December 7th
The morning air is
tainted with a decaying smell that wafts up from the beach. I raise my
binoculars to search the vast expanse of sand and surf to see a dense
aggregation of black vultures, a clear sign that the tide has washed up a
fresh meal. The hungry crowd of scavengers
parts upon my approach, revealing the remains of a large sea turtle. Although it
is impossible to say for sure, this is likely one of the thousands of sea
turtles killed by fishery activities every year in Costa Rica. A study by the
conservation group PRETOMA looked at one long line fleet in Playa del Cocos,
just north of my location on the Nicoya Peninsula. The fleet consists of over
500 vessels using 700,000 hooks that are strung on “motherlines” that can
extend for up to 40 miles. The estimated annual
catch of sea turtles in this one fleet is approximately 300,000, not mentioning
the thousands of sharks, rays and other fish species that are caught as bycatch
and discarded, lifeless, back into the ocean. I set-up my camera and used a
wireless remote to trigger the shutter from afar as the vultures feasted.
I hope that my next sea
turtle encounter will be more pleasant.
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Often in the
mornings I walk up the riverbed that dries with the receding tide. The thick mud reveals the previous nights
activity; a deep gash in the sand where a crocodile drug its tail, the favorite
fishing hole of a raccoon or the bone filet remains of the coatimundis midnight
snack. The sun is low and the air is cool, often with a breeze that blows ocean
air from the direction of the rising sun. The river is lined with hungry
egrets, shorebirds and chattering kingfishers. The raucous calls of scarlet
macaws echo from afar and the dawn song from forest birds is a chaotic mixture
of chirps and whistled tones. Through the cacophony I recognize the guttural calls of tiger herons, large handsome birds with barred necks and broad wings that are held like a shroud over their
proportionally small bodies. This particular species has a patch of yellow skin
on its throat that is expanded during courtship, giving it the name of
bare-throated tiger heron. Mixed with an upward stretch and swaying motion,
they produce a deep and resonating call from their expanded throat, making for
a very interesting scene.
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| Bare-throated tiger herons |
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| Bare-throated tiger herons |
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| Bare-throated tiger herons |
The distinction
between a “heron” and “egret” is fairly vague and relies mainly upon appearance
rather then taxonomic relations. Indeed, the terms can often been used
interchangeably. In general, egrets are a type
of heron that are characterized by long plumes that are developed in the breeding
season. These ornamental feathers were once prized by market hunters as
decorations for women’s hats and the relentless hunting of breeding birds
caused some species to become endangered. There are 64 species of herons
worldwide, some are given the name of “bittern” but all are members of the
family Ardeidae. This group is well represented here on the Panica river, with
9 species commonly seen stalking the margins of the river mouth.
There is the snowy
egret in immaculate white plumage. He poses motionless over the small waves
that lap up against the gravel, breaking stance only to jab wildly
at a passing fish, or chase after a missed opportunity with long and erratic
strides.
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| Snowy egret |
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| Snowy egret strike |
The little blue
heron, a distinguished member of the Ardeids, with plumes that hang like coat
tails behind an elegant frame. It prefers to search for crabs in calm backwaters
and eddies.
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| Little blue heron |
The tricolored heron,
with subtle tones of red, blue and white...
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| Tricolored heron |
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| Tricolored heron |
The snowy egret is
soon distracted by the arrival of a female. He extends his plumes and
headdress and chases after her in elegant steps. Despite
his persistence, she wants nothing to do with him.
Their activity is
watched by the night-herons, full from a night spent foraging, these nocturnal
predators roost on shaded mangrove branches overhanging the river. Their large,
red eyes are adapted for spotting crustaceans and fish in the blackness of
night.
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| Yellow-crowned night heron |
Just before dark,
the river becomes a flyway for many birds that have spent the day further
inland and are now coming to the coast to roost in the protective canopy of the
mangroves. The image below was taken just after sunset, with a slow shutter speed in the low light causing the image to blur.
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| Cattle egrets |
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Further efforts to
photograph the mangrove hummingbird have yielded nothing. Yesterday I arrived to
find the two tea mangrove trees occupied by a larger and more aggressive species, the
scaly-breasted hummingbird. Even the name sounds intimidating. The female
mangrove hummingbird that once defended these trees was nowhere to be found and with great dismay I watched as the scaly-breasted tyrant chased away all that
encroached. Further research revealed that they too coveted the nectar
from tea mangrove and perhaps I was witnessing an interesting aspect of the natural history of mangrove hummingbirds; competition with other species. This
experience really pushed me too look for more trees,
but a thorough search of the area has produced nothing but the more common red and black mangroves. Surely it could not be true that there were the only two tea
mangrove trees left at the mouth of the Panica river. If so, the status of the
mangrove hummingbird in this area is in a desperate state and may consist of
only a handful of individuals, if that.
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