Get an inside look at science as it happens in the Caribbean. This week we document biodiversity in St. Martin.

I recently did a rapid assessment of biodiversity at two sites on St. Martin. Environmental Protection in the Caribbean (EPIC) is restoring habitat there—planting native trees to make the sites better for local plants and animals. I was there to record all the lizards, insects, spiders, snails and other small animals I could find.

Many truths about Caribbean field biology are seen in this little project. For starters, it was a little project. I studied each location for just a day. I started in the afternoon and finished in the dark with the animals that come out at night. With an infinite budget, I could have spent weeks, months or years studying these sites. I could have set traps and dug into the soil. The longer you look, the more you can find.

There’s never enough time, but we make the most of the time we have. I found over 70 species at each site. Field research is science, but there can be an art to it as well. One needs knowledge of the area, familiarity with local wildlife and perhaps a bit of luck to be successful.

There’s no rule book for this work. There are established methods for finding, counting and identifying animals in the field, but each project is different. Different techniques are used for insects or lizards or birds. Different tasks might be needed depending on the end goal.

For this project, there were multiple goals. One was to know what animals lived in each location. This tells us which species can benefit from the habitat restoration. For this, it is often important to focus on key species, like ones that only live on St. Martin. Improving habitat for these species may be more valuable than improving habitat for common species.

For a habitat restoration project, it would also be ideal to compare data from before and after the project. After a successful restoration, more species might be living in the same area. This is a big challenge for a rapid study. It usually takes a lot of time to have enough data to make these comparisons.

This project also has educational and citizen science components. With this in mind, I took photos to document the species I found. These photos can be used in school presentations, or in a tool for citizen scientists surveying the area.

One other way that this little survey captured the essence of field research was in the moments of discovery. Amidst all the familiar critters, there are always new surprises. Coming across a group of squash bugs I had never seen before was a real treat. It is this—perhaps more than anything else—that keeps us going out into the field.

Get an inside look at science as it happens in the Caribbean. This week we find plenty of life in a busy urban park.

Nature and civilization are two ideas that seem like opposites. There is a lot of difference between the wildest parts of the world and the most urban. Remote mountaintops are quite different from crowded subways. On the other hand, the natural world is all around us, even in the middle of our cities.

In the Caribbean, the relationship between human spaces and natural spaces is fluid. The beach and the sea are social spaces. The distance between downtown and the forest is walkable. We live with the wind, the sun, the waves, the trees and all sorts of living creatures.

The wildlife of St. Kitts is everywhere we look. The Central Forest Reserve is certainly a wild and magical place. The surprisingly lush forests on Monkey Hill are surrounded by urban development. There’s even a lot to see in Independence Square Park, right in the center of Basseterre.

The Scaly-naped Pigeon is often rather shy. A popular bird for hunting, shyness has probably served it well. Still, on a recent visit to the park there it was. Although usually seen in the treetops, this one was on the ground gathering material for a nest.

The Scaly-breasted Thrasher is another bird that is often timid around people. Yet there it was in the bustle of the park. Lunchtime crowds walked back and forth while it looked down from a tree with curiosity.

Cattle Egrets, Zenaida Doves, Gray Kingbirds and a host of other species can be seen in Independence Square every day. They’re a testament to the vibrance of Caribbean nature. Open space and a few trees can sustain a community. That magic is of vital importance to the future of nature in the Caribbean.

Access to nature is a great gift. Being familiar with these birds inspires us to protect them and their habitat. In these city birds we also see the resilience of nature. We see the ability to adapt—from forest to farm to backyard. Between their ability to survive and our willingness to set aside a place for nature, there is hope.

Get an inside look at science as it happens in the Caribbean. This week we investigate the nest of a lone pair of birds on St. Kitts.

Visiting the one of the salt ponds on the southern peninsula of St. Kitts, I happened upon a pair of Least Terns and their nest. In typical Least Tern style, their nest was basically just a pair of eggs on the ground. In this case, they were on a piece of garbage. Perhaps they thought it made the eggs less noticeable.

