Exam 3 - Reptile and Birds of Galapagos

Reptiles of Galapagos

22 reptile species

20 endemic

Testudidae - tortoises

Cheloniidae - Marine Turtles

Iguanidae - Lizards and Iguanas

Gekkonidae - Geckos 

Colubridae - Snakes 

C. nigra

Also known as Floreana Tortoise

Extinct tortoise species

Darwin said they were heavily hunted

C. wallacei

Also known as Rabida Tortoise

Extinct tortoise species 

Single species was removed by California Academy of Sciences in 1906

Not sure if it is a separate species or not

C. phantasticus 

Also known as Fernandina Tortoise 

Thought to be extinct (one found and killed by C.A.S. in 1906) until a female was found in 2019

C. abindonii

Also known as Pinta Tortoise

Lonesome George was last member (extinct), though scientists are still trying to find any remaining individuals of this species

Current # of tortoises in Galapagos

about 15,000

San Crisobal 

common ancestor to the different tortoises/subspecies was most-likely first on

Espanola

greatest # of tortoises released by CDRC

Scutes

sections of shell on tortoises

differences of tortoises across Galapagos 

varies in size, shape, color of body and of shell across Islands (sometimes even in same species)

C. darwini

Santiago Tortoise (female pictured) 

C. donfaustoi

East Santa Crus Tortoise

species named after Lonesome Georges’ caretaker

C. duncanensis

Pinzon tortoise

C. porteri

West Santa Crus Tortoise

C. chathamensis 

San Cristobal Tortoise 

C. hoodensis

Espanola Tortoise

C. becki

Isabela (Volcan Wolf Tortoise)

C. vicina (subspecies of niger)

Isabela (Volcan Cerro Azul Tortoise)

C. microphyes

Isabela (Volcan Darwin Tortoise)

C. guentheri

Isabela (Volcan Sierra Negra Tortoise)

C. vandenburghi 

Isabela (Volcan Alcedo Tortoise) 

Diet of Tortoises

Hippomane mancinella (posion apple)

Psidium galapageium (galapagos guava) 

Azolla microphylla (mosquito fern) 

Tillandsia insularis (tillandsia) 

Opuntia species 

Behaviors of Tortoises

often seen wallowing in pools of water or mud baths (to keep cool and avoid bugs)

finches and/or mockingbirds’ clean insects off of their skin, the tortoise will stretch their neck out longer, so the birds are able to reach the insect pests

become sexually active at about 20-25 years of age (toward warm season - start breeding) 

males will fight for territory or females by stretching their necks as high as possible, highest head indicates the more dominant tortoise 

males have a concave-shaped plastron that allows it to easily mount the females when mating 

eggs are laid between june and december (sandy-dry soil is required for nests), hind legs are used to dig a 30 cm deep hole, then about 2-16 eggs are deposited: nest then capped with layer of mud and urine 

young hatch about 120-140 days later between december and april (hawks are only native predator to hatchlings) 

Chelonia mydas agaggisi

Pacific green turtle

• only marine turtle resident 

• mating season peaks november to january 

• female is typically larger and does swimming during copulation (male holds on using his flippers) 

• many males mate with one female 

• males have a concave-shaped plastron

• weighs up to 150 kg (typically range from 50-100kg)

• shells vary from black to green (rare but sometimes orange or yellow) 

• food source = seaweed 

• lays eggs on sandy beaches (70-80 eggs each time)

  • digs small nest with flippers 

  • nesting takes place at night usually 

  • december to june 

  • eggs/young turtles are hunted by ghost crabs, birds, pigs and rats (introduced) and once in ocean; sharks, fish, more birds

Snakes

two species - both endemic and all of them are constrictors 

• Philodryas 

• Alsophis 

  • comprised of two species, with each of the two species having 2-3 subspecies 

• maximum length of 1 m 

• mainly brown in color, with yellowish stripes or spots on their back 

• prey - 

  • lava lizards, geckos, young marine iguanas, rats, and grasshoppers

Geckos 

Genus - Phyllodactylus (6 species, 5 endemic)

