Cave Inhabitants of Oregon
By Matt Skeels
This quick reference guide covers the majority of cave fauna found throughout Oregon. It is divided into three categories: Trogloxenes, Troglophiles, and Troglobites. The topic of bats is expansive and they will receive little mention here. Check for separate articles that review bats specifically. Special thanks and credit go to the photo contributors: Brent McGregor took all the photos except for the Pika which was taken by Kim Luper.
This group of cave fauna is identified as anything that lives near a cave, in the entrance of a cave, or cannot live its entire life within a cave. This is the most expansive group of cave life, and many creatures at one time or another may have wandered into a cave, or utilize a cave entrance frequently. This list is so large that pictures and descriptions will not be listed for all. Anything from domestic cats, cougars, porcupines, skunks, chipmunks, squirrels, gopher snakes, pigeons, wolf spiders, bears, slugs, pika, daddy-long legs, bats, rattlesnakes, scorpions, rubber boas, rabbits, salamanders, camel crickets, millipedes, wood rats, swallows, tissue moths, coyotes, bobcats, and so on. What follows are pictures of some of the more notable ones encountered.
Tissue Moth or Triphosa haesitata
Tissue Moths are perhaps the most common of all cave life in Oregon and encountered in nearly every Oregon cave. As a caterpillar they live entirely outside of caves. After becoming a moth, they will seek safe environments in which to live. If a cave is nearby, they will make it their home often huddling in large clusters if the cave is ideal. The tissue moth will most likely be found on the ceiling of a cave. Often you will discover the leftover wings of a tissue moth on the floor of a cave. This is usually a sign that bats have been in the cave feeding on the moths.
Harvestman or Daddy Long Legs or Sabacon occidentalis
The common Harvestman will seek out dark places to hide away, whether it's your basement, or a cave. Harvestman are common throughout most Oregon environments. If that environment also holds a cave, Harvestman will make it their home. Typically, Harvestman will only live near the entrance and feed on other insects that enter the cave, or they will exit the cave to feed from the surrounding territory. The photo taken above was from outside of a cave. Notice the lack of black pincers when compared to Taracus marchingtoni (see below).
Cave Cricket or Camel Cricket or Tropidischia xanthostoma
Cave crickets aren't very common in central Oregon and are more often found in the humid and nutrition rich environments on the west side of the Cascades. The crickets can be found in many locations, but when a cave is available, they will move in and set up shop. The crickets can get to be very large (up to 8 inches) because of their long antennae and powerful back legs. Like most insects, they will be clinging to a wall or ceiling. This cricket was photographed at Incline Cave.
Springtail or Pogonognathellus celsus
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Sometimes referred to generally as the scientific Collembola label, springtails are small, wingless insects, most of which have the ability to hop relatively large distances. The springtails in central Oregon usually have a silver-like coloring. It is likely that springtails feed off microorganisms. In central Oregon caves, springtails have been noted where there is usually an abundance of detritus consisting of debris brought in from woodrats or fecal matter of animals.
Pika or Ochotana princeps
Pika are some of the most elusive cave inhabitants. More often than not, a pika is heard but never seen. Their telltale sound "Eeeeek!" is high pitched and often muffled as it emanates from behind rocks or elsewhere. You will also see their distinct round fecal pellets, or sometimes their little nests. Pika may be briefly seen at a cave entrance or inside a cave before they dart into a hole for protection. They are most often encountered at higher elevations and prefer a mountainous habitat. The tail of a pika is very short, kind of like a hamster. Pictured here is a rare shot of a pika taken by Kim Luper from a cave in Washington.
Woodrat or Packrat or Neotoma cinerea
Pictured here is a bushy-tailed woodrat. The bushy-tailed woodrat is one of three woodrats found in Oregon. They are more adaptable to different environments than a pika and not as skittish. While still prone to hiding out of sight, they will on occasion come out for a visit, or crawl along a cave ceiling or wall while you are exploring. The nests of woodrats are commonly seen in many caves and have a round bowl-like shape inside a mound of dead grass, usually at the rear of a cave, or just inside the entrance. In central Oregon, woodrats will often collect juniper branches, twigs, and mushrooms to last winter months of hibernation in a cave. The other two species known to exist in Oregon are the Desert Woodrat (Neotoma Lepida) and the Dusky-footed Woodrat (Neotoma fuscipese).
Tree frogs & Toads
Tree frogs and toads are quite common in the caves of central Oregon and elsewhere. They usually live right at the entrance feeding on anything that strolls by. Also quite common are tree frogs that become trapped in a cave and cannot escape, such as in a pit or a steep vertical entrance. It's not uncommon to find them emaciated or dead.
In central Oregon, salamanders are very rare because the climate is too dry for them. The closer you get to the Cascade mountains the better your chances are of spotting a salamander in a cave. Salamanders are rarely found in central Oregon caves except when they have fallen into a cave and cannot escape. In western Oregon, salamanders are more likely to be trogloxenes and pass in and out of entrances or sometimes travel further into a cave if it remains moist and food remains plentiful.
This group is described as any species that may live in a cave its entire life, but may also just as easily live on the surface. Perhaps the most common form of this group is mycelium which form small mushrooms.
