THE BEACH AT
MAZATLÁN
October 18, 1996

Notes from a birding trip through Mexico by Jim Conrad

Mazatlán, SinaloaAt midnight the train arrives in Los Mochis, Sinaloa, population around 165,000. This is an agricultural boomtown surrounded by mango orchards and fields of cotton, wheat, rice, corn, tomatoes, sugarcane, and safflower, the latter grown for its seeds containing an oil used in cooking. The town lies about twenty-five kilometers (fifteen miles) inland from the important deep-sea port of Topolobampo on the Pacific coast.

The night air is hot, heavy, and murky. Five of us stuff ourselves into a taxi and head for the bus station. Within minutes I'm in an air-conditioned bus rolling down the coast toward the southeast, the destination window on the bus's front reading MAZATLÁN. Arriving in Mazatlán a little before daybreak I take a quick nap in the bus station's lobby.

Though buses come and go and half a dozen keep their diesel engines idling right beyond an open barrier, I sleep profoundly. Nonetheless, when shortly the sky grows milky pale I am awakened by unearthly whistles, crashing sounds, grating clacks, and other fabulous noises of Great-tailed Grackles cavorting in palm trees just outside the station. I strap on the backpack and in semidarkness hike three blocks to the beach, to sit on the stone wall separating the waterfront boulevard, the Malecón, from the sandy beach. The ocean with knee-high waves breaks onto the beach a good stone-throw away.

With a population of about 300,000, Mazatlán's shoreline is impressive at dawn. Along the Malecón's seventeen-kilometer length (eleven miles), streetlights twinkle as the sky flushes pink. My awakening here has been very unlike all the others experienced during this trip. I miss my habitual solitude and peace and feel profoundly out of place as traffic rumbles behind me, chubby men jog along the beach, a woman with a poodle leaves the odor of coconut-oil suntan lotion, and an aerobics class begins on the second floor of an ugly building across the street.


PELICANS

Still, it's a real  pleasure to see Brown Pelicans. With wingspreads of up to 230 centimeters (7½ feet) they fly by singly as well as in flocks of three to seven individuals. Usually they're flying so low that their wing tips appear to touch the higher waves' crests. As they fly up and down the beach I don't see them fishing and none lands anyplace I can see. It's tempting to think of these primitive-looking creatures as making their morning promenade, to see what the tourists are doing.


JOGGERS

I rise from the stone wall, strap on my backpack, and  begin walking northward along the beach, next to the Malecón.

I'm surprised that the sandy beach is so empty of birds. Surprised, that is, until I see what happens to a large, long-legged, brown shorebird at the water's edge up the beach, a Whimbrel. It's a handsome bird that nests in the Arctic tundra, but winters along both of Mexico's coasts, and south all the way into South America. The bird runs along the sand occasionally darting to the side and stabbing with its long, decurved beak into the silvery-wet sand behind retreating waves. The problem is that the Whimbrel spends more time flying out of the way of morning joggers than foraging. Joggers, it seems, keep the beach less birded than expected.

Just beyond the harried Whimbrel there's a large, full-color, hand-painted sign with a stylized representation of a turtle with the word Sálvame, or "save me," lettered on its shell. Below the turtle it's written that if you see a big turtle on the beach it's a mother about to lay eggs, but if it's a small turtle, it has recently hatched. They give a telephone number to call if you see one.

For half a mile beyond the sign the beach is birdless. Finally joggers thin out and two shorebirds appear standing beside one another, just looking around. Eventually one turns into the sun and begins preening, and then the other does the same. This is interesting because, while the birds are about the same size, one is brown, with a long, decurved beak, while the other is gray, with a slightly shorter, straight beak. One bird is a Whimbrel, but the other is a Willet. Not only are these birds different species, they belong to different genera. This is like a gorilla finding companionship with a chimpanzee.

After preening awhile, they must fly away to escape another jogger. Then they return, preen a few moments, and settle into a resting posture. The Willet pulls a leg into its feathers. When a large wave comes in, the Whimbrel flutters higher onto the sand but the Willet appears unwilling to either fly or let down its second leg. It hops upslope on one leg, and I cannot decide whether this is mostly laziness, or ingenuity.