Some things about this nest were pretty normal. It was in the middle of the sandflat beside the pond. This is exactly the type of location Least Terns prefer for their nests: a bare, sandy area. It was also close to the shallow water of the pond and nearby shore where the terns could fish. The odd thing about this nest was that it was that it was alone.

Like many seabirds, Least Terns usually nest in colonies. Colonies may be as small as a few nests, or as large as several hundred. There are many potential advantages to nesting in a colony. For example, it would be hard for a small bird like the Least Tern to defend against a larger predator like a seagull. A group of Least Terns might be able to defend their chicks more easily.

Birds may also nest in colonies because they like a certain type of nest area. The Least Tern likes open sandy areas near water, but they also have to avoid sites where big waves would wash away their nests. If the number of great spots is limited, birds might be more likely to nest near each other.

So, why was this pair nesting all alone? There’s no easy answer. Least Terns are known to nest alone on occasion, but we don’t know why. Could it have been the first pair of a larger colony? Probably not. If it were, there would be other terns nearby, even if they hadn’t started their nests yet. Could it be the last pair from a colony that had already failed and moved on? It’s doubtful. If this happened, it’s unlikely that their nest would have survived.

Perhaps this lonely colony reflects the larger challenges facing Least Terns. Although the species is not near extinction, it does face many threats. Invasive predators—like monkeys, mongoose and rats—add to the dangers of native ones like herons and egrets. Suitable habitats are destroyed, and nests are crushed by off-road vehicles. Is the lonely colony the sign of a lonely future?

Get an inside look at science as it happens in the Caribbean. This week we don’t find a gecko on St. Kitts and Nevis.

There’s no eureka moment when you go into the wild and don’t find something. No lightbulb flashes on. It’s more like mood lighting. Each time you don’t see it, an idea in the back of your mind gets a tiny bit brighter. It starts to feel odd that you haven’t seen it yet. Eventually, you realize you may not see it at all.

In general, we know which lizards should be on each island. There aren’t very many. St. Kitts and Nevis each had less than ten native species. We can use geography to predict what lizards should be on each island. In particular, we know that St. Kitts, Nevis and Statia were connected into one island about 10,000 years ago. So, they probably had the same lizards.

In the nature, 10,000 years is not a long time. Still, things have happened since then. Sometimes animals disappear from islands. The Lesser Antillean Iguana was massacred by the mongoose on St. Kitts and Nevis. On mongoose-free Statia it still survives.

The Least Island Gecko is another lizard that seems like it should be on St. Kitts and Nevis. It is a tiny gecko that is found on islands from Anguilla to Statia. Unlike the Lesser Antillean Iguana, dwarf geckos often coexist with mongoose. In fact, the closely-related Saban Dwarf Gecko is doing fine on St. Kitts and Nevis.

We searched all the places the Least Island Gecko goes. We looked under logs on the forest floor and in the loose bark of the tamarind tree. We looked for it at night. We looked for it in insect traps that sometimes catch these tiny lizards. We didn’t find it.

What does it mean when we don’t find an animal? It is hard to say. For starters, we can’t really say it isn’t there at all. Maybe we just failed to find it. We can say that it is at least very rare. We don’t know why we didn’t find it, but we do know there must be a reason.

St. Kitts and Nevis are not tiny islands. They include plenty of space for a tiny lizard, even when sugarcane covered much of the islands. It probably wasn’t wiped out by a single big event, like a hurricane. The infamous monkeys? No one thinks the monkeys ate them all.

Nature is complex. Everything is connected, but there’s rarely a straight line from cause to effect. Maybe there isn’t one reason why the gecko is missing. And maybe the missing gecko is just a clue to a bigger change in life on these islands.

