Featured Photo: Bald Eagle (green), River Otter (orange) and Greater Yellowlegs (yellow) tracks in mud and aquatic vegetation near an American White Pelican carcass at Plat I Reservoir. Marked and unmarked photos are compared later in the post.
With this post I continue an exploration and exposition of tracking locations in the Umpqua River Basin, Douglas County, Oregon. This is the third. The previous two are from River Forks Park and Lemolo Lake. Tracking can be practiced nearly anywhere, but I am specifically targeting publicly accessible areas with a high likelihood of good track variety. My purpose is to provide information and education for others interested in tracking in the Umpqua River Basin and Douglas County, Oregon.
Plat I Reservoir is located about 5 miles east of Interstate-5 at Sutherlin, Oregon. It is owned and managed by the Sutherlin Water Control District (SWCD) to provide water for recreation and irrigation in the summer months and flood control in the fall through spring. Each year, beginning October 15, the water is released to make room for potential surges of water from storms or snow-melt. Most years, however, muddy edges begin to show in late summer due to evaporation, diminished input, and shallow depths. Typically, by August, muddy edges have attracted small numbers of fall migrating shorebirds.
On November 27, I ventured out to the mudflats of Plat I Reservoir. I had accessed the area in years past by walking in from the SE or NE sides (see parking spots labeled P on above map), or even taking a canoe across, but this time I obtained permission from the SWCD to enter from the end of Bingo Road. I learned that the SWCD leases some of their land to grazing, so it is not advisable to enter through outer fenced or gated parcels owned by SWCD without permission. Also note that duck hunting is allowed at this reservoir in winter so it would be best to avoid open days (see here).
As I made my way towards the reservoir from the end of Bingo Road, I walked through the short end of a leased field with Angus cattle. The cattle stared at me, curious of my purpose, but completely relaxed. Then I noticed a doe and buck Columbian White-tailed Deer somewhat beyond the cattle. The doe moved quickly west towards greater cover beyond an old sagging wire fence. The buck followed shortly behind. White-tailed Deer run more like dogs when escaping to cover, versus the bouncing “stot” of Columbian Black-tailed Deer. This was mating season and the buck seemed to want to stay with the doe. Both deer leapt gently over the old fence and disappeared into the English Hawthorne shrubland between the pasture and the reservoir.
Another fun greeting on the way to the mudflats was a flock of an estimated 21 Western Meadowlarks that flushed from the edge of the grass and hawthorn field. Ungrazed or lightly grazed fields, increasingly rare in western Oregon, sometimes attract relatively large numbers of our state bird. Also of interest was a multi-trunked Oregon Ash with bark distorted by sapsucker holes like I have not seen before. Next to this altered tree were some raccoon tracks in a muddy trail pummeled by out-of-bounds cattle.
Leaving the upland grass, hawthorn, and Oregon Ash riparian, I entered an area that was likely only submerged for a few weeks or very few months per year. It was well over 50% covered with vegetation, and contained some interesting mounds I don’t yet know how to explain. In similar habitats around Fern Ridge Reservoir west of Eugene, mounds such as this were often associated with ant colonies and Tufted Hairgrass. While I didn’t tear one of these apart, I saw no outward sign of ants, nor hairgrass. They were largely composed of vegetative material, so perhaps they are merely tussocks created by another species of grass. I don’t think they are old crayfish chimneys as they are 8-12 inches in diameter and largely composed of grass roots. If you have an explanation, let me know in the comments.
Between this somewhat grassy area and the remaining water, the substrate became more and more muddy with less vegetative cover. I stopped for a moment to scan the mud and water to see what was around. Most visible were at least 30 Greater Yellowlegs, 50 or so Least Sandpipers, and at least three Long-billed Dowitchers. Dunlin are regularly present here in winter, but I did not see any today. I watched the movements of the shorebirds so I could attempt to find tracks of each of these species where they exited the water and walked on the mud.
I continued out onto the mudflats and noticed dozens of small digs. This reservoir contains thousands of invasive Red Swamp Crayfish. These crayfish take refuge in small burrows in the ground, many of which are covered with water in the spring and summer months. Now, however, many burrows are exposed. Not surprisingly, the vast majority of these exposed crayfish holes were predated by raccoons, leaving somewhat enlarged holes, adjacent piles of excavated mud, and various crayfish parts. Raccoon trails were ubiquitous across the mudflats where they sought out crayfish burrows and other delicacies.
A week prior to this excursion the Umpqua Valley had quite a bit of rain, so the current reservoir level was actually a foot or two higher than it was a couple weeks prior; therefore, parts of some of the raccoon trails and other tracks were inundated with water. Some species of course do walk in shallow water, but there were many tracks that appeared to have fairly sharp edges indicating they were probably made before being inundated. Also, some of the larger tracks were surrounded by tracks of smaller creatures such as Least Sandpipers that would not have waded in water as deep as current conditions. But I remain uncertain about age interpretation of the larger tracks.
