Category Archives: Nerdy News

Tweeting History and the Sex Lives of Water Striders

I have managed to get through almost the entire semester without blogging! Good thing I have some students who are willing to catch us up to spend on the latest and greatest in biological news…

Tweeting History by Bio 94 Student Ahmed Akkad

Twitter! What a magnificent web program that has grown, in only 6 years, to one of the most used (ranked by Alexa as the 9th website in the world) and known social media apps in our world today. We humans use tweets nowadays to communicate anything from jokes to rumors to news and everything in between. We humans are also pretty late to the tweeting business, about 200-145 million years late to be (somewhat) precise. And, yes, as you surely figured out by now, we’re not talking about Twitter tweets anymore. We’re actually talking about bird tweets, sparrow birds in particular.

White crowned sparrow (Zonotrichia leucophrys) Photo by: Mike Baird

Almost every species in the world communicates between themselves and other fellow species. Birds primarily sing and tweet to communicate, although they also have other means of communication. Contrary to popular belief, communications between animals can get very sophisticated and have many functions, tones, frequencies and even have “accents,” like the sparrows we will be talking about. As any kid knows, there are even some animals that (other than humans) can utilize human language for communicating with humans, “Polly wants a cracker?” And as with most other traits in animals, they are all subject to evolving over the centuries.

According to a recent study by David Luther, Elizabeth Derryberry in 2012, a recent example of this evolution is the evolution of sparrow tweets of white-crowned sparrows living in San Francisco. The study, which is named “Birdsongs Keep Pace with City Life: Changes in Song Over Time in an Urban Songbird Affects Communication,” juxtaposes the sparrow’s songs from 1969 to the songs they sing today. The authors attribute the reasons the sparrows changed their songs to the level of noise in San Francisco, which, according to a different study, has grown considerably nosier from 1974 to 2008. As Luther muses, “We’ve created this artificial world, although one could say it’s the real world now, with all this noise — traffic, leaf blowers, air conditioners. A lot of birds are living in these areas, and what, if anything, is this doing to their songs?” The amount the songs changed is quite astounding, if I may say so myself. Keep in mind the study only revolved around the male white-crowned sparrow, and male birds typically sing more than the females.

Luther explains it in common day to day interactions; “Just as we raise our voices to be heard when a car speeds past, birds making their homes near busy intersections have to tweet a little louder. But it’s more than just whistling the same tune and turning up the volume.” The birds had to omit whole songs from their playlist because the old songs couldn’t make it through all the noise. Songs are the main means of communication for birds in general. They use various noises to mate, organize and warn each other of a predators, and not hearing a specific tweet or tune from another bird could result in a mess, maybe even an injury to the sparrow. What’s really interesting though,  in my opinion, is how these San Francisco sparrows now only have one shared “dialect,” as opposed to the three they had back in 1969.

Read more at Science Daily.

The Sexual Struggles of Pond Skaters by Bio 94 Student Brian Ngo

Pond skaters (Rheumatobates rileyi), aka water striders, are water skimming bugs found in a variety of freshwater habitats.  As a group they are known to fight over sex like many other organisms such as the banana slug’s penis chewing and the hermaphoditic flatworm’s penis fencing. Professor Locke Rowe from the University of Toronto suggested that the male pond skater antennae evolved to match the female pond skaters in efforts to make reproducing easier as female pond skaters are very resistive to males that they deem unfit or unworthy as a mate. The antennae of the male is used to pin down a female and restrain them to prevent any resistance at all from the female and they proceed to mate this way.