Get an inside look at science as it happens in the Caribbean. This week we discover some of the smallest scary beasts on St. Kitts and Nevis.

In the wild and diverse tree of life, we often imagine ourselves at the top. Fair or not, we do have incredible power to shape the world. Beside us, we place animals we respect: the wise orangutan, the majestic eagle, the powerful elephant, the friendly dog and the dominating shark. Like us, all of these animals have a literal backbone.

What about the endless variety of invertebrates? What about the insects, worms, crabs and corals? For much of history, the average person didn’t think of them as animals at all. These spineless creatures were a lower class of being, worth little thought.

Though they are small, we’ve come to respect some insects. We know we can be laid low by the bite of a mosquito. We’ve watched beetles destroy forests. But we still tend to think of bugs as food for those with backbones—birds and lizards and frogs—and never the other way around.

In the ponds of St. Kitts and Nevis, the tables are often turned. While a caterpillar is a soft and juicy snack for a bird, a tadpole is often a soft and juicy snack for a bug. Aquatic insect hunters don’t care if you’ve got a backbone.

There is a surprising variety of aquatic beetles. A group known as Water Scavenger Beetles are often scavengers as adults. Their larvae, on the other hand, are almost always hunters. One specimen on St. Kitts was several inches long, with huge piercing hooks for mandibles. In our aquarium, it took to eating Cuban Tree Frog tadpoles one after the other.

Dragonfly nymphs can also eat tadpoles and small fish. They have an extendable “jaw” that is longer than their head. It can snap out to grab prey in the blink of an eye. The Creeping Water Bug is smaller, but still quite deadly. It has grabbing front legs like a praying mantis, but more pointy. Its mouth is like a straw, and it is happy to use a tadpole as a juice box.

These tiny terrors can’t do anything worse to us than perhaps a painful bite. But they are a reminder that insects and their kin can be deadly. They can dominate, and in their world just having a spine doesn’t make you safe.

Get an inside look at science as it happens in the Caribbean. This week we watch a frog invade St. Kitts.

For a long time, it was very hard for a frog to cross the sea. A lizard can cling to a fallen tree and drift to the next island—not easy, but not impossible. For a frog, a voyage at sea is almost always deadly. Salt from the sea water poisons the frog, while also dehydrating the frog.

The Cuban Treefrog needed human help to make its great conquests. One of its first stops was Florida. It probably hitched a ride on a cargo ship in the 1920s. It prospered there, and was well positioned to invade new islands in the Caribbean.

Many new species come to the Caribbean from Florida because there is so much trade between Florida and the West Indies. Imported plants and trees are a key source of accidental introductions. Lizards, frogs, snails and insects have all traveled unseen in plant shipments to new island homes.

With human transport, the Cuban Tree Frog has become one of the most successful invaders. Although it needs water for its tadpoles, it has managed to survive in dry islands like Anguilla and Bonaire. It will use any source of water available, from wells and ponds to mud puddles. If tadpoles are trapped in a shrinking puddle, they will eat each other to improve the chances that at least a few survive.

Surprisingly, the Cuban Tree Frog was not documented on St. Kitts until this year. It has been on many nearby islands for years, including Nevis. The wet forests of St. Kitts are certainly suitable habitat for this frog. Perhaps it was just luck that this species was not introduced much earlier.

The timing of the frog’s arrival does allow us to watch as it spreads around the island. If we check for tadpoles in freshwater habitats, like ponds, wells and roadside ditches, we can probably see how it moves across the island. Because the tadpoles need fresh water it is easy to monitor specific locations over time.

One interesting wrinkle is the presence of the Cane Toad or Crapaud. This species has been on the island much longer, and its tadpoles also need freshwater habitat to survive. During surveys on St. Kitts and Nevis, no locations had both Cane Toad and Cuban Tree Frog tadpoles. It was always one or the other. In spots with tadpole-eating Tilapia and large crayfish, neither species was found.

