Get ready to take flight alongside migrating shorebirds for an exciting trip to the Copper River Delta in the Chugach National Forest near Cordova, Alaska. Millions of shorebirds return to the spectacular wetlands of the Copper River Delta to rest and refuel on their long journey to the breeding grounds in western and northern Alaska.

Shorebirds are truly ambassadors to our world. Migrating to Alaska from many places, such as Mexico, Central and South America, Japan, Hawaii, and the West Coast of the United States, some shorebirds fly as many as 10,000 miles one way. However, shorebird numbers are declining and scientists are concerned about their future.

How can you bring the shorebird excitement into your classroom? “Winging Northward: A Shorebird’s Journey” provides this information-rich web site and free electronic field trip that brings the birds to you! Your students will be fascinated by shorebird adaptations, their wetland habitat, and their migration flyways across international lines.

No matter where they live, students will learn how public and private lands, whether a neighborhood park or National Forest, provide wetland habitat and how students can help protect these habitats in the United States and around the globe.

Copper River Delta in Cordova, Alaska

Where is the Copper River Delta?
The Copper River winds between the rugged Chugach Mountains and meets the Gulf of Alaska just east of the coastal community of Cordova. Along with the town’s remote location, the prized Sockeye and King Salmon that return each year drive the town’s economy and give Cordova a unique Alaskan flavor.

The Copper River runs 287 miles through Southcentral Alaska from the headwaters in the Alaska Range to the tidal mudflats bordering the Gulf of Alaska. Linked to five other glacial rivers and their wetlands on the perimeters of the Copper River, the Delta forms the largest continuous wetland on the North Pacific coast.

What kinds of wetlands are found within the Copper River Delta?
Tidal flats and sloughs, saltwater marshes, estuaries, freshwater ponds, and waterlogged muskeg (peat soils) of the Copper River Delta compose this vast interwoven wetland of 700,000 acres. The Copper River Delta provides abundant vegetation and endless mud flats for shorebirds and other animals to feast. Did you know that the Delta is considered one of the most productive wetlands in the world?

Why is the Copper River Delta so special to shorebirds like Maya?

Five to seven million shorebirds visit the Copper River Delta every spring! The Delta has 36 species of shorebirds, primarily Western Sandpipers and Dunlins, with the astonishing amount of energy they require to make the next leg of their journey during spring and fall migrations. South of the marshes of the Delta, the tidal mud flats present Maya and her friends with tasty, energy-rich morsels like pink Macoma clams and marine worms. Some shorebirds remain on the Delta to breed, but most head further north to other Alaskan wetlands. The Copper River Delta is a major stopover site in the western hemisphere, making this wetland a vital link in the chain of wetlands.

How is the Copper River Delta formed?
In the summer months, “The Copper” carries a million metric tons of sediment each day and dumps it along its meandering journey to the sea. The Copper adds more sediment to the Pacific Ocean than any other source. Six glacial rivers contribute to the Copper River’s enormous load, which has formed over thousands of years the 600-foot deep mud flats at its mouth. These mud flats offer shorebirds a feast of mollusks and other invertebrates living beneath the surface.

What other fish and wildlife use the Copper River Delta besides shorebirds?

The Cordova Ranger District of the U.S. Forest Service manages this magnificent wetland habitat primarily for fish and wildlife. The savored salmon runs of the Copper River depend on the cold, silty waters as a highway to the streams where they hatched and will lay the eggs of the next generation. In addition, brown bear, black bear, moose, wolves, coyotes, mountain goat, sheep, Stellar sea lions, trumpeter swans, and three species of amphibians make the Copper River Delta their home.

Sinaloa, Mexico

Where is Santa Maria Bay, Sinaloa?

Sinaloa, one of the 32 states of Mexico, is located on the northwest coast long the southern Gulf of California. To the north is the state of Sonora (which borders the U.S.) and to the south is Nayarit. On the east are the states of Durango and Chihuahua with the Sierra Madre Mountains. Sinaloa is famous for it’s natural beauty with tropical beaches, rain forests, and great coastal wetlands with large lagoons and mangroves. If you’ve enjoyed fresh mangoes, tomatoes, cucumbers, or sweet peppers in the winter they may have come from Sinaloa!

What are the wetlands like at Santa Maria Bay?
Santa Maria Bay, recognized as one of the country’s most important wetlands by the government of Mexico, is a large coastal lagoon in western Sinaloa made up of dense flooded mangrove forests and extensive open tidal mud flats. The Bay provides important wetland habitats for millions of birds, including ducks, pelicans, herons, gulls, terns, and, of course, shorebirds by the thousands. Also, there are approximately 60,000 people living around the Bay in 10 principal communities. Primary economic activities are agriculture, fishing, and shrimp farming.

Why is Santa Maria Bay so important to shorebirds?

At least 1/3 of all the Pacific flyway shorebirds spend their winter in the Bay area (almost one million shorebirds!) plus many thousands more use it as a stopover on their way to and from Panama and South America. There is no other wetland of this size or quality along the entire west coast of Mexico so shorebirds really depend on this site for their habitat.

What other wildlife use the Santa Maria Bay wetlands?
Almost one-half of the 1,018 bird species of Mexico can be found in Sinaloa, including beautiful exotic birds like the blue-footed booby, elegant terns, and brown pelicans. Offshore from the Bay are the famous waters where the Gray Whales spend the winter with their newborn “calves”.

Maya’s Story
A story for your class

Experience the last 24 hours with Maya, the Western Sandpiper, before she migrates from Mexico to Alaska. [See her route on the map] Stay tuned to this space, because in January 2002, students will learn about Maya’s amazing migratory journey. In March 2002, students will learn how we can help Maya and other shorebirds like her.

Get ready! We are about to embark on an adventure that will take us thousands of miles from Mexico all the way to Western Alaska with only brief stops along the way.

Chapter 1: Maya on a Mexican Shores

Hi! Hola!

My name is Maya. I am a Western Sandpiper and just a little under one year old. I am basking in the warm Mexican sun and listening to the waves crash on the beach in the distance. I am on the edge of an estuary. While it is a beautiful day with a warm breeze at my back, I am nervously considering what migration means. What is migration? As far as I can tell, it is scary because it means a very long journey without many stops. My family flies this marathon two times a year with a few short stops along the way to rest and eat. That’s like driving thousands of miles in a car with fewer than five rest stops! We travel north up the Pacific coast to our breeding grounds in Alaska. At the end of the summer in Alaska, we migrate south back to Mexico. “It’s … well… like endless summer!”