The antennae of water striders (Rheumatobates rileyi) are more complex and specialized in males (left) than females (Photo Credit: BBC Nature News)

This is a perfect example of sexual dimorphism and sexual selection because in this case the males head form is drastically different than the females due to the evolution in males head to combat the resistance of female sexual selection. To understand this more in detail Professor Locke Rowe used high speed video recording to capture the mating process of the Pond Skaters. They flash froze the data and analyzed it under the electron microscope to gain a better understanding and at that level of detail researchers could perfectly view the process and see that the male’s antennae were made perfectly and solely to restrain the female heads allowing the male to avoid any resistance and come on top of the female. This evolution of a strong male head to counter the strong resistance of females was not a simple one as there were multiple parts that evolved in the male head allowing them to gain leverage in successful mating. This specialized male head was found to be controlled by a single gene which was then manipulated by scientists and they found that the simple manipulating of this single gene resulted in an increase of successful mating of the males who were modified.

Read more at BBC Earth News.

Pool Hopping….Cephalopod Style

This octopus clumsily cruising through the intertidal is threatening to dethrone the reigning champ in my World’s Favorite Cephalopod Competition (See the current winner: Octopus Uses Coconut for Shelter).

This frisky octopus was captured at the Fitzgerald Marine Reserve in San Mateo, CA. Apparently, its not all that rare for cctopuses to venture out of their ocean habitat and cruise around on shore – but most octopuses are nocturnal, so it is rare for this behavior to be observed. Why might an octopus leave its cozy ocean home and risk exposure to air and potential predators? For food, of course! Once it clears one buffet table (aka a tidepool) it moves on to the next buffet table in search of some yummy shellfish or snails or other tasty invertebrates. Launching onto land could also be in response to an immediate threat – for example, sensing the danger that a potential predator poses.

Read more about this land-walking octopus at Octopus Chronicles and for even more on these intriguing animals, check out The Cephalopod Page

Climate Change Talks in Durban and Beyond

The United Nations Climate Change Conference is underway in Durban, South African and its been pretty quiet on the western front…..at least here in the U.S., where it seems most are more concerned with Black Friday deals than carbon dioxide emissions. We are in the 15th year of international climate negotiations and many view these talks as epic failure. This particular conference is expected to usher in the end of the Kyoto Protocol and attempt to create a successor plan. David Biello over at Scientific American points out, “…..it has become more clear that all the carbon dioxide emitted to shuttle diplomats from city to city to hash out a regime to curb climate change has been largely wasted.” Despite a new administration, the US never officially signed on to the Kyoto Protocol. Canada, among the worst emitters, is backing out and Japan is buying its way out of emissions reductions and refusing to sign up for more.

This conference is commencing on the heels of big headlines on climate change — NOAA recently released its Annual Greenhouse Gas Index. The good news first – concentrations of some CFCs are dropping, thanks to the ban on ozone-depleting aerosol spray propellants. The bad news – carbon dioxide levels jumped by the largest amount on record in 2010, a 6% increase over 2009. Since the start of the Kyoto Protocol, carbon dioxide has increased 29%. Yikes. WMO reported that 2011 has been a year of extreme weather. Drought in East Africa has left tens of thousands dead; lethal floods submerged large areas of Asia; the United States suffered 14 separate weather catastrophes with damage topping $1 billion each, including severe drought in Texas and the Southwest, heavy floods in the Northeast and the Mississippi Valley, and the most active tornado season ever known. (Source: LA Times)

With all of this buzz it is probably not a surprise that many of my IVC students have been thinking about climate change lately and its ecological impacts. Here are a few highlights…

March of the Trees

By IVC Bio 1 Student Iden Shahir

Do you enjoy going backpacking or simply visiting state parks for site seeing? For those who enjoy the wilderness and choose to backpack or camp on a regular basis, might find themselves in for a treat within the next few years. California and other “green” areas around the world are slowly but surely approaching a new era within the wildlife. As time has progressed, a display of “survival of the fittest” seems to be occurring as tree species across the western hemisphere are being altered. Because of global warming, insect attack, diseases and fire, trees that have been present for multiple centuries are said to die out, while new ones will move in and replace them over time. Scientists discovered that at one point these trees were sufficient and adapted well to their environment but as the centuries have passed on newcomers, who are environmentally more stable, will come in and push the old ones out. Furthermore, the climate is affecting the wild so much that areas such as a forest might shift into grass savannah or sagebrush desert completely.

