HELENDALE, CALIF. - A rare, federally threatened western yellow-billed cuckoo and two pairs of federally endangered least Bell’s vireo have been identified on a Mojave River property recently purchased by the Mojave Desert Land Trust. These sightings, along with other special status birds and new range extension records, underscore the property’s future role as a haven for imperiled Mojave Desert species.
Bird surveys were carried out as part of a year-long project to develop a restoration plan for Palisades Ranch, a 1,647-acre property that spans 3.5 miles of the Mojave River. The rich plant community and presence of surface water attract around 40 special-status wildlife species, making it one of the Mojave Desert’s most important habitat areas.
Stunning palisade bluffs overlook approximately 600 acres of cottonwood-willow riparian habitat. Once slated for 1,300 homes and a golf course, the former ranch was identified in 2010 by the California Department of Fish and Wildlife as a high-priority acquisition in southern California because of the property’s outstanding habitat values. It was acquired by the Mojave Desert Land Trust in October 2018 with the goal of making it a sustainable and resilient oasis in the West Mojave.
In July 2020, the secretive western yellow-billed cuckoo was heard in one of the cottonwoods, important nesting and foraging habitat for this federally threatened species. There are estimated to be fewer than 2,000 breeding pairs in the cuckoo’s range, and it has lost 90% of its breeding habitat due to the removal of riparian forests for agriculture, urban development, and flood control.
Two pairs of federally threatened least Bell’s vireo were also identified during the recent surveys. In 1998, the population size for this species was estimated at 2,000 pairs.
Palisades Ranch is prime avian habitat. There is a healthy riparian forest with dense stands of cottonwoods and willows. Beaver dams on the property are helping to create wildlife habitat and raise groundwater levels by impounding water. These conditions support a great diversity of plants and animals, including rare birds and the potential for reptiles such as the southwestern pond turtle.
The bird survey also recorded one of the westernmost breeding season records of a Lucy’s warbler, a special status species. The area also appears to be stellar habitat for the federally endangered southwestern willow flycatcher. On just one 400x400 m plot, 17 yellow warbler territories were recorded, with many of the males paired with females. Other nesting species included ash-throated flycatcher, bushtit, marsh wren, and Nuttall’s woodpecker. Very few records exist for some of the species recorded in this area, indicating they are at the limits of their normal ranges.
The former ranch is a complex desert river ecosystem in need of a long-term restoration plan. Former agricultural fields have become overgrown and include invasive plant species such as perennial pepperweed, which are seriously impacting the native plant population. The agricultural fields were formerly riparian habitat, and the Mojave Desert Land Trust now has an opportunity to restore it, offsetting the extensive loss of this important habitat. Moreover, there may be an opportunity to create a refugia for southwestern pond turtles, Mohave tui chub and the Mojave River vole, species which have been extirpated or greatly reduced in number.
SWCA was retained to help plan the restoration. Among other things, we have mapped the vegetation and soils, modeled the hydrology, measured the depth to groundwater at various locations, and conducted bird surveys. Groundwater well data and soil surveys will inform which plants can be grown and how the riparian system should be managed.
SWCA began surveys in the first half of 2020 and designs are expected to be presented to the public in early 2021 through stakeholder engagement and the CEQA regulatory process.
In the long-term, the Mojave Desert Land Trust also hopes to introduce compatible public access opportunities on the property for the high desert community, particularly the nearby cities of Victorville and Barstow. The ranch lies within a 30-minute drive for over 350,000 residents.
Other animals that will benefit from the restoration of the property include migratory birds, long-eared owl, vermillion flycatcher, Mohave ground squirrel, and Mohave shoulderband snail. The ranch’s upland habitat supports the threatened desert tortoise.
There are surveys underway for the arroyo toad, red legged frog, southwestern pond turtle, Mojave River vole, Mohave ground squirrel, as well as rare plants.
“Palisades Ranch is a unique property in the Mojave Desert. It has huge potential as a wildlife refuge, with a constant source of water in an increasingly arid landscape, providing rare habitat for a variety of bird, mammal, reptile and amphibian species. The Mojave Desert Land Trust knew this property needed to be preserved. Our long-term goal is to restore the site to more closely represent its historical condition as a verdant desert oasis that can support a multitude of species representative of the Mojave River ecosystem. We are excited to begin the hard work of restoration with the help of our partners and supporters,” said Geary Hund, Executive Director, Mojave Desert Land Trust.
“We are thrilled to be a part of this very important project. After having worked in many different riparian areas throughout the Mojave Desert, our ecologists were stunned by the diversity of the riparian forest and extent and density of the multi-story canopy at Palisades Ranch. Reconnecting the abandoned agricultural field with the Mojave River floodplain to expand the cottonwood / willow forest will increase the ecological integrity of the Mojave River through Palisades Ranch. We are designing habitat that will benefit multiple special status species and restore the ecosystem as a whole,” said Susan Mortenson, Senior Restoration Ecologist at SWCA Environmental Consultants.