Audio
Ecology
Transcript
[Intro music Piper: Thank you for joining us on the Tower Frequency. My name is Piper Lewis, here at Devils Tower courtesy of GeoCorps and the Geological Society of America. Today we’re going to be exploring the ecology of Devils Tower. Joining me today are three members of Resource Management. Rene: My name is Rene Ohms and I’m the Chief of Resource Management at Devils Tower National Monument so I manage the natural and cultural resource program here. In resource management we’re in charge of managing and protecting the natural and cultural resources of Devils Tower and under natural resources there is of course the wildlife, the prairie dogs, the prairie and peregrine falcons, porcupines, mountain lions, all the animals of the park. There’s also plant management including exotic plant management, and also the physical resources, the river and the geologic resources too. Megan: I’m Megan Chapman and I’m a biotech here at Devils Tower national monument and I help reduce the amount of invasive plants that we have here at the Tower Phil: Hi my name is Philip Knecht and I’m a climbing biological science technician here at Devils Tower national monument. Basically what that entails is I climb the tower and pull weeds in the cracks and on the summit. Amy: I’m Amy Hammesfahr and I’m a biological science technician. Piper: We’re also joined today by an interpretative ranger. Beverly: My name is Beverly Swift Pony. I’m an interpretive ranger at Devils Tower National Monument. [Music] Piper: Visitors who come to see the Tower find an abundance of life at its base and in the surrounding park. Devils Tower is home to 471 different plant species. 70 of those species are non-native invaders. Devils Tower National Monument works hard to keep the balance of nature and remove invasive, alien plants from the park. Chief of Resource Management, Rene Ohms tells us about these programs. Rene: There are many exotic plant species at Devils Tower and some of the most problematic of those are the ones that are perennial and those are the ones that come back year after year. These plants are predominantly rhizomatous. Which means they spread through their extensive root systems. One exotic plant that we have here that is extremely problematic is leafy spurge. And leafy spurge was introduced as an ornamental plant, back in the 1800s people thought it was beautiful and they planted it and now it has spread. It’s extremely invasive it out competes native plants and that’s why it’s a problem. And so what we want to do is control the leafy spurge and give those native plants a chance. Another one of the rhizomatous perennial plants that is a problem at Devils Tower is Canada thistle. Canada thistle spreads very easily through the root system. It does produce a lot of seeds but thankfully the germination rate of those seeds is fairly low. So the methods used to control these plants vary depending on the type of plant it is. What type of growth cycle it has so with some of these plants that have extensive deep root systems like leafy spurge, hand pulling that plant isn't going to do any good. If you try to pull that plant you’re just going to break off a little piece of the root and you actually can stimulate it to grow more. So you can actually do a little bit more harm than good by pulling leafy spurge. So we use a variety of methods to control leafy spurge. It’s an integrated pest management approach. SO we use bio controls those are flea beetles that are actually released on the spurge to and kill the plant they are in the genus amphora. So they’re a couple of different types of flea beetles that can be released on spurge. Those were released here back in the early 2000's and actually a little bit prior to that there were actually a couple of other releases here at Devils Tower. And those have done quite well and have reduced the spurge significantly. We’re looking at perhaps augmenting that population of flea beetles in the next year. Another method that’s used to control leafy spurge is herbicide treatment. We use a couple of different types of chemicals in a backpack sprayer at a very low rate to control the leafy spurge. This summer at Devils Tower a new invasive plant species was found that had never been found in the park before. And in fact it was the first occurrence of this species in the entire state of Wyoming. And that plant is garlic mustard; garlic mustard is another biennial exotic plant species. So it creates a rosette the first year and seeds in the second year. Thankfully the patch that was discovered was very small in size we were able to take care of it right away. There were a few second year plants in that patch so it looks like it may have been there for about two years. And those seeds can remain viable in the soil for a few years so what we wanna do is go back, revisit that site and make sure that we've gotten it all over these next few years and then hopefully we can just take care of it and it will no longer occur in Wyoming. Park visitors can help us control the spread of invasive plants by looking for seeds that may have attached themselves to their clothes or their backpacks and instead of picking those seeds off and tossing them on the ground, put them in the nearest trash receptacle. There’s a plant