Richard Waring, a professor at the Oregon State University, mentions “some of these changes are already happening, pretty fast and some in huge areas.” Furthermore, Waring also stated that it has been difficult to say which tree (species) will die off and which ones will replace it, but the forests of our future are going to look quite different. Waring said tree species that are native to a local area or region are there because they can most effectively  compete with other  species given the specific conditions of temperature, precipitation, drought, cold-tolerance, and many other factors that favor one species over another in that location. Once climate conditions change, everything else does as well. Those tree species that have been established for thousands of years eventually “lose their competitive edge” and will slowly die off.

March of the Bristlecone Pines?

The article also mentions that the weather will be expected to be between five to nine degrees warmer by 2080, causing more precipitation in the winter and spring, and less rain fall during the summer. Ecosystems are always changing as time progresses and it has been very difficult for humans to notice. But Steve Running, the University of Montana Regents Professor stated, “Now the rate of change is fast enough we can see it.” Although this may seem like a big concern, there isn’t much individuals can do about this incident but continue to be observant and further our research on the ecosystem. For more information, and more specific findings, see article at Science Daily.

The News on Greenhouse Gases

By IVC Env 1 student Harry Amm Chung

                  Ever since the start of the Industrial revolution during the 1880s, humans have been increasing the output of greenhouse gases without almost no sign of slowing down. In order, the top five greenhouse gases are carbon dioxide, methane, nitrous oxide, and CFCs 11 and 12. The Natural Oceanic Air and Atmosphere’s (NOAA) 2010 Annual Greenhouse Gas Index (AGGI) shows that there are statistics to prove that this increase in the top greenhouse gases have been exponential, even in the course of twenty years. With the baseline of measurement starting in 1990, there is a 29% increase of GHGs, resulting in the AGGI of 2010 to be 1.29, even worse than the worst climate models predicted. Even in 2009, the AGGI was at 1.27, 27% higher than in 1990.

In the long term, unfortunately, it seems as if these long-lived greenhouse gases in our atmosphere will be a lasting issue for society in the future. One might ask, “What’s so important about all of this information?” Well here’s the thing, GHGs have been on the rise for quite some time, and what GHGs do is trap heat in various amounts depending on the type of gas and releases them in all directions. In addition to land, water, and clouds re-emitting the infrared radiation, our sun’s solar radiation will add to the heating up of our earth. According to the data, CO2 has a global warming potential of 1, methane has a GWP of 25, nitrous oxide has a GWP of 298, and the combined GWP of CFC 11 & 12 is 13,500. All of these gases leads the atmosphere to trap more heat than was previously and naturally intended, with anthropogenic intensification being the cause.

While GHGs trapping heat is a natural process, our immense output of GHG emissions in a global scale gave way to a possibly disastrous result in the form of climate change, which leads to global increases in temperature (global warming), melting ice caps, and even greatly increasing the rate of extinction. More specifically, a continued increase in GHGs will influence almost all aspects of our society, including water supplies, agriculture, ecosystems, and economies. In recent years, through the Kyoto Protocol, the world has been trying to desperately reduce our GHG emissions, but to no avail. However, with stricter laws put in place, the top 4th and 5th GHG has been decreasing.

If all of us joins in the efforts to decrease emissions of greenhouse gases, we might still have a chance at reversing the oncoming effects of even the top three GHGs. Read more about this at esrl.noaa.gov/gmd/aggi/, researchmatters.noaa.gov/news/Pages/aggi2011.aspx, giss.nasa.gov/research/news/20110112/, and worldcitizen.net/green/.

Ocean Warming Sends Australian Seaweed Packing

By IVC Env 1 Student Mariela Herrera

It is no doubt that climate change has begun to affect several species on Earth. Seaweed–marine algae that often grow in shallow waters of the oceans—is now being affected by climate change. Seaweed are the trees of the seas — they are very important to marine life because they are a major food resource and provide habitat for many species, such as fish, turtles, and seals. As the waters of Australia experience temperature increases, seaweed species are going to migrate southward in order to search for cooler waters. According to a study this could force species off Australia’s continental shelf and could lead to extinction.

