Blanco J.M.,Aquila |
Blanco J.M.,U.S. Department of Agriculture |
Long J.A.,U.S. Department of Agriculture |
Gee G.,Patuxent Wildlife Research Center |
And 2 more authors.
Animal Reproduction Science | Year: 2011
A comparative approach was used to evaluate the cryosurvival of turkey and crane sperm frozen in a dimethylacetamide (DMA) cryodiluent supplemented with osmoprotectants and ATP. A range (6-26%) of DMA concentrations was used alone or in combination with ATP (30, 60 or 118. mM) or one of the following osmoprotectants: (1) sucrose (turkey, 8.0%; crane, 5.0%); (2) 5.0% sucrose and 5.0% trehalose; or (3) betaine hydrochloride (0.1, 0.2 or 0.4. mM). The viability of thawed sperm was assessed using the nigrosin-eosin stain and sperm motility was determined using the hanging-drop technique. For semen frozen only with DMA, post-thaw sperm motility was greatest (P< 0.05) for the 6.0%, 10.0% and 18% concentrations, regardless of species. Turkey sperm frozen with the sucrose/trehalose combination had greater (P< 0.05) post-thaw motility for all DMA treatments compared to DMA alone. The lowest concentration of the osmoprotectant betaine hydrochloride substantially improved turkey sperm viability post-thaw in all treatments compared to DMA alone (P< 0.05). The post-thaw motility of crane sperm was improved (P< 0.05) with a combination of 18.0%, 24.0% or 26.0% DMA and 30. mM ATP. Moreover, in the presence of osmoprotectants, crane sperm motility decreased as the osmoprotectant concentration increased. The lowest concentration of ATP also improved crane sperm viability post-thaw, especially for DMA concentrations 18% or greater. The combination of sucrose and trehalose improved (P< 0.05) crane sperm viability only with 6% and 10% DMA. These data affirm that there are avian-specific differences in sperm survival after cryopreservation and suggest that post-thaw survival can be enhanced by including species-based osmoprotectant/ATP combinations in a cryodiluent where DMA is the cryoprotectant. © 2010. Source
Blanco J.M.,Aquila |
Blanco J.M.,U.S. Department of Agriculture |
Long J.A.,U.S. Department of Agriculture |
Gee G.,Patuxent Wildlife Research Center |
And 2 more authors.
Animal Reproduction Science | Year: 2012
A comparative approach was used to evaluate semen cooling rates, thawing rates and freezing volume on the cryosurvival of avian sperm. Turkey (. Meleagris gallopavo) and sandhill crane (. Grus canadensis) sperm were cryopreserved with dimethylacetamide (DMA) concentrations ranging from 6% to 26%. Experiments evaluated the efficacy of (1) rapid, moderate and slow cooling rates, (2) rapid and slow thawing rates, and (3) final volume of semen frozen (0.2. mL compared to 0.5. mL). For crane sperm only, additional experiments were conducted to evaluate the effect of sucrose on cryosurvival. The functionality of frozen/thawed crane sperm was evaluated by fertility trials. For all studies, sperm viability was assessed using the nigrosin-eosin stain. Higher percentages of crane and turkey sperm maintained intact membranes when frozen with moderate or slow cooling rates compared to rapid cooling rates (. P<. 0.05), regardless of DMA concentration. Turkey sperm viability was not affected by thawing rate at any DMA concentration (. P>. 0.05). Crane sperm viability was only affected by thawing rate for the 24% DMA treatment, where moderate thawing was better than slow thawing (. P<. 0.05). Sperm viability was not affected by the semen volume used for freezing for either species (. P>. 0.05). The percentage of membrane-intact crane sperm at lower DMA concentrations was improved by addition of 0.1. M sucrose (. P<. 0.05) but not 0.29. M NaCl. The mean fertility rate from frozen/thawed crane semen was 57.5%, and 71.4% of the fertile eggs hatched. The viability of crane sperm was always greater than turkey sperm, regardless of cooling rate, thawing rate or volume of semen frozen. These data verify avian-specific differences in sperm cryosurvival, further emphasize the need for species specific studies to optimize cryopreservation protocols. © 2012. Source
News Article | March 14, 2016
