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They inhabit nearly every aquatic environment
on earth; from the abyssal depths of the deepest oceans to high altitude lakes
and rivers. The fish, as ancient as they are adaptive, have diversified into a
staggering 35,000 species, making them the largest of all vertebrate groups.
500 million years of evolution has produced fish that can fly, crawl, light up,
breathe air and yes, even climb! It seems absurd that a fish, with its
streamlined body designed for an aqueous lifestyle could manage to scale even
the most modest of heights. So you can imagine my surprise when while perched
atop a cascading waterfall deep in the forest I noticed hundreds of tiny bodies
clinging to the vertical rock wall below me. I had to take a second look, but
indeed these one inch forms came complete with eyes, gills, fins, and strong flattened
mouths from which they gripped firmly to the wet rock. They were arranged in
large groups, traveling up a narrow band of rock that was kept damp by the
falls constant mist. Incremental movements of their lower jaw facilitated their
slow ascent, inching upwards like tiny vehicles in rush hour traffic.
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| At the top of the falls, rock-climbing fish on rock |
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| Rock-climbing goby on vertcial rock face |
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| Rock-climbing goby |
I found
very little information about these fish on-line, but I am fairly certain that
they are juveniles of the poorly known Sicydium
salvini, a species of Goby. They begin life in the ocean and young fish
migrate up tropical rivers, scaling massive waterfalls to reach the deep and
cool pools at higher elevations. It is here that they can develop into adults
and breed in the absence of larger predators. The new generation will be washed
out to sea to begin the cycle anew. No locals that I had talked to had ever
remembered seeing the fish, so it is likely that these amazing upstream climbs only
occurs for relatively short periods of time.
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Ventrel view of rock climbing goby, Sicydium
salvini
|
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| Rock climbing goby, Sicydium
salvini |
The waterfall itself was an impressive site;
clear pools and cascading chutes that descended a steep gorge for hundreds of
feet. It seemed impossible for such a tiny fish to conquer. It was
quintessential Costa Rica, a perfect image of lush tropical seclusion.
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| Panica falls full shot of lower section |
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| Panica falls main chute |
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| Panica falls main chute |
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| Small jungle stream |
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| Bottom of Panica falls |
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Lately I have been spending a lot of time in a
steep jungle ravine hoping to capture some rarely seen behavior of an
incredible bird. The long-tailed manakin lives in the dense undergrowth of
tropical forests throughout north pacific Costa Rica. It belongs to an
extremely fascinating family; the manakins, with 60 species distributed
throughout central and south America. They are small and stubby birds with
round wings and big eyes for seeing in the dimly lit understory. The males of many species bare colorful patches of feathers,
while the females are nearly always a plain hue of subtle green. Long-tailed
manakins are exceptionally beautiful with a sky blue back set against a black
body and crimson crest. The costume is complete with two long tail streamers
that can nearly double their overall length. However, it is not the males colorful
plumage that makes them of interest, but their complex social lives and
courtship behavior. Male long-tailed manakins form well-practiced dancing
troupes that perform at special “dancing arenas”. Each arena is controlled by an
"alpha" male; an experienced and well connected individual who has come do
dominate the local social scene. The alpha male has at his beckon call multiple
"beta" males that cooperate with him to perform a synchronized dance for females.
The dance consists of cartwheeling overtop eachother while singing an unusual
buzzy song. It is performed on a low horizontal display perch that is favored
and used by many generations. The female watches carefully during the entire
dance, which terminates when the alpha male calls out with a piercing PWEET! This abrupt call
dismisses his backup dancers so he can copulate with the female. So the
question is, why do the beta males cooperate so devotedly when it is always the
alpha male that gets the girl? It turns out that it is the quality of dance
that is attractive to the female, not individual males. Cooperation among males
contributes to the reputation of certain dancing sites, which the females map
out and visit regularly, tending to visit the sites where the performances are
best. A young male must work his way into a dance group, forming a long-lasting
relationship with the alpha male and together they must work hard to make a
site attractive to passing females. Their bond, a union of song and dance, can
last for over a decade. It is only when the alpha male of a site dies that the
beta male will have a chance to become an alpha, and ensure his genes are
passed to the next generation of regal dancers.
I felt extremely fortunate to “inherit” a
dancing arena myself when I stumbled upon one in the boundaries of Finca Tropical.
Within this teak and mango farm are sections of primary forest, as the owner
has left a generous buffer zone where a small stream runs down through the
hills. We have been building a system of trails to access this beautiful area,
where wildlife is abundant. During a morning birding tour in the area, a couple lucky
guests were witness to the amazing dance of the long-tailed manakin. We
could just make out the tiny dancing figures as they leaped up and down through
the thick undergrowth. Long-tailed manakins tend to display in very dense vegetation,
which makes it hard to get an unobstructed view. I went back to the area afterwards
and spent hours waiting for them to dance again. I did not see another dance, but
I did catch a glimpse of a well dressed male descending to a low perch. It was
a vine that stretched horizontally just long enough to provide adequate dance
space before twisting chaotically back into the undergrowth. The ground beneath
was cleaned of leaves and debris and the sparse canopy let narrow rays of sun
penetrate like spotlights on a lighted stage. I was certain that this must be
the dance site, and I set-up a camouflaged photography blind with a clear view
of it.
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| Manakin blind set-up |
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| View from inside the blind |
For the next five days I spent a total of 15 hours in the blind, during
the early morning hours when the birds are most active and likely to display.
Although I have yet to see them in full dance from the blind, I have been lucky
enough to get lots of great looks and learn even more about the peculiar habits of these
birds. It turns out the males visit the dance perch quite regularly to clean
off fallen debris, call out to other males, or even practice their dance steps.
I watched one young male, not yet with full adult attire, as he practiced each component
of the dance and song. It was clear that he had a lot of practice to do and I
found it quite comical. Also evident was the complex communication between
males, who use a wide array of whistles, calls and buzzy tones to interact and
synchronize their behavior long before any dancing begins.. At one point I was
sure I was going to see the dance when a female showed up at the perch and three
males descended to join her. For whatever reason, the group broke up before a proper dance. I plan to spend a lot more time in the blind and hopefully
photograph the full dance as well as lots of other interesting behavior. Here are some shots from the blind so far...
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| Alpha male long-tailed manakin on display perch |
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| Alpha male long-tailed manakin on display perch |
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| Beta male long-tailed manakin in canopy |
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| Alpha male long-tailed manakin in canopy |
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| Beta male long-tailed manakin practicing dance |
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| Female long-tailed manakin on display perch |
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| Female long-tailed manakin on display perch |
No progress on the mangrove hummingbird
project, the tea mangrove trees haven’t bloomed lately and the female I spent
so much time with is no longer tending the two trees. She, or possibly a
different female, shows up at the feeders at Tambor Tropical a couple times a
day, a reminder of unfinished business.
Hopefully the trees will start producing blooms again and I will get
some more chances in the near future.
I can hear the distant tune of “O Holy
Night” playing at one of the local bars. Up until now I’d barely thought about
the fact that it is approaching Christmas. It certainly doesn’t feel like it
with 30 degrees and sun everyday. It will be a lot different then Christmas
back home and I will very much miss spending time with friends and family. I
hope that many of us can talk, be it through skype or e-mail. Until then, Merry
Christmas to everyone and I wish you all a safe holiday season.
-Nick
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