I was born in an Alaskan wetland and flew all the way down to Mexico at the end of last summer. But that was many months ago and I was so young then. I barely remember the trip. The amazing part about the journey is the fact that shorebird parents leave their fledgling babies [“yep, like me!”] behind to find their way south all by themselves! I can’t believe I really did that! Somehow, the stars and some kind of internal compass guide us all the way to our final destination. The fact that we can do this all alone is an incredible mystery–even to scientists, who are still trying to figure it out. And then upon our arrival in Mexico, we reunite with our families.

Since I don’t remember my first migration very well, I am told that when I arrived in Mexico, I was exhausted and so, so very happy to see everyone again. Jorge, my brother, and Abulito, my grandfather, showed me how to quickly regain my energy by eating nutrient-rich food and getting the rest I needed. Once I recovered, I soon met Oxy and Maria, who are now my two best friends. They are young Western Sandpipers, too, and they will soon join my family and me as we embark on my first migration north from Mexico. It can be confusing: we live in Mexico in the winter and in Alaska in the summer. Humans call my winter home in Mexico “wintering grounds”

Historically, I’m told, my family makes four stops along the Pacific Coast. [See the map to enlarge and to find the wintering, staging, and breeding areas we will visit.]

Our journey will take us to the Alaskan tundra where I will find a mate and breed. Such a long journey makes me very nervous. We start off from here, Sinaloa, Mexico, and make our first stop in Southern California. After this stopover, called a “staging area”, we stop in other wetlands along the West Coast like the Copper River Delta, my brother Jorge’s favorite place in the world. Jorge tell us that there’s a huge variety of clams and worms as well as many different kinds of shorebirds to meet here, in the Mexican State of Sinaloa, and make.

Chapter 2: Maya Gets Ready

In part I’m nervous because my body tells me to eat faster, eat faster!!! This is an unsettling feeling. I’m trying to eat as much as I possibly can. My body says, “stuff yourself!” before taking off for spring migration. Oxy and Maria are puzzled by many of the same things and share some of the same fears, although everyone agrees that I ask too many questions and have far too active an imagination for my own good!

From my vantage point on the shoreline, I can see my brother, Jorge, in shallow water, probing in the sand with his beak for aquatic insects and invertebrates. He, like all of us, is working on increasing his body weight by 50%! Can you imagine? If you weighed 75 pounds you would weigh 112.5 pounds in just a week! That is one gigantic difference. And he will soon lift off the ground in spite of this load! I am envious that he has migrated several times already and knows all the tricks of survival as well as the lay of the land.

I’m amazed that Jorge can continue to noodle around in the mud–non-stop–without stopping for a break. Even if Maria or Oxy tease him by screeching, he ignores them and continues to search for little marine worms. No doubt in the back of his mind he’s thinking about how he can get them back later.

The sun is now setting and I admit that I am tired from gorging on so many little marine critters. But more than that, I am frustrated that my parents and Jorge cannot explain something so simple: why do we have to take such a huge journey? Their answers are always different. My mother says it’s because we need to take advantage of the plentiful insect life in the Arctic during the summer months. No one disagrees with her, but my father says it’s because we have some instinctual need or urge to head north, one that has existed for many, many generations. We will fly over 250 miles a day!

I get worried not so much because of migration, but because our survival depends on healthy wetlands and resting areas where we stop during the journey to the nesting grounds. My grandfather, Abuelito, tells us that each time he flies north there are fewer wetland habitats and more houses and developments built by humans. How can we be sure that we will find the resting spots (also known as “stop over” sites) that we depend on for rest and food?

Abuelito, is nearby and I look over at him. He has been on the beach for years and years. After he completes a full migration, he gets a bit grizzled and his feathers get a bit frayed. But now, his feathers are clean and shiny and ready for our imminent departure. He tells us amazing stories about his adventures and “near misses” during migration. It is miraculous he’s lived so long considering how many times he’s been close to dying. He always reminds me that I should be very proud to be a “Western Sandpiper.” I wonder what this label really means. I guess it’s “Western” because we migrate along the west side of the continent while many other shorebird relatives fly through the middle of the continent, or along the East Coast–the two other primary migratory corridors, or flyways. There are over 79 species of shorebirds in South and North America and they all use one of the flyways.

Abuelito is old and we have a lot to learn from him. The one thing I hear over and over again is how neat he thinks it is that other shorebirds have different types of bills. This means that we don’t compete for the same food on the shoreline. For instance, Jorge’s best friend is a Long-billed Curlew. He is very elegant and probes deeply into the ground with his long curved bill to reach buried invertebrates. Curlews especially enjoy ghost shrimps that live in very deep burrows. And then Jorge’s other friend couldn’t be more different! He is a Snowy Plover and has a short, stout bill, which he uses to pick up prey from the surface of sand and rocks. Abuelito reminds me, too, that Western Sandpipers are special, because our beaks aren’t either long or short. This means they are more versatile so that we can choose between a larger variety of food and habitats, too.

When I get scared about our coming migration, Oxy and Maria tell me not to be so nervous, because nature has blessed us with many advantages. I’m told that by the time I reach Alaska my feathers will change and I will have “breeding plumage.” This means my head and shoulders will be rust and tan speckled, my belly will be a light color, and my breasts and sides will have dark, arrow-shaped spots. This is comforting. These colors will make me blend into the environment better so that it is more difficult for predators to spot me. I see it as my own “camouflage.” They tell me that before the winter I will grow once again, new, gray feathers that blend well with the sand and mudflats.

Chapter 3: Maya’s Unique Design

Jorge thinks I worry too much and tries to relax me by focusing on all the amazing qualities that we have. He gets very excited when he lists off to me the remarkable number of adaptations that help us survive. He insists that we are unique and different than other birds–and much better (but how would he know?). One thing is for sure: an adaptation gives us an advantage, or an edge, for survival in our wetland habitats.

According to Jorge, my entire body–from the tip of my bill to my tiny toes–is uniquely designed so that I can survive more easily in a wetland habitat. This means that I am “physically adapted” I am told. Last night as we were feeding by the shadow of the moon, Jorge rambled on and on about how I need to begin to appreciate how lucky we are. These are the reasons he gave:

• Our bills are like surgical instruments that can probe the mud for tiny animals and work just beneath the surface. (And Papa reminds us that our bills are also important for building nests and courtship as well.)
• My long, pointed wings allow me to fly long distances at a fast speed during migration. In fact, some of my shorebird friends can fly 50 miles per hour. If I had short, stubby wings, I wouldn’t be able to fly great distances, or I’d have to migrate slower and stop more often, which would slow me down.
• I have hollow bones that keep me “light as a feather.” They help make flying easier.
• I have large air sacks that supply me with lots of oxygen to nourish my flight muscles. I fly hours and hours at a time.
• Located at the base of my tail I have an oil gland. Even though I live in and around water, I like to stay dry. Oil from my gland keeps my feathers waterproof–it’s like an instant raincoat that goes with me everywhere I go. All I do is preen my feathers with the oil using my bill or the back of my head. The oil also keeps my feathers clean.
• My long legs allow me to wade in water or mud while my long toes give me stability when walking, kind of like wearing the right types of shoe. I don’t swim so I don’t need webbed feet.