How will the Cuban Tree Frog take over St. Kitts? How long will it take? How will relationships with other species impact the process? It is a fascinating opportunity for study. It’s also a chance to learn more generally about how invasive species invade and how they harm native life.

Get an inside look at science as it happens in the Caribbean. This week we look at different kinds of discovery on St. Kitts and Nevis.

Perhaps you’ve heard of the scientific record. I couldn’t find an actual definition of it, but it is basically all the science that has been published. You might imagine it as a huge library of books, journals, papers and more. But as big as it is, there are countless empty shelves waiting to be filled.

There are endless opportunities for scientists to make new discoveries in the Caribbean. The Caribbean is rich in plants and animals, and has been studied less than many other places. A scientist working here can expect to find many things to add to the great library of science.

But discovery can be a tricky term. The scientific record is only a small part of all knowledge. Scientists often “discover” new species that are well known to local non-scientists. Often, discovery is just making an official record of information that was already known. This is still important, because the information is available more widely.

On St. Kitts and Nevis, our ecological survey team was tasked with making discoveries of all sorts and adding them to the record. The nature of these discoveries depended a lot on how much was already known.

For a well-known group like birds, we mostly recorded sightings of birds that were already known to live on St. Kitts and Nevis. About 200 bird species have been seen on these islands since people began keeping records. Occasionally a new one is spotted, but often these are rare visitors. But keeping records of where birds are seen is still important. It helps us know what habitats are important and how bird populations change over time.

Unlike birds, beetles on St. Kitts and Nevis have received very little attention. The two islands are probably home to over 1,000 different beetle species, but perhaps only 10% have actually been collected and recorded. Most of these beetles are species that are already known from other islands and beyond. Still, knowing the beetle diversity on each island is very valuable. Comparing islands can help us understand bigger questions, like how evolution happens.

Dr. Michael Ivie and his beetle team collected between 200,000 and 300,000 beetles on St. Kitts and Nevis during their work this year. From this treasure trove, they hope to confirm most of species expected on these islands. They will also find many species found only on St. Kitts and Nevis. Most of these species will be entirely new to science. The Caribbean beetles shelf in the great library of science may be relatively bare, but it is filling up fast!

Get an inside look at science as it happens in the Caribbean. This week we explore some freshwater mysteries on St. Kitts and Nevis.

Diving into the vibrant ecosystems of mountain streams on St. Kitts and Nevis, one has to wonder—how did everything get here? Imagine starting at the coast and heading up a ghaut—the local term for the steep ravines found all over these islands. You’re bound to hit a long stretch of dry riverbed before reaching water at higher elevations.

Where there is water—at places like Wingfield River, Cayon River and New River Spring—it can be full of freshwater shrimp, crayfish and goby fish. It is amazing to think that these animals can survive in these remote streams. It’s even more amazing to realize that all of these animals traveled here from the sea.

Many Caribbean freshwater species need to live in the sea for part of their life cycle. It’s not rare to catch a river shrimp or crayfish with a mass of tiny eggs under its tail. But their tiny newborn babies will die if they don’t reach the sea within a few days. They depend on a good rain to wash them down the ghaut into the sea.

After they have grown some, young shrimp and crayfish will return to fresh water, again depending on the temporary flow of rivers and streams reaching the sea. They travel upstream to mature and complete their life cycle.

One of the most amazing abilities these creatures share is a talent for climbing. River shrimp, crayfish and the Sirajo Goby fish are all able to scale rocks and climb up waterfalls to reach their mountain homes. The Sirajo Goby uses specialized fins that form a suction cup.

This all seems pretty complicated, but if these animals didn’t spend part of their life in the sea they wouldn’t have reached these islands. They also use their climbing skills to escape from predators. Some larger fish—like Mountain Mullet—are predators that eat young shrimp and crayfish. By climbing above obstacles like waterfalls they can reach areas that can’t be reached by predatory fish.

