Wildlife of the Galapagos

This past week, I shared with you our discoveries while we were in the Galápagos in a five-day series titled, The Islands of the Galápagos. Today, I would like to share with you the wildlife of the Galapagos archipelago, while also showcasing the life zones and ecology of the islands.

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Visitors to the islands notice that there are few species on the Galápagos archipelago. The geology of the islands, with the constant volcanic activity, creates a harsh, desert climate with very little rain and high temperatures so that only the higher slopes of the larger islands have enough rain to nourish a luxuriant growth of plants.

This, in turn, results in an environment that is very hostile for most animals that are found on the continent. Most of the islands are low and what little rain they get comes during a short rainy season, with the rest of the year being very dry. The amount of rain varies from one year to the next.

“The natural history of these islands is eminently curious, and well deserves attention… Considering the small size of these islands, we feel the more astonished at the number of their aboriginal beings, and at their confined range…Hence, both in space and time, we seem to be brought somewhat near to that great fact–that mystery of mysteries–the first appearance of new beings on this earth.”  ~ Charles Darwin, The Voyage of the Beagle

“Eminently curious” well describes the natural history of the Galápagos, from its sere landscapes to its comical birdlife. For over 400 years this volcanic archipelago has both puzzled and stunned its visitors, and no aspect of the islands is as stunning as its wildlife. The ease of approach to the birds, iguanas, tortoises and other creatures of the Galápagos is due to their isolation from natural predators, a condition that first stirred Charles Darwin in 1835.

Eco-zones of the Galápagos

There are a total of seven zones within the archipelago housing a variety of plant life. Varying amounts of rainfall with altitude, and from island to island, have led to the formation of vegetation zones ranging from desert to lush cloud-forest.

Various plants and animals have adapted over the years to the conditions of the islands and in some cases the condition of the zone. Plantlife (or flora) is normally found in a specific zone and the animal life (fauna) dependent on those plants can be found in the same zone.

lifezones

Image from MIT.edu

Coastal Zone

The lowest life zone on the island is the coastal zone. Those plants here can be divided into the Wet Coastal Zone (or Mangrove Zone) and the Dry Coastal Zone (beaches and high tide areas). Saltbush is found near most shores, where it forms a dense low shrubby tangle.

Mangroves are salt-tolerant trees and shrubs that thrive in shallow and muddy saltwater or brackish waters. In the Galápagos there are 4 varieties of Mangroves including the Black Mangrove, White Mangrove, Red Mangrove, and Button Mangrove.

Here most of our walks in the Galápagos took place — with the scuttle of the bright orange Sally lightfoot crabs underfoot, beneath the gaze and snort of the marine iguanas, to the barking of sea lions and the crashing of the surf off the shore. This is the environment we will remember when we look back on our time spent in the Galápagos.

Lowlands Zone

As an island slopes from the beach to an elevation of about 197 ft (60 m) elevation an arid desert like zone occurs. This region is home to the many Cacti that live in the Galápagos including the Prickly Pear Cactus, Lava Cactus, and Candelabra Cactus .

Vine plants also make their home here; the endemic lava morning glory and endemic passionflower can be found in this zone. At the top of the Arid Lowlands the silvery leafed Palo Santo Tree with its collection of lichens can be seen.
wildlifegalapagos

Transitional Zone

Rising up the island, plants become more frequent. In the Transition Zone plants from both the Arid Lowlands and the Upper Moist Zones occur. This zone is home to a variety of small trees or shrubs including the endemic Pega Pega Tree and the endemic Guaybillo, which produces a small white flower that develops into a fruit similar to its cousin the Guava.

