Hematology, Plasma Biochemistry, Protein Electrophoresis, and Pathogen Surveillance in Headstarted and Wild-Reared Populations of Blanding's Turtles (Emydoidea blandingii) in Three Northern Illinois, USA, Counties

Blanding's turtles (Emydoidea blandingii) are a species of conservation concern throughout their natural range. Headstarting is a common chelonian conservation technique in which neonates are reared in managed-care settings before release, but health assessments are rarely incorporated. From 2020 to 2021 we assessed headstarted turtle health pre-release and 1 mo, 1 yr, and 2 yr after release using physical examination, hematology, plasma biochemistry, protein electrophoresis, and pathogen detection in three Illinois counties. Results were compared to wild-reared juveniles in the same habitats. Overall, 767 assessments from 561 turtles were included. Wild-reared and 2 yr post-release headstarts had higher incidence of hemoparasites, asymmetrical nares, and increased creatine kinase and aspartate aminotransferase activities (P<0.05) compared to all other groups. Erythrocyte sedimentation rate and heterophil:lymphocyte ratio were greater, while total leukocyte and lymphocyte counts were lower (P<0.05) in pre-release headstarts compared to wild-reared juveniles. Total solids, albumin, and beta globulins were higher, while the calcium:phosphorous ratio was lower (P<0.05) in pre-release headstarts and wild-reared juveniles vs. other groups. Bile acid levels were highest in pre-release headstarts (P<0.05). Body condition and gamma globulins increased following release, while alpha globulins and the albumin:globulin ratio decreased following release (P<0.05). Two pre-release and one post-release headstart tested positive for Emydomyces testavorans, one post-release headstart was positive for Mycoplasmopsis sp., and nine post-release turtles were positive for adenoviruses. Overall, rearing conditions have a profound and temporally dynamic impact on Blanding's health assessment parameters. Future studies should evaluate long-term impacts on morbidity and mortality to support positive health status and conservation outcomes.

Head-started Agassiz’s desert tortoises Gopherus agassizii achieved high survival, growth, and body condition in natural field enclosures

We measured survival, growth, and body condition of 8 hatchling cohorts of desert tortoises Gopherus agassizii (living in predator-resistant outdoor pens in the Mojave Desert, California, USA) over 11 yr to evaluate head-starting methods. At 11 yr of age, 7 times as many of the first cohort had survived than if they had been free-living tortoises. Subsequent improvements in predator control, food and water supplementation, and pen structure increased survival from 7 to 10 times that under wild conditions in younger cohorts. Annual survival averaged 96%. Carapace length (CL) increased 6.95 mm yr-1, similar to that of free-living tortoises. Annual growth rates varied with calendar year (possibly reflecting food and water supply), age, cohort (year hatched), mother, and in 4 dry years, with crowding. Most of the first cohort grew to a releasable size (CL >100 mm) by their 9th year. Body condition indices remained high, indicating little dehydration despite droughts in 8 of the 11 years, because irrigation offered drinking opportunities. Head-started tortoises developed fully hardened shells (≥98% of adult shell hardness) earlier (10.1 vs. 11.6 yr), but at a larger CL (117 vs. 104 mm) than did free-living tortoises. Selective feeding in head-start pens decreased subsequent germination of favored wildflower species, apparently by reducing the natural seedbank. Consequently, we reseeded and irrigated each autumn to promote subsequent spring food supply. We irrigated in early summer to enable drinking and ensuing consumption of dry, dead plants and Bermuda grass hay, a supplement. These procedures can greatly improve juvenile survivorship, and increase numbers of hard-shelled, midsized juveniles to help augment wild populations.