Zoo_BI,_Carts,_Komodo_Dragon

Question 1

Q: When do Komodo dragons stop growing?

Answer 1

Like other reptiles, Komodo dragons continue to grow throughout their lifetime. This growth slows after 6 years when dragons reach their average adult size.

Question 2

Q: Komodo dragon diet?

Answer 2

Predators and scavengers.
Strictly carnivorous.
Birds, mammals (deer, pigs), smaller dragons, invertebrates, carrion.
As juveniles, small animals. As adults, larger prey, as large as water buffalo.

Question 3

Q: Reptile teeth, ingestion, waste

Answer 3

Generally simple and conical (peg-like).
Uniform in shape and size throughout jaw (homodont). Vary slightly in size.
Upper and lower tooth rows do not contact one another.
Continuously shed and replaced throughout life.
Used for killing and holding.
Swallow food whole.
Waste is uric acid, which is low in water content, reducing water loss.
[duplicate card: Reptiles, BI Komodo dragon]

Question 4

Q: Skull identification, reptile vs mammal

Answer 4

Reptiles are homodonts; all teeth are similar. Usually long, conical. (Turtles lack teeth.)
Reptiles have proportionately smaller brains than mammals.
Reptiles have two nasal openings in their skull. Mammals have one.
Reptiles have a single point of attachment between skull and spinal column. Mammals have two.
Lower jaw of reptile is comprised of several different bones and is hinged to the upper jaw and skull through the quadrate bone. Mammal lower jaw connects directly to skull.
The tuatara and most lizards also have a small hole at the top skull due to the parietal eye.
[duplicate card: Skulls, BI Komodo dragon]

Question 5

Q: Something crocodilian teeth have in common with mammal teeth?

Answer 5

They are socketed. Other reptiles do not have socketed teeth.

Question 6

Q: Discuss a some differences between alligator and iguana teeth.

Answer 6

Alligator: socketed with deep roots like that of humans (crocodilians are only reptiles with socketed teeth.
Iguanas: sharp, jagged teeth that are capable of shredding leafy foods.

Question 7

Q: Burmese python teeth

Answer 7

Back curving teeth that grab prey and don’t let it escape.

Question 8

Q: How many teeth do Komodo dragons have?

Answer 8

About 60

Question 9

Q: Komodo dragon teeth

Answer 9

Serrated.
About one inch long.
Frequently replaced. Further rows of replacement teeth lie behind.
Also have rear facing teeth to help grab on to prey.

Question 10

Q: How many sets of teeth will a Komodo dragon go through?

Answer 10

Four or five sets of teeth in a lifetime.

Question 11

Q: Are Komodo dragons venomous?

Answer 11

Yes.
They have a venom gland in their lower jaw. Venom prevents blood from clotting and decreases blood pressure, causing massive blood loss and inducing shock. [link below]
ALSO: Harmful bacteria lives in their saliva. Bits of rotten flesh get stuck in serrated teeth, “turning their saliva into a mini-habitat for harmful bacteria that can cause untreated bite wounds to become septic.” [link below]
https://nationalzoo.si.edu/animals/news/how-dangerous-are-komodo-dragons-and-other-komodo-dragon-facts#:~:text=Researchers%20have%20also%20documented%20a,blood%20loss%20and%20induces%20shock.

Question 12

Q: Unique/surprising Komodo dragon senses?

Answer 12

Jacobson’s organ (details on other cards)
Parietal eye (details on other cards)
Strong sense of smell: can detect rotting carcasses from 10 kilometers away.

Question 13

Q: Other term for a Jacobson’s organ?

Answer 13

Vomeronasal organ (VMO)

Question 14

Q: What is a Jacobson’s Organ?

Answer 14

-Some animals have auxiliary olfactory sense organ (the VMO or Jacobson’s Organ) at the roof of the animal’s mouth
-Chemical receptor used to detect chemical stimuli.
-Can be found in all vertebrates, but is only enhanced in a few: snakes and lizards (squamata order), cats, wolves, ungulates, and lemurs.
-In some mammals (i.e. cats and hooved animals), organ is involved in the flehmen response (lifting upper lip, grimace), and is used to detect pheromones, chemical messengers carrying info between individuals of same species.
[card duplicated: biofacts-skulls, Komodo dragon cart]

Question 15

Q: What is a benefit of snake/lizard tongues being forked?

Answer 15

Reptiles smell using the tip of their tongue.
Tongue picks up airborne molecules and is withdrawn into mouth where scents are interpreted by Jacobson’s organ (details on other card), which has two opening ducts.
Forked tongue allows them to sense direction of smell.
Also provides more surface area.