“The distribution of the tenants of this archipelago would not be nearly so wonderful, if, for instance, one island had a mocking-thrush, and a second island some other quite distinct genus…. But it is the circumstance, that several of the islands possess their own species of tortoise, mocking-thrush, finches and numerous plants, these species having the same general habits, occupying analogous situations, and obviously filling the same place in the natural economy of this archipelago, that strikes me with wonder….”   ~ Charles Darwin, Voyage of the Beagle

Scalesia Zone

The lowest of the “humid” zones, the Scalesia zone is named for the daisy tree that grows between 970-1970 ft (300 – 600 m) elevations. The Scalesia is one of the few trees in the Aster Family and grows to heights 16 – 50 ft (5-15 m) in height. Its trunk and branches are covered with moss and lichens. This area is humid and has the essence of being in a rainforest.

Scalesia Trees have been greatly reduced in numbers since humans arrived in the islands. With them came pigs and goats, which devour the young plants and feed on older plants. People also introduced the Guava, a plant whose dense growth patterns steals nutrients and eventually makes it impossible for competing plants to survive.

Brown Zone

An intermediate zone between the dense Scalesia forest and the Miconia shrubb vegetation, the Brown Zone is an open forest dominated by cat’s law, tournefortia pubescens, and aunistus ellipticus. Trees are heavily draped with epiphytes, mosses, livertorts and ferms, which give this zone a brown appearance during the dry season. However, on the islands with this elevation, this zone has disappeared because of colonization by man.

Miconia Zone

Above the Scalesia Zone at 1950 – 2300 ft (600-700 m) is the humid zone named for the Miconia shrub that once dominated this region. Miconia Robinsoniana grows to heights of 10-13 ft (3-4 m). The yellow or reddish shading on the edges of its leaves easily identify it.

The Miconia is endemic to the Galápagos, but since the arrival of man it has become the most endangered plant in the islands. Introduced cattle have grazed the Miconia into dangerously low levels.

Pampa Zone

On islands with elevations over 3000 ft (900 m ) the highest vegetation zone in the Galápagos can occur, the Fern-Sedge Zone or Pampa Zone . The appearance of this zone depends on the amount of moisture it receives. This region contains no true trees or shrubs. The tall Galápagos Tree Fern and Liverworts are commonly found in this zone.

galapagoswildlifeWildlife of the Galapagos *

BIRDS

  • Blue-footed booby (Sula nebouxii)  ✓
  • Red-footed booby (Sula sula)
  • Nazca booby (Sula dactylatra)  ✓
  • Waved albatross (Diomedia irrorata)   ✓
  • Magnificent frigatebird (Fregata magnificens)   ✓
  • Galapagos penguins (Spheniscus mendiculus)   ✓
  • Lava heron (Butorides sundevalli)   ✓
  • Great blue heron (Ardea herodias)   ✓
  • Yellow-crowned night heron (Nyctanassa violacea)
  • Striated heron (Butorides striata)   ✓
  • Brown pelican (Pelecanus occidentalis)   ✓
  • Flightless Cormorant (Nannopterum harrisi)   ✓
  • Lava gull (Larus fuligihosus)   ✓
  • Flamingo (Phoenicopterus ruber)
  • Galapagos hawk (Buteo galapagoensis)   ✓
  • Red-billed tropicbird (Phaethon aetheus)   ✓
  • Storm petrels (Hydrobatidae)  
  • Swallow-tailed gulls (Creagrus furcatus  ✓
  • Galapagos mockingbird (Nesomimus parvulus)   ✓
  • Cactus ground finch (Geospiza scandens)   ✓
  • Warbler finch (Certhide a olivacea)   ✓
  • Great egret (Ardea alba  ✓
  • Cattle egret (Bubulcus ibis  ✓
  • Galapagos rail (Laterallus spilonotus)    ✓
  • Lava gull (Leucophaeus fuliginosus  ✓
  • Brown noddy (Anous stolidus  ✓
  • Galápagos dove (Zenaida galapagoensis  ✓
  • Darwin’s finches (Tanagers)   ✓
  • American yellow warbler   ✓
  • Galapagos pintail duck (Anas bahamensis galapagensis)  ✓

REPTILES

  • Tortoise (Geochelone elephantopus) – fourteen subspecies   ✓
  • Land iguana (Conolophus sp.) – two species   ✓
  • Marine iguanas (Amblyrhynchus sp.) – seven subspecies   ✓
  • Lava lizard (Tropidurus sp.) – seven species   ✓
  • Gecko (Phillodactylus sp.) – seven species
  • Snake (Dromicus sp.)

