Actinemys pallida

Spinks et al. (2010, 2014, 2016) demonstrated deep phylogeographic divergence within the genus Actinemys, corresponding to the previously recognized subspecies, and recommended species recognition for A. pallida (Crother et al. 2017).

This species has a limited range in southern California and northern Baja California, México. The population has declined by at least 50% and is projected to continue declining sharply. It is threatened by native and invasive predators, upland and aquatic habitat loss, drought and hydrologic changes, and direct mortality from vehicles and agricultural equipment.

This species ranges from northwestern Baja California, México north through western California to central California, United States (Seeliger 1945, Bury 1970, Spinks et al. 2014). The northern extent of the range terminates at the southern end of Monterrey Bay and the San Joaquin Valley (Spinks et al. 2014, USFWS 2023). Using Global Biodiversity Information Facility (GBIF) (2025) records from 2000-2025, range extent is estimated to be 147,947 km² (RARECAT 2025).

In central California, this species intergrades with A. marmorata (Seeliger 1945, Bury 1970, Spinks et al. 2014).

Applying a 5 km separation distance to GBIF (2025) records, 166 occurrences are estimated (RARECAT 2025).

This species is threatened by native and invasive predators, upland and aquatic habitat loss due to development and agriculture, drought and hydrologic changes, severe floods, pathogens, pollution, and direct mortality from vehicles and agricultural equipment. Drought, invasive predators, pathogens, and floods are the most serious threats to this species (Manzo et al. 2021, Gregory et al. 2024a). Droughts and human water usage are drying out wetlands (Lovich et al. 2021, Muth et al. 2024). These threats are projected to continue to cause serious declines through the rest of the 21st century (Gregory et al. 2024a). Several invasive species pose a threat throughout its range. Pond sliders (Trachemys scripta) compete for basking sites (Ernst and Lovich 2009, Manzo et al. 2021). Invasive American bullfrogs (Lithobates catesbaei) and largemouth bass (Micropterus salmoides) are predators of hatchling turtles and are suspected of drastically reducing juvenile survival when present (Bury and Germano 2008, Ernst and Lovich 2009, Manzo et al. 2021, Gregory et al. 2024a). Nest predation by native predators is also a major threat, particularly near anthropogenic habitats, which has been responsible for very low nest success rates across its range (Bury and Germano 2008, Ernst and Lovich 2009, Davidson and Alvarez 2020). Mortality from habitat management activities, particularly discing and mowing uplands in nesting areas, can cause serious injury and mortality (Alvarez et al. 2017, Cummings et al. 2022). A recently discovered infectious disease, pond turtle shell disease fungus (Emydomyces testavorans), is an emerging threat with yet-unknown consequences (Lambert et al. 2021, Manzo et al. 2021). Other infections are also declining the overall health of individuals (Green et al. 2025).