Certainly this means that our chances of survival are greater–and I feel much better. I thank Jorge for reminding me of these advantages. Oxy interrupts me by raising her beak from the sand and screeching from the mudflat, “You can’t argue with that. Now, that’s enough talking–you’d better get eating.” She gets easily annoyed with Jorge for being a know-it-all, but the truth is that she is right. Almost every minute must be used to build our fat reserves–which to humans is like extra gas for a car. The food we eat is the energy that allows us to fly for long distances without stopping. So last night was a long night of stuffing our faces with as many little pink clams as we could get our beaks on. Thank goodness we have long, pointed beaks to help with this job. Well, I’m going off to use my bill right now!

Chapter 4: Shorebirds Special Gifts

Earlier this afternoon I watched Maria fly over to Jorge. I could hear her chirping to him quietly. She wants to be sure he understands that not all adaptations are physical. I heard her suggest that, in fact, shorebirds also possess behavioral adaptations. She explained, for example, that these adaptations include migrating and defense mechanisms (such as dragging a wing to distract a  predator from a nest of eggs). It’s incredible what she has learned in less than a year. She gives Jorge another example of a behavioral adaptation. For instance, when we migrate, we fly at high altitudes to take advantage of the stronger more prevailing winds than can be found at lower altitudes (and the air is not so hot!). I could see the expression on Jorge’s face. He was feeling a little embarrassed that he had overlooked this point. He responded with a quick retort: “Well, we might as well fly incredibly high since we shorebirds can’t set down in the ocean to rest–because as you know, we can’t swim!–at least for very long.”

Chapter 5: Fear of the Falcon

Suddenly I hear my mother cry with a high-pitched cheet, “Falcons are coming–take flight!” Her short song consists of a few notes rising in pitch and then fades off with the breeze. What she “cheets” to us may sound like a strange suggestion, but the best defense for a shorebird against a raptor is to become airborne. Once in the air, we can get up to an evasive flight speed, maintain a tight flock formation and thus outmaneuver that menacing beast.

I can see through the grasses at my back that they aren’t threatening. I “cheet” back to my mother so that she doesn’t worry about me and knows that I am ok. I scan the shoreline and see Oxy and Maria in the distance. They look safe, too.

I look back again at my mother and think about how beautiful she is. Now that the danger of the falcon is gone, she is preening her feathers. She has arrow shaped spots on her breast and sides–and has other common Western Sandpiper features like a belly that is a light buff color. She looks identical to other shorebirds, but she is my mother and very special to me. I’m told that when we reach the breeding grounds in Alaska her coloring will change so that she has a rust- and tan-speckled head and shoulders. In other words, we have two sets of clothing: the breeding plumage and the non-breeding plumage, which are like two different dresses to humans. In each situation, a change in the way we look ensures that we blend into the background. That way, we can hide from predators.

Now the sun has set into the ocean and the breeze has died down completely. This is the time of day when I think about the future and make myself more nervous than usual. But I have a good reason to be. Tomorrow we start off on our very long journey north. Jorge, Oxy, Maria, Abuelito, and my parents have gone to great lengths to help me prepare. We will be together for the whole journey, which makes me happy.

I doubt I will be able to sleep tonight. I see Abuelito just six feet away, and he already has one leg tucked into his chest for at least part of the night. I want to ask my mother one last question, but she is already asleep. She did a good job over the past two weeks insisting that I eat and eat and save my energy for the long flight ahead of me. I am as ready as I can be. I have doubled my body weight in just a few weeks; I have preened and re-preened my feathers so that they are clean and prepared for the upcoming journey. I have asked all the questions I can think of and can picture many wetlands from Abuelito’s stories, which we will soon see.

Right as I’m about to fall asleep, Jorge swooshes right above my head and cheeps, “Get a good night’s sleep, because tomorrow you start one long, wild, and crazy ride!”

Chapter 6: Maya Heads North
Late March in Sinaloa, Mexico

The sun rises this morning and I watch it inch up over the horizon. Today, I can’t stop thinking about the huge journey ahead of me. I am about to begin a 7,000-mile migration! That is hard to imagine. We’ll fly about 250 miles a day, depending on the weather and other unexpected events. How funny to think that this journey is routine for Abuelito, and the others who have done it before.

As I think of the trip, Jorge lands on the mud next to me and feeds. Most of the time he acts silly or mischievous and flies in funny ways to catch my attention. Today however is different. He knows that I am anxious about leaving and wants to help me feel better. He calls out to me, repeating, “remember… persistence and accuracy, persistence and accuracy.” If I focus on these two things I just might make it to the Arctic!

Above us, many kinds of birds fly over in a beautiful sweeping motion. They are heading north. Suddenly our group takes flight and joins the patterns in the sky. I too am swept into the scene and I spot Maria and Oxy off to the west. I know that there will be many days, and even weeks, when we won’t see each other. But, maybe, just maybe, we’ll land next to each other after our 2,000-mile trip.

Here we go! What in the world makes us take this long journey? How is it that our breeding and wintering grounds are so far apart? It is hard for anyone to answer this question. All we know is that we seek “eternal spring” – warm sun and lots of food resources. During migration, we stop at wetlands along our route to rest and eat. These staging areas, or migratory stopover sites, are nutrient-rich wetlands that give us space to rest and rebuild our food reserves for the next part of the trip. We basically leapfrog – “hopping” from wetland to wetland all the way from the tropics to the Arctic.

Gusts of wind push me from behind as I think about all of this. It is a “rush” to be carried by the winds at two or even three times my normal flight speed. We spend many hours searching for the best pockets of air to fly in. At 6,000 feet it isn’t always easy to see land when many clouds block my view. Abuelito taught me to look for ‘visual aids’. A “visual aid” is something that helps me navigate. I look for landmarks like coastlines, rivers, and mountain ranges or even the moon and sun and stars. Some believe that an “internal” compass in my head helps me find my way by following the Earth’s magnetic field. Visual aids make our survival possible. If we fly or are blown off course by just one degree, we could miss our destinations and die along the way. The fact that many of us complete our journey shows the incredible accuracy of our navigational aids.

As I fly, I think back to Abuelito and his descriptions of what California looked like from the air. Now, what he described is opening up in front of my very own eyes. It is amazing to peer down and see the coastline and all the human settlements. There are many parts of Southern California where the air has a yellow or brown haze to it. There must be many creatures that live and breathe below this pollution.