MAMMALS

  • Sea lion (Zalophus californianus wollebacki)   ✓
  • Fur seals (Arctocephalus galapagoensis)
  • Galápagos rice rat
  • Hoary bat
  • Eastern red bat

INVERTEBRATES

The Galápagos islands are also home to innumerable marine invertebrates. This very diverse group includes molluscs (e.g., shells and snails), marine annelids (e.g., segmented worms), echinoderms (e.g., sea urchins, sea stars, and sea cucumbers), cnidarians (e.g., corals and gorgonians), sponges, and many others. Some of the more notable species we observed include:

  • Sally Lightfoot Crab   ✓
  • Sea Cucumbers   ✓
  • Chocolate Chip Star   ✓
  • Blue Sea Star   ✓
  • Galapagos Carpenter Bee   ✓
  • Large Painted Locust   ✓
  • Galapagos Scorpion   ✓

* checkmarks indicate the animals we observed

galapagos unitIf you would like to further explore the Galápagos from the comfort of your home or if you are planning to visit yourself, my multidisciplinary unit study, Galápagos Across the Curriculum, provides ample opportunity for kids to explore the diversity and remarkable history of the islands through a variety of hands-on science activities and projects.

The Geology & Geography of the Galapagos

This past week, I have been sharing with you our discoveries while we were in the Galápagos in a series titled, The Islands of the Galápagos. The strange beauty and attraction of these volcanic upwellings wove their mystery around us just as they have others who have visited since the archipelago was first discovered in 1525 by the Bishop of Panama, Tomas de Berlanga.
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Today, I would like to expand upon the geology and geography of the Galápagos archipelago and share with you some of the resources that aided in our understanding of these enchanted islands.

The Galápagos archipelago consists of 18 main islands, 3 smaller islands, and 107 rocks and islets. The islands are located at the Galapagos Triple Junction – a confluence of three tectonic plates, the Cocos Plate, the Nazca Plate (which is moving east/southeast), and the South American Plate. It is also atop the Galapagos hotspot, a place where the Earth’s crust is being melted from below by a mantle plume, creating volcanoes.

Geology of the Galápagos

Geology (from the Greek γῆ, gē, i.e. “earth” and -λoγία, -logia, i.e. “study of, discourse”) is a field of science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change.

Plate Tectonics

Using our North Star Geography program as our guide, we learned about plate tectonics prior to our departure. There are three types of boundaries between tectonic plates:

  • Divergent Boundaries – where two plates are moving away from each other
  • Convergent Boundaries – where two plates push up against one another
  • Transform Boundaries – where two plates move horizontally, slipping past each other in opposite directions

After reading the chapter, we created edible models of the boundary types in STEM Club (see my earlier post, Plate Tectonics, for lesson details). This was a great activity and the kids really enjoyed manipulating the earth’s plates (i.e. graham crackers).

North-Star-Geography

As a Brand Ambassador for Bright Ideas Press we have received a complimentary copy of North Star Geography in exchange for our honest insights about how this program is working in real life with our family.

Dynamic Plate Boundaries

The lithosphere is broken up into 15 major plates, which move with respect to one and other. Mid-oceans ridges, a type of divergent boundary, are located at the edges of plates moving away from one and other on the ocean floor. One such mid-ocean ridge, the Galápagos  Spreading Center, is located just north of the archipelago.

Mid-ocean ridges are often offset by fracture zones or transform faults. A major transform fault is located just north of the islands.

galapagosspreadingcenterSubduction zones occur where plates collide. A major subduction zone is located where the Nazca and Cocos Plates are subducting beneath the South American and Carribean plates. Subduction zones are marked by deep trenches and overlying chains of volcanoes (the Andes, for example).