The Australian seaweed, Pterocladia retangularis (Photo: CBS News)

According to researcher Thomas Wernberg of the University of Western Australia the increasing water temperature are as followed: 0.007 degrees Fahrenheit per year in the Indian Ocean over the Western Australian continental shelf, 0.013 degrees Fahrenheit per year on the pacific side, which has been fed by the East Australian Current. It has been found that seaweed species are already responding to warming. These measurements were found using the herbarium records of seaweed, looking at shifts in temperate seaweed communities over the past 50 years in these locations.

“We found that temperate seaweed communities have changed over the past 50 years to become increasingly subtropical, and that many temperate species have retreated south towards the Australian south coast,” Wernberg said.

Seaweed species are increasing their populations to warmer water, while they are moving farther south. The outcome of this can lead to many species going south and farther away from the edge of Australia. Which if these species were to move away they would not have a sustainable habitat and may go extinct.  It has been estimated that in 2030 the water temperature could be increase by 1.8 degrees. With temperature increasing at this rate there could be a massive lost of species ranging from 100- 350 of them.

If temperatures keep increasing there could be a massive loss of species diversity all over the globe. Specially with seaweed loss, seaweed can only grow between the hide mark tide and 262 feet deep. Any deeper than that would not sustain seaweed because ocean that deep is like a desert.

Want to end on a more positive note? Check out this oldie-but-goodie at Scientific American, “10 Solutions for Climate Change

And we’re back!

Thank goodness I have students to pull me out of my blogging rut. Here are a couple exciting news stories that caught the eye of some of my Bio 94 students recently! Off to Big Sur this weekend and will return with lots of pictures!

Bulking up for the Winter – Courtesy of Climate Change

by Bio 94 Student Christina Cooley

Bigger birds in California (Photo credit:© Celso Diniz / Fotolia)

            As winter begins, the temperatures begin to drop, the frosty air becomes clearly visible when you speak, and snowflakes start to appear. With the coldest season in session, many people begin to dress in multiple layers with two jackets, jeans, mittens, scarves, hats, and even earmuffs! Each individual packs on as many layers of clothing as they can manage to keep themselves warm, therefore, making them appear larger and bigger with all of the extra clothing. Not only are humans appearing larger during this time, but so are birds!

Rae Goodman and Professor of Biology, Gretchen LeBuhn, discovered that birds’ wings have grown longer and birds, themselves, have increased in mass over the last 27 to 40 years in central California. Their discovery can be explained through an ecological rule, known as Bergmann’s Rule, which states that animals tends to be larger at higher latitudes because larger animals conserve body heat better than smaller animals, which allows them to thrive in a colder climate of higher latitudes. In addition, climate change can affect body size in various ways, such as, birds may get bigger as they store more fat to survive through the severe weather events, which are common under global climate change. Also, climate change can alter a plant’s growth, which leads to changes in a bird’s diet, thus, affecting its size.

Goodman and LeBuhn’s data came from two long-term “banding stations” in central California, where a variety of birds were captured, banded with an identification tag, weighed, and measured before being released. Their data consisted of 14,735 birds collected from 1971 to 2010 near the Point Reyes National Seashore and 18,052 birds collected between 1983 and 2009 near the San Francisco Bay area.

Goodman, who graduated from San Francisco State in 2010, stated, “At the time I started my research, a few studies had looked at body size changes in a few species in Europe and the Middle East, but no one had examined bird body size changes in North America.” Furthermore, her discovery allowed her and her colleague to “find an unexpected result-a gem in research science.” Both of them were completely stunned and surprised at their findings. Moreover, they concluded that birds “may be responding to climate-related changes in plant growth or increased climate variability in central California.”

Overall, this discovery has given other researchers a new perspective on the effects of climate change across a wide range of species, particularly in important traits like body size, where it is not expected to see many changes. Read more at Science Daily.

