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Biology subjects

Anglister, N.

Publications and source records attributed to Anglister, N..

2 recordsLinked to original sources

Factors affecting the individual probability of infection with a prevalent pathogen (Mycoplasma) and the effect on Griffon vultures' movement behavior

Mycoplasmas are known as commensals and pathogenic bacteria of various raptor species causing clinical or subclinical infections. However, little is known about the prevalence of mycoplasma in captive and wild raptors and its significance to their health. In Israel, the Griffon vulture (Gyps fulvus; hereafter Griffons) is considered critically endangered, and its intensive management program includes population monitoring and restocking (captive-born or imported rehabilitated wild Spanish Griffons). Here we survey the prevalence of Mycoplasma species in both the wild and captive populations. During 2019-2020, we collected 244 tracheal swab samples from 167 unique individuals. We used PCR analysis to identify Mycoplasma species. First, we identified nine spp., including species not yet described in Israel or for Griffon vultures. Second, imported Griffons showed a higher prevalence and a different diversity of species in comparison to the local ones, suggesting that at least one Mycoplasma species (Sp 18b) was introduced into the native population. Third, juvenile Griffons had a higher prevalence, different species composition, and stronger reduction in movement compared to adults, confirming the susceptibility of this group to mycoplasma infections. GPS-tracking of 60 free-ranging individuals showed that even in the absence of apparent clinical signs, Griffons infected with mycoplasma, and especially sub-adults flew less (shorter distances and periods). These findings underscore the importance of considering potential pathogen introductions in population reinforcement and reintroduction initiatives, providing valuable insights for similar conservation programs globally. Further, they demonstrate the potential of long-term tracking for detecting subclinical effects that are unnoticeable in clinical examination.

ecology↗

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

Conservation translocations (reinforcements and reintroductions) are central for managing various endangered species, yet, their implementation is logistically and financially challenging. Because many translocations fail due to the mortality of released individuals, identifying and preventing these factors is crucial. Here we examine risk factors affecting the post-release survival of the Griffon vulture (Gyps fulvus). The Israeli population is facing extinction, and the recovery efforts by the local Nature and Parks Authority include supplemental releases of individuals from captive-breeding or rehabilitated birds (mostly imported from Spain). We use GPS tracking and thermometers to compare movement, behavior, and weather conditions experienced by released and wild-born individuals active in the same area and time. Our results show that the Judean Desert release site had a significantly lower survival rate than other release sites included in the program. After excluding several possible factors (e.g. known pathogens) with pathological examinations, we found that released individuals at this area were exposed to higher temperatures preceding their death (compared to wild-born griffons nearby), suggesting heat stress as the cause of death. Arguably, they failed to avoid the harsh environmental conditions, resulting in overheating due to their inexperience and undeveloped flight ability, as reflected by their lower probabilities of flying and shorter travel distances per day compared to wild-born vultures. These findings have led to adjustments of the local release protocol, (namely winter releases) resulting in a significant improvement in the early survival of translocated Griffons in the Judean Desert. Accounting for the harmful effects of extreme weather conditions is particularly important in a world facing climate change. More broadly, this sequence of scientific investigation with data integration from ecological, clinical, and biotelemetry sources, leading to improvement in translocation success demonstrates how conservation practices can be optimized by supporting studies to ensure the survival of endangered species in the wild.

ecology↗