Chapter 7: San Francisco Bay
First Migration Stop-Over Many Days Later

Excitement surges through the flock as we approach San Francisco Bay. I’m exhausted from hours of non-stop flight, but I feel a tiny burst of energy just before landing. I keep repeating Jorge’s last words “persistence and accuracy.” I am so tired I can only follow the flock. Each wing beat is painful and is a huge effort. I don’t know if I can make it.

San Francisco Bay should offer a number of good places to stop and refuel. There are tidal marshes, mudflats, salt ponds, seasonal, brackish or freshwater wetlands, tide pools, islands, rivers, creeks, as well as bay shoreline. But about 85% of San Francisco Bay’s shoreline and tidal wetlands have been altered since the 1950’s. This gives us fewer and fewer places to land and rest. Historically, many shorebirds have used the wetlands south of the San Mateo Bridge (South Bay). But this is also where humans built big buildings and where we want to rest and eat. How can we both use the wetlands?

Our flock swooshes down toward this marsh. Huge new condominiums greet us and we panic as we lose energy looking for a new place to feed and rest. There is no choice but to stop. We are too tired to go any further and we have no fat reserves left. We land in a marsh that borders the development and hope that there are no dogs or water pollution.

For three days we gorge ourselves non-stop on crustaceans and mollusks. All I care about is eating and eating and eating. I am not aware of much else around me.

On our fourth day at this marsh, I learn that the decision to stop here saved our lives. If we had tried to find a different wetland not too far away, we would have died. A local bird told us the sad news. Chemicals from a smoke stack were caught in clouds; they poisoned the rainwater and then poisoned marine life in that wetland.

Shorebirds like us depend on healthy wetlands for survival. When we hear about situations like this it seems like a miracle that we survive our migrations. This has been an exhausting several weeks. But there is still something that pushes me on – something beyond my ability to understand. All I know is that I must move on. My friends and my flock fly north.

Chapter 8: Gray’s Harbor, Washington
Several Days Later

I fly over southern Washington State and think about my family and friends. Even though we are all flying north, we are spread over a wide band along the Pacific Coast. Migration routes are not distinct, direct flyways, but area wide, broad routes. These ‘highways’ in the air lead us to a place where we get funneled together in a ” staging area.” Once we arrive at a staging area, we cluster in large numbers. Because we group together in a fairly small area, we are very vulnerable. If something bad happens – like nasty weather, or an oil spill – many of us will die.

These “staging areas” are important because they are very few and very far between. There are not many places along the coast that are good places to stop and rest. There are so many of us flying north and it is only in these special wetland “staging areas” that our huge flocks can rest and feed. Scientists don’t know why, but we use the same stopover sites year after year. Due to our adaptations, we are instinctually locked into our staging areas.

Favorable winds push me north. I wonder where Jorge is and if he is being helped by the same winds? As my energy begins to wind down, I spot the coastline of what I think is Gray’s Harbor. I see healthy estuaries including open water areas (subtidal) and mudflats with rocky shores (intertidal). Here humans have made some changes to the landscape but there is also open marshland. The flock swoops down to join a busily feeding group. I am relieved to land, but I am SOOOO hungry. Rest can wait. I must eat.

How many weeks has it been since we left Mexico? I spot Abuelito! I am so excited! I try to take off before my wings are ready for flight. I chirp and chirp in glee as I approach him from the west. He looks weathered and drained but is focusing on eating as many mollusks as he can. Neither of us has energy to do more than push our beaks into the sand. It is so nice to be in the safe presence of someone familiar and wise. I feel like I can relax a little bit. We are lucky because it is low tide. The mud flats are not covered by water and it is easy to find worms.

After many hours of feasting, Abuelito raises his beak out of the mud and wants to know how my journey has been. I tell him that I almost died at San Francisco Bay but that I feel a bit more confident now. Abuelito says that my feathers are starting to change. My head and shoulders are speckled with rust and tan. “Another miraculous advantage that nature provides us,” he laughs. We are very fortunate to have “camouflage.” We blend into the environment better and predators like hawks can’t see us as easily.

Abuelito points out other shorebird friends who use a similar “short-hop” strategy as they migrate to the Arctic. Across the mudflats are flocks of dowitchers, yellowlegs, dunlins, and semipalmated sandpipers.

Several days of gorging with Abuelito has me ready for the next leg of the trip. When the flock lifts, we join the group. Once again, we are airborne and on our own.

Chapter 9: The Beautiful Copper River Delta

The air is crisp and inviting. The sun feels stronger. I fly hour after hour, thinking about the next stop-over. Many shorebirds like Copper River Delta best of all because there are expanses of beautiful marshes – the Delta is the largest intact wetland on the North Pacific coast!

The best thing about the Delta is the amount of habitat it provides. Over a million birds can use the Delta in a single day. Over 20 million birds use the Delta during spring migration. All my western sandpiper friends will stop at the Delta. Scientists have found that the entire population of western sandpipers passes through this staging area within a week. The Delta is one of most important and heavily used staging areas in the world for western sandpipers!

The Copper River Delta region is a wonderful resource for us. It’s wonderful to not worry about human disturbances, like skyscrapers and shopping malls. Here, on the Delta, we just need to worry about falcons and spring storms. Here there are bald eagles, moose, swans, and beavers. It’s a very different world from our flight through California. Here we feed on tasty insects, tiny clams (mollusks), worms and crustaceans buried in the mud.

Like all Western Sandpipers, we feel incredibly lucky when we finally reach our final destination at the end of migration. It is wonderful to have some confidence now and feel surer of myself. We are almost there!

As I go over in my mind what will soon happen at our breeding grounds in the Arctic, Maria and Oxy suddenly appear! We are so happy to see each other again. It turns out that they had winds that helped them arrive 36 hours before me. They had a chance to rebuild their energy reserves and could spend the energy to try to find me!

Maria tells Oxy and me all the details of what we should expect when we reach the Arctic. We will each find a nesting site and will defend it against other birds. This is called territoriality and it ensures that my mate has a nesting site when I arrive – which is the first step in starting a family. My mate will show flight displays that may include wing fluttering, tail cocking, or nest scraping. Oxy and I giggle at the thought! These are more examples of behavioral adaptations. The females select the males. Once this happens we will breed and take turns incubating the eggs. After the chicks hatch, both my mate and I will help care for our young until they are almost ready to fly. Taking turns incubating and caring for them are behavioral adaptations of the western sandpiper to ensure the survival of the species.

With that brief lesson finished, the sun is setting and we continue to eat and eat and eat.

Chapter 10: A Sudden Storm

Today we are supposed to lift off to our final destination, but we can’t! The soft snowflakes keep falling and falling. The only thing left to do is eating, and keep eating! So far, two feet of snow have built up in places. It’s actually quite beautiful. Finally the snow stops in the late afternoon. A good strong wind arrives from the east. I lift off with the flock and head toward the breeding grounds where I am going to raise chicks of my own. I think about the cycles in nature and how miraculous they are. Off we go… I hope I find Jorge up in the breeding grounds. I have a lot of news to share with him!

