BY JULIANNA HOZA
LONG-TOED SALAMANDERS: MICROHABITAT PREFERENCE AND MOVEMENT IN THE UNION BAY NATURAL AREA
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from ponds to forests, and forested areas must support adults throughout the non-breeding season. Since both aquatic habitats, terrestrial habitats, and the area in between are required for a healthy amphibian population, amphibians in a wetland restoration site are one indication that the site as a whole is functioning well. So are amphibians present in UBNA and the Amphibian Corridor? To figure out whether the Amphibian Corridor had succeeded in providing new amphibian habitat and connectivity between existing habitats, I studied amphibians in UBNA with a focus on long-toed salamanders (Ambystoma macrodactylum ssp. macrodactylum). Long-toed salamanders have blotches of yellow in patterns unique to each individual, like a fingerprint, so these patterns can be used to “mark” individuals photographically in a markrecapture study. I intended to illustrate how long-toed salamanders use the Corridor to move, as well as which
Corridor microhabitat features the longtoed salamanders use most frequently. My survey methods captured longtoed salamanders at a wide range of times and in many activities. These salamanders are nocturnal, breeding at night in the middle of winter here in the Seattle area, so I conducted nighttime surveys two hours after dusk. However, I also wanted to see where the salamanders went during the day, both on land and in the water. So I alternated between daytime and nighttime as well as aquatic and terrestrial surveys. On terrestrial surveys, I flipped over every piece of woody debris in the hopes of finding salamanders underneath, and on aquatic surveys I waded through shallow water with my eyes peeled for eggs or adults with a bucket in hand to capture them (see Fig. 1 for survey areas). This broad set of surveys gave me data on where long-toed salamanders were during a range of activities from breeding to hiding under logs. When I found long-toed sala
CONSIDERED TO BE INDICATORS OF CLEAN WATER AND “LONG HEALTHY ECOSYSTEMS, THESE SMALL ANIMALS’ PRESENCE HELPS US UNDERSTAND HABITAT AVAILABILITY IN THE UNION BAY NATURAL AREA.
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he Union Bay Natural Area, now a vibrant ecological site renowned for its birding opportunities, was once a landfill. The landfill was capped with clay in 1964 (Ewing et al. 2010), and restoration efforts headed by the UW have been ongoing since the ‘90s. However, there are only a couple of feet of real soil under this wetland. With this, does the wetland function like a natural system should? Amphibians can help us find out. Long considered to be indicators of clean water and healthy ecosystems (Blaustein 1994), these small animals’ presence helps us understand habitat availability in the Union Bay Natural Area (UBNA). A small restoration site within UBNA, the Amphibian Corridor, aims to boost amphibian populations in UBNA. To do this, it increases habitat connectivity between a pond where amphibians could breed and upland forested habitat where amphibians could spend the non-breeding season. The site was installed by a Masters of Environmental Horticulture student in 2015 with hopes that the Corridor could increase amphibian habitat and link terrestrial and aquatic habitats (Walter 2015). Ponds are required for amphibian egg and larval development. Juveniles must successfully migrate