Throughout the past decade, valuable strides have been made in the studies of tiger health and recovery. A major finding in tiger health research occurred in 2001, when WCS field veterinarians and molecular scientists were first to genetically characterize and discover the presence of canine distemper virus (CDV) in the rare Amur tiger (also known […]Read more...
Throughout the past decade, valuable strides have been made in the studies of tiger health and recovery. A major finding in tiger health research occurred in 2001, when WCS field veterinarians and molecular scientists were first to genetically characterize and discover the presence of canine distemper virus (CDV) in the rare Amur tiger (also known as the Siberian tiger). Now WCS teams are expanding their studies to better understand how the disease is spread to tigers and might impact the larger population.
Canine distemper virus is the second most common cause of infectious disease death in domestic dogs, but also poses a significant threat to endangered and non-endangered wildlife around the globe. With the pressures of habitat loss, poaching, depletion of prey species, and CDV, WCS scientists and conservationists remain tireless in their efforts to combat these risk factors and protect and grow the remaining tiger population.
It is now understood that canine distemper virus tragically causes abnormal behaviors among tigers before eventually killing them. This is a distressing realization because there are likely no more than 3,500 tigers left in the wild, and all of the living subspecies are currently listed as Endangered by the International Union for the Conservation of Nature. Specifically, the Amur tiger is among the most endangered cat species on the planet, with only 400-500 individuals left across their range in the Russian Far East and China.
Since the discovery of distemper among Amur tigers, WCS has participated in further studies to delve into various transmission scenarios and impact. One study involves extracting genetic information from archived tiger tissue as well as from a variety of species in their territory. These samples are being tested and compared with the intent of pinpointing the most likely sources of infection among wild tigers. This testing is crucial in understanding the risk that the virus represents to wild tigers and local communities, and in developing methods to managing this risk, such as through the design of targeted oral vaccination programs.
WCS also participated in a study which extrapolates known CDV metrics to the larger tiger population. While the illness has been shown to lead to the deaths of individual tigers, its long-term impacts on tiger populations had never before been studied. The authors evaluated impacts on the Amur tiger population in Russia’s Sikhote-Alin Biosphere Zapovednik (SABZ), where tiger numbers declined from 38 individuals to 9 in the years 2007 to 2012. In 2009 and 2010, six adult tigers died or disappeared from the reserve, and CDV was confirmed in two dead tigers—leading scientists to believe that the disease likely played a role in the overall decline of the population. Using models, scientists were able to simulate the effects of the infection on isolated tiger populations of various sizes through various transmission scenarios. The study found that smaller populations of tigers are more vulnerable to extinction by CDV. Populations consisting of 25 individuals were 1.65 times more likely to decline in the next 50 years when the distemper virus was present. This was an alarming finding given that more than half the world’s tigers in 2010 were limited to populations of less than 25 individuals.
The results are alarming, but will allow teams to plan conservation strategies that address the finding and design new conservation approaches.
While canine distemper virus has presented an additional concern in tiger repopulation efforts, WCS has seen great success in the reintroduction of orphaned and rehabilitated tiger cubs back into the wild. In the spring of 2014, five young tigers were released into the wilderness of the Russian Far East as part of WCS’s effort to recolonize lost Amur habitat.
As studies increase our knowledge of the threats facing tigers and reintroduction efforts show success there continues to be greater hope for the overall survival of the species.
MIAMI – A scientist at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is leading an upcoming international research campaign to study a significant contributor to regional climate warming – smoke. The first-of-its-kind research experiment begins on June 1, 2016 from Ascension Island in the southeastern Atlantic Ocean. The experiment, called […]Read more...
MIAMI – A scientist at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is leading an upcoming international research campaign to study a significant contributor to regional climate warming – smoke. The first-of-its-kind research experiment begins on June 1, 2016 from Ascension Island in the southeastern Atlantic Ocean. The experiment, called LASIC (Layered Atlantic Smoke Interactions with Clouds), is part of a broader international scientific collaboration led by the Atmospheric Radiation Measurement (ARM) Climate Research Facility deployment. The broad collaboration is detailed in a new article in the July Bulletin of the American Meteorological Society.
Southern Africa is the world’s largest emitter of smoke particles in the atmosphere, known as biomass-burning aerosols, from the burning of grasslands and other biomass. The project will help researchers better understand the effects of widespread biomass burning on Earth’s climate.
The study will investigate how smoke particles flowing far offshore from the African continent affect the remote and cloudy southeast Atlantic climate. Smoke, which absorbs sunlight, is a warming agent in the climate system when located above a bright surface, such as clouds. The smoke overlying the southeast Atlantic provides one of the largest aerosol-based warming of climate on the planet, since the region is also home to one of the largest low-cloud decks on the planet.
“Ascension Island is an ideal location since it is very remote and allows us to sample the smoke after it is well-aged, about which less is known,” said Paquita Zuidema, professor of atmospheric sciences at the UM Rosenstiel School and principal investigator of the research experiment. The long deployment time will allow us to characterize the marine low clouds both with and without the presence of smoke. This is ultimately valuable for understanding the Earth’s energy balance.”
By evaluating how the low clouds respond to the presence of sunlight-absorbing aerosols, scientists can better understand low cloud behavior, which is currently an uncertainty in model predictions of future climate, since no fundamental theory on low cloud processes is yet in place.
Low clouds dominate the atmosphere over the southeast Atlantic Ocean all year. Bright white cloud appears darker when viewed from above when smoke is present. The southeast Atlantic overall is brighter, not darker when smoke is present, suggesting that the clouds become thicker and more extensive when smoke is present.
Zuidema received a $365,050 seed grant from the U.S. Department of Energy to plan the study. And a $440,225 grant from NASA which further supports related aircraft investigations as part of the NASA Earth Venture Suborbital-2 ORACLES project.
NASA will complement the DOE surface-based measurements with airborne experiments during a month of each year in 2016-2018. This will allow researchers to take airborne samples of smoke particles as it ages, information that will improve satellite retrievals of this mixed smoke-cloud regime. The United Kingdom will also participate with its research aircraft, and French, Namibian, and South African scientists will collect and interpret aircraft and ground-based measurements closer to the Namibian coast.
The UM Rosenstiel School-led research team will study how smoke is transported through the atmosphere and across the Atlantic, how the aerosols change when transported, and the response of the low-lying clouds to the smoke. The information from the experiments will ultimately be used to improve global aerosol models and climate change forecasts.