Sea level surge floods nesting beaches at peak laying season

July 14, 2026

Water levels have run 30 centimeters above predicted tides for the past two weeks along this flat karst coast — a sustained surge that is now pushing well up into the nesting beaches at the height of the breeding season. and both deposit eggs well above the normal wash line — an adaptation to protect clutches from regular tidal cycles. When water levels hold 30 centimeters above predicted heights for weeks at a time, those eggs are flooded, and sustained inundation starves them of the oxygen they need to develop.

This coast lacks a ridge or other topographic buffer to shelter the upper beach. The eggs laid here over recent months are now directly exposed to conditions they evolved to avoid.

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Milk frogs calling through summer nights

June 26, 2026

After dark in Mérida, when the heat of the day finally softens and the air thickens with humidity, the city's trees become something else entirely. The rains have arrived. Standing water collects in tree hollows, in bromeliads, in the gaps between roots. This is what the milk frog has been waiting for.Milk frogs are large, pale, and built for the canopy. An adult is broad-headed and heavy-bodied, with adhesive toe pads that let it move across bark and leaf surfaces with ease. The skin is smooth and whitish, sometimes faintly mottled, and the eyes are large and gold-rimmed. During the dry months they are quiet and largely invisible, sheltering in tree cavities and waiting. But when the summer rains saturate the Yucatan Peninsula and water gathers in elevated pools, the frogs descend from their retreats and begin to call. The sound is loud and repetitive, a low resonant honk that carries well through dense vegetation. A calling male stations himself near a water-filled hollow and calls through the night, sometimes for hours. Other males respond. The result, on a good rainy night, is a layered chorus that bounces off walls and canopy alike.The vocalization does two things at once. It draws females, who select mates based on call quality and persistence, and it signals other males about occupied space. Males that approach too closely trigger escalating call exchanges, sometimes followed by physical contact. Females move through this acoustic field and eventually approach a male at the water source. Eggs are laid directly onto the surface of the water pooled in the hollow, and the male fertilizes them there. The hollow matters: it protects the eggs from the kind of predation that ground-level clutches face, and the enclosed space keeps humidity high around the developing embryos. Tadpoles hatch and develop in the same water column, feeding on algae and organic debris that accumulates in the hollow. In a tree cavity with enough volume and shade, a clutch can develop through to metamorphosis in a few weeks.The milk frog's reliance on arboreal water means it is sensitive to the availability of large, mature trees. Old-growth trees develop the deep cavities and structural irregularities that hold standing water; younger, smoother trees rarely do. In and around Mérida, that means the frog is concentrated in older parks, established neighborhoods with large shade trees, and patches of remnant forest. It shares some of this space with the invasive greenhouse frog, a small direct-developing species that needs no standing water at all and breeds in moist soil and leaf litter. The two frogs occupy different microhabitats and don't compete directly, but the greenhouse frog's presence is a measure of how modified the surrounding landscape is. Where greenhouse frogs are common, the original structure of the habitat has changed.The ferruginous pygmy-owl hunts at dusk and dawn in the same trees where milk frogs call at night, and a large frog on an exposed branch is within range of what that owl will take. The northern potoo, which roosts motionless against bark during the day, is active in the same hours as the frogs. Whether potoos take milk frogs directly isn't certain, but they occupy the same nocturnal canopy and hunt by sight in low light. The gray fox moves through the understory below and would take a frog that descended to the ground.The milk frog's skin produces a thick, whitish secretion when the animal is stressed, which is where the common name comes from. The secretion is irritating to mucous membranes and likely discourages some predators, though it doesn't deter all of them. It's not venom in the strict sense; it's more of a deterrent, something a predator learns to avoid after an unpleasant encounter.If you are outside tonight, or near an open window, listen past the ambient noise for something low and repetitive coming from the trees. Not an insect. Not a bird. A deliberate, carrying call from something sitting still in the dark. The rain will have brought them out. The sound, if it reaches you, is coming from a hollow somewhere above.

June 26, 2026

have made over 40 visits to a single urban pond in Mérida during the first five months of this year, a striking testament to how raptors adapt when their natural habitat vanishes. This threatened species depends almost entirely on apple snails, and what was once dispersed across vast wetlands now concentrates on whatever shallow ponds persist in the city's margins. appeared at the site in late June—a sign of trouble. These floating plants mat over open water, eliminating the shallow habitat snails need to thrive. For a raptor species that has already lost most of its range to agricultural conversion and wetland drainage, the presence of invasive vegetation in one of its last urban refuges is a reminder that survival in fragmented landscapes is perpetually precarious.

