Caves A cave is defined as an underground passage large enough for a person to crawl into, naturally formed, and in complete darkness.
How does a cave form? • Rain dissolves Carbon Dioxide into Carbonic acid • Carbonic acid dissolves minerals in rock • Rock is sculpted in weak spots • Water seeps through rocks and makes underground waterways • When the water level drops, the waterway exits the rock through the exiting hole (resurgence) • Collections of water creates deep gaps in caves. • When the water level outside the cave drops, the cave empties and dries out.
Stalactites Formed by water that drops from the top of the cave that contains calcite The calcite is left when the water drops Constant winds blowing cause stalactites to grow in crooked. Occasionally, stalactites will grow together with the stalagmites and will create a column. Stalactites
Stalagmites: Form from the bottom of the cave They grow about 1 cm every 1000 years because it is hard for water to evaporate in the moist cave Stalagmites
Types of Stalactites • Types of Stalactites • Icicle Straw Drape
Types of Stalagmites • Dish Stack Fir Cone
Cave Sections • Cave environments fall into three basic categories: • Endogean: parts of cave that come into contact with the surface • Example: cracks, rock seams, groundwater seepage, and root protrusion • Parahypogean: regions near cave mouths that extend to the last penetration of sunlight. • Hypogean: deep in the cave, only come into contact with the surface through wind, underground rivers, or the migration of animals. • Considered to be “true” cave environments • The deeper the cave becomes, the less biodiversity is found.
Erosional- formed by the action of water or wind, carrying abrasive particles capable of carving rock Types of Caves
Types of Caves • Lava Tube-lava travels beneath the surface and is expelled by a volcanoduring an eruption
Sea Caves- form from wave actions along the coast where areas are weak in sea cliffs Types of Caves
Solution Caves- form where rock is dissolved away Types of Caves
Cave Organisms • Cave organisms fall into three basic classes: • Troglobites: “cave dwellers” animals that are specialized for cave life. • Can leave for short periods of time • Can complete parts of their life cycles above ground • Can’t live entire lives outside of the cave • Examples: some bacteria, some flatworms, and blindfish
Cave Organisms 2. Troglophiles: “cave lovers” can live part or all of their lives in caves • Can complete a life cycle in certain environments on the surface • Examples: cave crickets, millipedes, pseudoscorpions, and spiders
Cave Organisms 3. Trogloxenes: “cave guests” • Frequents caves • May require caves for a portion of it’s life cycle • Must return to the surface • Examples: Hibernating reptiles and mammals
Cave Organisms • Troglophobes: “cave haters” • Can’t survive in caves for any time period • Example: organisms that fall through sinkholes or frogs swept into caves by flash floods
Adaptations of Things that Live in Caves • Loss of pigment • Loss of eyes • Blue eyes (can absorb light better) • Elongation of appendages • Enhancement of other senses (can sense vibrations in water) • Echolocation
Bats • Nocturnal • They sleep in the back of caves to keep from being eaten • Are found everywhere except Antarctica and the Artic • Hibernate in caves • When weather is warm, the bats leave the caves at night to find food • They are the only mammals that can fly • Wings are a membrane of skin that stretches from their body to their fingertips.
Have horseshoe shaped structure around their nostrils to help direct sound for echo location They wrap their wings around themselves to keep warm during hibernation When they are asleep, they tuck their wings to their sides Horse-shoe Bats
Bat Communication and Pregnancy • Pregnant bats move to a warmer area in the cave to give birth • When the baby is young, it goes with the mother to get food • When it is older, it is left behind and calls to the mother so she can find her way back
Where do cave dwellers get food? • Some get food from outside the cave • Some eat things inside • Guano (Bat Poo) falls to the ground where millipedes, beetles, and fungi get their nourishment • Dead animals • Organic debris washes in from streams • Cave crayfish • Cave shrimp • Flatworms
Cave Studies • Speleology- the scientific study of caves. • Spelunking- recreational exploring of caves. • Cave cartography- creating cave maps • Cave geology- study of cave rock. • Cave Hydrology- study of water features in caves.
Endangered Species • Tooth cave spider
Endangered Species • Trapdoor spider
Endangered Species • Gray Bat