Question 16

Q: What can we learn about a reptile by looking at its tongue?

Answer 16

The degree of the tongue’s fork indicates the use of the Jacobson’s organ.
Reptiles with deeply forked tongues have a more developed Jacobson’s organ.
E.g., common green iguana has very shallow fork and doesn’t use its Jacobson’s organ as much as a Komodo dragon, which has a deeply forked tongue.

Question 17

Q: Can we directly observe anything related to the Jacobson’s organ on the Komodo dragon biofacts cart?

Answer 17

You can see the receptor pits on the Burmese python skull.

Question 18

Q: Parietal eye

Answer 18

(pineal eye)
Light sensitive (photoreceptive) organ on top of the head which looks like a clear scale.
Associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation
Also acts as defensive measure, since approaching predator will cause the light to change.
Found in some reptiles, some amphibians, and some fish.
Note: the parietal eye is especially visible on the common green iguana skull but not on the alligator skull on the komodo dragon biofact cart. Crocodilians lost this adaptation as have birds and mammals.
Note: the parietal eye is why proper UV lighting in the Komodo dragon exhibit is important.
[duplicate card: reptiles, komodo dragon cart]

Question 19

Q: By what characteristic are modern reptiles split into subclasses? What is notable about the evolution of these characteristics?

Answer 19

-Modern reptiles: four subclasses based on number and position of temporal fenestrae, openings in the sides of the skull behind the eyes. [TODO needs clarification: all modern reptiles have either 0 or 2 fenestrae, so positioning must distinguish further? Early amniotes (some of which evolved into mammals) are divided into 3 groups based on fenestrae.]
-Early in reptile history, changes occurred in muscle attachment to the lower jaws and the skull in amniotes having to do w/ development of stronger and more efficient jaw muscles and a diversification in what they ate. Allowed more powerful and faster bites.
–Three patterns of holes (fenestrae) in the temporal region of the skull, just behind the eye. (details on separate card)
–Provided space for the large muscles needed for feeding when shifting from an aquatic environment to a terrestrial one where the vegetation was more coarse.
[duplicate card: Reptiles, Komodo dragon cart]

Question 20

Q: Fenestrae

Answer 20

a small opening in the bone
[duplicate card: Reptiles, Komodo dragon cart]

Question 21

Q: Three patterns of holes that developed in skulls of early amniotes.

Answer 21

-Different patterns of fenestrae in temporal region of skull behind eye
-0 temporal fenestrae: anapsids- turtles, tortoises and terrapins
-1 temporal fenestrae: synapsids- evolved into mammals
-2 temporal fenestrae: diapsids- birds and major reptiles (lizards and snakes, tuatara, alligators and crocodiles, dinosaurs)
[duplicate card: Reptiles, Komodo dragon cart]

Question 22

Q: How are modern reptiles classified?

Answer 22

Temporal fenestrae, or lack thereof.
Most have two fenestrae with the exception of the turtles, tortoises, and terrapins, who lack fenestrae.
[duplicate card: Reptiles, Komodo dragon cart]

Question 23

Q: Common green iguana diet?

Answer 23

Herbivore
Leaves, flowers, fruit

Question 24

Q: Common green iguana habitat?

Answer 24

Rain forests of northern Mexico, Central America, the Caribbean Islands, and southern Brazil. They spend most of their lives in the canopy, descending only infrequently to mate, lay eggs, or change trees.

Question 25

Q: Common green iguana conservation status?

Answer 25

Status (IUCN Red List)
Least concern. Not listed.
However, of the 63 iguana species listed on the Red List, [more than] 20 are Endangered and 1 is Extinct (Navassa rhinoceros iguana) (TODO needs updating)

Question 26

Q: Burmese python diet?

Answer 26

Carnivores
Primarily small mammals and birds

Question 27

Q: Burmese python habitat?

Answer 27

Jungles and grassy marshes in Southeast Asia.
Young pythons spend time in trees, moving to the ground when body size prevents easy climbing.
Excellent swimmers.

Question 28

Q: Burmese python conservation status?

Answer 28

Vulnerable.

Question 29

Q: Do Burmese pythons live anywhere outside of southeast Asia?

Answer 29

They have been introduced as an invasive species in southeastern US.
Found primarily in and around the Everglades ecosystem in south Florida where the snake represents a threat to native wildlife.
Causing declines in many species.

Question 30

Q: American alligator diet?

Answer 30

Carnivore.
Mainly fish, turtles, snakes, and small mammals.