Mycelium is the organism that mushrooms grow from. It is usually a mass of root-like membrane that grows underneath the soil, but in caves can be observed on the surface of a dirt floor or sometimes spreading out over moist rock surfaces. The number of mycelium species is too great to summarize in any detail here, but a few caves in central Oregon have been noted to harbor their fruit, the mushroom, at different times of the year. Mushrooms have been seen growing on rotting logs in cave entrances, dirt floors, or even on pinecones that have been carried in by woodrats. Because mycellium doesn't need sunlight to grow, it can carry on indefinitely within a cave, as long as nutrients remain. However, mycelium is not noted to be cave adapted.
Campodean or Twintail
Another species found in central Oregon, is the Campodean or sometimes just referred to as the broad Diplura term. It is an arthopod and the species found in central Oregon have not been identified, although William Shear of Hampton-Syndey College has a hunch that they are a new species as well. They have been noted living alongside the cave-adapted millipedes as well as living in caves harboring ice. Campodeans can also be found in small cracks of rocks on the surface, also called microcaverns. This campodean was photographed in Alpine Ranch Cave.
At this time, these millipedes are considered new to science, but still not fully indentified. This species has been predominantly located in lava tubes of central Oregon as well as caves of western Oregon. Although, these millipedes may also inhabit small cracks in surface rock, sometimes referred to as microcaverns. The millipedes are common where mold or bat feces is scattered on the cave floor. This species has been studied and collected by Neil Marchington of our grotto.
Grylloblattid or Grylloblatta sculleni
The Grylloblattid, or uncommonly referred to as the cockroach cricket or ice crawler, is a primitive wingless insect that was much more common during the mid-Cenozoic. They love cold temperatures ranging from 26.6° to 41°F and high humidities. The grylloblattid pictured was observed in May of 2012 in a cave that historically has harbored lots of ice. Grylloblattids love snow and ice, are nocturnal, and live off of detritus. Their closest living relative is the Mantophasmatidae from Africa.
Troglobites (sometimes known as Troglodytes)
A Troglobite is any species that has adapted to live in a cave and cannot survive outside of the cave. These adaptations can take on different aspects, but the most common is a loss of pigmentation which makes the species look white or translucent. Another adaptation happens when the eyes become useless in the dark and disappear altogether. Other changes may include giantism, slower metabolism, and elongated appendages. This can happen in fish, salamanders, and crayfish most notably, but Oregon does not have any those. All known troglobites in Oregon are invertebrates. Neil Marchington of the Oregon High Desert Grotto has worked with the Deschutes National Forest and Bureau of Land Management, among others, to help discover new species. The Taracus marchingtoni has been named after him and was first identified in 2008. In 2012, the Trogloraptor was declared as a new species of spider and Neil Marchington played a role in its discovery as well.
This species of harvestman has been spotted in over 14 different caves in central Oregon and probably exists in many more. It was noted in several caves in times past, including Lava River Cave prior to 1982 and a specimen was located there in 2008. Oregon High Desert Grotto member Neil Marchington was the first to study the harvestman and submitted it to Dr. William Shear of Hampton-Syndney College for identification. Shear noted it being a part of a new species endemic to Oregon. Marchington has observed the harvestman feeding on cave adapted millipedes (see above). It utilizes its long front pincers (in black) to grab prey and hold it while it feeds. The picture on the left was taken in Pucker River Cave in November of 2012.
Trogloraptor or Trogloraptor marchingtoni
As a cave or spider lover, you may have heard of the recent discovery of the Troloraptor that made the news in 2012. With the help of Geo Graening, Neil Marchington, Ron Davis, and Daniel Snyder, the spider was located in a few caves of southwestern Oregon. A few species were submitted to Charles Griswold, Traci Audisio, and Joel Ledford. Audisio named the spider after Neil Marchington for all the help he did in helping out the arachnologists.
The spider grows small webs made up of only a few strands to trap prey. Although its main prey of choice remains unknown. Trogloraptor has six eyes, is yellow-brown in color, and has hook-like claws at the ends of its legs. A mature spider is roughly about a third of an inch in size.
Here is an unidentified species, likely to be a spider. The specimen in the picture has a body roughly between 1 and 2 millimeters long. Its legs appear to have small bristles. The most important feature of this specimen is the white color. This is a good indicator, though not definitive, of cave adaptation. It could also be that this spider has just molted. The pictured specimen was located in the newly discovered Talking Scroll Cave from 2012 in the central Oregon region.
Photographed in No Name Cave, this picture shows the similarity to real scorpions in everything but the thorax. Pseudoscorpions lack stingers. This species is currently unidentified.
Central Oregon had a new species of pseudoscorpion collected by J. Valentine in 1938 at the Redmond Caves. Joseph Chamberlin identified and named it Parobisium charlotteae after his wife. Since then, no charlotteae has ever been found in these caves and may be extinct there now. *In 2013 a group of cavers from the Oregon High Desert Grotto collected a pseudoscorpion in central Oregon that appears to be charlotteae. If so, this would be an exciting discovery. Pictured here is the specimen collected in 2013.
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