Bill McShea broke into an infectious belly laugh when I ask him the question I’ve been posing to biologists, conservationists, and zookeepers for months: What is it about the panda? “Look at it,” he said, gesturing to snapshots of him jovially clutching baby pandas to his chest, which were tacked in his office at the Smithsonian Conservation Biology Institute in Front Royal, Virginia. “It’s cute as hell. You have to say, ‘Is that real? Does something really look like that?’” McShea, a rosy-cheeked, bespectacled research biologist, has spent the last two decades devoting part of his studies to pandas, including annual pilgrimages to China to study the species’s habitat and collaborate with local conservationists. If pressed, he’ll admit a deeper fascination with the lesser-known creatures that share the pandas’ habitat—the Asiatic black bear, the takin, the tufted deer—but McShea has no trouble identifying what it is about pandas that’s so appealing to everyone else. And you really only have to look at one photo, or video, or GIF of a panda to solve the mystery. With its round ears, fluffy fur, stub snout, tubby tummy, and those distinctive, big black polka dot eyes, it’s not hard to see why people around the world are enamoured. But there’s a growing group of dissenting voices who openly and actively hate pandas. Bill McShea at the SCBI in Front Royal, Virginia. Image: Derek Mead/Motherboard They resent that this creature’s adorable features have allowed it to take over so much of our conservation consciousness, vacuumed up so much funding, and eclipsed the plight of other endangered species. The effort to save giant pandas from extinction is an expensive, time-consuming, and difficult endeavour. It’s one that some in the field have argued isn’t even possible to achieve. “They’re vegetarian!” “They suck at sex!” “They only have one baby a year!” The panda is an “evolutionary dead-end,” they argue, one that ought to be left to die while we focus our efforts on more likely candidates for preservation. At its core, this debate is really an issue of conservation theory. We’ll never be able to rescue every species from the brink, so we’re left with a difficult question: How do we decide where to devote our time, attention, and money? Which species make the cut, and which ones are left to disappear into history? A species that struggles to breed and dwindled in the wild seems like an unlikely candidate, especially if its only qualification is being cartoonishly adorable. But when you actually dive into the ecological reality, the arguments for not putting effort into panda conservation don’t hold up. The advantages of saving a species people actually care about are numerous, including that species acting as an umbrella for less dynamic but equally threatened species, like those takin—a hearty, furry ox-like creature that is listed as vulnerable—that share the panda’s space. Whether you love them or hate them, when you take a close look at the issue, one thing becomes utterly clear: If we can’t save the panda, we can’t save anything. Before humans came along, pandas were doing just fine. Though the species was always elusive, the panda’s prehistoric habitat was vast. Panda fossils have been discovered across southeast Asia: in China, of course, but also in Myanmar, Vietnam, Laos, and Thailand. Even as China developed and its population grew, the giant panda’s habitat remained hearty into the 19th century, occupying a vast range that covered six provinces. But by the 1950s, the panda’s habitat and population numbers had diminished significantly due to population growth and expanded logging and agriculture. In the early 1960s, China started to pay attention to panda conservation. The government established its first panda reserves, outlawed hunting the animal, and successfully bred its first cub in captivity. At the same time, the Chinese government reignited its practice of gifting the rare bear to other countries as a sign of diplomacy. The country truly began to embrace the animal as a national symbol and prioritize its preservation. “The giant panda only exists in China,” McShea told me. “The Chinese are not different from a lot of other cultures in that they like things that are theirs and theirs alone. And giant pandas are theirs. It’s a great national symbol for them.” Unfortunately, the panda’s habitat of cool, mountainous bamboo forests shrunk further—by 50 percent from 1973 to 1984—due to continued deforestation and farming over the next two decades, even as the Chinese government opened more reserves. In 1984, the practice of giving away pandas was replaced with loaning bears to other nations to display at zoos, for a maximum of ten years at a time and with a hefty annual cost. That same year, the International Union for the Conservation of Nature moved the panda to an appendix I listing, prohibiting the international trade of the species for commercial reasons. By 2003, there were still only an estimated 1,596 pandas left in the wild, but efforts were beginning to pay off. Since the 1980s, the Chinese government has doubled down and invested significantly in panda conservation. The vast majority of captive