Lava Lizards

• genus - Microlophus (7 endemic species)

• on all major islands (except Genovesa, Darwin, and Wolf) 

• San Cristobal, Floreana, Marchena, Espanola, Pinta, and Pinzon each have their own species 

• males are typically 2-3 times larger than females; body is normally more brightly colored or distinctly patterned 

  • the lizards vary in color depending on the surrounding substrate

• Behaviors- 

  • push-ups 

    • territorial display that can vary from population to population 

  • sensitive to movement 

• Food - 

  • moths, flies, beetles, grasshoppers, grubs, spiders, and scorpions 

• Preyed upon by - 

  • hawks, snakes, mockingbirds, herons, and centipedes 

Land Iguanas

genus - Conolophus

• found in drier parts of several islands

• food consists mostly of opuntia (fruits and pads)

  • Portulaca flowers are favored when in season

• male land iguanas are larger and more brightly colored than females (color also affected by body temp and level of excitement)

• live about 60 years or more, 8-12 years to reach sexual maturity

  • males mate with female by grabbing hold of her neck in his mouth, hooking his leg over her, and bringing his tail around underneath her (often results in female running away after mating completed) 

• females lay between 2-25 eggs in burrows up to .5 m deep; breeding season varies from September to January to June, depending on the island 

  • hatchlings leave the nest and become food for herons, egrets, hawks, and owls 

• No longer on Santiago Island due to influence of humans and introduced animals 

Conolophus subcristatus

Found on Fernandina, Isabela, Santa Cruz, Plaza Sur, and Seymour Norte

Conolophus pallidus

Found on Santa Fe; yellower than the other species

Conolophus marthae

New species recently discovered from Isabela Island (Volcan Wolf) 

• pink body with some dark stripes

• discovered in 1986 and identified as a separate species in 2009 

Marine Iguana

Amblyrhynchus cristatus

• only sea-going iguana in the world, found throughout the entire archipelago (prefers exposed southern coastlines)

• larger, stronger males feed offshore by diving; younger males and females typically feed intertidally or on exposed reefs 

  • diving behavior- 

    • 5-10 minutes, but sometimes lasting as long as 60 minutes 

    • may go as deep as 12 m or more below the surface 

• take in a lot of salt as they feed/dive, must excrete lots of salt through these glands above the eye and connected to the nostrils 

• exothermic

• black with few gray, green, or reddish spots 

elevated basking

marine iguana faces the sun and raises the front half of its body allowing the breeze to circulate under the body

• during swimming, they may lose body heat, so will flatten their body, and orient themselves so as to receive as much sunlight as possible 

Breeding season - marine iguanas

males become brightly colored and territorial

males will court a female by circling her and nodding at her, if successful, the male will hold her by the neck, twist the tail around her to the point where the genitals meet

when nesting begins, the females will become aggressive

• nest in sandy areas, guard their nest from other females 

• 4 eggs laid in each burrow 

• 3-4 months hatchlings emerge 

Galapagos Birds

3 major types

• seabirds

• shorebirds

• landbirds 

Spheniscus mendiculus 

Galapagos Penguin 

• endangered 

• endemic species 

• 3rd smallest in the world - about 35 cm tall 

• descended from Humboldt penguin (southern SA) 

• 5,000 individuals in the islands

• adults - black and white with stripe on front of the face

• juveniles - greyer, without the stripes

• Behaviors - 

  • breed along the west coast of Isabela and on Fernandina

  • seen resting on rocks along shoreline

  • Prey - fish and crustaceans 

  • fat layer under feathers allows them to cool their body when on land, hold their wings out so air can circulate around their body 

    • keep feet shaded and pant rapidly

  • mate for life 

  • females lay 1-2 eggs in holes/caves 

    • parents take turns watching the nest until the eggs hatch 

Phoebastria irrorata 

Waved Albatross 

critically endangered 

endemic species - about 12,000 pairs nest on Espanola 

wingspan over two meters 

Behaviors - 

• mate for life

• spend months away from Galapagos (Espanola), return in March at beginning of breeding season