Question 31

Q: American alligator habitat?

Answer 31

Freshwater rivers, lakes, swamps, and marshes of the southeastern United States, primarily Florida and Louisiana

Question 32

Q: American alligator conservation status?

Answer 32

Least concern.
A conservation success story, as American alligators were once on the verge of extinction due to hunting. Listed as endangered in the 60s. Regulations on hunting and movement of alligator hides allowed the species to recover.

Question 33

Q: Komodo dragon habitat?

Answer 33

Primarily in the tropical savanna forests of the Lesser Sunda islands of Indonesia. Young dragons find safety in trees from cannibalistic adult dragons and other predators

Question 34

Q: Komodo dragon conservation status and threats?

Answer 34

Endangered (https://www.iucnredlist.org/species/22884/123633058)
Populations are declining.
They used to live across many Indonesian islands and in Australia. Now they only live in a very small area.
There are approximately 3000 surviving individuals in the wild.
Threats to Komodo dragon survival are habitat destruction, loss of prey species, and hunting.
Outside of the Komodo National Park, human population growth has led to a reduction of dragon habitat.
Poaching of rusa deer, one of the dragon’s favorite prey, has led to drastic population reduction and even localized extinctions.
Komodo dragons do not swim very frequently among islands. This means that a disturbance on one island could result in a local extinction because it would take a long time for ocher lizards to re-establish the population.

Question 35

Q: What is the largest lizard?

Answer 35

Komodo dragon

Question 36

Q: SF Zoo Komodo dragon conservation efforts?

Answer 36

The zoo actively supports Komodo dragon conservation through the AZA Komodo Dragon SSP.
This program supports field research and conservation efforts, provides funding, staff and captive breeding at zoos around the world.

Question 37

Q: Komodo dragon conservation efforts?

Answer 37

SSP (see other card)
Komodo dragons are protected within the boundaries of the Komodo National Park, which only covers a portion of their native habitat.
Park protects habitat, however, low funding means fewer park ranger patrols. Even protected areas are at risk.

Question 38

Q: One way Komodo dragons compete?

Answer 38

Males often wrestle with each other by standing on their bock legs.
The winner will get access to females or a favored basking site.

Question 39

Q: One common place female Komodo dragons lay their eggs?

Answer 39

Female dragons lay their eggs underground, often using (abandoned) large mound nests of the megapode bird. Mounds may be up to 1.5 meters tall.
Sometimes females dig decoy nests to fool predators.
Female may lay on the nest for some period of time to protect the eggs, but no evidence of parental care for hatchlings (Source: National Zoo)
Komodo eggs take 7-8 months to hatch.

Question 40

Q: Are Komodo dragons terrestrial?

Answer 40

After hatching, small Komodo dragons live in trees until they are 3-4 years old.
Living in trees gives them access to the right food and protects the juveniles from being eaten by the larger dragons living on the ground.
Komodo dragons do not swim very frequently among islands.

Question 41

Q: Lifespan: Common green iguana, Burmese python, American alligator, Komodo dragon

Answer 41

Common green iguana: Wild: 20 yr.
Burmese python: Wild: 20-25 yr.
American alligator: Wild: 35-50 yr.
Komodo dragon: Wild: 25+ yr.

Question 42

Q: Length: Common green iguana, Burmese python, American alligator, Komodo dragon

Answer 42

Common green iguana: 6 ft.
Burmese python: 16-23 ft.
American alligator: 10-15 ft.
Komodo dragon: up to 10 ft.

Question 43

Q: Weight: Common green iguana, Burmese python, American alligator, Komodo dragon

Answer 43

Common green iguana: 11 lb.
Burmese python: up to 200 lb.
American alligator: 1000 lb.
Komodo dragon: 150-300 lb.

Question 44

Q: Name 11 interesting hooks/facts for the Komodo dragon cart.

Answer 44

How many eyes does a KD have? Parietal eye…
Why do KDs have a split tongue? Jacobson’s organ. Show the receptor pits on Burmese python skull.
KD teeth continually replaced, like a shark!
KD Venom.
Baby KD live in trees! Why do you think that is?
Parthenogenesis.
Enrichment example in KD exhibit (sprinkler/light system).
Where do you think Burmese pythons live in the wild? Did you know they can be found in the US? Invasive… so don’t buy exotic pets!
Look where the eyes and nose are on a crocodile’s head. Why do you think they’re positioned that way?
What might we learn about the iguana diet and alligator diets by observing their skulls?
Like mammals, and unlike other reptiles, crocodilians have socketed teeth.