pandas still live in China—only 50 live outside of the country—and now about 65 percent of the wild pandas’ remaining habitat is protected by the Chinese government (although it’s merely a sliver of the species’ historic range). Last year, we learned the wild population had grown 17 percent in the last decade. There are debates over the best way to estimate panda populations, such as measuring feces samples or tracking DNA, but scientists agree no matter how you tally it up, the wild population appears to be growing. Yet not everyone is as impressed by the cautious success of the global panda conservation effort. One reason: Although the Chinese government has invested significantly in the cause, it’s also benefitted greatly from it. Pandas are big business for China, which still owns every bear around the world. Zoos outside of China are only able to lease pandas, and it’s not cheap. Each zoo negotiates its own contract, so the fees vary. The Edinburgh Zoo reportedly pays about $850,000 to the Chinese government each year for its panda pair, while the National Zoo in DC forks over $500,000total per year for its four bears, according to a spokesperson. Elsewhere, panda pairs can go for as much as $1 million per year, with an additional one-time fee of about $200,000 for each cub born. Oh, and those cubs have to be sent back to China once they turn four. Bao Bao, born in captivity at the National Zoo, gets a fruit and ice "cake" to celebrate her second birthday. She will eventually go home to China to breed. Image: Jim and Pam Jenkins/Smithsonian's National Zoo “China now has a very profitable rental service for pandas all over the world,” said Ernest Small, a research scientist with the Canadian government who has written extensively on prioritization in conservation. “They’re exploiting this to the hilt and you have to admire them for it, but it’s not realistic to think of preserving them in the wild outside of very small preserves.” The fees paid by foreign zoos are ostensibly to support continued wild panda conservation efforts, but that hasn’t always been carefully monitored. In 1998, a lawsuit against US Fish and Wildlife Services over breeding-age captive pandas led to the development of a federal policy that dictates strict policies for any zoo wishing to bring in pandas. Zoos must prove that a significant portion of the fees they pay to China will directly benefit wild panda conservation, as well as show an active participation in research to advance captive breeding, habitat preservation, and reintroduction. But even with the stricter panda policy, not all of the money sent from US zoos to China for its panda loans is put toward conservation. A lot of funds raised for pandas also get eaten up by the cost of keeping pandas in zoos, which can tally upwards of $1 million per year—the National Zoo spends $3.6 million on its panda program annually. These dollars and even the money that is put toward conservation, some argue, could be put to much better use. Ever since we marveled at Mei-Mei and Mei-Ian, America’s first breeding pair of pandas, fumble around and fail to get it on back in the 1940s, we’ve been amused by the giant panda’s apparent ineptitude in the bedroom. We’ve wondered at the female panda’s uniquely narrow reproductive window—they’re only able to conceive once a year, for a period of about 30 to 48 hours. We’ve learned that female pandas can have fake pregnancies. We watched multiple panda couples flail about and fight instead of copulating. Much captive breeding is done through artificial insemination, and even then we’ve seen the death of more than one newborn cub. Newborn cubs are very fragile, like this cub, one of a pair born this summer at the National Zoo. One cub died within a week, the other survived. Image: Pamela Baker-Masson/Smithsonian's National Zoo In this context, it really makes it seem like pandas are terrible at reproducing. And that makes dissenters argue that we ought not bother trying. “Their breeding habits don't suggest a species brimming with vitality,” journalist Timothy Lavin wrote in a column for Bloomberg entitled “Why I Hate Pandas and You Should Too.” “Females only ovulate for a few days each year, and if a mother does manage to have more than one cub, she abandons the weakling. That's fine; nature's mean. But don't whine when a species with such habits falls into inexorable decline.” The trouble with this argument is that it’s based on a misunderstanding, according to David Wildt, head of the SCBI’s Center for Species Survival. If pandas were such poor breeders, it’s unlikely the species would have survived as long as it did before humans