The Shore
Land and water — they are the two most basic geographic features of the earth’s surface. What happens along the narrow lines where these two great bodies meet? This fragile strip contains some of the greatest diversity (variety of living organisms) on our planet. It is enriched by life-sustaining water, yet must also endure some very powerful natural forces. It is called the shore, and it is land that:

• faces regular and irregular periods of drying out, dampness, or flooding;
• contains a tremendously fluctuating range of salinity; and
• is eroded by wind and water.

Shorebirds
Organisms that live in this precious environment have adapted to thrive in these conditions. Shorebirds are a group of special birds that are adapted to live near these coasts, or shores. Because of their lifestyle, particularly during their spectacular migrations, of walking through water and mud to find food, Europeans call these long legged birds “waders.”

Each spring and fall, enormous flocks of shorebirds swarm along the coasts in great migrations. It is a thrilling sight when the shore comes alive with feeding birds, or a flock swiftly wheels and turns in flight. These flocks pulse to and from with the cycles of the tides, and, on a broader scale, with the cycles of the seasons. Shorebirds eat, breed, travel, and rest as a part of these cycles of nature.

Shorebirds are more accurately described as birds of open land, including, but not limited to, the shore. Shorebirds include the sandpipers, plovers, oystercatchers, snipes, and stilts, among others.

Besides their regular migrations, their lifestyle includes other highly developed rituals of behavior, including elaborate courtship displays. Most of us have never had the pleasure of witnessing these displays, because many migratory shorebirds nest in remote Arctic tundra or open grassland.

There are about 214 species of shorebirds in the world. Almost 80 of these regularly occur in North America. Seventy-five species breed in the Holarctic region. This means they summer in either the North American Arctic (Nearctic) or Northern Europe and Russia (Palearctic). Many species of these great migrators breed in both of these areas. See if you can tell why this might be so by looking at a globe.

Morphology

Morphology refers to what an organism physically looks like. Shape, color, and size are all examples of morphology. In his book Shorebirds of the Pacific Northwest, Dennis Paulson states, “Each shorebird is a beautifully functioning organism, the parts finely tuned by natural selection to work together to adapt the bird to its environment.”

One of the most striking physical traits of shorebirds is their stately posture. They stand up very straight on long legs. Shorebirds that wade to find food have the longest legs. They also have long pointed bills with which they probe in the mud or water for small animals to eat. Shorebirds have long pointed wings and are strong, fast fliers. There is variation among the species, but in general their size is relatively small.

The coloration of shorebirds might at first be thought of as rather ordinary. One realizes the value of their brown, banded plumage the first time one sees a beach with 10,000 legs! Their coloration is an adaptation of camouflage. Shorebirds are generally speckled brown, rusty, and white on the back. Some have white or black patches on the head, breast, or belly. They blend in well with the sandy, muddy, or grassy areas where they feed and nest. Their camouflage helps protect them from predators such as eagles, hawks, gulls, and foxes.

Shorebirds tend to be darker colored on the back than on the belly. Have you ever seen a flying flock of brown sandpipers turn together in the air and suddenly appear white as their undersides are flashed at you? Perhaps this bicoloration is an adaptation similar to that of many fish. When observed from below, against the light, the bird is inconspicuously light-colored to a potential predator. When a flying hawk observes shorebirds from above, their darker backs blend in with the beach or mudflat. As you learn more about shorebirds and their environment, see if you think this theory makes sense.

Behavior

One of the most notable and beautiful characteristics of shorebirds is a particular behavioral adaptation – scattered feeders lift off and swiftly consolidate into a graceful flock at the approach of a predator. Each individual’s chance of avoiding being eaten is then increased. Some shorebird species are generally solitary, but most will readily join a flock in response to a disturbance. Mixed-species flocks are common. Mixed flocks also make birdwatching more fun for the beginner, who can use contrasts of size, color, or behavior to spot different species.

During the breeding season, shorebird pairs defend territories. In the following lessons, we will learn more about how and why they do that. Individuals of some species also defend mobile feeding “territories” around their moving bodies as they forage during the winter.

Another distinctive behavioral adaptation of shorebirds is their one-legged posture while roosting. Keeping one leg and the bill tucked under the body feathers conserves heat, an important consideration in the often chilly open areas of their habitat.

Migration

The tremendous importance of the strategy of migration to shorebirds cannot be overstated. Most shorebirds migrate long distances between their summer and winter homes. They are dependent upon at least three distinct habitats: their breeding habitat, non breeding habitat, and stopover sites along the migration routes. They are physically designed for long distance flight, as you will learn in the activities to follow.

All Arctic-nesting shorebirds migrate. The Arctic refers to that region of our globe that is in the far north, generally north of the imaginary latitude line known as the Arctic Circle. Some shorebirds that breed in northern Alaska spend the winter as far away as southern Chile. Some plovers, curlews, and tattlers fly non-stop from Hawaii and other Pacific islands to Alaska, a distance of over 3,500 miles in two or three days. Many species of shorebirds form large flocks for the long migrations between North America and South America.

Feeding and Habitat

Shorebirds depend upon wetlands for food. Wetlands include marshes, river deltas, mud flats, tundra, and intertidal areas. While wintering and migrating, shorebirds feed upon tiny clams, snails, sand fleas, and worms in the mud and sand near the water’s edge. Bill size and shape, like coloration, is an adaptation to the shorebird’s environment. Shorebirds with short bills probe for animals that live very near the surface. Those with longer bills can reach animals buried deeper in the mud. Millions of shorebirds breed and raise their chicks each summer in the Arctic. During this short breeding season in the northern tundra, they feed on insects, grubs, and worms that they capture in the vegetation.

When humans fill wetlands with gravel to construct parking lots and buildings, shorebirds cannot find food. Many shorebirds return instinctively to the same feeding areas every time they migrate. Thousands, hundreds of thousands, and even millions of shorebirds might be found together in one place during migration. If the wetlands to which they return each year by instinct are destroyed, they do not have the ability to look somewhere else. Even if they did, where would they find another wetland when all the wetlands have been filled? Where will the shorebirds go? What will the shorebirds eat?

Identification

Some people think shorebirds are hard to identify, but it’s a skill anyone can learn if they know what to look for. Here are some clues:

• Notice the size. Large shorebirds are about the size of robins or pigeons. Small shorebirds are about the size of sparrows.
• Notice the color of the plumage (feathers). Look for distinct white, rust, or black patches. Does the bird have spots or streaks on its breast?
• Is the bill long or short? Is it straight or curved slightly up or down? What color is the bill?
• What color are the legs?
• When the bird is flying, can you see wing stripes or a distinct tail pattern?
• Observe its behavior. Is it picking up its food or probing below the surface for prey? Is the bird you are observing alone, in a small group, or part of a large flock?