Walking up to a mountain stream can be a challenge for us. It is almost unbelievable that a crayfish or fish could travel from mountain to sea and back again. The unstoppable spirit of nature is a wonder to behold.

Get an inside look at science as it happens in the Caribbean. This week we find out who rules the streams and rivers of St. Kitts.

In nature, every habitat needs an animal at the top of the food chain. Often these animals are called an apex predators. They play crucial role in the health of an ecosystem. By preying on the animals below them in the food chain, they maintain balance in an ecosystem.

In the biggest rivers and streams of St. Kitts the apex predators are often crayfish. Unlike many apex predators, crayfish are not just hunters. They have a diverse diet that includes plants and scavenged food. But their size and powerful claws give them the power to hunt most of the things living in the water with them.

There are at least two of these crayfish in Wingfield River. The smaller species is the Southpaw Crayfish because it develops a huge left claw. They are beautiful shades of red and blue. Adults are easy to identify by their big left claw, which is also covered in fine hairs. A big adult can be about the length of your hand, claws included.

The Bigclaw River Shrimp is much larger, reaching up to a foot long. It is typically cream and brown with bands running down its long tail. Its claws are thin, and almost as long as its whole body. Weighing up to a pound and a half, there’s no question who rules the river when you see a Bigclaw.

These amazing crustaceans are not necessarily very common. Due to their size typically need running water—which is richer in oxygen—to live. They tend to live in the larger pools and deeper sections of the river. Bigclaws in particular tend to be territorial, with only one per pool.

So how do these crayfish kings manage their freshwater kingdom? While no one has studied their diet on St. Kitts, they are definitely able to catch and eat aquatic insects, guppies and tadpoles. A careful observer will note that there are no guppies or tadpoles where our predatory crayfish are found. Guppies and tadpoles are often common in still water or streams that are too small for large crayfish.

Long live the masters of the ghaut! Though few in number, they are critical to the of clean water we depend on and the health of the river ecosystem.

Get an inside look at science as it happens in the Caribbean. This week we dive into the freshwater ecosystems of St. Kitts and Nevis to see who keeps the water clean.

Ah, the ghaut! Is there any better place to be on St. Kitts or Nevis? The bottoms of these steep ravines are cool in the shade of tall trees. If you’re lucky, crystal clear water rushes or trickles through. Tiny waterfalls fill tranquil pools. The sound of running water joins the songs of birds and the hum of insects.

You might wonder how the streams and pools in the ghaut stay so clear. They certainly look nothing like the water in a roadside ditch. Also, those trees above are constantly dropping leaves into the water like they do on the forest floor. It’s a miracle that the pools in a ghaut aren’t entirely full of leaves.

The natural flow of water pushes dirt and leaves downstream, especially during big storms and strong rains. During other times, the task of breaking down leaves and other materials is done by a diverse crew of critters. Some are aquatic insects, like fly larvae and beetles. Freshwater snails get in on the action, too. Fish and tadpoles also help out, if they’re around.

Perhaps the most important ghaut cleaners of all are freshwater shrimp. Two kinds in particular use a remarkable tag team approach. The Yellow-nose Shrimp is small, fast and almost clear. It’s also a shredder: it takes large leaves and shreds them down to particles of different sizes. It eats some of what it shreds, and the smaller bits flow downstream more easily than big leaves.

The shredding process also fills the water with nutrients. This could be a recipe for streams full of rotting muck. Luckily, fan shrimp are there to take over. There are a few kinds living on St. Kitts and Nevis, and they are perfectly adapted to grabbing and eating the particles the Yellow-nose Shrimp creates. Their four front feet end in specialized brushes. They fan out these brushes to collect food particles from the water.

Our dynamic duo solves a very important problem: they take dead leaves and turn them into delicious shrimp. Streams run clean and birds like the Green Heron have a great source of food. Catchment points on mountain streams also feed into the water supply for people on St. Kitts and Nevis. When you turn on the faucet, chances are some of that water was filtered by shrimp!