Mantle Plume

The Galápagos Islands are one of most active oceanic volcano areas in the world. Like many oceanic islands, the Galapagos are thought to be the product of a mantle plume – columns of hot rock that rise from deep within the Earth. These plumes rise because they are hotter and therefore less dense, than the surrounding rock.

As a lithospheric plate moves over a mantle plume, a chain of volcanoes is created. The volcanoes get older in the direction of plate motion. The Galápagos Islands are located on the Nazca Plate, which is moving east-southeast. Thus, the islands get older to the south-southeast and it has produced a chain of seamounts known as the Carnegie Ridge.

A second seamount chain, the Cocos Ridge, extends northeast from the Galápagos Spreading Center. Thus a chain of volcanos was produced on both the Cocos and Nazca plates.

Geography of the Galápagos

Geography (from Greek γεωγραφία, geographia, lit. “earth description”) is a field of science dedicated to the study of the lands, the features, the inhabitants, and the phenomena of the Earth.

Volcanoes

In our North Star Geography text, we also learned that there are a number of different kinds of volcanoes. We observed two distinct types of volcanoes in the Galapagos. In the west, on the islands of Isabela and Fernandina, large volcanoes with an “inverted soup-bowl” morphology and deep calderas occur. In the east, smaller shield volcanos with gentler slopes occur.

One of the activities suggested in the North Star Geography activity guide, is to make a topographical salt dough or cookie dough map. The Galápagos islands were the perfect “model” for this activity.

In addition to the salt dough map, the kids enjoyed creating an accordion-style picture dictionary as we were traveling. You can download this free printable, Geography Picture Dictionary, for your personal use. It is a great supplement for North Star Geography. Children can sketch the geography specific to a region (as we did) or use it in a more general sense.

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Craters & Sink Holes

The twin craters of Los Gemelos (one of which is pictured above) are a highlight of the Santa Cruz highlands. Though a lesser know attraction, Los Gemelos, are actually sink holes, not volcanic craters, on the highest part of Santa Cruz. These depressions were formed by collapsing underground lava tunnels.

Upland Forests

This region also boasts of a beautiful Scalasia forest with trees covered by many epiphytes. In recent years, however, some plants have been introduced that are invading the Scalesia pedunculata forest rapidly. What was interesting here was that in addition to the Scalasia, cacti were also present (though more abundant in the lowlands).

In contrast to the dry coastal lowlands, the highlands are covered by mist in the garua (foggy) season and receive thus much more moisture and support a more luxuriant vegetation.

galapagos unitIf you would like to further explore the Galápagos from the comfort of your home or if you are planning to visit yourself, my multidisciplinary unit study, Galápagos Across the Curriculum, provides ample opportunity for kids to explore the diversity and remarkable history of the islands through a variety of hands-on science activities and projects.

The Islands of the Galapagos: Espanola

espanolaThis is the fifth post of a five day hopscotch series. Join me each day this week as I share with you our discoveries in the Galápagos Islands.

Isla Española

The kids and I would agree that Isla Española is our favorite. We spent the entire morning here on our seventh day – walking very slowly as there was so much wildlife to see here, particularly the baby sea lions, Waved Albatross, Nazca boobies, and Blue boobies.

Located in the extreme southeast of the Galápagos archipelago, Isla Española is considered, along with Santa Fe, one of the oldest – and thus the first to which animals arrived. The climate is very dry, like most of the archipelago, but due to the flatness of the island, it is the driest of these islands, with only a few inches of rain per year.

nazcabooby

As one of the oldest islands, Española is slowly becoming a rocky, barren land with little or no vegetation giving way to large bays with sand and soft shingle which attracts a number of Galápagos Sea Lions.

