Verde Valley Search and Rescue volunteers are frequently called out to join search missions after dark. In fact, night time search and rescues are more typical on the National Forest than daylight events. It is rare, however, for volunteers from Friends of the Forest to be out and about in the forest after sunset and to be on a search mission of any sort. Yet this was exactly the task for a group of citizen science volunteers during March and April this year.
Under the guidance of Red Rock Ranger District Wildlife Biologist Janie Agyagos, volunteers engaged in a search for a small amphibian – the Arizona toad (Anaxyrus microscaphus). The Arizona toad is native to the southwest but its range is shrinking so it may join the list of endangered and threatened species in the future. A systematic survey to verify current locations of toad populations on or near the Red Rock District is needed to help the Fish and Wildlife Service determine if the Arizona toad needs protection under the Endangered Species Act.
The Arizona toad’s usual habitat is the vicinity of perennially flowing streams, especially during the spring breeding season when egg strings are laid at the bottom of pools or edges of streams. To the surprise of seventeen eager volunteers, even in a dry spring following a dry winter there were more than one hundred locations to be surveyed. After training and assignment of sites, volunteers conducted weekly surveys over an eight-week period at call points along rivers, streams, springs, a lake and water features on private lands.
Why search and survey in pitch dark? The breeding call of the toad was the primary method of species identification and the toads’ calls only occur at night. The volunteers were trained in auditory identification of the most common Verde Valley toad and frog species. The Arizona toad’s call is a long musical trill of 5 to 20 seconds rising in pitch at the start and ending abruptly. By contrast, the more prevalent Woodhouse toad, which can hybridize with the Arizona toad, calls with a nasal “waaah!” resembling the call of a sheep. Mexican Spadefoot toad calls sound like running a fingernail over the teeth of a comb and Great Plains toads trill at high pitch for up to 50 seconds. Volunteers were supplied with toad call recordings as well as protocols for use in the event of visual sightings of toads.
Why put such effort toward documenting this small creature? Healthy ecosystems depend on plant and animal species as their foundations. When a species becomes endangered, it is a sign that the ecosystem is out of balance. Each species that is lost triggers the loss of other species within its ecosystem. Deteriorating or unhealthy ecosystems affect our lives in various ways including adverse affects on the natural resources upon which humans depend. The Arizona toad is among a variety of riparian species that are diminishing due to loss of habitat and increase in non-native predators. Hybridization with Woodhouse toads that thrive in habitats altered by agriculture is an additional factor.
After miles of bumpy forest roads and careful treading on foot, what did these citizen scientists discover? They did not have need for newly acquired knowledge about dorsal stripes, cranial crests, or ventral spotting for up close visual verification of Arizona toads. Nor did the volunteers need to distinguish between kinds of trills or trill versus a “waaah”. Although 90 sites were surveyed along 7 rivers, 9 streams, 1 lake, 15 springs and 5 water features on private lands, no Arizona toads were heard, much less seen, during this breeding season! Woodhouse toads, red-spotted toads, and canyon tree frogs on the other hand, were observed toward the end of the survey season. Volunteers also detected a population of non-native frog not previously documented in the Verde Valley, the Pacific treefrog, along Oak Creek.
Does this mean that the Arizona toad is already gone from our area? Janie Agyagos says, “Based on our survey results it appears that Woodhouse toads, through hybridization and competition for resources, have overtaken the aquatic habitat in the Verde Valley. Some of the headwaters of our perennial drainages, like Sycamore, Wet Beaver Creek and West Clear Creek may still support Arizona toads. Survey of these locations in the future will require overnight backpacking trips or arduous daytime hiking to set out long-duration recorders.”
In anticipation of next year’s inventory of Wilderness area toads, Friends of the Forest volunteers are already training in how to analyze sound recordings! Information about how to join this and other wildlife or conservation projects can be found at https://www.friendsoftheforestsedona.org.
Serving Sedona, written this week by Jennifer Young of Friends of the Forest, appears Wednesday in the Sedona Red Rock News.