started chopping down its habitat. And in the wild, pandas don’t particularly struggle to reproduce at all. The difficulty with natural breeding in captivity is that we’re limited to just two animals, and that’s not the way nature works. In the wild, a female panda will attract lots of males, who will fight it out for the chance to mate with her. She might even mate with multiple partners in one ovulation period, Wildt explained. “This concept that they’re evolutionary dead-ends is just a fallacy,” Wildt said. “They’ve survived even though they’re only sexually receptive for 72 hours a year. I’m a reproductive biologist. I’ve been doing this since 1972. I don’t know another animal that actually reproduces like that. So I think they’re exquisitely successful because they devote very little of their energy to sex but when they mate, they not only have a baby, frequently they’ll have twins.” Lackluster libido isn’t the only criticism lobbed at pandas. Many conservationists have questioned whether the entire endeavor is in vain when you consider how much the panda’s habitat has shrunk. Even with China’s dedication to protecting land, the species’s habitat is a shadow of its historic range. Currently, wild pandas are limited to just 20 pockets of bamboo forest that dot six mountain ranges in China’s Sichuan, Shaanxi, and Gansu provinces. Those small groups of pandas average at about 50 bears, making them extremely vulnerable to environmental stressors like the mass bamboo die-offs that occur periodically. And because the habitats aren’t connected, those populations can’t merge. Even if the panda had a much larger habitat restored, part of the goal of captive breeding is to eventually reintroduce bears into the wild, an effort that so far has been unsuccessful. In 2006, China released a captive-born giant panda back into the wild, only to see it die a year later after falling from a tree following a fight with other pandas. But conservationists learned a lot from the first attempt to reintroduce a captive-bred panda, and future attempts will need to take place in areas that aren’t already the territory of wild bears. To make that happen, more habitat needs to be carved out, and those islands of bamboo forest need to be connected. So that’s what they’re planning to do. Conservationists are surveying possible corridors that could be protected to join the scattered panda reserves, expanding the effective area and providing new options for releasing captive-bred bears. Still, all the optimistic outlooks in the world aren’t enough for some skeptics who question whether decades of research and hundreds of millions of dollars are worth it to try to save a species with a population that still sits at fewer than 2,000. It raises the question: Were the last four decades and mountains of cash worth it for a few thousand bears? “Maybe if we took all the cash we spend on pandas and just bought rainforest with it, we might be doing a better job,” wrote naturalist Chris Peckham in a column in The Guardian. “I'm not trying to play God; I'm playing God's accountant. I'm saying we won't be able to save it all, so let's do the best we can.” In his argument, Peckham is cutting to the heart of the matter. For all the chatter about breeding habits and failed reintroduction attempts, the true debate circles around a question of conservation strategy. In an ideal scenario, we could protect all endangered species from slipping away. In a slightly-less-ideal scenario, we could approach the problem like one of economics: Where will we get the most bang for our buck? “It’s just benefit divided by cost, which is what you would do if you were buying rice,” said Hugh Possingham, a professor of mathematics and ecology at the University of Queensland. “It’s about as profound as grade three maths.” Possingham helped create a mathematical approach to conservation funding allocation that calculates the benefits, costs, and likelihood of success for conserving different species, while allowing the calculator to weigh the benefits however they see fit. A species could be deemed particularly beneficial because it is a key ingredient in the local ecosystem, or because it’s a pollinator for food, or because it’s the last of its genus. This approach was adopted by the New Zealand Department of Conservation to tackle its list of about 700 at-risk endemic species, and it proved extremely effective. New Zealand estimated it can now save 2.5 times as many species as it once could, Possingham said. This logical strategy still isn’t widely used, but it’s gaining more and more attention, especially from politicians looking to balance