• most eggs laid at the beginning of May

• hatchlings feed on oily liquid consisting of digested fish and squid (part of parent’s stomach), they eat up to 2 kg of this oily substance

• chicks leave the island and spend next few years at sea, then in 4th or 5th year, return to seek a mate

• Courtship reaches peak around October, revolves around a complex mating dance

  • the pair faces each other and each one’s bill circles the other, often making a clacking sound, then bowing occurs, and male will stick its bill straight upwards and make a high pitched “whoo-oo” sound, then more bowing and bill-clacking begins

  • another part of the dance, both birds open their bills in a gaping fashion, then bill is snapped shut, making a “cluck” sound

  • then a sway-walk, a highly exaggerated rocking back and forth while walking to a different location, then one of the pair begins a “forward bobbing” movement that indicates ownership of that particular location 

Phaethon aethereus 

Red-Billed Tropicbird 

• Resident, not endemic 

  • nests in the cliffs on several islands in the archipelago but flies far out to sea to feed

• White tails and bright red bills

• Prey consists of squid and fish

  • feed by plunge diving

• single egg is laid in each nest

• breeding may occur throughout the year

Pelecanus occidentalis 

Brown Pelican 

• few thousand pairs - residents 

• more commonly observed birds around boats 

• feeds by plunge diving in shallow water

  • drain water from large throat pouch, swallowing any fish that remains 

• excellent fliers 

• beginning of the breeding season, adults have white and chestnut brown markings on their heads and necks 

  • often with a tinge of yellow at the top

• typically nest in mangroves or other coastal plants like the saltbush

• breeding occurs throughout the year

Sula nebouxi 

Blue-footed Booby 

• most commonly seen of the three species 

  • nest and feed near the shoreline

• females have a much larger eye pupils than the males

• courtship dance

  • male starts “sky-pointing”

  • female notices him, they approach each other

  • males raise its feet alternately, like showing off

  • more sky-pointing follows by both male and female

  • then mating

• 1-3 eggs are laid on bare ground; 3-5 days apart

  • nest surrounded by a ring of guano (poop and urine) - represents boundary of the nest

  • facultative silicide - kicking other siblings out

• males take on fishing duties while chicks are in the nest, later both male and females will do the fishing

• predators of the chicks when small include hawks and owls

• maintains hemostasis by releasing salt through beak/nose

Sula granti 

Nazca Booby 

• largest of the Galapagos boobies 

• 25-50,000 pairs 

• nests on ground 

  • lays two eggs, both hatching and only one survives to maturity

    • aggression by the older/bigger chick is more responsible for the death of the younger rather than food availability as in blue-footed

• females are larger than males, pupils seem similar

• females make a “quacking” sound, and males make a “whistle” sound

• gray feet, white body and black wings

Sula sula 

Red-footed booby 

• smallest and least seen booby, though most abundant 

• red feet are most distinctive feature 

• most are a brown color (some being white) with a blueish bill color

• eye entirely black

• nest in trees and shrubs 

  • incense and mangroves (red), salt bush as well

  • prehensile feet (wrap around the branches)

• males and females have similar calls, males have higher-pitched and more nasal quacking than gruffer quacking of the female

• egg laying occurs throughout the year

  • 1 egg at a time

  • young don’t have red feet or blue bill

Phalacrocorax harrisi 

Flightless Cormorant 

• vulnerable 

• endemic bird, only of the species that can’t fly 

  • wings are too small and lack a strong breastbone

  • wings used to dry out after swimming

• adults are dark brown to black above, brownish below 

• males larger than females 

• very good swimmers

  • swim low in water when on surface, but can dive for fish

  • do not often feed far offshore

• courtship dance

  • aquatic dance involving both partners

  • both swim around each other, with their necks stretching out in a snakelike form, while making growling sound

  • will raise up from water a bit, point their beak upward, flap its wings, and shake itself

• nests are comprised of seaweed and other flotsam collected from sea

  • 2-3 eggs are laid

• 700-800 pairs in archipelago

• mostly found on isabela and fernandina

Fregata minor 

Great Frigatebird 

• adult male is all black with a faint green sheen on back, brown band across the wings 