Importance of Shorebirds

Did you know that shorebirds contribute to a healthy ecosystem? An ecosystem is the collection of all living (biotic) and nonliving (abiotic) things that are linked and fueled by energy from the sun in a particular geographic area. For example, some of the components of an ecosystem might be land, water, shorebirds, phytoplankton, zooplankton, fish, and guano. The living components of any ecosystem have adapted to live and reproduce in the presence of the other particular components and rely on many of them.

Shorebird droppings, called guano, fertilize the mudflats in which they feed and the water over which they fly. The guano helps microscopic plants, called phytoplankton, grow. Phytoplankton form the base of the food chain upon which the fish we eat depend.

Because shorebirds are dependent upon wetlands, they are good indicators of wetland health. The health of an indicator species tells biologists something about the health of other creatures using or composing that habitat. For instance, if there is a change in population of a shorebird, then perhaps populations of worms on which it feeds are being similarly changed. A change in condition of one shorebird species might lead us to hypothesize that other shorebirds using the same resources will be similarly affected. Perhaps one of the abiotic (nonliving) components of the ecosystem, like the water, is polluted. An indicator species is usually an easily observable organism, and you might find that a change in a shorebird population is the first indication, or hint, that a water source is polluted.

Think of some other indications that studies of shorebirds might give us about a habitat or other species. How many hypotheses can you come up with to finish this sample sentence:
If shorebirds at my local pond (or beach or estuary) are declining in population (or health or number of healthy chicks produced), then perhaps it is because…

Habitat
A habitat is the place where an organism obtains energy (food) and water and finds shelter. Without suitable habitat, the organism would die. Plants, animals, and all other organisms are adapted to live in a particular type of habitat. Terrestrial habitats may be hot or cold, dry or wet, with sandy soils or peat, and include endless other characteristics. Aquatic habitats may be salt or freshwater, shallow or deep, warm or cold, just to begin describing them. Plants generally only live in one habitat in their lifetimes, but animals that can move large distances might use several.

Migration
Migration is when an animal moves from one place to another, often from one habitat to another. Usually migration refers to a somewhat predictable pattern of such movement. Some planktonic organisms migrate up and down in the water in response to the amount of daylight. In turn, some fish migrate up and down in response to the migration pattern of these plankton upon which they feed. Animals may migrate because of changes in season, food availability, or number or success of competitors. How are these different reasons related to each other? Can you think of any other reasons for migration between habitats?

Significance for Shorebirds of Migration between Habitats
Birds are capable of the most advanced method of movement on earth: they can fly. Because of this ability, many of them have evolved to use more than one habitat. Arctic?nesting shorebirds undertake some of the longest migrations in the world. Many of them fly incredible distances each spring to nest on the arctic tundra, and then fly far south again in the fall to spend their “nonbreeding season” in a very different habitat. They do this in response to food availability, presence of fewer competitors in the Arctic, and weather change, all of which are very closely associated.

Shorebirds Habitats
In its most basic definition, the habitat of a shorebird is “open space.” “Open,” in landscape terms, means “without significant canopy cover (plants blocking the sky above).” A few shorebird species live or roost in trees or wooded areas, but in general they are adapted to live on sandy or rocky shores and open grassy areas. For adult shorebirds, “shelter” is provided more by flocks than by habitat. Individuals in a flock of roosting shorebirds take shelter from the wind behind each other. The bird at the front of the flock that faces the wind will eventually hop to the back of the flock, forcing another to take its turn as windbreaker before it, too, hops to the leeward side. Watch for this when you observe a roosting flock on a windy beach!

Migratory shorebirds spend about two months each year nesting and raising their young in inland tundra, muskeg, or grasslands or on ocean, lake, or river beaches. They live for most of the rest of the year in generally more southern and coastal areas. In fact, because the nonbreeding season is so long, shorebirds are more physically adapted to those southern habitats where they spend most of their lives.

There is at least one more habitat, and often several more, that Arctic-nesting shorebirds are dependent on each year. Besides their breeding and nonbreeding habitats, shorebirds depend on the habitats where they stop to rest and feed during their migratory journey. These stop-over sites tend to be beaches and estuaries (the wetland area where a stream or river drains into the sea) that are relatively small in size. They are full of abundant food and may support a concentration of thousands or even millions of shorebirds every spring or fall (many shorebirds have migratory paths that differ in the fall and spring).

These migratory paths and stops have been used year after year for a very long time. When a large portion of a population of birds are all present at one time on one site, storms or oil spills could kill or injure many individuals and, therefore, have a significant effect on population size.

Many migrating shorebirds are not flexible enough, nor have the time, to find alternatives to the preferred habitat of their traditional stopover or nesting sites.

Significance of Wetland Habitat for Shorebirds
Although a given shorebird species may nest on the grassy tundra, stop on migration at ocean beaches and estuaries, and spend its winter on distant mudflats or beaches, all of these different habitats have something in common. Most of the habitats that shorebirds depend on are wetlands. As we shall see, there are many types of wetlands. Because they have shallow water (allowing plant growth, penetration of light and warmth, and buoyancy and nourishment for developing young), most wetlands are important sources of food and shelter for many organisms. In other words, they provide essential habitat.

Many shorebirds, like Western Sandpipers, nest on upland tundra in the Arctic. This relatively dry type of tundra is still formed on permafrost, which does not allow precipitation or melting snow to drain, and pools of water abound. Migration and wintering habitats tend to be wetter than breeding habitats.

Shorebirds and Humans share an Important Habitat
Wetlands are attractive habitats for humans as well. Humans use wetlands as a source of water for power, crop irrigation, transportation, drinking, and recreation. We find these areas attractive for housing and desirable as ports. Highway bridges span them, and water and sewer plants are built near them. Runoff water from streets and polluted ditches, and sometimes even sewage, empties into them. Great cities like San Francisco, Seattle, and Anchorage have grown up in what were formerly vast wetlands. Nonnative (“exotic”) species are being introduced into wetlands from such sources as the ballast water of ships, and sometimes these introduced species can outcompete native ones and seriously alter the structure of the wetland.

Unfortunately, the amount of wetland habitat on our planet is limited. Also, most of our use of these fragile wetlands has been permanently destructive. Because wetlands receive runoff water from the surrounding landscape, they receive agricultural chemicals that run off in this water as well. Does water containing the oil from cars and the soap from car washings on your street make its way to a storm drain that empties into local wetlands? Wetlands are being drained and polluted. Our port cities and coastal wetlands face the dangers of accidental oil spills.

