I awoke to a sea lion barking impression sent out over the intercom system throughout the
boat. "Time to wake up to the first full day in paradise," he continued. I was too sleepy to hear whatever he said afterwards,
but slowly arrived at consciousness and went out onto the back observation deck. We were in a large bay surrounded by steep,
whitish-gray rock walls and covered by even grayer, low lying overcast skies. The air was fresh and moist hinting that it would
probably be a hot and humid day ahead. The Letty was anchored in a triangle formed by its sister boats the Flamingo and the Eric,
all of which traveled together during the week long tour.
The Cliff that surrounded us is the crater wall, or caldera, of a dormant volcano that formed what is today Genovesa Island. To
the South the rim was lower and had an area submerged deep enough to allow the boats to enter what is now Darwin Bay, even though
Darwin himself never visited this island on his journey aboard the Beagle. The bay or caldera is very deep reaching depths of
277 m (900 ft) and would serve as the location for our first snorkel later in the day.
I made my way down to the dining room where a breakfast buffet of fresh fruit, cold cereal and hot coffee awaited consumption.
I made myself a cup of coffee and loaded a plate of fruit before sitting down to enjoy the first meal of the day. My headache
seemed to have gone away and I was feeling ready to get on with the day's activities. As the group was wrapping up breakfast an
announcement was made that we would be boarding the pangas in 15 minutes and that we would have a dry landing.
The first stop on this day was St. Phillips Steps, a narrow crevice in the rock wall where steps had been constructed to
compliment the natural rock steps that lead 25 meters (82 feet) to the top of what is known as "The Cliff." Pepé's group
disembarked first while my group, led by Harry, waited at the cliff walls for our turn. While sitting in the panga we watched the
activities of the
Nazca boobies (Sula granti)
perching on ledges in the cliff where they tended to nest. Because the Nazca boobies
are somewhat large, nesting in the high reaches of rock walls aid them in taking flight helping them to conserve their energy for
other needs such as flying out into the open ocean to forage.
After scaling St. Phillips Steps we discovered a landscape of bushes and shrubs, mostly
palo santos (Bursera graveolens)
in the arid zone, most of which looked dead or dormant devoid of green foliage. However, the diversity and abundant populations of bird
life present made the island come alive. Located on the ground were dozens of Nazca booby nests while the bushes were teeming with
great frigatebird (Fregata minor),
magnificent frigatebird (Fregata magnificens)
red-footed booby (Sula sula)
nesting sites. In addition, I spotted at least two of the four species of Darwin's finches found on the island, a pair of
and a colorful
Galápagos dove (Zenaida galapagoensis).
While the group was taking in the scenery and the array of birds crammed closely around us, Harry provided verbal insights and
information regarding the species of this island. Having been an active member of a study that had been conducted in the recent
past on the Nazca Booby he opened our eyes to the practice of infidelity that occurs within these majestic birds' populations. It
was found that the Nazca booby female will copulate with other males when their mates are absent even though they tend to have
life-long pair bonds. That being said, the female will exclusively copulate with her chosen mate when she is fertile, possibly
indicating that this species may participate in sexual acts for the purpose of fun.
The morphology of the Nazca booby and the masked booby found in Columbia are quite similar, but based on this cultural finding
of the study they were determined to be a separate species. It was also discovered that the Nazca booby males will always return
to their birthplace year after year to nest and produce their offspring.
Nazca and red-footed boobies fly far out to sea to catch their prey with the Nazca boobies venturing out the furthest. However,
these two inhabitants of Genovesa possess two distinct strategies in rearing their young.
The Nazca booby seemingly employs a cruel method to increase the odds of having their chicks survive by laying two eggs each
mating season. Because of the time and energy required for these birds to fly out to sea to forage, they can only bring back
enough food to support one chick. So, of the two chicks born, only one will survive - the strongest.
In what is known as siblingicide the strongest, usually the first born, forces its sibling out of the nest where it will soon
die without nourishment from its parents. This practice increases the chance of a successful mating by ensuring a second chance
in case the first chick dies. The red-footed booby on the other hand simply lays a single egg and raises a single chick.
Red-footed boobies share the same territories with the Nazca boobies to nest and raise their young on Genovesa Island. However,
the red-footed booby makes its nests in the bushes and shrubs rather than directly on the ground like the Nazca boobies. In fact,
the red-footed booby has developed claws on its webbed feet to aid them in grasping onto tree branches where they perch. The
red-footed booby is the only tree nesting booby found in the archipelago.
Given that we were visiting the islands in May and towards the end of the mating season for these two species of boobies, we
were able to see many booby chicks and juveniles. The Nazca booby chicks were like little balls of fluffy, white down feathers
with gray beaks extending back and adjacent to their black eyes.
Red-footed booby juveniles tended to be brownish-gray with gray feet and beaks. These chicks will mature into one of two
morphologies, one being white bodies with black feathers on the edge of their wings and the other having a brown body. Both
morphologies have blue beaks and bright red webbed feet that may be a result of red dyes they ingest from their favorite food
source - squid.
As if the large number of these big birds habituating the area was not enough, occupying the same vicinity were the great
frigatebirds. Frigatebirds get their name from their hooked beaks and their thieving, harassing behavior. Frigates are pirate
ships and these birds are pirates of the skies. Because these birds cannot dive into the water for food lest their feathers become
water logged and they drown, they have evolved a unique way of obtaining a meal.