Also nearby was a set of Great Blue Heron (or Great Egret) tracks showing a landing. The tracks started here (there were none behind) and show a drag of the rear toe.
By far the most abundant tracks on these mudflats were those of raccoon. It was interesting to see the different gaits or patterns used by the raccoons on the mudflats. Most were the typical 2×2 or side by side pattern. In this pattern the tracks come in pairs right next to each other, alternating left-front/right-hind, left-hind/right-front, and so forth. See if you can tell which is which. Less common was a lope where the track arrangement is more like an otter. Following are some examples.
Following are a few photos of raccoon trails from a longitudinal view.
As I moved farther out on the mudflats, I noticed a large bird carcass. Based on the large size and black and white color on the wings, I figured it was an American White Pelican. In recent years, these pelicans have become regular fall visitors to Plat I Reservoir and Ford’s Pond (just west of Sutherlin), sometimes arriving as early as mid-summer or even spring. However, before I arrived in the immediate vicinity of the pelican carcass I noticed a new type of track. These had four bulbous toes, noticeably thicker and stubbier than raccoon toes. They presented in what looked like a slight understep in the mud. They also seemed to show very little of the meta-pad as if the animal was tip-toeing. I initially mistook these for a Bobcat tip-toeing in the mud, but Kim Cabrera (bear-tracker.com) helped me see they were River Otter tracks. The 5th toe is absent or hard to see on most tracks, but after staring for a while I could pick up the 5th toe on some of the tracks. The nails seemed mostly absent, but after closer examination I could see many of them; very small and sharp and very close to the end of the toe. In quite a few cases the metapodial pads are fairly well defined. Because I had already convinced myself that this Bobcat was tiptoeing, I concluded these indentations were just the front end of the pad of the Bobcat. Also, while doing some studying I also learned that “toe heavy” is a common track presentation for otters.
I followed the River Otter tracks for 20 or 30 feet until they disappeared into the water. As mentioned before, the reservoir level had risen recently and I suspect the rising water had covered part of the otters terrestrial trail. Since I lost the otter trail, I walked directly toward the pelican carcass about 70 feet away. Just as I was approaching the carcass, the otter tracks appeared again, coming “out of the water,” toward the carcass. How cool! Was the otter scavenging from the pelican carcass? I took some photos of the carcass and noticed some other interesting tracks near the carcass. They were large and the general size and arrangement of a Great Blue Heron (three toes forward, one back), but these looked different, a slightly different toe orientation, thicker, bulbous toes, and noticeable claw marks, or rather …talon marks ( ! ), separated from the end of the toes: Bald Eagle! This made sense. Bald Eagles are frequent scavengers. This discovery began to reveal a rich scene of scavengers visiting this pelican carcass.
Having been quite enriched by the unfolding scene at the pelican carcass, I began to focus on looking for clear tracks of shorebirds and other waterbirds. I visited locations where I had seen Greater Yellowlegs and Least Sandpipers to look for clear tracks there and I wasn’t disappointed. Also present were tracks of Great Blue Heron (or Great Egret), and a species of duck, but I hadn’t seen any of these species make the track so I didn’t know which species they were.
While I was busy taking photos of shorebird tracks, some Greater Yellowlegs approached closer than before. I paused to take a few photos. What beautiful and elegant birds.
I began to wander toward drier substrates and found some scat that reminded me most of Canada Goose scat, but it seemed a bit larger than usual. I’m not sure what to make of it. If you can help me out with this, let me know in the comments.
I decided it was time for me to head back to the pickup. Along an old fence line were some deer tracks, presumably one of the local Columbian White-tailed Deer, as well as a scat that based on size, roundness, and contents, I think was likely Raccoon.
Continuing on, I walked an open area between the fence and some thicker hawthorn shrubs. Under a lone hawthorn shrub near the fence line was a Raccoon latrine, with an abundance of old and new scat. Contents appeared to be primarily apple with hawthorn berries mixed in from the canopy above.
As I left the area where clear tracks might be found, a Peregrine Falcon flew by on a reconnaissance flight. I appreciated the escort at the end of a great experience!
This Post Has 4 Comments
Mud is your friend when you look for tracks. On dry ground you see more scat. Sometimes it’s from something that might like to eat you. I like the mud you chose !
Matt,
How interesting to read this! I felt like I was out there with you! Thanks for sharing!
Very much enjoyed this and learned a lot. Thank you for taking the time to photograph and document.
thanks for sharing! an enjoyable learning experience.