As wetland habitat shrinks, shorebirds and countless other animals and plants lose the habitats they rely on. We humans lose wetland habitats important to us for reasons as diverse as clean water, fish, flood control, and tranquil beauty. Is it possible that humans and shorebirds can survive, even thrive, together using the same wetlands? One thing is certain, the more we learn about the components that make up the habitats of our earth, and the intricate interactions between all the organisms living here, the better our chances of making the best decisions for the future.

Gee Whiz Facts

Did you know that…?

Egg laying by sandpipers in the Arctic is timed so that hatching will occur when the main hatch of insect food also occurs, thus providing the growing chicks with an abundant insect diet.

Some sandpipers in the Arctic ingest lemming teeth as a source of calcium for eggshell formation.

The calcium content of the shells of a four-egg sandpiper clutch is greater than the calcium content of the female, which laid the eggs.

Western Sandpipers weigh about 25 grams, which is less than one ounce. They lay four eggs, and each one of them weighs 7.5 grams. That’s almost 1/3 of the female Western’s Sandpipers body weight per egg.

Biologists think shorebird eggs are pointed on one end so that they can fit together smoothly in the nest in a pinwheel shape. This keeps more surface of each egg covered and helps them stay warmer during incubation.

Black-bellied Plovers have a migration that can be thousands of miles long, but they often return to build their nest within 300 feet of last year’s nest.

Short-billed Dowitcher males are believed to roll their eggs to a new nest if threatened.

Shorebirds that breed in Alaska migrate to Australia, South Pacific Islands, Africa, Southeast Asia, the Lower 48 (contiguous) states, Central America, and South America to spend their winter.

Only seven species remain in Alaska in any significant number during the winter (Black Oystercatcher, Black Turnstone, Surfbird, Sanderling, Rock Sandpiper, Dunlin, and Common Snipe).

The diet of migrating Dunlins using Alaskan mudflats consists almost entirely of tiny clams.

Some plovers, curlews, and tattlers fly non-stop from Hawaii and other Pacific Islands to Alaska in two or three days, a distance of over 3,500 miles.

Up to one-half of some migrating sandpipers’ body weight is deposited fat that provides energy for long distance flights.

Sandpipers are genetically programmed to stop, rest, and replenish their energy stores in certain wetlands along the Pacific coast from South America to Alaska. If one of these wetland areas is lost to development, sandpipers that depend on that area might not survive to migrate further.

Western Sandpipers migrate over 250 miles per day between stopover points along the Pacific coast flyway to Alaska.

Western Sandpipers stop to rest, feed, and replenish their energy reserves for three to five days in each stopover point in their migration northward along the Pacific coast to Alaska.

There are only 50,000 to 80,000 surfbirds in the world, and over 12,000 are known to stop in Homer, Alaska, during spring migration.

The total number of shorebirds along the Pacific Coast and worldwide is decreasing due to loss of wetland habitat.

Ruddy Turnstones may be the most playful of shorebirds. They frequent beachfront restaurants in Trinidad and Tobago to get handouts of French fries and cookies from customers.

The average Red Know, weighing 135 grams, gains 54 grams during its visit to Delaware Bay. To gain this much weight and to meet its daily energy needs, the Red Knot must consume roughly 1,052 grams of horseshoe crab eggs-about 285,000 eggs in all! Approximately 90,000 Red Knots do this every year. This is equivalent to a 150-pound person gaining 50 pounds in two weeks.

Bog, mudflat, quagmire, muskeg, tundra, swamp, fen, marsh, pothole, beach. These are some of the many areas that people recognize as definitely land, but also definitely wet. What do we need to know about a wetland to understand why it is important and how it functions?

Let’s start by looking at some common features of any wetland. They are measured and studied by people with different jobs.

How wet is it?
A hydrologist, someone who studies the water cycle, is concerned with the wetness of a specific area. Wetness varies according to how much water falls on it in the form of rain or snow, flows across it from the ocean or upstream, or enters it as runoff from surrounding higher lands. How long an area stays wet and how wet it stays depend on the type of soil or plants, and how steeply the land slopes to the next downstream area. Water disappears down into cracks and holes between rocks or soil particles, is taken up by thirsty plants, or quickly streams off steep cliff faces. However, some water remains on the surface in areas where a subsurface layer of rock or permafrost won’t let it continue down into the ground or where it enters an existing pond or stream. Wetlands are areas where water remains pooled on or near the surface and saturates the soils, leaving no airspace for oxygen between the grains.

What adaptations does it take to live there?
To a biologist, wetlands are places where the plants and animals must have adaptations for both terrestrial (on land) and aquatic (in water) life. If the amount of wetness changes, the organism must be able to quickly respond. What would you do to survive if the tide came over your head twice a day? Also, the saturated soil has limited or no oxygen. This means that plants with their roots in the soil and other organisms that live in the soil must have adaptations to these anaerobic or low-oxygen conditions. The plants and tiny animals with these special traits are part of the wetland food web that includes shorebirds.

How do laws define “Wetlands”?
Because humans use wetlands for many things, and because humans recognize the importance of wetlands to the overall cycles of nature, there are many laws concerning wetlands. Is the land that you want to build a gravel road across a wetland? Is the land where you saw two rare snowy plovers feeding a wetland? Legal definitions are ones that people use to help answer these questions. These definitions come before the really important questions, like how will people and shorebirds be affected by any changes you make to the area?

There are regulatory agencies that are charged by the Clean Water Act to protect the important functions of wetlands (like providing drinking water). The regulators have a specific legal definition that recognizes hydrological and ecological conditions described above. However, because the water cycle is dynamic and the wetness of an area varies accordingly, determining whether the legal definition is met in a specific area is often very difficult.

Stream and River Corridors

In many parts of the world, wetlands undergo a natural change with the seasons. In the spring, snow and ice melt in the mountains. The meltwater causes streams and rivers to rise and seasonal floods to rush downstream. The streams and rivers overflow all along their routes to the estuaries at the sea and fill lowlands.

The meltwater carries nutrients (natural chemicals from water or minerals needed by plants for making food). These nutrients fertilize plants growing in the flooded lowlands. The plants provide food for many different kinds of small animals. Fish, mammals, and birds feed on the small animals.

Shorebirds flying north stop and probe in the mud for snails, worms, and insect larvae. Inland stream and river corridors are good wetland habitat for shorebirds in the spring. Some shorebirds that can be found in these habitats in the spring include Solitary and Spotted Sandpipers and Yellowlegs. These are migratory shorebirds like the Western Sandpiper but, unlike the Western Sandpiper, they breed primarily south of the Arctic.

After the spring meltwater has all run downstream, the rivers and streams fall to very low water levels. This tends to be true in late summer (July to September, depending on where you live). The plants and animals that live along the river corridors must be adapted to survive a couple of months of dry conditions. Fall rains will then come. They will cause the rivers and streams to rise and flood the lowlands again before winter. Is there a river near where you live? Look carefully for shorebirds and other birds along the banks of streams and rivers.