Punta Suárez is of particular interest to birders because of its varied bird life. As it is one of the oldest islands, this island has its own endemic species, amongst them the Española Mockingbird which has a longer and more curved beak than the one on the central islands; the Española lava lizard; the Marine Iguana of the subspecies venustissimus, which has red markings on its back; among others.

espanolaiguanaAs we walked along the trail on the cliff, we observed a surprise at every bend. We were able to watch a male Nazca booby court a female calling her attention and placing “gifts” of stones and sticks on a nest. We also watched a female Blue booby feeding her chick who was as white as snow and fluffy white.

As we returned to the Evolution later that afternoon, and what I later realized was the last time (for the next day we anchored off at Isla San Cristobal for our departure flight back to Guayaquil), we were captivated by a number of small golden rays that circled the panga and stayed with the ship for sometime after.

sallylightfootRead my other posts in The Islands of the Galápagos series:

Baltra & Santa Cruz

Isabela

Fernandina

Santiago & Bartolomé

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The Islands of the Galapagos: Santiago & Bartolome

santiagobartolomeThis is the fourth post of a five day hopscotch series. Join me each day this week as I share with you our discoveries in the Galápagos Islands.

Isla Bartolomé

Isla Bartolomé is a volcanic islet just off the east coast of Isla Santiago. It is one of the “younger” islands in the Galápagos archipelago. This island, and Sulivan Bay on Santiago island, are named after a naturalist and lifelong friend of Charles Darwin, Sir Bartholomew James Sulivan, who was a lieutenant aboard HMS Beagle.

Bartolomé has a volcanic cone that is easy to climb and provides great views of the other islands. We began our tour here by hiking up this cone in the morning – a relatively easy hike via a raised wooden walkway and stairs.

From the viewpoint we could easily see Pinnacle Rock, the distinctive characteristic for which Bartolomé is famous and the most representative landmark of the Galápagos.

pinnacleThe majority of our group chose to spend the afternoon on the beach (pictured just behind us above) where marine iguanas, sea lions, fur seals, land and sea turtles, flamingos, crabs, dolphins, and sharks can be found. While the flamingos continued to evade us, we did observe a shark playing in the surf, just a few feet from where we stood.

The afternoon was a little windy and cold and thus Patrick and Buddy were the only passengers to join Cristina on a snorkeling outing. They were rewarded handsomely, however. Not only did they see sharks resting on the ocean floor, but they were also able to swim with a pod of dolphins. I was so jealous – I’ve always wanted to swim with wild dolphins!! I am kicking myself for being a wimp and not want to get cold.

Isla Santiago

Isla Santiago consists of two overlapping volcanoes, atop the northwestern shield volcano. The volcano in the island’s southwest erupted along a linear fissure, and is much lower. There are many volcanic fissures and a variety of red, orange, green, and glistening black volcanic formations.

We spent the evening meandering about Sullivan Bay, which is especially fascinating for those who are interested in geology and volcanology. Here you can walk over the un-eroded, black lava flow covered with lava bubbles and tree-trunk molds in the surface.

pahoehoeRead my other posts in The Islands of the Galápagos series:

Baltra & Santa Cruz

Isabella

Fernandina

Española

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The Islands of the Galapagos: Fernandina

fernandina

This is the third post of a five day hopscotch series. Join me each day this week as I share with you our discoveries in the Galápagos Islands.

Fernandina

Isla Fernandina is the third largest, and youngest, island of the Galápagos Islands. It is considered the most pristine of the Galápagos Islands and has had no species of mammals introduced, which sets it apart from most of the other islands in the archipelago.

The westernmost of the islands in the archipelago, it was named in honor of King Ferdinand of Spain, who sponsored the voyage of Christopher Columbus. Like the other islands in the archipelago, it was formed by the hotspot and is an active shield volcano that has been erupting since April 11, 2009.

In 1968, the caldera underwent a collapse when parts of the caldera floor dropped 350 meters.  Since then, a small lake has intermittently occupied the northern caldera floor, most recently in 1988. Due to the active volcano, there is not much plant life on this island and has a mostly rocky surface.

marineiguanasWe landed at Punta Espinoza, a narrow stretch of land where hundreds of marine iguanas gather in large groups on black lava rocks. We had to be careful where we stepped because they literally carpeted the ground and camouflaged so well with the ʻaʻā and  pāhoehoe. 