WILLETS

Willet winter & summer plummage, Catoptrophorus semipalmatus

The Willets right now show both summer and winter plumages, and everything in between. At the right I sketch the paler winter plumage (bird on left) and the darker summer plumage (bird on right).

Willets stand a little over a foot high, which is larger than most beach birds, such as the Sanderlings and various plovers and sandpipers. Often Willets seem like loaners to me, or at least much less gregarious than most other beach birds. I see them standing around a lot, alone, gawking.


SMALL, DARK & SODDEN

Farther up the beach a small, dark, sodden creature, maybe a rat or tiny dog, is being manhandled by the waves. A wave withdraws, dragging the animal oceanward. The exhausted, half-drowned thing manages to crawl a little upslope but then another wave comes in, boots it from behind, tumbles it head-over-heels in surging foam, pounds it onto the sand, and then begins dragging it oceanward again, repeating the whole cycle. Up close I'm astonished to see that the creature isn't a rat or dog at all but rather a bird that typically is utterly at home on water. It's an American Coot.

Most of the time coots are seen floating atop the water looking like small, black ducks with white, narrow beaks, and red eyes. On land, however, it can be seen that their legs are much longer than a duck's and instead of having webbed toes like ducks their toes are "lobed," with curious flaps along their toes flaring out to push against the water as the feet are pushed backward.

But this coot is going nowhere. Just as I begin running toward it, three or four small waves in succession enable it to progressively drag itself up the sand slope. Thinking it better if the coot can save itself, I stop, and watch it finally reach dry sand where it collapses onto its breast, with its quivering wings spread wide. It lies there a long time with its head raised and wobbling, gazing toward the Malecón. Eventually it draws in its wings and laboriously assumes a normal sitting position. Just by looking you wouldn't know that anything has happened, except that the bird's feathers are matted together into clumps and spikes.

Maybe this coot was migrating south, but its guts were so infested with parasites that it simply ran out of energy and collapsed at sea. Or maybe on its last stop up around Topolobampo oil from a tanker got onto its feathers so that now they no longer repel water, and when the bird landed this morning it sank instead of floated. Who knows? It's sad and all I can do is walk away.


FAR FROM THE NESTING GROUNDS

Semipalmated Plover (Charadrius semipalmatus) & Sanderling (Calidris alba)

Farther north, beach erosion has scoured the sand away leaving only dark, smoothly sculpted mud between the surf and a stone wall. A couple of shallow, house-sized ponds attract no tourists, but they are just the thing for two Semipalmated Plovers and about fifty Sanderlings, all of which stand around the ponds' edges preening, stretching wings, and doing nothing else discernible. In my sketch above, a plover is on the left, a Sanderling on the right. The plover is about 5¾ inches long (14.5 cm), and the Sanderling is a bit larger. Both the plovers and the Sanderlings are smallish, short-tailed shorebirds, both are mostly gray and white, and both possess medium-long bills and legs.

What's not seen here is that both of these species also nest in the Far North. Therefore, recently they have both flown long distances. Semipalmated Plovers nest from Alaska across northern Canada to Newfoundland, and Sanderlings nest even farther north, in the tundra from Alaska to Baffin Island.

The small, gray, nondescript little birds have just accomplished epic journeys. Surely what they're "doing" is recuperating -- just being still while their bodies digest food and replace fat that was burned during their long flight.


SANDERLING BEHAVIOR

These Sanderlings are in the same family as the Spotted Sandpiper seen at Témoris. Like Spotted Sandpipers with their polyandrous nesting practices (one female nesting with two or more males at the same time), Sanderlings also have a nonstandard mating system. Both male and female Sanderlings incubate their own separate clutches, and sometimes they even enter into polyandrous relationships like Spotted Sandpipers.