Get an inside look at science as it happens in the Caribbean. This week we dive into the freshwater ecosystems of St. Kitts and Nevis.

Ghaut, ghut, gut: however you spell it, it refers to the steep ravines that link hills and mountains to the sea. Nestled in the bottom of some, we find streams or springs. These may flow always, seasonally or only during heavy rains. A common geological feature in the Caribbean, they are a key resource for both man and nature.

Ghauts are often home to massive trees. Even ghauts that are typically dry may have water beneath them, accessible to trees and plants. In some cases, it seeps from the cliffs and steep walls of the surrounding valley. The shade of a dense canopy overhead also traps moisture. In some cases, the lush forest of a ghaut quickly transitions into dry forest or scrub on the slopes to either side.

Ghauts are pathways connecting inland areas to the coast and vice versa. Running streams are an obvious example of how these pathways work. Some fish and crustaceans that live in freshwater streams send their eggs to sea, where they grow before returning to fresh water. Nutrients—like dead leaves and decaying material—flow from the hills down to coast areas where they are trapped by mangroves to provide nutrition for these wetland areas.

Other animals use ghauts as pathways, too. Bats may nest in the overhangs on the walls of a steep ghaut, and follow the valley floor like a tunnel to food sources. The fishing bat may also use streams and pools in ghauts as hunting grounds.

Streams and pools at the bottom of ghauts are important water sources for many animals. Some animals live in them: fish, crayfish, tadpoles and aquatic insects. Other animals, like birds and bats, may depend on them for drinking water.

From prehistoric times to the present day, people have also used ghauts in many of the ways that animals do. Most obviously, streams and springs are tapped for drinking water and water to irrigate agriculture. Many paths and trails also make use of ghauts. Even the harvesting of crayfish and freshwater shrimp has been done on a small scale.

Today, ghauts are largely ignored. A few key water sources are closely monitored. Some receive occasional visits by hikers. Many are clearly seen as a convenient place to dump trash. They are as important as ever to our natural systems. Will we consider them valuable enough to protect in the 21st century?

Get an inside look at science as it happens in the Caribbean. This week, how do you know if something’s wrong in the local ecology, and how do you know what it is?

During a February 2017 field visit to St. Kitts and Nevis, I marveled at the forests. There were huge trees, hanging vines, graceful ferns and lush mosses. Still, while bursting with greenery, many areas seemed oddly lifeless. Anoles—the small tree lizards that are incredibly common in the Caribbean—seemed to be unusually scarce. Snails weren’t crawling across every damp leaf and tree trunk, they were almost absent.

Other members of the research team—experts on plants, reptiles, birds and more—noticed many similar anomalies. The heliconia plants were surprisingly rare, geckos that we would expect to find weren’t seen at all. Tiny moths and other insects that often erupt in clouds when walking through field or scrub seemed unaccountably sparse. Almost immediately, we were all wondering what was going on.

Our first intuition was to blame the monkeys. Vervet Monkeys from Africa were introduced to St. Kitts and Nevis in the 1600s. Smart and voracious, they’ve had hundreds of years to impact the local ecology. More importantly, they are the one thing that is most obviously different about St. Kitts and Nevis, compared to most other islands in the area. All the Lesser Antilles have rats, many have mongoose, but Barbados is the only other one that has had monkeys for centuries.

The intuition of a group of scientists with extensive research experience in the Caribbean is valuable, but it doesn’t prove anything. Implicating the monkeys would require data showing that ecosystems were damaged, and experiments to show that monkeys were the culprit. Although that is beyond the scope of our project, the data we collect could support the need to look further.

Another culprit had been upsetting the ecological balance over recent years as well. From a serious drought in 2015 to erratic rainfall in the years since, weather may have influenced what we observed. By the time we returned in May, the islands had received some spring rains. Lizards and snails still seemed less common than they should be, but the symphony of insect sounds at night seemed richer and fuller.