called Hounds Tongue here which is another invasive plant. It’s a biennial plant. And those seeds are little nut-lets and they are sticky and they stick to animals’ fur and to peoples pants and socks and backpacks. And that’s how they spread. So as a park visitor if you can just be aware of what seeds you’re picking up and not spread them to other places, you can certainly do your part. Piper: Another problematic species at Devils Tower is Mullein, Megan tells us about this plant. Megan: This is Verbascum thapsus, or common Mullein. This plant can produce up to 200,000 seeds in the environment, one plant can do that. And also the seeds can remain viable in the soil for over a hundred years. SO its’ really important that we try to collect all of the seed heads and help get rid of that seed bank. [Music] Piper: There are four different ecological zones present in the park. The river, the prairie, and the Ponderosa Pine forest, and the top of the tower. In spring wildflowers dominate the prairie environment. Megan Chapman works hard to protect wildflowers by pulling invasive species: Megan: Most wildflowers will probably be blooming from May to August, that’s the best time of year to come. It’s a mix of western and eastern species of plants, like they have a mix. It’s a pretty good mix of different ecological regions, different ecosystems. I think, I guess maybe the most interesting thing is that there’s a good mix of eastern and western plant species. And I really actually like the dark throat shooting start, but the harebells are really pretty. Harebells are definitely one of my favorites; those are really delicate pretty flowers. Or and actually the Sego Lily is really cool as well, I really like the Sego Lily, that’s really pretty. Sego Lily and Gunnison’s Lily look exactly the same. Very similar, except Sego Lilies usually bloom in may and Gunnison Lilies usually bloom from July until august, so if you see a lily that looks like that and it’s July or august its going to be a Gunnison’s Lily. The Sego Lilies can be kind of pinkish or purplish on the inside versus the Gunnison’s Lilies don’t really get that coloration, but they’re, yeah I love seeing those, those are really cool. I see them a lot around like Joyner Ridge trail. In prairie dog town I always see globe mallow which is these little like orange flowers that are like really pretty, and usually by the tower I see a lot of Gunnison’s Lily. There’s wildflowers all over the park if you’re looking for them. [Music] Piper: Spring also brings prairie falcons to Amy Hammesfahr tells us about the raptors in the park. Amy: We also have a couple of species of falcons. We have prairie falcons, peregrine falcons, and American kestrels. All of these birds can breed at the tower. And we have had both prairie falcons and peregrine falcons nest on the monument itself throughout the past years. Piper: Along with raptors Amy also works with prairie dogs, another important part of the prairie ecosystem. Amy: Prairie dogs are with groups called coteries. Coteries consist of one to two females and a male with several yearlings. The organization is pretty complex they have several different burrows that they use for different purposes and harbor the whole family within. Visitors enjoy coming to the prairie dog town and watching the prairie dogs yip. The population of prairie dogs in this area is pretty isolated. There are no prairie dogs in this immediate area. And so the population here at Devils Tower is really important to conserve the species. There are a couple of predators of prairie dogs such as the coyote, badger and they come into the town at night and they will take the prairie dogs. Prairie dogs are a keystone species, from digging up their burrows, when they vacate burrows, other species come in and use those vacated burrows so badgers will come in and eat prairie dogs but they’ll use those burrows as dens, foxes will also come in and use those burrows as dens. As well as smaller creatures such as black widows and tiger salamanders and voles and mice. Prairie dogs have a great threat of bubonic plague from fleas that can come into the colony from predators that are coming to feed on them or from insects or other just getting into their environment and that’s a concern for Devils Tower because if plague happens to happen to this colony we’re going to loose our prairie dogs. So we monitor them every week to record the amount in the population and to try and get an idea of what’s going on with the colony to monitor for plague. If you are visiting the park and you want to see prairie dogs its best to come a few hours after sunrise you’re not going see as many prairie dogs later in the day, they go to rest in their burrows. When you go out to look that prairie dogs you will here them barking and yipping and making all sorts of sometimes entertaining sounds and these are a form of communication between members of those coteries and rival members of burrows adjacent to them. They’re communicating things such as predators if they’re present, or just a variety of other things that they may be communicating about. Prairie dogs the threat in Devils Tower is not only plague, but dying from being fed. When prairie dogs eat human food there’s a lot of fat, there’s a lot of salt and eating that