Plasma cholinesterase activity: A benchmark for rapid detection of pesticide poisoning in an avian scavenger

Extreme temperatures impede the release success of captive-bred avian scavengers

“…Beyond the spatial heterogeneity among release sites, our findings of causes of morbidity and mortality in wild-born griffons were consistent with previous research of vulture populations worldwide (Ogada et al . 2012; Buechley & Şekercioğlu 2016; Anglister et al, 2023). Expectedly, poisoning (mainly pesticides, but also heavy metals and anti-inflammatory drugs) along with electrocutions and collisions with infrastructure were the main risks for wild-born griffons.…”

“…The griffons released at the Carmel and Golan were analyzed together as they were found at similar locations, and had similar fates. We used six categories for cause of death: (1) ‘Poisoning’ - including pesticides (mostly Choline-esterase inhibitors; see Anglister et al 2023), lead and veterinary drugs; (2) ‘Persecution’ – including gunshot; (3) ‘Infrastructure’ – which accounted for collisions with power lines and electrocution; (4) ‘Illness’ - griffons with signs of disease; (5) ‘Other’ – a small subset of mortalities from other identified factors such as bite wounds, dehydration, emaciation; and (6) ‘Unknown’ - cases with no confirmed cause of morbidity or mortality. To define the cause of death, several methods were employed, including x-rays to identify gunshot pellets (persecution), and fractures to indicate trauma (e.g., from infrastructure); blood or organs (liver, kidney, gut content) were analyzed for poisons (to identify poisoning, see Anglister et al, 2023); clinical/post-mortem hematology (including biochemistry and blood smears) as well as PCRs for pathogens (Newcastle disease virus, West Nile virus, and Avian influenza), and histopathology to identify the disease (illness).…”

“…(4) 'Illness' -griffons with signs of disease; (5) 'Other' -a small subset of mortalities from other identified factors such as bite wounds, dehydration, emaciation; and (6) 'Unknown' -cases with no confirmed cause of morbidity or mortality. To define the cause of death, several methods were employed, including x-rays to identify gunshot pellets (persecution), and fractures to indicate trauma (e.g., from infrastructure); blood or organs (liver, kidney, gut content) were analyzed for poisons (to identify poisoning, see Anglister et al, 2023); clinical/post-mortem hematology (including biochemistry and blood smears) as well as PCRs for pathogens (Newcastle disease virus, West Nile virus, and Avian influenza), and histopathology to identify the disease (illness).…”

“…The griffon population in Israel declined rapidly - from thousands of individuals a century ago, to approximately 500 individuals a couple of decades ago, to less than 200 individuals today. This decline is caused by poisonings, collision with infrastructure and electrocutions, habitat loss and low reproductive success rates (Mayrose et al, 2017; Choresh et al, 2019; Anglister et al, 2023). To address this decline, the Israeli Nature and Parks Authority (hereafter, INPA) runs an extensive management program, that includes: A.…”