A Very New Very Old Discovery – Stromatolite Colony Found

By IVC Bio 94 Student Naveen Hothi

Stomatolites have recently been found in Ireland. These structures are formed by the buildup of tiny algae or bacteria. They are the oldest known fossils, dating back more than 3 billion years. The colony of stromatolites found in Northern Ireland was found by accident and a surprise to all. Usually they have only been found in environments vastly different from the one located off of Ireland. These environments include ones such that predators are kept to a minimum. Environmental characteristics such as hyper saline waters that hinder the presence of these predators are most common living grounds for stromatolites. Now here is where this new discovery becomes interesting because The Giant’s Causeway environment does not have these characteristics……

Giant’s Causewy (Photo: BBC News)

The Giant’s Causeway is located on the northeast coast of Northern Ireland. It is a protected area created by volcanic eruptions from ancient times. This area of Ireland, probably its most visited and popular tourist attraction, has environmental characteristics that differ greatly from those normally inhabited by stromatolites. This is seen with its lack of warm and non-hyper saline waters. This environmental difference invites predators who are now not threatened by harsh living conditions to reside there. These two points, unusual living environment and greater exposure to predators, are the reason why the discovery of stromatolites in The Giant’s Causeway is surprising.

Professor Andrew Cooper, a scientist from the University of Ulster’s School of Environmental Sciences, made this discovery. Luckily, Cooper had seen the structures before when he did work in South Africa and was able to identify the importance of finding them off of Ireland’s cold waters. The found colony was recently formed as detailed by the fact that it’s just one layer thick. One proposed reason for why not many stromatolites have been found is because perhaps scientists do not actually know what they are looking for. Most research on stromatolites have been done on the ancient stromatolites that helped in creating our current atmosphere. It is very possible that current living stromatolites are different from those that lived billions of years in the past. This new site can help to overcome this possible problem by being able to study stromatolites in this unusual for them environment. Read more at BBC News.

The Dog Days of Summer…

…are over! I’m back! If I am lazy with posts in the future and you’re interested in staying in the science news loop, consider checking me out on Twitter @DrDevMo.

I am working on compiling plant and animal pictures from my summer adventures – local SoCal hikes, a trip to the Sierras, a day-trip to Santa Cruz Island, etc. In the meantime, I will leave you with this gem of a story.

Virus makes zombie caterpillars ascend to their doom

A molten European Gypsy Moth (Lymantria dispardripping virus onto the foliage below

I should’ve saved this one for Halloween. Close your eyes and picture yourself and the break of dawn in a European forest. Most gypsy moths are are laying low hiding out in bark crevices or underground, hoping to avoid the early birds searching for a meal. You notice this one gypsy moth behaving quite strangely – it is marching up to the top of the tree in plain sight hungry predators. As it reaches the topmost leaf, it liquefies. What is it doing??

This wayward moth is infected with a baculovirus – a large, rod-shaped virus with very species-specific forms among over 600 invertebrate hosts. This virus is in fact what compelled this moth to climb and liquify.

How? Why?

The virus contains a single gene (called egt) that inactivates a caterpillar hormone that controls molting. Normally, this hormone would help guide the caterpillar to a high position and then trigger molting. The virus apparently deactivates just enough of the hormone so that the caterpillar does in fact climb – but not enough hormone that the caterpillar molts. Instead of shedding its skin, it dies.

The virus benefits from this death at heights – the high position helps the virus to spread by gusts of wind in search of new hosts to replicate within. Additionally, healthy caterpillars pupate at the tops of trees and the female moths don’t fly. Instead, they emerge and walk all over the molten victims that are left behind further aiding the spread of the virus.

Richard Dawkins deemed this phenomenon the “extended phenotype” – the capacity for genes to influence events beyond the body they live in. This study is the first to describe a case where a single virus gene can control the behavior of another animal.

Read more at Nature News. The original article was published in Science.