Snail kites hunt in summer shallows

June 11, 2026

The wetlands around Mérida shimmer in the late morning heat, shallow pools scattered between stands of cattail and sedge. Water levels have risen with the summer rains, flooding the margins where apple snails cluster on submerged stems. If you are walking near water today, listen for the splash of a large bird dropping to the surface.A snail kite hangs motionless above the marsh, slate-gray wings spread wide against the white sky. This threatened raptor has shaped its entire existence around one prey: the apple snail. The kite's bill curves into a sharp hook, designed precisely to extract snails from their shells. Its talons grip differently than other raptors, holding the rounded shell steady while the specialized bill works. When the kite spots movement below, it drops with controlled precision, feet first into the water.Apple snails surface to breathe through a tube-like siphon, making them visible to hunting kites. During summer, these large freshwater snails reproduce rapidly in the warm, oxygen-rich shallows. The snails scrape algae from plant stems and filter particles from the water column, converting plant matter into protein that feeds not only snail kites but also limpkins, which probe the mud with their long bills for the same prey. The kites follow water levels closely. When summer rains flood new areas, snail populations expand, and the kites adjust their hunting territories accordingly. A single kite may cover several square kilometers, moving between productive pools as conditions change.The kite that just landed carries its catch to a nearby perch, often a dead snag or the top of a palm. Here it performs the delicate work of extraction, using its bill tip to sever the muscle that holds the snail in its shell. The empty shells accumulate below favored perches, white spirals scattered on the ground like discarded pottery. Young kites must learn this technique through practice. Parents bring whole snails to the nest, and juveniles spend weeks mastering the precise movements needed to access their only food source. This specialization makes snail kites vulnerable to habitat changes, but it also makes them supremely efficient hunters when conditions are right.The water stills after the kite's departure, rings spreading outward from where it touched down. Somewhere in the shallows, another snail extends its siphon toward the surface, and overhead, another kite begins its patient circle through the humid air.

More about Hawksbill

Hawksbill turtles nest along the summer beach

June 27, 2026

The beach near Nandayure goes quiet as the light drops. The dry season birds have pulled back into the forest edge, and the surf takes over the soundscape. This is the hour the hawksbill turtles come ashore.Hawksbills are smaller than the leatherbacks or greens that share these Pacific waters. An adult female weighs around eighty kilograms, and her shell is narrow and tapered at the front, with overlapping scutes that give it a ridged, shingled look. Her beak is pointed and slightly hooked, shaped for pulling sponges off coral heads. She spends most of her life at sea, feeding in the reef systems offshore, but summer draws her back to this stretch of sand. She navigates by the earth's magnetic field, detecting both the intensity and inclination of the field lines, and she returns to the same beach where she hatched. Not the general region. This beach. Researchers have documented females nesting within meters of where they emerged decades earlier.She comes ashore after dark. She moves across the wet sand slowly, pulling herself with her front flippers, pausing to rest. Above the tide line she begins to dig. First a wide body pit, scooped out with all four flippers. Then, from the back of that pit, the egg chamber: a flask-shaped cavity about forty centimeters deep, excavated with her rear flippers working in alternating scoops, one at a time, each one curling and pressing the sand out to the side. The chamber takes twenty minutes to an hour to dig, depending on the sand. When it is finished she lays between one hundred and two hundred eggs, each one soft-shelled and slightly smaller than a golf ball. She covers the chamber, filling it and tamping the surface, then sweeps sand across a wider area to obscure the site. By the time she returns to the water the work is done.The eggs incubate in the sand for about sixty days. The temperature inside the chamber matters: cooler incubation produces more males, warmer produces more females. The nest is not tended. The female may return to this beach three or four more times this season, laying another clutch every two weeks or so, but she does not come back to the eggs she has already buried. When the hatchlings emerge they dig up through the sand together, usually at night, and orient toward the ocean by moving toward the brightest horizon. On a dark beach with no artificial light, that is the sea. Light from buildings or roads pulls them in the wrong direction, and many do not make it to the water.

More about Green Sea Turtles

Three sea turtle species nesting amid rising tides

July 13, 2026

All three threatened sea turtle species—, , and —are nesting here this season, with activity recorded as recently as mid-July. This coast has long been among the world's most important loggerhead nesting grounds, drawing females year after year to lay their eggs in the sand.But tides are running nearly 10 centimeters higher than predicted for much of the summer—a modest but consequential deviation for nests laid in the intertidal zone. Even shallow inundation can damage or destroy eggs before hatchlings emerge. The convergence of peak nesting season and anomalously high water creates a narrow window of risk for hundreds of clutches already developing in the sand.