Animals

Birds:

             Sometimes in the swamp it is fun to be as quiet as possible. Sometimes there are great blue herons just on the other side of the cattails and you can get a real good look at them they don’t hear you too early. When they fly away they make the most prehistoric dinosaur-like sounds that you wouldn’t expect to hear right here within the city. Once you (accidently) scare any herons away, there are many other interesting birds to be seen as well. There are almost always a couple pairs of mallard ducks swimming about. The males have the bright green heads and the females are mostly brown. To eat, they have bills that act as strainers to filter out everything they don’t want. There are also gadwalls. The female gadwall looks very similar to the mallard female, but the male gadwall is a grayish color and of similar size as the mallard. If you bring binoculars you can look out toward the opening of this little inlet and see some massive groups of coots that appear to just be swimming around as a pack.  Occasionally if you’re really lucky, you can see a bald eagle soaring above hoping to spot his next meal. One of the most fun things about birds is that if you observe one of them long enough, you can see that they’re often trying to do something. Birds don’t just fly around all day. If you sit and watch you can see them eating or foraging, building a nest, singing for a mate, calling to warn others of dangers, and much more.

Beavers:

             One of the most unique and amazing parts of Yesler Swamp are the beavers that can be seen! At the end of the right-turn trail there is a great view of the lake and across the small inlet you can see a beaver lodge. There aren’t always beavers swimming about, but I have found that the best time to go and see them is at dusk. When I’ve seen them at dusk they are normally just swimming with their heads poked up out of the water. Occasionally they will dive and they curl their whole back as they go under, which really shows how big some of them are! During the day I have seen them once and it was quite fascinating. The usual calm and serene inlet would occasionally be chaotic with water thrashing. I believe these were beavers, but I wasn’t sure what they were doing because I believe their diet is strictly vegetarian, so I don’t see a reason for the attack looking behavior. Either way, the things you can see when you sit near the lake and stay patient are very interesting. Another thing I have seen the beavers do is slap their tail. I’ve only seen them do this when I have rented canoes and gotten in between them and their lodge. The sound and splash they make is very impressive and definitely worth seeing for yourself! 

Invertebrates:

              At the end of the trail you come to the lake and many low hanging trees that really give Yesler swamp that swamp kind of feel. Occasionally there will be some ducks back this far, but one of the coolest things to do at this spot is to look for invertebrates! There are logs on land and some in the water pretty close to the shore. Every time I have looked under these logs I have found quite a few invertebrates. The ones under logs in the stream are benthic invertebrates, benthic meaning lake bottom in this case. The majority of the invertebrates found tend to still be in their larval stage. Some examples are mayflies, caddisflies, stoneflies, and dragonflies. These speicies belong to the orders ephemeroptera, trichoptera, plectoptera, and odonata respectively. The biggest you will find them is usually about the length of the diameter of a coin. Mayflies can be identified by their 3 tails whereas stoneflies have 2. Caddisflies make shells out of things around them and they typically just cling to the piece of wood or rock you pick up. 

            Some other insects you can see outside of the water include fire ants, which have bit my ankles and made them quite itchy, and you can find plenty of bees. Both of these species belong to the hymenoptera family. Some rarer things to find (at least in my experience) are butterflies (lepidoptera) and beetles (coleoptera). I’ve briefly seen one medium sized orange and black butterfly, and to my amazement have yet to see a beetle, so keep your eyes open!

Animal behavior:

              As you approach the water, I recommend being as quite as possible. Not only does this enhance our senses a little, but it can also help you to see more animals up closer. There are often frogs, turtles, and a few birds along the shoreline and once they hear you, they will think you’re a predator and they’ll dive into the water or fly away. The turtles are typically basking in the sun on a log floating on the lake so that they can plop right in just in case an eagle or hawk comes after them – but they’ll also treat humans the same if we get much closer than about 20 feet from my experience. When herons suspect danger they fly away and make loud squawks which probably lets other animals know that there is something dangerous where they were. Some animals are more subtle in letting other animals know about danger. Chickadees have a call that sounds like “chick-a-dee-dee-dee” and the amount of ‘dee’s vary depending on the level of danger; the more dee’s – the more dangerous. It is fun to listen for this and try to figure out what the danger is that they are worried about. More often than not, I think that when I hear a chickadee call with many dee’s it’s because I am the danger rather than a true predator.

  

Ecological interaction:

              An easy part of the swamp to overlook is the interactions taking place among smaller organisms. It takes some time to get an eye for it because we are surrounded by big trees and singing birds that easily capture our attention. However, this specific part of the swamp is neat because there are often fire ants at work. Twice I have observed them and the last time I saw them they had a banana slug that I assume had been killed by the ants. This is a great example of some of the predator-prey interaction going on within the swamp. It is imperative to keep an eye on these fire ants because they are good at swarming together and attacking. Recently I was in this spot and suddenly I felt some sharp stinging pain on my ankles and I looked down to see 5 or 6 ants on me. I ended up with 4 or 5 bites that all swelled up and felt similar to mosquito bites after the initial stinging sensation left me. If they can do that to me, then the banana slug probably didn’t stand a chance! This made me wonder if there may be some kind of ‘arms race’ between fire ants and their prey. An example of an arms race would be if the banana slug evolved to be resistant to the fire ants’ bite, followed by the fire ants evolving to alter their toxins or lethalness of their bite, and so on. This is just one of the many interesting and thought-provoking questions that can be raised from this seemingly small scale ecological interaction.

Fire ants and worms