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!