although the nerve connection is poorly developed and the eye is covered by a translucent scale in adults. Mammals and birds only possess the associated pineal gland, which plays a role in regulating circadian rhythms.

Beneath the crocodile-like skin of the tuatara, more intriguingly primitive features can be found. Its vertebrae look more like those of fish than reptiles and it possesses abdominal ribs. Its teeth are merely sharp projections of the jaw bone, not separate structures. Like some lizards, it is capable of shedding and regenerating its tail. It also sheds its skin like a snake. Its brain, heart, lungs, and stomach are all shockingly simple for a modern day amniote.

Tuataras once flourished on the two main islands of New Zealand, a “lost world” protecting them from more specialized predators. Rats and other introduced predators have extirpated the tuatara from the mainland, leaving only a smattering of coastal islands as last refuges from extinction. Not all hope is lost for the tuatara, however. The New Zealand government and indigenous Māori alike are invested in protecting this exceptionally unique, prehistoric beast.

 

By Matthew Hardcastle
BU News Service

Meet the pangolin. Sometimes called scaly anteaters, they are actually quite distinct from other mammals. The eight living species in the genus Manis actually comprise their own order, Pholidota. Four species live in tropical Asia and four are distributed across sub-Saharan Africa.

Pangolins dine exclusively on ants and termites, so they do share some features with more familiar anteaters. They have no teeth and a long sticky tongue; the longest mammalian tongue relative to body size, in fact, with muscle attachments on the pelvis. They have large front claws for digging into termite mounds; to protect these brittle claws some species walk on their knuckles or even travel bipedally, using their long tails as a counterweight.

Pangolins also have many unique features, most notably the greenish brown scales covering much of their body, apart from their soft underbelly. Like some armadillos, pangolins roll into a ball as a defense mechanism. Looking like a cross between a basketball and an artichoke, their hard, serrated scales act as effective armor against large predators.

While effective against lions, the pangolin defense mechanism makes them easy targets for poachers, who simply pick them up and toss them in a sack. Pangolin meat is regarded as a delicacy in China and Vietnam, with pangolin fetuses considered to be an especially auspicious display of wealth. The pangolin’s scale are also made of keratin, the same biologically inert but mythically curative substance as rhino horns.

Lax enforcement of the few protections pangolins do have and black market demand makes their scales and meat perhaps the most heavily trafficked mammal contraband in the world. The impacts are hard to estimate, with the thousands of specimens seized each year comprising just a fraction of the total trade. Conservationists also know little about the wild populations or ecology of this vastly understudied mammal, which fairs poorly in captivity.

Despite the lack of data, the sheer volume of illegal consumption likely justifies IUCN red listing for all eight species, of which only the Chinese and Sunda species have so far received. But protections will mean nothing if the vast maw of the Asian black market for animal parts isn’t shut up through education and harsher international sanctions.

By: Sara Knight
BU News Service

To mark the boundaries of our yards, most people plant hedges or construct fences. Hyenas, on the other hand, use paste – an oily, waxy, yellowish substance secreted from their anal glands.

Last fall I spoke with evolutionary ecologist Kevin Theis about his fascination with hyenas and his time spent tracking their various cliques as they roamed about the Kenyan Masai Mara National Reserve. During his time there, Theis became particularly interested in the hyenas’ scent-marking behavior.

Many mammalian species take advantage of their odiferous excretions – usually glandular goop, urine, or feces – to stake a claim to their territory. This behavior is known to biologists as “scent marking.” Hyenas mark their clans’ territory by extruding their anal pouch and dragging it along the ground, leaving a pungent paste trail behind them. Theis also suspects they use paste to communicate more nuanced information like fertility or advertising social status.

To determine the true nature of paste messaging, Theis first needed to identify what paste is exactly.Through a chemical analysis of the anal paste of hyenas from four different clans, Theis found that each group had a distinct “perfume” – allowing individuals to rapidly recognize if they were in a friendly or rival clan’s territory.