Frigatebirds will wait for the boobies to return from their deep sea foraging and attack them in mid-air usually grabbing their
tails continuing the harassment until they drop their bounty. Once the food is released the agile frigates will quickly dive after
and catch it before it hits the water. The frigate's scissor-like tail enables them to maneuver ever so quickly in this feeding
process known as cleptoparasitism.
During our class time we had learned that the male frigate will inflate his bright red, modified gular sack to attract females
in which to mate. Luckily, touring the islands in May, we got to observe these birds during their mating season. It was an
incredible sight to watch the males with their inflated "man sacks," wings spread wide and heads thrown back to watch the skies
for passing females. When females approached the males would sound their call, similar to a turkey gobble, in an attempt to
attract the female to their nest for mating. I was even more amazed that the males, "man sack" inflated, were able to fly!
Female frigatebirds do not have the red gular sack, but they do have a bright red ring around their eyes. Males possess black
plumage with a green sheen. Unlike their male counterparts with black throats and breasts, the female frigates have white throats
and breasts. Chicks are completely white at first and then their heads and necks will turn hazelnut in color.
Genovesa has two distinct species of frigatebirds. The great frigate described above and the magnificent frigate. The
morphological differences in these two species are: magnificent males have a purple sheen on their feathers, females have a black
triangular patch on their breasts and do not have red eye rings, and they feed closer to shore than do their great counterparts.
I found the cliff's top rim area quite intriguing given that three large bird species all inhabited the same location and lived
amongst each other in seeming harmony, especially that the boobies share territory with their pirating enemy, the frigatebirds.
Moreover, other small ground birds forged out niches in the same area taking advantage of insect and seed populations ignored by
the larger sea birds.
As we made our way off the rim to the outer edges of the island the scenery gave way to barren, red rocky terrain with a large
crevice spanning across the small island. This crevice or crack was created when fluid lava flowed back into the fracture before it
hardened. The only plant life in this section of the island is
lava cactus (Brachycereus)
and a low growing bright green ground plant.
This environment supported yet another bird species,
Castro's storm petrels (Oceanodroma castro),
that inhabited lava holes and lava flow edges. These birds were flying around the coast in vast numbers (hundreds of thousands) on
Genovesa where they forage on small sea fish and squid. The primary predator of the storm petrel is the
short-eared owl (Asio flammeus)
of which we did not spot on our tour of the island.
Having walked across this end of the small island of Genovesa, we made our way back to St. Phillips Steps and the panga. Once
back at the Letty we would have a quick rest and then snorkel for our first time in the deep waters made by the volcanic crater
that long ago formed the island.
The final activity of the day involved a choice: 1) snorkel from Darwin's Bay Beach, or 2)
relax on the beach. Because I was a little shaken up by the first snorkel I thought I would relax on the beach and take up
snorkeling the following day. Unfortunately, I missed out the first shark sightings of the trip, not to mention a chance to
photograph one. Mike T. and Chris M. spotted and photographed some small
whitetip reef sharks (Triaenodon obesus)
in the lava rocks adjacent to the beach. Meanwhile, I strolled along the beach taking note of the terrestrial wildlife and plant life existing
on this opposite end of Genovesa Island relative to St. Phillips Steps.
The beach itself presented a very different ecosystem than we had visited on top of the cliffs. The beach was located in what
seemed to be a break in a corner of the crater's wall. The Cliff continued to run along one side of the beach creating a walled
area in which
cactus (Opuntia echios)
were growing and Nazca boobies were nesting on the rocks. The other side of the beach was
separated from the outer caldera wall by a tide pool that flowed into the bay. It has white sands from millennia of coral erosion
and is lined in the back by vibrant green mangroves called
black mangroves (Avicennia germinans)
supporting the nesting sites of red-footed boobies and frigatebirds.
Other life I saw on the beach included what I thought were three different species of gulls. As it turns out I only saw two
species, the third was a morphological variation of the
swallow-tail gull (Creagrus furcatus)
during its juvenile period having a black and white spotted appearance. The swallow-tail gull is quite a beautiful bird with a black head,
tail feathers and beak, gray back and wing feathers and a white chest and breast. The gull features a bright red eye ring that is thought
to help these nocturnal feeders find food in the dark by acting as a sort of sonar. The legs and webbed feet of the gull are bright red as
well. The tip of its black beak is white, which helps chicks find the mother's beak in the dark to receive their meals.
The other gull species I spotted had a call that sounded like a baby crying. This gull is an endemic resident of the island and
is thought to have only 400 breeding pairs. It is known as a
lava gull (Leucophaeus fuliginosus)
and has a black head, tail, feet and beak with gray body and wing feathers.
yellow crowned night heron (Nyctanassa violacea)
was wading in the fresh water river and is commonly seen overlooking tide pools at Darwin's Bay. Also present on the beach were a few female
sea lions and numerous bright red, sally lightfoot crabs standing out against the black lava rocks making up the crater wall.
When the snorkelers made their way back to the beach the pangas were dispatched to pick us up and return us to the Letty. Back
on the boat we were met with soda and snacks after which we would prepare for dinner. I chose to have large shrimp served with
cauliflower and green beans, another delicious and healthy meal. After dinner we all settled in for the next day's briefing. We
were going to be traveling through the night up and around the north edge of Isabela Island and then back down where we would have
our first hike of the day on Fernandina, the youngest island in the Galápagos.