In evolutionary terms, the Sanderlings' one-nest-for-each-mate system is thought of as the probable "first evolutionary step" toward polyandry. In fact, the Sanderlings' relationship is technically referred to as protopolyandry. Protopolyandry makes sense in the Arctic region where Sanderlings breed, for Arctic summers are so brief and unpredictable that if a nest is lost to a predator or a storm, renesting is impossible. Having two nests reduces the risk of total loss of young.

Sanderlings are sometimes seen doing something else that at first glance seems unlikely. Down the beach we just saw a Willet. Sometimes Willets, which are much larger than Sanderlings, will be seen tearing apart prey such as large sand crabs and a Sanderling will draw near the Willet and begin running off other Sanderlings in the Willet's vicinity. It looks as if a turncoat Sanderling is protecting a Willet from the Sanderling's brothers and sisters. What's really happening is that crabs are too large for Sanderlings to rip apart themselves, so the Willet-protecting Sanderling is actually just hoping that as the big Willet tears into its crab a few fragments will fly to the side for the Sanderling, and that Sanderling doesn't want any Sanderling competition for the scraps.


MAGNIFICENT FRIGATEBIRD

Magnificent Frigatebird, Fregata magnificens

Now what should fly by but  a Magnificent Frigatebird. This species has a pretty interesting trans-species behavior, too. Magnificent Frigatebirds are kleptoparasites.

When Magnificent Frigatebirds come across members of other bird species who have have managed to acquire some food, the frigatebirds are likely to chase the other species down and rob it of its food. The robbing process is more than a quick exchange of a fish, though.

In the early 1990's, J.L. Osorno and others studied Magnificent Frigatebirds on Isla Isabel, or Isabel Island, off the coast of the Mexican state of Nayarit, just south of here. Isla Isabel is home to a great many Blue-footed Boobies, which are goose-size seabirds a little like gulls, but with much larger beaks and narrower wings -- and the adults really do have large, bright-blue, webbed  feet, as well as bluish bills. On Isla Isabel these boobies, then, were the frigatebirds' main victims. In other places it might be gulls and terns.

Blue-footed Boobies have wingspreads of 163 centimeters (64 inches), but Magnificent Frigatebird wingspreads are even larger, spanning  229 centimeters (90 inches). Clearly, when a frigatebird attacks a booby, it's a thing to see. Typical attacks consist of the victim being caught by the wing or tail and then the frigatebird forces its victim to regurgitate whatever happens to have accumulated in its crop.

One of the most interesting observations made by Osorno and his group was that frigatebird success in actually obtaining food was very low. Of 1,553 attacks, or chases, initiated by frigatebirds on Blue-footed Boobies, in only ninety-one cases did the victims actually end up regurgitating food, and in those cases only fifty-eight times did the frigatebirds actually get the food being regurgitated. That's less than a four-percent success rate.

Because longer chases provided proportionally higher success rates for the frigatebirds, Osorno thought that possibly the frigatebirds were evaluating their targets before the attacks began. Specifically, maybe the frigatebirds could see from a distance how full their potential victims' crops were. The larger the crops appeared, the longer the frigatebirds were willing to keep up the chase.


BIRDLIST #6

Here is this stop's Official List:

October 18: latitude 23º11'N, longitude 106º25'W

MEXICO: Sinoloa;  sandy beach of Pacific Ocean at Mazatlán three blocks west of the bus station at Deportes & Ejército Mexicano

RESIDENCY STATUS:
permanent resident
winter resident
  1. Brown Pelican
  2. Magnificent Frigatebird
  3. American Coot
  4. Semipalmated Plover
  5. Whimbrel
  6. Willet
  7. Sanderling

EARLY DEPARTURE

By 11 AM the sound of traffic behind me and the onstreaming hoards of tourists have caused in me a troubling uneasiness. When yet another woman smelling of suntan lotion and being led by a poodle passes by, more or less on impulse I stand up, strap on my backpack, and hike back to the bus station.

By noon of the same day on which I arrive in Mazatlán, I am on a bus heading back into the blessed highlands, far, far from here, to where I can at least get a peaceful night's sleep.

Go to Stop 7
Return to Trip's Index Page