With specimens, data and observations collected across two field work sessions, interesting ideas about the ecology of St. Kitts and Nevis are bound to emerge. Do monkeys harm the local ecosystem? Almost certainly. Could animal and plant populations be temporarily lowered due to drought and rainfall irregularity? It’s definitely possible. Do St. Kitts and Nevis have less overall biodiversity that we might expect? Survey results should give us an idea. Most importantly, the data should give us ideas about what these islands can do to help preserve and protect their natural heritag

Get an inside look at science as it happens in the Caribbean. This week, join the bat people to study these furry flying critters on St. Kitts.

The bat people don’t have a lot of time to rest. Scientists studying these flying mammals spend their days scouting good locations to catch them and their evenings setting up nets and other bat-catching contraptions. Nights, of course, are spent studying the bats that they catch.

Studying bats is challenging. Bats are smart, so they are not very easy to catch. They use echolocation to find their way in the night, which also helps them see nets and traps. They are also incredibly agile in the air.

The first step is finding places that bats are likely to be. Some species roost in colonies in caves and abandoned buildings, but many live in harder to find spots like trees. The bat team looks for areas near fruit or flowers that bats like, and pathways leading to resources like water. Trails and streams can create natural tunnels through the forest that are used by bats.

Once a promising area is found, mist nets are set up before twilight. These very fine nets are suspended between poles across flyways. Although most bats will notice and avoid them, careless or tired bats fly into them and are caught. Other types of traps can be used as well, and sound recordings are made. Each species makes unique sounds that can be identified from the recordings.

Captured bats are processed in the field. Processing includes identifying the species and sex of the bat, taking measurements and recording other information. The team records when bats are pregnant or nursing young. Male bats only have visible testes when they are breeding, so this is also recorded. Bats with bald spots or large numbers of parasites are also noted. Once processed, the bats are released.

Although it is a lot of work, studying bats is useful. Bats are important pollinators, seed distributors and insect eaters. Studying them can help us understand if the ecosystem as a whole is healthy. Work on St. Kitts and Nevis may also shed new light on how bats colonized the Lesser Antilles. The data to unlock these secrets is gathered by the team, night by night and bat by bat.

Get an inside look at science as it happens in the Caribbean. This week, we shine a light into a world of darkness in the field on St. Kitts.

Beyond the narrow beam of the headlamp, the world is dark. There are no streetlights here, and the forest canopy blocks out the moon and stars completely. A festival of sounds fills the cool air: chirps and tweets and the ping of the mountain blacksmith.

A river runs through the forest, right here at my feet. It swirls through the holes in my Crocs and around my toes. It does this because I’m the sort of person who walks up a rocky forest stream in the dark, alone, in my Crocs. And because, at the moment, that’s my job.

Field work at night is an adventure. It is mysterious, sometimes holding a hint of danger. To be alone in nature is a great joy. The solitude at night is immersive and absolute.

The night is a critical time for studying all kinds of animals, too. A half-hour walk from here, a team of scientists are catching bats with near-invisible mist nets. I’m searching this stream for crayfishes and other nighttime aquatics. Every few meters a Cane Toad jumps into the stream with a plop.

The beam of the headlamp is fantastic for one’s focus. It is easier to spot camouflaged critters like stick insects. Whatever is in that small circle of light is sharp and clear. Free from the need to process a full field of vision, he mind wanders. What is this stream like in a wetter year? How long have people depended on it for water? Why are there no river gobies swimming here? When was the last time it ran all the way to the sea?

Satisfied that I had spotted every crayfish species living here, I began to head back downstream. My thoughts drifted back towards the rest of the world. Were the bat people having a good night? Were they frustrated and ready to pull down their nets and go home?