Not your everyday Before and After picture

Gotham City’s Newest Bat-Signal

By IVC Bio 94 Student Natalia Lisek

Macragravia evenia leaves — a satellite dish for bat sonar

Plants have a repertoire of ways to attract pollinators: colorful flashy flowers, lovely or repugnant odors, and now…sound! A team of scientists has found the world’s loudest plant. Marcgravia evenia is a Cuban rainforest vine that depends on bat pollination that has specially adapted leaves that have evolved to act like satellite dishes for bats.

The structure of the plant is disc-shaped leaves that are “suspended above a ring of flowers, below which hang cup-shaped nectarines.”  Ecologists at the University of Ulm in Germany  used loud-speaker microphones  to play sounds towards the plant which resulted in echoes. It was noted that regular plants produce moderately strong echoes when the microphone is facing the leaves, but the echo decreased as soon as the microphone was angled to the leaf’s edge. However, the disc-shaped leave’s echoes remained the same whether the microphone was placed facing it or at “an 80-degree arc in front of the leaf.”

Dr. Simon Ralph believes that the disc shaped leaves help bats locate the flowers because of the echo bats use in the rainforest. The only downfall to the disc shaped leaves is that photosynthesis does not work as well, but attracting bats compensates for the inefficiency for photosynthesis because the bats help with the Marcgravia flower’s reproduction.

Dr. Simon and researchers conducted experiments on trained nectar-feeding bats. The idea was that the bats had to search for a feeder that was about 2.5 centimeters wide and hidden. When researchers placed a replica of the disc shaped leaf near the feeder, the bats found the feeder about half the time it required a bat to find the hidden feeder without the accompaniment of the disc shaped leaf. The benefit of using bats as vector pollinators is that Marcgravia evenia can attract bats from a distance, so they are able to exploit bats in order to successfully survive. This plant is really fascinating because if the hypothesis is true, it is a clear example of coevolution still occurring between flowering plants and animal pollinators.

Because this plant appeals to bats through echolocation by using acoustic tricks it should make it a lot easier for the bats to find nectar. Since rainforests are occupied by dense vegetation and the patterns of sound are continuously changing, this plant would reflect a loud constant echo in varying directions allowing the bat to locate it more easily. According to Brock Fenton, ” An ultrasonic beacon is an astonishingly effective thing – its the same principle that airports use to guide aircraft in to land……The plants are obviously exploiting the bat. There are all these little jewels waiting our there for someone to pursue.”

See the original study at Science Magazine and recaps at New Scientist or National Geographic.

Noteworthy Nerdy News

It’s been a sloooow and lazy summer. Luckily, we have my IVC Bio 94 students to keep us informed of the latest and greatest science news!

And stay tuned….I just returned from an AMAZING trip to the Eastern Sierras and am sorting through some beautiful photos of glacial lakes and stunning wildflower displays.

Researchers Found What? Where? by Bio 94 Student Tara Okuma

Anyone with general biology knowledge would probably expect to hear about unicellular bacteria or archaea thriving in extreme conditions deep underground. None of them would even think of looking for multicellular organisms down there, much less expect to find them. Until recently.

According to Alexandra Witze’s article in Science News, the existence of nematodes, multicellular organisms also known as roundworms, were found deep within three South African gold mines. Witze reports that Gaetan Borgonie, a worm specialist from the University of Ghent in Belgium, and his colleagues’ drilled six boreholes to collect water and soil samples from three gold mines. They discovered a female nematode at 1.3 kilometers (less than a mile) below ground in the Beatrix gold mine. Generally environments this deep would not have the required nutrients and necessary environmental conditions for multicellular organisms to survive; however, Borgonie says that nematodes do not need vast amounts of oxygen and these mines might carry just enough water, oxygen, and nutrients for nematode survival. According to his hypothesis, Borgonie and his colleagues were right. Borgonie brought the female nematode back to the laboratory for observations and waited to see if the female would lay an egg. It laid eight of them with each of the tiny nematodes being approximately 0.5 millimeters in length. The differences between these nematodes and other nematode species were great enough to be considered a new species, so they named it Halicephalobus mephisto after Mephistopheles, a German folklore demon.

