By Héctor Sánchez and Daniel Olguín
Coastal Lagoons is a binational project, so far 40 researchers and students from 13 institutions from both from Mexico and the United States are actively collaborating, as well as community members from La Chorera, in San Quintin, and the Estero de Punta Banda, in Ensenada.
The goal of this project is to monitor the light-footed Ridgway’s rail (Rallus obsoletus levipes) in the wetlands of San Quintin Bay and Estero de Punta Banda to determine the spatio-temporal abundance of individuals during 2 years and estimate the populations at each site. To date, a total of 24 routes and 110 sampling points have been conducted.
As part of this, 6 GPS have also been installed in the Estero de Punta Banda and 1 in the Bay of San Quintin, in order to know its ecological niche and interaction with the habitat within the wetlands. In addition, 7 blood samples have been taken for genetic studies that reveal the genetic variability present within the species.
The project seeks to generate a habitat characterization through biological monitoring of the different taxa involved in the biological cycle of the light-footed Ridgway’s rail, which is why interdisciplinary collaboration within the project has been essential. Monitoring of reptiles, birds, fish, mammals, arthropods, vegetation, sediment and water has been carried out, obtaining as a record for the first year more than 257 species present in the ecological niche of the Ridgway’s rail, some are of priority relevance for the richness of flora and fauna that characterize the area (Table 1).
| Mammals | Reptiles | Vegetation |
| –Microtus californicus –Sorex ornatus juncensis –Dipodomys gravipes –Dipodomys merriami quintinensis –Chaetodipus arenarius | –Arizona elegans occidentalis –Chilomeniscus stramineus | –Ambrosia psilostachya -Encelia californica × E. farinosa -Pluchea odorata var. odorata -Cryptantha arenophila -Cryptantha clevelandii var. clevelandii -Acmispon glaber var. brevialatus -Ruppia cf. maritima -Datura discolor |
By implementing constant monitoring of these taxa within the wetlands of San Quintín and Ensenada, changes in the flora and fauna habitat, disturbances and immediate impacts to the habitat can be evaluated, and thus create timely and well-argued management actions for the conservation of these habitats.
Among the achievements of the first year is the monitoring of the San Quintin kangaroo rat (Dipodomys gravipes), a species that was thought to be extinct and was rediscovered in 2018 by Terra Peninsular and researchers from the San Diego Natural History Museum. Since then, a large amount of monitoring has been carried out to evaluate its populations, distribution and create conservation actions.
Other relevant species include the tule shrew (Sorex ornatus juncensis), California vole (Microtus Californicus), species of importance as indicators of habitat modification, climate change, endemism, and under a conservation label of importance in Mexico.
During the reptile monitoring, the variable sandsnake (Chilomeniscus stramineus) was found, a species that had not been recorded in San Quintin Bay for more than 40 years, and which was recorded repeatedly within the Monte Ceniza Nature Reserve.
Aquatic monitoring within the bay has included sampling of fish, vegetation, waste discharge areas from nearby desalination plants, and aerial drone flights in order to demonstrate and measure any significant changes in the study habitat.
Camera traps were installed in strategic areas in the wetlands in San Quintin Bay to record the fauna that interacts with the site, finding a great diversity of birds, coyotes (Canis latrans), and bobcats (Lynx rufus). With these results we gained knowledge of the active predators that influence the study area and how they directly impact resident and migratory birds and our project’s umbrella species.
Summary of activities
Reptiles and amphibians
- 12 trapping arrays installed: each with 4 pitfall buckets and 3 box traps.
- 6 monthly trapping sessions: April to September 2022.
- 5 days per trapping session.
- Each individual weighed and measured.
- 16 species captured.
Notable findings
- California glossy snake (Arizona elegans occidentalis): rare in California (single population left in San Diego County).
- Variable sandsnake (Chilomeniscus stramineus): last confirmed record in San Quintín plain was 44 years ago, in 1978.
Plants
- Vegetation assessments at 8 plots in Estero de Punta Banda and San Quintin Bay, and an extra one for rare species.
Notable findings
- 477 iNaturalist observations.
- 19 new plant species records, including 11 non-native and 8 native.
Arthropods
- 8 plots in San Quintin and Estero de Punta Banda.
- Each plot: 20 pitfall cups (sampled daily), Blue Vane and Malaise Traps (sampled weekly).
Notable findings
- Total 307 samples of Estero de Punta Banda.
- 13 taxonomic orders were collected, with Hymenoptera, Isopoda, and Coleoptera most predominant.
- Total 348 samples of San Quintin.
- Great community diversity between plots.
- Samples include tiger beetles, centipedes, scorpions, amphipods, pillbugs, and a great diversity of spiders.
Mammals
- 8 plots in San Quintin and Estero de Punta Banda.
- Per plot: 30 Sherman traps, 10 Tomahawk traps and 20 pitfall cups.
- 5 motion-detection cameras.
- 5 bat detectors.
Notable findings
Estero de Punta Banda
- 25 species identified.
- 12 species captured.
- 77 trap total captures.
- 18 specimens at UABC Ensenada.
- California vole (Microtus californicus), previously thought to be rare in the region but these surveys plus other recent efforts have uncovered a substantial population around the estuary.
San Quintin Bay
- 23 species identified.
- 10 species captured.
- 61 trap total captures.
- 13 specimens at UABC Ensenada.
- San Quintin kangaroo rat (Dipodomys gravipes): 2 individuals captured.
- Merriam’s kangaroo rat (Dipodomys merriami quintinensis): 10 individuals
- captured.
- 8 bat species detected so far.
Birds
Estero de Punta Banda
- 8 mist-net stations.
- 6 point-count stations with acoustic recorders.
- 124 bird species identified.
- 22 bird species captured.
- 156 birds captured.
- 36 specimens (deposited at UABC Ensenada).
San Quintin Bay
- 87 bird species identified.
- 20 bird species captured.
- 53 birds captured.
- 31 specimens (deposited at UABC Ensenada).
Organizations
- Southern California Coastal Water Research Project (SCCWRP).
- Rocky Intertidal Monitoring (RIM).
- Department of Fish and Wildlife (CDFW).
- US Geological Survey (USGS).
- University of Idaho.
- San Diego Natural History Museum.
- Fauna del Noroeste A.C.
- Pro Esteros A.C.
- Terra Peninsular A.C.
Teams
- Herpetology: Brad Hollingsworth, Anny Peralta García, Jorge Valdez Villavicencio, Frank Santana, Daniel Olguin, Rafael Lara Reséndiz, Marco Solis, Andrés Esquivas, Mayra Flores, Jessica Barba, Sofía Daniela Flores Mejía, Ricardo Gibert.
- Botany: Jon Rebman, Sula Vanderplank, Carlos Gonzalez, Brenna Ogg, Rachel Allingham.
- Entomology: Natalia Rodriguez Revelo, Rachel Allingham, Pam Horsley, Michael Wall, Brenna Ogg, Vryce Hough.
- Mammalogy: Scott Tremor, Héctor Manuel Sánchez Márquez, Daniel Olguin, Esteban Esquivias, Vryce Hough, Brenna Ogg, Drew Stokes.
- Ornithology: Philip Unitt, Lori Hargrove, Hiram R. Moreno-Higareda, Liliana Ortiz, Tonatiuh Gaona, Ángela Tamayo, Daniel Olguin, Esteban Esquivias.