Outbreaks of emerging infectious diseases in wildlife have intensified in recent years. Combined with other stressors, wildlife mortality from disease can cause serious conservation challenges, and threaten food security, livelihoods and economies. Wildlife diseases can impact production, companion animal, and human health, with the majority of animal diseases transmissible to humans originating in wildlife. Robust national wildlife health surveillance systems are an invaluable tool to identify threats and act as early warning systems with benefits for conservation, people, and livestock. WCS's WildHealthNet project is supporting the governments of Vietnam, Laos, and Cambodia to build sustainable wildlife surveillance platforms with a One Health approach. The networks have already facilitated the rapid detection and response to avian influenza and African swine fever outbreaks. Greater investment in wildlife health should accompany vital efforts to combat deforestation, forest degradation, and wildlife trade, and reverse the devastating trajectory of human-driven biological degradation that is driving the increased emergence of wildlife and human diseases.
The Cayman Blue Iguana, while still endangered, is a conservation success story. Devastated by predation and habitat loss, the species was considered functionally extinct in 2002, when only 5-15 individuals remained in the wild. Thanks to a captive-breeding program, supported for the past two decades by the WCS Zoological Health Program, the population has rebounded, with the 1000th iguana released into the wild in 2018, and natural breeding occurring. From 2015-2017 conservation efforts suffered a setback when iguanas began dying from an unknown cause. Investigations by WCS and partners identified a novel Helicobacter species as the likely disease causing agent. Further screening detected the same Helicobacter sp. from clinically normal, invasive green iguanas sharing the same habitat, suggesting they could be asymptomatic carriers and a potential source of the pathogen.
Wildlife forensics provides scientific evidence to support investigations of crimes against wildlife and help secure convictions. Determining the identity of traded wildlife products, establishing the species, geographic origin, relatedness, and individual identity can be key to proving that a crime has taken place, and to establish links between the animal, scene, trade chains, and suspects. Species identification through DNA sequencing is routinely used. Newer high-throughput DNA sequencing approaches can generate millions of reads in a single experiment but are prohibitively expensive for many resource-limited countries tackling wildlife crimes. WCS and partners recently demonstrated that a more affordable, portable technology can provide rapid, reliable DNA sequencing of wildlife. Already proven valuable for disease detection, the hand-held Oxford Nanopore MinION device could be a game-changer for wildlife forensics in the field.
'Condor' is the common name for two species of vultures; the largest flying land birds in the Western Hemisphere. In Peru, WCS veterinarians recently facilitated the rescue and rehabilitation of a poisoned Andean condor. Vultures are the most threatened group of birds in the world, primarily due to poisoning. Vultures often become unintended victims through feeding on carcasses contaminated with certain veterinary drugs (e.g. diclofenac), fertilizers, and pesticides, sometimes used to poison wild carnivores in retaliation for livestock predation. Whilst they may not be the most beautiful of birds, vultures fulfill essential roles in protecting human and ecosystem health, preventing the spread of disease, regulating scavenger populations, and spreading nutrients across landscapes.
In addition to being responsible for the health of more than 16,000 fish, amphibians, reptiles, birds, and mammals of over 1,000 species at WCS's five New York City facilities—the Bronx Zoo, New York Aquarium, and the Central Park, Queens, and Prospect Park Zoos, WCS’ Zoological Health Program also assists multiple city, state and national authorities and agencies by caring for sick or injured native wildlife, and wildlife confiscated from illegal trade. From May 2020 to April 2021, through the midst of the COVID-19 pandemic, the dedicated staff of the Wildlife Health Center cared for 16 wildlife admissions and 56 confiscated animals, including the ornate uromastyx (Uromastyx ornata ornata), pictured above, that was part of a United States Fish and Wildlife confiscation.
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The Wildlife Conservation Society was among the first zoos in the world to have full-time veterinary care for their animals, with a clinician and pathologist hired in 1903 and a zoo animal hospital opening at the Bronx Zoo in 1916. We were also one of the first conservation organizations with a dedicated team of wildlife veterinarians deployed around the world to address the health of free-ranging wildlife and problem-solve at the wildlife / domestic animal / human health and livelihoods interface, all underpinned by a foundation of environmental stewardship.

To learn how to support the One World - One Health portfolio at WCS, please contact Dr. Chris Walzer at cwalzer@wcs.org or Dr. Paul Calle at pcalle@wcs.org.

Photo Credits: Bat sampling in Vietnam © WCS; Cayman blue iguana © Julie Larsen Maher/WCS; Sharkfins in Indonesian trade © WCS; Andean condor © Fondacion Neotropical; Uromastyx © WCS