Witze also writes that Borgonie speculates that the ancestors to H. mephisto were probably surface-living nematodes, which ate bacteria as they made its way down through the rocks over generations. In other words, speciation had occurred over time and the differences (e.g. morphological, biological, molecular, ecological) between H. mephisto and its ancestors were great enough to warrant their own species. But a new nematode species is not all Borgonie and his colleagues discovered. In addition, they found two known surface species in a second South African gold mine at 900 meters deep (about 0.5 miles) in the Driefontein mine. A third mine reviled trace amounts of nematode DNA in waters leeching from rocks in the Tautona gold mine at 3.6 kilometers (about 2.2 miles) below ground. These results imply that other known or unknown species of nematodes may be found at these depths or much deeper.

But despite their findings, Borgonie and his team decided to run a bunch of tests to rule out the possibilities of these newfound roundworms hitchhiking down the mine via gold miners. The results showed that H. mephisto are in fact living in waters that is at least thousands of years old and survives in temperatures of up to 41°C, suggesting that the worms are thriving and reproducing deep within the gold mines. Borgonie plans to go back to South Africa in a few months for further research and the possibilities of finding new nematodes. However, a deep biosphere expert at Cardiff University in Wales questions if the boreholes changed the nematode’s environmental conditions, which leaves Borgonie’s future research and findings up for more questioning. But regardless of the skeptics, Borgonie’s discovery unleashes the possibilities of finding other multicellular organisms surviving in extreme and deep environments, and perhaps the existence of life deep within the surface of other planets, such as Mars.

Teeny Tiny Snails Survive Digestion by Bio 94 Student Galt Dunn

Tornatellides boeningi, a teeny snail that is able to survive bird digestion

If you’re normal, you probably aren’t particularly fond of snails, unless you’re like my dad as a kid and eat them. They’re slimy and go “crunch,” especially when you least expect it. Most land snails are members of the molluscan class Gastropoda. Snails respire by either a lung or gills, and both types are found on land and sea. Some snails such as the Giant African Snail can grow to be 38cm and weigh 1kg. On the other hand, some snails are extremely small. These “micro snails” can fit multiple end to end inside of one centimeter.

One particular species of micro snail is only 2.5 millimeters on average! This is the Tornatellides boeningi, a native to the Japanese island of Hahajima, part of the Bonin Islands archipelago 1000km south of Tokyo. One of the T. boeningi‘s common predators is the Japanese white-eyes bird (Zosterops japonicus). However, the white-eyes bird isn’t normal as far as predators go. It eats the snails, but it doesn’t always kill them! According to a study, 15% of all snails eaten survived digestions and were found alive in the bird’s feces after passing through the bird’s gut. There is already a lot of evidence of plant seeds being dispersed by birds that eat fruit, and there has been research showing that pond snails can survive being eaten by fish, but this is the first documented case of invertebrates being spread in this way.

What does this mean for science? This evidence suggests that bird predation could be a key factor in how these snail populations are spread; a bird eats a snail, flies away, poops it out, and just like that, the snail is in a new population (I wonder if it flies first class?). Researchers also studied the genetic variation of different T. boeningi populations across the island chain and found a surprising amount of variation, considering their geographic isolation. In this perfect example of gene flow, snails of different populations are mingled by virtue of being consumed.

Are there special adaptations that allow these snails to survive digestion by bird? “The main factor allowing the snails to survive being eaten is their small size.” In previous studies, larger snail’s shells were severely damaged by the bird’s digestion. However, researchers say that further study is required to find out whether T. boeningihas and special adaptations that allow them to survive.

The Bonin Islands were recently added to the UNESCO (United Nations Educational, Scientific and Cultural Organization) World Heritage List for their rich ecosystems that “reflect a wide range of evolutionary processes.” Call me abnormal, but I am fond of this snail. Click here to ready more at BBC Earth News.

A few other catchy headlines….