Tundra

The tundra is a vast, treeless land of northern and western Alaska and northern Canada. The temperature is very cold in winter and cool in summer. The wind almost always blows. Because of the cold and wind, no trees grow on the tundra. All the plants grow very close to the ground because it is warmer there.

Many people think the tundra is flat. Once you’ve walked on the tundra, you see that it is made up of lots of little mounds of grass, sedges, and lichens. The low spots are wet or even filled with water, forming little ponds or lakes. The ground is squishy. Even where it looks high and dry, it often isn’t. Try sitting on a grassy mound for a few minutes!

Although the tundra feels wet, very little rain or snow falls on the tundra each year. Why is it wet? Because there is permanently frozen ground, called permafrost, under the thin layer of topsoil. Because of permafrost under the soil, most of the rain and snow that falls stays on or near the surface. It can’t drain away through the frozen soil. Permafrost doesn’t thaw, even in summer. You cannot dig more than a few inches into the frozen soil. However, centuries of decaying vegetation have produced a thick, spongy layer called peat.

Because of permafrost, plants on the tundra have roots that grow sideways (prostrate) instead of straight down. One example is dwarf willow. There are also many berry-producing plants like cloudberry and bearberry on the tundra. Fungi and lichens (Are these plants? What are they?) are very important tundra organisms too.

Millions of shorebirds nest each year on the tundra. They feed on the billions of larvae and hatching insects that appear each summer. They also find aquatic prey like copepods and fairy shrimp.

Marshes

Marshes can fill broad, flat areas or be contained in tiny pockets surrounded by higher land. They are often found on the edges of ponds, lakes, or rivers. Often a saltwater marsh is associated with an estuary, the place where the freshwater of a river mixes with the saltwater of the ocean. If there is a stream or other water movement through a marsh, nutrients are brought with the water flow. When water drains from a marsh, it carries nutrients to the next wetland or to the ocean.

Marshes are open, wet, grassy areas. There are two kinds of marshes: inland freshwater and coastal saltwater. The inland marshes obtain freshwater from creeks and streams or directly from rain and snow. Tides regularly bring a source of saltwater to the coastal marshes. Both inland freshwater marshes and coastal saltwater marshes have plants that are adapted to the type of water in the marsh. On a windy day marsh plants rustle with their own unique music. The plants that grow in a marsh are special. Their roots are always under the water. Their stems and leaves rise out of the water into the air and sunlight. Marsh plants grow where water is shallow and slow moving. Some marsh plants of western North America include sedges, rushes, and grasses. That’s why a marsh looks like a wet meadow. Marshes also have small shrubs and delicate flowering herbs.

Insects, snails, and other small animals thrive among the plants in the slow-moving water. Fish and aquatic insects find shelter among the underwater parts of the plants. Young salmon start their lives in freshwater far upstream. Before they graduate to the ocean, they need time to adapt to saltwater. Coastal saltwater marshes are the perfect place to do that. Shorebirds and other birds can find lots of food to eat in a marsh. They can hide in the tall grass from predators. Have you ever seen a Common Snipe, a Yellowlegs, a Dowitcher, or a Phalarope in a marsh?

Rocky Intertidal

The intertidal zone is the part of the ocean shoreline that is covered by saltwater when the tide is high, and exposed to the air when the tide is low.

Life in intertidal areas has both challenges and rewards. Plants, animals, and other organisms like algae (“seaweed”) must be very tough to live there. They must be able to adapt to the movement of the tides. This means being able to live covered and then uncovered by water once or twice a day:

• They must be able to get oxygen in air and in water.
• If living cells dry out, they die. Living creatures of the intertidal must be adapted to keep from drying out when the tide is low.
• They must be able to adjust to changes in salinity (level of saltiness). As the last drops of water dry in the sun at low tide, salt is often left behind and conditions can be even saltier than when underwater (how could you test to see if that is true?). When it rains, these same plants and animals must be able to adjust now to lower salinity.

Saltmarshes, sandy beaches, and mudflats can all occur in the intertidal zone. Because the rocky intertidal zone has no soil to retain water, some might argue that it is not really a “wetland” habitat. Well, the rocky intertidal is that part of the zone made up of boulders or cliffs or gravel or shale or just plain rocks. Wherever there are pools or crevices to retain enough water, the rocky intertidal teems with life. This is why we also know this zone as the place of tidepool habitat. Like most wetlands, it is a very productive place!

There are other challenges facing the tidepool life and the hardy organisms that cling to exposed rock walls. These include being able to adapt to the rolling or even pounding of the ocean waves. Wave action is often high in these areas, and often the cause of why there is no soil on these exposed rocks.

Almost no plants at all grow in the rocky intertidal habitat. There is no soil for their roots. Large seaweeds and kelp, members of the Protista Kingdom, take the niche of plants. This means that they do the job of plants at the base of the food pyramid and in the general ecology of the habitat. They capture the sun’s energy to make food that tiny animals graze on, and they provide a sheltered place for these tiny animals to live.

The larger animals (predators and scavengers) that feed on the smaller animals face their own challenges here. This habitat is exposed to a lot of wind, and there is not much shelter for them. Many shorebird species are well adapted to find food in the rocky intertidal. As a matter of fact, as birds go, shorebirds are the most significant users of the rocky intertidal. The Black Oystercatcher feeds almost nowhere but here most of the year. Its strong, red bill is adapted specifically for prying hardshelled animals off rocks or prying them open. Turnstones and Surfbirds also live here during migration and winter.

Mudflats and Sandy Beaches

Mudflats and sandy beaches are important shorebird habitat. They can occur inland, but sandy beaches especially are found in the intertidal zone along the ocean shores. Mudflats are made of differently sized particles than those composing sandy beaches. Inland they can occur around inland lakes and rivers. What do coastal mudflats and sandy beaches have in common besides the tide? They are both very open habitats with few plants but often rich in invertebrate prey.

Organisms that can adapt to conditions of periodic wetness and salinity changes do well because there are lots of nutrients in these mudflat and beach habitats. These elements are carried down by rivers and mix with nutrients from the ocean or lake. Such wetlands, especially in coastal areas, are some of the most productive (maker of food) areas on the earth. If you scooped up one pail of mud or sand from the beach below the high water mark and examined it with a microscope, you would see hundreds or thousands of tiny snails, worms, and invertebrate eggs and larva. There would be larger animals like clams and long worms as well. There are millions of clams, shrimp, and worms buried in the mud and sand in intertidal mudflat and sandy beach zones.

The flight path for millions of migrating shorebirds follows the shoreline as they move north in spring or south in fall. The birds need a lot of energy-rich food to fly thousands of miles. Their next stop might be hundreds or thousands of miles away.