The former subspecies arizonense and durangoense were elevated to species by Serb et al. (2001). Subspecies spooneri is generally considered synonymous with flavescens (Berry and Berry 1984, Iverson 1992, Serb et al. 2001, TTWG 2021). Hurtado-Gómez et al. (2024) analyzed phylogeographic structure and taxonomic limits within the genus Kinosternon that demonstrated deep intrageneric divergences; they proposed the recognition of three subgenera: Kinosternon, Cryptochelys, and Thyrosternum. The subgenus Thyrosternum was found to include K. baurii, K. durangoense, K. flavescens, K. steindachneri, K. stejnegeri, and K. subrubrum. TTWG (in press) agrees with this proposed taxonomy.

Despite some localized declining populations, especially at the northeastern extent of its range (e.g., Illinois, Iowa, and Missouri), this widespread adaptable species does not appear to be of significant conservation concern across most of its range. It is therefore assessed as Least Concern (LC) at this time. It was also previously assessed in 2011 as Least Concern (van Dijk 2011).

Kinosternon flavescens inhabits the western Mississippi region, as well as isolated populations in Nebraska, eastern Oklahoma, the Illinois and middle Mississippi valleys (Illinois-Missouri-southeastern Iowa), south and west to the Pecos-Grande river basins of Texas, southeastern Arizona, southwestern and eastern New Mexico, and Chihuahua, Coahuila, Nueva Leon, and Tamaulipas, to northern Veracruz in Mexico (TTWG 2021). The estimated historical indigenous range (area of occupancy, AOO) for the species was 1,321,499 sq. km, and the estimated historical indigenous extent of occurrence (EOO) was 2,749,266 sq. km (TTWG in press). An estimate of current AOO of K. flavescens using a maximum entropy distribution model (MaxEnt) delineated a smaller potential AOO of 1,231,104 sq. km (Berriozabal-Islas et al. 2020).

In Mexico, Kinosternon flavescens is considered common to very common (Mexico Red Listing Workshop 2023). In the United States, the species is generally considered to be common to very common, though peripheral range  populations are localized and uncommon (Iverson and Christiansen 2023). 

Current Population Trend: Unknown, but slow declines suspected within the main range; however, peripheral, isolated populations are in rapid decline (e.g., Illinois, Iowa, and Missouri). This species was not detected during recent surveys in extreme southeast Kansas (Hollender and Ligon 2021). Overall decline across the entire range suspected to be less than 25% over three generations (84 years). Future population reductions may be expected due to lowering of water tables for ranching and agriculture, thus causing elimination of preferred ephemeral pond habitats.

Kinosternon flavescens occurs in almost any type of water body in desert and prairie areas, but avoids lotic systems. In the United States it prefers temporary water bodies (review by Iverson and Christiansen 2023), while in Mexico it appears to prefer permanent and temporary wetlands in grasslands. The species often occurs in high densities (up to 600 individuals/ha) in human-constructed ponds. The species typically estivates during dry weather when ponds recede and brumate terrestrially during the winter, at distances up to 2,300 m away from water bodies. Individuals can remain underground for at least two years under drought conditions (Iverson and Christiansen 2023).

The species feeds opportunistically on a variety of items, primarily animal matter; feeding on earthworms while underground has been reported (review by Ernst and Lovich 2009). In the Nebraska Sandhills, females mature at ages from 9–15 yrs, but farther south in Oklahoma, they apparently mature at 5–8 yrs (Iverson and Christiansen 2023). Generation time in Nebraska was calculated at 28.2 yrs (Iverson 1991), and longevity at that location certainly exceeded 50 yrs, perhaps beyond 60 yrs (Hedrick and Iverson 2017).

Kinosternon flavescens across its range generally produces a single annual clutch of four to seven eggs (range 1–10), but females may sometimes skip reproduction in some years (review in Iverson and Christiansen 2023). In at least Nebraska, females show unique parental behaviour, remaining buried over the nest site for some time, ranging from several hours to over 38 days (Iverson 1990, 1991). Eggs incubated in the laboratory hatch after 94–125 days. Upon hatching, neonates in at least Nebraska and Iowa burrow downward for brumation, and first emerge and move to wetlands the following spring (Iverson and Christiansen 2023). Hatchlings typically measure about 21–23 mm SCL (range, 18–31 mm; Ernst and Lovich 2009).

Habitat degradation and loss likely impact some populations, but are not important factors across the main range of the species. Reduction of the water table, leading to the disappearance of surface ponds, is a concern. No specific threats have been reported from Mexico. Because this species undertakes long terrestrial migrations, it incurs significant road mortality, especially of females moving to nest. The Illinois, southeastern Iowa, and northeastern Missouri populations, previously considered distinct as Kinosternon flavescens spooneri, have been the subject of intensive conservation attention as they have declined due to habitat loss, and are currently in serious peril (Christiansen et al. 2012).

Climate modelling by Butler et al. (2016) found that the areas most suitable for K. flavescens were expected to increase substantially by 2070 in an extreme global warming modelling scenario such as RCP85 (Representative Concentration Pathway 8.5). In a similar subsequent study, Berriozabal-Islas et al. (2020) instead predicted a moderate range decrease by 2070 for RCP85. However, the latter study included fewer localities than the former, with most localities being from Mexico and much less sampling in the USA. What seems clear from both studies is that predicted climate change and warming will move the centre of distribution of the species northwards, with a potential decrease in habitat suitability in Mexico and an increase in the USA.

Kinosternon flavescens is traded in very small numbers in the pet trade and is not known to be exploited for human consumption.

Kinosternon flavescens has been included in CITES Appendix II as Kinosternon spp. since 2023. In Mexico, turtles in general are protected from exploitation under Mexican wildlife and natural resource legislation; implementation is uneven. In the United States, the species occurs on many protected areas (especially National Wildlife Reserves, and State management areas). Many populations exist on large tracts of private ranches (thousands of hectares) that offer some protection in their remoteness. The construction of ponds for livestock or agriculture in arid climates secondarily offers optimal, additional habitat for this species. Populations in Illinois, Iowa, and Missouri are probably unlikely to persist despite intense efforts to preserve and protect them (Christiansen et al. 2012). Populations in southeastern Arizona and southwestern New Mexico are in need of status surveys, especially given recent climate-change induced droughts.