• females have white abdomen and breast feathers extending up to the chin with red around eye 

• young have a white head with a rusty tinge

• males have bright red gular sacs, that they inflate during courting season

Fregata magnificens

Magnificent Frigatebird

• males have purple sheen on its back, and no brown band

• females have white area that only extends up to the throat 

• young has an all white head

• males have bright red gular sacs, inflate during courting season 

Courting/breeding of both Frigatebirds

females fly overhead of the males, the latter shake their wings, display their pouches, and call to the former

once the female selects a mate, nest building begins 

young must develop for about 5 months before they can fly 

• predators include other frigatebirds, hawks, and owls 

once mature, very good fliers 

primary prey is fish and squid, but also swoop down to snatch other food items in the sea, as well as baby sea turtles from the beach 

Creagrus furcatus

Swallow-tailed Gull

• endemic genus 

• 10-15,000 pairs 

• one of the few gulls that feed at night 

• large eyes adapted for night vision 

  • also have special coloration that helps them see each other in the dark 

  • chicks are mottled white, helps the parents see them at night 

• lays a single egg in nest

• alarm call 

  • “rattle-and-whistle” 

  • loudest call made by this gull

• display of unmated males is the “upward jerk” in which the head is jerked backward several times 

• “foot watching” - sign of submission 

Leucophaeus fuliginosus

Lava Gull

• vulnerable 

• endemic gull - probably one of the rarest in the world 

• 300-400 pairs 

• dark gray color 

• nest alone, lay two eggs 

• primarily a scavenger, but also catch small fish 

  • known to eat the eggs of other seabirds and baby iguanas and sea turtles 

Ardea herodias

Great Blue Heron

• largest of herons that live in archipelago 

• primarily gray, with some black and white markings on the head, neck and breast 

• diet consists of primarily fish, supplemented by lizards, young marine iguanas, and sea turtle hatchlings 

  • stab their beak at prey 

Ardea alba

Great Egret

• large white bird similar to great blue heron in its habits 

  • mainly each the same prey items as GBH, with some insects 

Butorides striata sundevalli

Striated Heron

• small heron often seen feeding along rocking coastlines 

• catches small fish in tide pools and in depressions in the lava where fish may be trapped 

• young are brownish in color, with dark streaking 

• nest under rocks or among mangrove roots 

  • lay up to 3 eggs 

• subspecies is considered by some to be endemic, going by name lava heron 

Nyctanassa violacea

Yellow-crowned Night Heron

• feeds at night, primarily on insects 

• distinctive yellow crown and large yellow-orange eyes 

• distinctive call when disturbed 

Phoenicopterus ruber

Greater Flamingo

• endangered 

• about 500 individuals of this species 

• feed in lagoons with their head’s upside down, sucks water in through the front of its bill, and pumps it out through the side, filtering out the small animals that comprises its diet 

• during breeding seasons 

  • single egg laid on mud/sand mound 

  • the bills of the young do not take on curved shape for about 3 weeks, fed by parents until able to themselves

Haematopus palliatus

American Oystercatcher

• about 200 pairs

• normally seen along beaches and rocky shores

• some suggest this species warrants recognition as a subspecies (H. p. galapagensis)

• lays two speckled eggs among the rocks on shoreline

• adults usually seen in pairs

• white belly, black back and neck, and orange beak

Numenius phaeopus 

Whimbrel 

• common shore bird

• downward curving bill 

• call consists of several rapid whistles 

Land Birds

not as common as sea or coastal birds, but almost 80% are endemic 

Buteo galapagoensis

Galapagos Hawk

• vulnerable

• endemic species 

• very tame 

• adults are dark brown in color

• juveniles lighter brown and heavily mottled 

• mating system which as many as four males may mate with one single female, then all of those males will help care for the eggs and young

• feed on lizards, young iguanas, rats, doves, mockingbirds, centipedes, grasshoppers, and young seabirds

Asio flammeus galapagoensis

Short-eared Owl

• endemic subspecies 

• hunts primarily during day 

• prey consists of smaller other birds 

• when sharing island with hawks, they will become more active during twilight hours to avoid hawks 

