Field Based Assessment of Clinical Signs of Irreversible Loss of Consciousness and Death Confirmed by Brain Destruction in Juvenile American Alligators (Alligator mississippiensis) After Penetrating Captive Bolt Stunning or Electrostunning with Probe Pithing.

To determine the humane use of slaughter methods we examined the clinical signs of life in 61 American alligators harvested on-farm using one of three methods: (i) captive bolt and spinal cord severance; (ii) electrostunning, spinal cord severance and pithing; and (iii) spinal cord severance and pithing. Loss of consciousness and the six clinical signs of life that can be used on-farm were assessed for evidence of irreversible unconsciousness and death at Time 0, 0.5, 1, 2, 5, 10, 20, and 30 min post slaughter. The brains of alligators from each slaughter method were removed to assess brain tissue disruption. A combination of loss of blink reflex, pupillary light response, jaw tone and respiration are a reliable on-farm tool for determining death. Heartbeat and withdrawal reflex persisted. Captive bolt and electrostunning methods were effective in immediately producing loss of response consistent with irreversible unconsciousness, subsequent death and destruction of neural tissue integrity in the mid and hind brain. They are therefore humane forms of slaughter in American alligators.

Extreme conditions reduce hatching success of green turtles (Chelonia mydas L.) at Karan Island, the major nesting site in the Arabian Gulf.

Survival in the early life stages is a major factor determining the growth and stability of wildlife populations. For sea turtles, nest location must provide favorable conditions to support embryonic development. Hatching success and incubation environment of green turtle eggs were examined in July 2019 at Karan Island, a major nesting site for the species in the Arabian Gulf. Mean hatching success averaged at 38.8 % (range = 2.5-75.0 %, n = 14). Eggs that suffered early embryonic death (EED) and late embryonic death (LED) represented 19.8 % (range: 3.3-64.2 %) and 41.4 % (range: 4.8-92.6 %) of the clutch on average, respectively. Nest sand was either coarse (0.5-1 mm: mean 44.8 %, range = 30.4-56.9 % by dry weight, n = 14) or medium (0.25-0.5 mm: mean 33.6 %, range = 12.0-45.5 % by dry weight, n = 14). Mean sand moisture (4.0 %, range = 3.2-4.9 %, n = 14) was at the lower margin for successful development. Hatching success was significantly higher in clutches with sand salinity <1500 EC.uS/cm (n = 5) than those above 2500 EC.uS/cm (n = 5). Mean clutch temperatures at 1200 h increased by an average of 5.4 °C during the 50-d post-oviposition from 31.2 °C to 36.6 °C. Embryos experienced lethally high temperatures in addition to impacts of other environmental factors (salinity, moisture, sand grain size), which was related to reduced hatching success. Conservation initiatives must consider the synergistic influence of the above parameters in formulating strategies to improve the overall resilience of the green turtle population in the Arabian Gulf to anthropogenic and climate change-related stressors.