Most of the lavas on Fernandina are ʻaʻā. Pahoehoe lavas on Fernandina are largely resticted to vents on the coast plain. ʻAʻā  is extremely difficult to walk on, making the climb to the summit a difficult one, however, tourists are kept to the outskirts of the caldera.

A nesting colony of Flightless Cormorant inhabits this island and we were able to get remarkably close.  Other endemic wildlife include Galápagos penguins, pelicans, Galápagos land iguanas, and sea lions. Mangrove forests abound on the fringes of the island.

groupcormorantsRead my other posts in The Islands of the Galápagos series:

Baltra & Santa Cruz

Isabella

Santiago & Bartolomé

Española

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The Islands of the Galapagos: Isabela

isabela

This is the second post of a five day hopscotch series. Join me each day this week as I share with you our discoveries in the Galápagos Islands.

Isabela

The seahorse-shaped Isabela Island is the largest of all the islands, measuring 120 km long and greater in size than all of the other islands combined. One of the younger islands and more volcanically active, it was formed by the joining of six shield volcanoes — from north to south — Ecuador, Wolf, Darwin, Alcedo, Sierra Negra, and Cerro Azul. With the exception of Volcano Ecuador (whose western flanks have collapsed), all are still active.

Wolf Volcano, with an elevation of 1707 m, is the highest point in the Galapagos Archipelago. Isabela provides visitors with excellent examples of the geologic forces that created the Galapagos Islands, including uplifts at Urbina Bay, tuff cones at Tagus Cove, and pumice on Alcedo Volcano.

In 1893, Antonio Gil, a well-known Guayaquileño, arrived in Galapagos and after visiting the other islands, colonized southern Isabela, founding the town of Puerto Villamil on the southern coast and later Santa Tomás in the highlands.

Villamil – named after a freedom fighter from the Guayaquil, José de Villamil – began as a center for a lime production operation where they burned coral collected in the coastal waters. Santa Tomás was the center for a sulfur mine in the caldera and a nearby coffee plantation.

sealionUrbina Bay

Located at the base of Alcedo Volcano on the west coast of the island, this area experienced a major uplift in 1954, causing the land (formerly red mangroves) to rise over 16 feet. The coast expanded half a mile leaving marine life stranded on the new shore.

On the morning of our third day, after a wet-landed from the panga, we walked in land about 1/2 mile and observed sea turtle nests, Giant tortoises, beautiful orange land iguanas, many small marine fossils, and several Galapagos hawks.

After our hike, we spent some time on the beach swimming and snorkeling with the sea turtles, sea lions, rays, and the diverse fish that were near the shore.

penguinsTagus Cove

Tagus Cove on the northwestern side of the island was named for a British naval vessel that moored here in 1814 and provided a sheltered anchorage for pirates, buccaneers, whalers, and others. One can still see the names of their ships carved into the rock, a practice that is now prohibited.

In the afternoon we first chose to snorkel from the panga. We saw many colorful fish but the most exciting were the penguins and sea horses, the latter of which were difficult to see they were so well camouflaged in the Sargassum.

seaturtleAfter returning to the Evolution to get warmed up and a little something to eat, the group split up – several (including Patrick, Jeffrey, and myself) ventured out again for a panga ride along the shore. Geneva chose to join the others for a “power hike” to Darwin Lake (he visited Tagus Cove in 1835).

The panga riders enjoyed many opportunities to observe boobies, penguins, iguanas, cormorants, and noddy birds along the cliffs and shoreline. I most enjoyed seeing the yellow and orange cup coral (just at the water line) in a small cove. They were so brightly colored!

darwinlake

Read my other posts in The Islands of the Galápagos series:

Baltra & Santa Cruz

Fernandina

Santiago & Bartolomé

Española

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