I brushed a branch that was hanging over the stream and it exploded. Zebra Longwing butterflies roost together at night and this was their chosen spot. Dozens of pairs of tiny wings flapped against my face and arms in a swirl of black and yellow. I stopped for a minute to watch as they settled back down one by one. Then I started down again, towards the team and the truck and the town below.

Get an inside look at science as it happens in the Caribbean. This week, we dip into freshwater habitats as part of a biodiversity survey of St. Kitts and Nevis.

Take a medium-sized mesh strainer and use some duct tape to secure it to the end of an old broomstick. Voilà, you just made a dip net! This simple net is one of the most useful and versatile tools for investigating life in freshwater habitats.

As part of the scientific team surveying the plants and animals of St. Kitts and Nevis, my specialty is freshwater aquatic life. This includes anything living in the streams and ponds and any other place where fresh water accumulates. Despite the clouds that often cling to the peaks of both islands, freshwater habitats are somewhat limited.

Like much of the Caribbean, these islands are recovering from the drought of previous years. The many the ghauts—a regional term for narrow valleys—on these islands that channel rainwater down the mountain to the sea in wetter times are mostly dry. At a few points on the forested slopes, water is running, but much of it is taken to provide water for the people living here.

Still, life is persistent. Multiple species of freshwater crayfish and a couple fish species manage to survive in the mountain streams. During times of rain, they take the temporary streams downhill and survive in pools as long as they last.

Caribbean crayfish and freshwater shrimp have a complex life cycle. They typically spend their larval phase in the sea, or in the brackish water a the mouth of a river or stream. It is a bit of a mystery how they manage to survive in these mountain streams during extended periods when they are not connected to the sea, or connected only briefly.

In lower elevations, the primary freshwater habitats are ponds, mostly manmade ones. The native animals living in these ponds are primarily insects: aquatic beetles, dragonfly and damselfly larvae and water bugs. Introduced species, particularly the tadpoles of marine toads and Cuban tree frogs, are also present.

Although widespread in the Caribbean, including Nevis, the Cuban tree frog has only recently been documented on St. Kitts. Surveying freshwater sources might give us an idea of how the Cuban tree frog spreads after arriving on an island. While we race to document the biodiversity of these islands, the islands themselves are changing right before our eyes. It is a challenge and an opportunity that makes our work here even more rewarding.

There are plenty of biologists in the world working in university laboratories and museum basements. In many ways, these indoor environments might be considered the primary natural habitat of the modern biologist. Some, however, are only truly at home when out in the field.

In biology, fieldwork is essentially any research that is done outside the lab or library. It usually involves observing, documenting and collecting plants and animals. It is often the dirtiest, sweatiest work a biologist can do, but it can also be the most fun.

In the past, work done in the field and work done in the lab or museum were often done by different people. In the Caribbean, many specimens were collected by non-scientists and sent to scientists in Europe or North America for study. Over the last hundred years or so, it became much more common for scientists themselves to travel to the Caribbean to do fieldwork. It has also become much more common for Caribbean scientists to do both fieldwork and analysis right here.

At the moment, a team of scientists from the Caribbean and beyond are conducting a survey of the terrestrial ecology of St. Kitts and Nevis. They are documenting as many plants and animals as possible, from birds to beetles and trees to mosses. The project will help the government of St. Kitts and Nevis protect the the biodiversity of their islands.

Due to the broad scope of the project, the team includes a variety of experts, specialized in studying insects, birds, plants, reptiles, bats and more. While each one researches their own specialty, they also share observations about the general ecology. The impact of invasive species—like monkeys and rats—or the recent drought, can be seen across multiple plant and animal groups.

Together, the team is making new discoveries, uncovering mysteries and overcoming challenges. In the Antillean Field Journal, we will follow their progress up the muddy slopes of Mt. Liamuiga and Nevis Peak, to the rarely-visited shores of Booby Island and many places in between. As we go, we will see how our understanding of nature in the Caribbean is improving, even as the islands themselves are rapidly changing.