type of food is causing them to be dehydrated and have high concentrations of nutrition they don’t normally eat, and so that can kill them. And really can harm the population. So they've got two things going against them, so it’s really important when you visit the park to enjoy them and certainly not feed them. [music] Another great creature we find at Devils Tower is the porcupine. Rene Ohms tells us more. Rene: porcupines are rodents and we find them throughout the park but they primarily like trees, the north American porcupine is a fantastic climber. They’re herbivores. They eat leaves flowers and forbs. They eat all kinds of vegetation and in the winter time they’ll often eat bark. And so you’ll see their chew marks on trees low to the ground. They need a stance where they can sit and chew on the bark, sometimes you’ll see those chew marks up high in a tree if there’s a place where the porcupine has been able to sit on a branch and access the bark then you’ll see those chew marks there. One project we’re really excited about over the next couple of years is we’re going to be studying the porcupines of Devils Tower, getting a better handle on the population size here and which parts of the park that they prefer. And one of the methods that will be used to examine the porcupine population is to look at those chew marks and measure the sizes of them. We’re working with a researcher that’s going to be developing a protocol for the monitoring of the porcupines and one of the things he’s going to look at is size of those chew marks and whether you can correlate that size with the number of porcupines that are using that site. Another thing we’re going to be dong this year is beginning development of a citizen science outreach program on porcupine monitoring and so park visitors can come out to the park and help us to track porcupines, look for their tracks in the snow, look for those chew marks and measure those. And so the protocol for the citizen science program is in development and in twenty sixteen is when we hope to implement that and invite park visitors out to the park to participate. Piper: Devils Tower is home to other fascinating Nocturnal Creatures. Rene Ohms tells us about the bats at Devils Tower. Rene: Another exciting project that we've started this summer is some acoustic bat monitoring. So we are recording the echolocation calls of bats throughout the monument and learning a lot more about what species are here and about what parts of the park they prefer to use. We have three acoustic monitoring stations that are set up and they record the high frequency echolocation call of bats and we have 10 species of bats at Devils Tower that we know of so far, we may have more. And one bat that’s particularly interesting is Myotis septentrionalis, that’s the Northern Long Eared Bat. The Northern Long Eared Bat has been proposed for listing as an endangered species. And a decision on that will be made next year by the fish and wildlife service. And this is one of the places where the northern long eared bat appears to be doing quite well. We’re on the far western edge of the species range and in the eastern United States that bat has been hit particularly hard by white nose syndrome which is a disease that is decimating bat populations. And so we’re really fortunate here at Devils Tower to have a healthy population of the northern long eared bat that we want to continue to preserve and protect. [Music] Piper: Visitors often have questions about the ecology at Devils Tower. I’ll answer some Frequently Asked Questions today. Many visitors ask “What’s the white stuff on the tower?” it’s not calcite, or frost, or mountain goats. The tower houses many flocks of pigeons and the white splotches along the top of the tower are actually years of build up of pigeon excrement. “Why does the tower look green?” The tower sometimes has a greenish hue due to the lichen that grows on the rocks. Are there really snakes around here? Beverly Swift Pony knows the answer to that question. Beverly: We have bull snakes, we have lots of garter snakes, we have, I would imagine we have racers, things such as that. We’ll find the prairie rattlesnake here, he’s pretty prolific here. I haven’t seen any since I've been here. I've had other people say they've seen several. I haven’t been fortunate enough to see one, but yeah, they are here. Pretty much the only venomous snake in the black hills is the prairie rattlesnake. But the rattlesnake is not anything to be feared. He’s more afraid of you than you are of him and he will avoid you at all cost. He’s not out to get you, he’s not going to fall out of a tree on your head. He’s not going to chase you down the trail, which is what a lot of people think. Which I think is kind of amusing. They know they can’t eat you, they’re going to waste their venom. Piper: So what should people do if they come across a snake or particularly a rattlesnake? Beverly: Stop. Just stop. The snake is there is and he’s telling you, if he’s rattling he’s telling you STOP. You’re too close, you’re making me nervous, I don’t like you being this close to me. He’s not saying I’m rattling because I’m going to strike at you, he’s rattling because he’s afraid. All snakes will shake their tail. That includes bull snakes, that includes garter snakes. If they’re afraid the reaction for them is to hit their tail on the ground. And everyone things that ‘that’s a rattlesnake, listen it’s hitting its, ooh it’s a rattlesnake!’ and everyone’s afraid, and I've noticed that. It doesn't matter what kind of a snake it is, all snakes will do that, it’s a nervous reaction. They don’t want you to get any closer they’re saying “please go away, I don’t like you being this close to me, I’m uncomfortable”. And you just need to stop and back away. And the snake will go and do his business, and you can go and do yours. It’s a mutual agreement. [Music] What are the birds circling the tower all summer? Amy can tell us about these birds as well. Amy: The most common raptor you probably will see is the turkey vulture. They are often seen hovering around the southwest corner of the tower, it’s the warmest spot of the tower and they look out for the thermals and once they feel the thermals they start to soar high, and once they’re on those thermals they’re just cruising those airways as they fly higher and higher. Turkey vultures are a species that eats only carrion. So they wont eat anything live, but going on those lower altitudes flying is pretty important for them so they can smell carrion. And when you see them kind of teetering like they’re unstable, that’s actually a part of them being able to fly low and smell carrion in the air. Turkey Vultures in some cultures are considered spiritual animals because they can symbolize renewal so that’s kind of a fun way to look at turkey vultures when most people just look at them they think they’re just some ugly bird. Piper: People often ask “when was the fire?”, when they see burnt trees. Often these are from proscribed burns. Rene Ohms tells us more. Rene: Proscribed fire is a necessary resource management tool. Fire historically happened throughout the western united states, was caused by lightning strikes. And you know as people began to settle the western united states we suppressed fire, obviously we were worried about the idea of fire burning peoples homes, the threat that fire can pose to humans. But in the process because we suppressed fire fuels built up on the forest floor and what happens now is if there’s a lightning strike those fires can be extremely catastrophic. So one tool use to manage this is we can use fire again, we can set proscribed fires so that we know exactly when the fires going to happen so we can light it under a more controlled circumstance. But another thing we can do is a little bit of thinning, and that can be mechanical thinning with chainsaws, trying to pull out some of that extra fuel that’s built up. But really fire is the preferred method. And fire releases nitrogen back into the soil, so the new regeneration that comes back up is green and healthy. There are so many benefits to fire. Fire can actually be used to control exotic plant species. You have to be careful using it as a tool for that because there are some exotic species that actually do better after a fire , so the roll of resource management is to guide the fire managers. We take a look at the fire burn plans before the proscribed fire happens and make sure that the fire is going to not only meet the objectives of reducing the fuel loading and preventing future catastrophic fires, but we also want to make sure that that fire is meeting ecological objectives. [Music] Piper: What does it look like on top of the tower? Philip has lots of experience on the summit. Phil: So the top of the tower is about the size of a football field, about an acre in size. And it’s relatively flat, so it’s rocky and dry. There’s a little bit of a dome shape to it. And it’s kind of an oval almost from north to south. So it’s a little bit longer north to south than it is wide east to west. It’s mostly grasses and sagebrush up there. Something really cool about the top of the tower is that there’s Wyoming big sage brush that grows up on the summit, and that’s pretty cool because you don’t really find Wyoming big sage brush anywhere else in the rest of the monument. So it’s a neat little endemic spot within the tower itself. [Music] Piper: Devils Tower is truly an enclave, sheltering these amazing plants and animals in their native habitats. If you get the chance to walk the tower trail, take some time to walk in silence and listen to the birds and insects that are part of what make this such an amazing place. Stop by prairie dog town and spend a moment observing our furry neighbors. Whatever you do at Devils Tower take time to steep in the amazing diversity of nature that is preserved in this wonderful place. Thank you for joining me on this exploration of the ecology of Devils Tower Nat Monument. As always my name is Piper Lewis, podcasting the Tower Frequency for you courtesy of GeoCorps and the NPS. For more information on Devils Tower please see our website www.nps.gov/deto. Our theme music was composed by Bensound. Thank you for listening
[Music] [Outro music]
Description
Explore the ecology of Devils Tower National Monument. Listen to interviews with park scientists which highlight the plants and animals of the park's ecosystem.
Duration
24 minutes, 38 seconds
Credit
Piper Lewis NPS
Date Created
11/07/2014
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