He also found that the waste products of microbial communities living within the hyenas’ anal pouches are responsible for paste’s distinctive odors. Each clan’s signature scent results from the unique composition of microbial species shared among that social group, meaning hyenas rely heavily on their resident cooperative microbe species for social communication.

Theis is continuing his work from the department of microbiology and molecular genetics at Michigan State University, where he aims to “elucidate the mechanistic roles bacteria play in the scent marking systems, and thus social lives, of solitary and social hyena species.” Read his blog here.

By Sara Knight
BU News Service

It was like a sudden B-horror movie infestation – on January 24^th up to 15,000 crocodiles swarmed out of the confines of Rakwena Crocodile Farm and poured out into the South African Limpopo River. The scaly escapees were taking advantage of the swelling floodwaters that had forced their warden, farmer Zane Langman, to open the floodgates, disarming the bloated river’s threat to consume his family’s house. Since then the freed reptiles have been spotted up to 75 miles downriver, one bold enough to take roost on a school’s rugby field. Langman has pledged to recapture his ne’er-do-well crocs. This raises the question, how do you wrangle these crocodilian beasts?

The answer varies with the crocodiles’ size, the environment, and the skill of the wrangler. Reptile farms typically house smaller crocodiles: an ideal farm croc is small enough to easily manage but big enough for its skin and meat to generate a profit. Langman’s crocs range from one meter to one-and-a-half meters in length, safely on the small side of the crocodile spectrum. Smaller crocs are neither as strong nor threatening as their larger brethren, but they are much faster. Luckily for Langman, farm-raised reptiles tend to be less wary of humans than their wild compatriots. These friendlier (than normal) human-acclimated crocs are much easier to approach and less likely to bolt; but since they tend to associate humans with feeding-time they are still quite dangerous.

The real threat posed by these ancient beasts lies in their needle-like teeth and powerful bite. Crocodiles have the most powerful jaws in the animal kingdom. John Brueggen, director of St. Augustine Alligator Farm, said a one meter croc can snap it jaws together with several hundred pounds of force. “When they bite their jaws lock and they shake their head,” crocodilian expert Adam Britton says, “if you pull your hand back their teeth will slice your flesh open like razor blades.” A small crocodile can easily rip your hand off.

To catch an escaped crocodile, you first need to find the scaly fugitive, which is rendered nearly impossible if the croc in question decides to hide. These masters of mimicry have over millions of years evolved their bumpy, lumpy, swamp-colored bodies to over disappear in muddy water. To overcome their powers of illusion Britton recommends searching for crocodiles at night with a strong spotlight, as their eyes cast a characteristically strong reflection. If the thought of hunting the rivals of dinosaurs with nothing but moonlight to guide you seems a bit too reckless, baited traps are also quite effective, Brueggen says.

For Langman’s more spontaneous-by-necessity wrangling experience, Britton recommends baited nooses. The noose is slipped over the croc’s long, flat head and then tightened, allowing the wrangler to securely guide the croc into the back of a truck. The safest way to approach an escapee croc, noose ready, is from behind Britton says. The widely-held belief that a crocodile’s tail is dangerous is only true for mammoth crocs; Britton explains that a croc’s tail is used as a counter-balance while swimming, never as a natural weapon. Langman’s diminutive variety can inflict no more than a hard slap. Other options for reclaiming delinquent crocodilians include using nets or hand-wrangling.

Quite the crocodile cowboy, Langman claims to have caught almost half of his crocodiles – though recently the local Environmental Affairs Agency clamped down on his retrieval antics. The National SPCA has also condemned Langman’s wrangling as inhumane – he has been caught shocking the unfortunate crocs with a stun gun for swifter retrieval.  And because live crocodiles do not come with letters of provenance and Rakwena Farm does not tag or brand, Langman cannot prove ownership of his reptiles – he is currently in negotiation with the Environmental Affairs Agency to work out a compromise. For now it is safe to say that Rakwena Farm’s fugitives can add a few more weeks to their Limpopo vacation.