Spring BioBlitz: Tortolita Preserve Report

Photo: PCMNs Izetta Feeny C6, Dave DeGroot C2, and Dre Hoerr C3 at the trailhead.

By Dave DeGroot, April 20, 2023

Master Naturalists find many previously unrecorded species – It’s amazing to see what a couple dozen highly motivated Master Naturalists can accomplish in just a few hours!

On Saturday morning, April 15, 24 iNaturalist-toting MN’s converged on the Tortolita Preserve in northwest Tucson for a Spring BioBlitz. Unlike other BioBlitzes in the Tucson area, this one was run by and for MN’s only, at the request of the Town of Marana, which oversees the Preserve.  Many participants drove down from Maricopa County. When the dust cleared, 293 observations had been made of 115 species. 

Many species were observed for the first time in the Preserve. Not only that, but when you look at iNaturalist’s map showing “all nearby observations” in about 80 square miles of desert north of Tangerine Road, many of the observed species are unique sightings for the whole surrounding area. For example, a little Rufous-Winged Sparrow, a well-known resident of Mexico, was observed at the extreme northern edge of its range.  Some unique plants included: Brittle Spineflower (Chorizanthe brevicornu), Woolly Plantain (Plantago patagonica), Pringle’s Woolly Sunflower (Eriophyllum pringlei), Barestem Larkspur (Delphinium scaposum), Doubleclaw (Proboscidea parviflora), and Fremont’s Pincushion (Chaenactis fremontii). 

The prize for the most heart-stopping sighting goes to Jennifer Spawn, who observed and confirmed a Coachwhip Snake that was approximately 8 feet long. 

There’s an interesting history behind this BioBlitz. It was a follow-up to a groundbreaking Fall BioBlitz in the Preserve (2022) which combined the efforts of seven organizations and agencies: the Town of Marana, Arizona Master Naturalists, the Tortolita Alliance, Arizona Game and Fish, the Coalition for Sonora Desert Protection, The Wildlife Society, and the Audubon Society.   The two BioBlitzes, one in the fall and this one in the spring, are now creating a first-ever list of plants and animals in the Preserve – a list that will be useful for conservation efforts in the future. 

This Rufous-Winged Sparrow, more common in Mexico, was seen at the northern edge of its range.

The Brittle Spineflower looked a little like the insides of a plastic dish scrubber, stretched apart!