Zenaida galapagoensis

Galapagos Dove

• endemic species

• found in drier zones on most of main islands, though seen in highlands at times

• very tame as well

• individuals on Darwin and Wolf are larger, and considered a separate subspecies

• feed primarily on seeds from Opuntia and their flowers, as well as insects

• nest under rocks, usually lay two eggs

Pyrocephalus nanus 

Little vermillion Flycatcher 

• endemic species 

• inhabits highland areas 

• primary food item is insects, which they snap out of the air, making a “clicking” sound as its bill snaps shut

• nests made out of mosses, lichens, and liverworts

• only male has bright red color

Myiarchus magnirostris

Galapagos Flycatcher

• endemic flycatcher is larger than vermillion flycatcher and has a wider bill 

• yellow tinged belly, with brown wings, head, and back 

  • neck is white 

Mockingbird - Mimus spp. 

4 mockingbird species in archipelago 

possible pollinators

Mimus melanotis

Mockingbird species

only found on San Cristobal 

Mimus trifasciatus

Mockingbird Species

Only found on Champion and Gardner-near-Floreana

did occupy Floreana during Darwin’s visit

about 250-300 individuals

Mimus macdonaldi

Mockingbird species 

Found on Espanola and Gardner-near-Espanola

Mimus parvulus

Mockingbird Species

comprises several subspecies (only one of them pictured)

found on remaining major islands 

Prey of Mockingbirds

young finches, lava lizards, insects, centipedes, and birds eggs

scavengers too 

Darwin’s Finches

18 species

example of adaptive radiation 

Captain Fitzroy and Simms Covington did a better job at collecting these specimens than Darwin 

all thought to be derived from a single introduction to the archipelago 

Pinaroloxias inornata

Cocos Finch

1 species

this genus is not found in the Galapagos archipelago, rather in Cocos Island, Costa Rica 

this species was started in the Galapagos 

Beak Color in ALL species/sexs of Finches

All black = breeding

Horn colored, partially or totally = non-breeding 

Yellow lower mandible = juvenile 

Whitish lower mandible = fledgling 

Geospiza

Ground Finches

• 9 species 

• plumage color varies from freckled gray in females and juveniles to darker blotchy gray in immature males to completely black in fully mature males 

Geospiza magnirostris

Large Ground Finch

• largest of the ground finches

• usually, large beak that is as deep as it is long

Geospiza fortis

Medium Ground Finch

• heavy beak, but more pointed than the large ground finch 

• break size can vary greatly, even on same island 

Geospiza fuliginosa 

Small Ground Finch 

• short, stubby beak

• feeds on small seeds and ectoparasites of reptiles 

Geospiza scandens

Cactus Finch

• longer, more downward-curved beak than other ground finches 

Tree Finches

Platypsiza and Camarhynchus

• plumage color in both sexes and ages is pale beige 

• older males, except woodpecker finch, gradually develop a black face or hood

• vegetarian and mangrove finches show variable mottling corresponding to age 

Platyspiza crassirostris

Vegetarian Finch

• one of the largest finches 

• beak short, deep, and broad 

Camarhynchus pallidus

Woodpecker Finch

• large, elongated beak that curves downward at the end 

Other Geospiza species 

Geospiza difficilus - Sharp-beaked Ground Finch 

Geospiza septentrionalis - Vampire Finch (will drink blood from scabs of other animals) 

Geospiza conirostris - Large Cactus Ground Finch 

Geopsiza propinqua - Genovesa Cactus Finch 

Geospiza acutirostris - Genovesa Ground Finch 

Other Tree Finches 

Camarhynchus heliobates - Mangrove Finch (most endangered of all finch species in galapagos) 

Camarhynchus psittacula - Large Tree Finch 

Camarhynchus pauper - Medium Tree Finch 

Certhidea fusca

Grey Warbler Finch

• plumage color is pale beige in all stages

Certhidea olivacea

Green Warbler Finch

• plumage color is pale beige in all stages