Caves – Video Questions (58 min)
1. Explain why caves are one of the least explored places on earth.
Hard to find, hard to get to, dangerous to explore..underground
2. How does New Zealand’s glow worm lure and catch insects within a cave?
living creatures  bioluminescence  New Zealand , live in complete darkness, silk strands lowered
from ceilings by the cave glow worm = fishing for prey – silk from glands in mouth are loaded with
mucous – each worm makes dozens of threads – waits inside a mucous hammock above threads—
creates a light at end of tail to lure prey in—reel in the line and consume the catch alive-3. Most caves are carved out of limestone. Explain how these underground tunnels and caverns are
produced.
One kind of rock makes this world underground possible = Limestone= 10% of earth’s surface=made of
minerals from marine shells and corals = formed underwater –
Rivers that flow over limestone seem to disappear -- when water reaches more resistant limestone the
course is altered – underground water = absorbed co2 from surface = mildly acidic = millions of years
acid eats away the limestone = caves –
4. What is the scientific explanation for the maze like qualities of caves?
Rivers that flow over limestone seem to disappear -- when water reaches more resistant limestone the
course is altered –
5. For what reasons, might the 3 million wrinkle lipped bats live in Deer Cave in Borneo?
roost hight on walls = protected from elememts and predatorys
6. What is the basis for the food chain in Deer Cave?
bats produce guano = 100 m. high mound beneath bats in the cave – surface is covered by cockroaches
– Gueano = basis for food chain !!! Not sun or vents!
7. How do the cockroaches, giant centipedes, and crabs obtain food within the cave?
-- Cockroaches feed on the guano and anything that falls into it – roaches eaten by giant cave
centipedes = 20 cm or more – crabs sift through the droppings – and eat the digested remains of food
brought in from outside the caves
8. All 3 million of the wrinkle lipped bats funnel out of the cave together. Describe the defense
mechanism employed by these bats as they fly out of the cave and into the sky.
2 hours 3 mill bats leave the cave—they are prey – form a donut shaped ring – confuse birds of prey b/c
it is harder to visualize a single bat —peragrine falcons and bat hawks = jet fighters of the bird world -= catch the bats in their claws – majority of bats = fine –
9. How do cave swiftlets unerringly fly, through the total darkness of the cave, directly to their personal
nest?
rely on loud clicks to find way in total darkness – cave swiftlets = find their individual nests using
echolocation even though they are only a few cms across – we are not sure how
10. What is unique about a cave swiflet’s nest?
– also make little cup like nests entirely out of threads of saliva – 30 days to make – 500 years people
harvest these nests – use ladders made of vines – climb up to 60 m. up - = dangerous – main ingredient
of birds nest soup – worth gram for gram as much as silver – bird rebuilds as soon as one is removed—
11. How does a stalactite form?
Water in caves = loaded with dissolved minerals from the limestone – when drips off the roof of a cave
and hits the air = forms calcite – as it builds = stalactites
12. How does a stalagmite form?
– if water seeps through ceiling too quickly = stalagmites – variations in water flow and air currents
shape – stalactite + stalagmite = column—can take 1,000 years to develop
13. What is the only source of fresh water found on the Yucatan Penninsula? What are these called?
Flooded caves in Mexico – cut off after the last ice age – unchanged since – huge impact for life at the
surface – 500 years ago – supported the Mayans – Yucatan peninsula has no rivers, lakes or streams so
the relied on the cenotes = flooded entrances to caves = provided the water for people – only source of
fresh water for the region = huge fresh water wells
14. Explain some of the risks a cave diver faces while exploring underground.
350 miles of underwater = mapped but not all has been discovered b/c very dangerous – dependent on
air tankds – use string as a lifeline – also doubles as a measuring tape to chart the cave – get through
“squeezes” = narrow gaps in the walls – could damage your life support – disorientation could also be
fatal – what seems like air isn’t = another kind of water = halocline = meeting of fresh and salt water =
confuses the mind – salt water layer = very low in oxygen – most creatures can’t survive – remipede =
an ancient crustacean lives in this layer -- = beginning of subterranean rivers that all flow out to the sea
15. If ocean water does not dissolve limestone, then how are sea caves made.
salt water does not erode limestone  (find out exactly why??)  so sea caves made by the waves –
17. It appears that there are species that are unique to only one cave. What is the explanation for this?
Caves = like islands cut off from outside world and other caves = evolved strange creatures = animals
that never emerge from the caves
18. What is a troglobite?
animals that never emerge from the caves  never see daylight = called troglobites –
(Troglobites from Thailand = very specialized = live only in cave waterfalls – entire pop of cave
angelfish = found in only two caves----Texas cave salamander – maybe less than 100 in the wild –
Belizian white crab unique to just one cave system ---All lost pigment in skin and eyes = takes 1000 of
years -- Salamander = highly sensitive organs  skin receptors detect motion of water – external gills
help breather in water low in oxygen – cave angel fish feed on the bacteria – keep grip with microscopic
hooks on fins – crab – eat whatever washes into the caves – the salamander might not eat for several
months – )
19. Describe the adaptations common to all troglobites.
---All lost pigment in skin and eyes = takes 1000’s of years for this to happen
21. Describe the environment of Villa Luz.
Inhospitable cave = Villa Luz cave = white with sulfuric acid – poisonous gasses – bats survive by
staying close to the skylights – going deep = dangerous – source of toxins = several miles below =
Hydrogen sulfide gas bubbles up from oil deposits in the earth’s crust – it mixes with oxygen in the
water and forms sulfuric acid—cave mollies thrive in acid and low oxygen –
22. Describe the organism that fuels the food chain within Villa Luz.
stalactite like formations = “snottities” drops dripping off the end = sulfuric acid that can burn through
the skin -- == vast colonies of bacteria -- = can grow a cm a day – no sunlight get energy from the
hydrogen sulfide gas == bacteria = extremophiles – they are the basis of the food chain – support
midges –
23. Describe the unique qualities of Lechugilla Cave in the U.S.A.
USA – one of longest deepest caves in the world – discovered in 1986 – Lechugilla – 120 miles have
been mapped – most beautiful of all caves – walls covered in crystals – made of gypsum – unlike all
other limestone caves – rock not eaten away by running rain water but by sulfuric acid – the unusual
nature of the cave formations led scientists to question how they are formed -- when sulfuric acid
dissolves limestone it leaves behind the mineral gypsum – Chandelier ball room – 6 m long crystals –
24. What are extremophiles and what is so extreme about the ones found with Lechugilla Cave?
extremophiles are bacteria = these feed on the rock in the cave!!
25. Describe 3 ways that cave habitats differ from other terrestrial environments.
-isolated
-weather
-food webs