budgets, Possingham said, adding that the US Fish and Wildlife Services recently started inquiring about the idea. But as rational as this approach is, when it comes to donating money for conservation efforts, humans are famously irrational. “When you think of the panda, it’s just so absolutely representative of all of the features that people fall in love with as soon as they see it,” said Small. “All experienced conservationists and organizations do understand that, in the final analysis, you must get public support to get funds from politicians. In the practical world, I don’t really see another way that’s nearly as effective at getting the public’s sympathy than the panda and all the other iconic animals. They’re absolutely essential.” Even the New Zealand conservation effort plucked out 11 iconic species such as the kiwi that, regardless of their ranking, were added to the list of priorities. Even when you’re practising prudence, you need some wiggle room for the animals that capture our hearts. People love pandas, and they’re willing to pay for it. It’s difficult to rank specifically, but the panda undeniably attracts more direct conservation dollars than almost any other endangered species. At the National Zoo, at least 80 percent of all attendees to the zoo visit the panda exhibit, a spokesperson told me. A single donor gave the zoo $4.5 million last year solely for the pandas. The WWF, which uses the panda almost exclusively in its marketing—its logo is even a panda—drew in more than $98 million in individual donations last year. And for those who don’t have extra cash, they happily donate their time. “We do basic behavior watch studies on pandas and our volunteers record data for us by monitoring our webcams,” Laurie Thompson, the National Zoo’s panda biologist, said. “People love pandas, so it’s not hard to find people to sit there and watch them on the camera for hours to see if they move.” The somewhat sad reality is that people might not be so willing to part with their money or time for a species like the takin. It also happens to live in the panda’s habitat. In fact, the panda’s protected habitat overlaps with dozens of other species that are also in need of protection, according to a study published in Conservation Biology last year. The study authors found that 96 percent of the panda’s reserves overlap with key conservation areas for other endemic species—70 percent of China’s forest-dwelling mammals, 70 percent of its forest birds, and 31 percent of its forest amphibians live in the same area as the panda. Protecting the panda helps protect them all, and there’s little evidence these species would be paid any heed if the panda had been left to go extinct. A takin, one of the species that partially lives in the panda's protected habitat. Image: Lucy Takakura/Flickr “There was nothing to take away [by focusing on pandas],” McShea told me. “So, yes, everyone is obsessed with giant pandas, but look at all the other stuff that’s coming along for the ride. You set up a giant panda reserve, and there are 10 other great species living in the same reserve that are now getting protection that they wouldn’t have gotten without the giant panda. I see the giant panda as the first step in developing a conservation ethic and a sense of biodiversity and sense of preserving nature.” Last December, a five-month-old panda cub named Bei Bei made his media debut. Reporters gathered around, snapping photos and rolling film, as a keeper cradled the pudgy bundle of fur in her arms and placed him on a table. He then promptly fell asleep. Of course, it didn’t matter. A sleeping baby panda is as cute as a rolling baby panda or an eating baby panda. The debut—which consisted of a short question-and-answer period with Thompson, a weigh-in, and the nap—was covered by multiple media outlets. It’s understandable why conservationists get frustrated by our obsession with pandas. There are reams of species that are disregarded and vanishing before our eyes. Nature is brutal, and species have emerged and disappeared throughout the history of the Earth without humans to blame. But many researchers believe we’re currently in the middle of a mass extinction event, one that’s seeing species wiped out at 50 times the normal extinction rate. Why are we seemingly wasting so much time on one chubby bear? But when you look at the challenges of conservation, the success of the panda program, and the utter devotion people give to these animals, it becomes harder to argue against. If there’s any species on this planet we ought to be able to save, it’s the panda. If we can’t even restore a species beloved worldwide, we don’t have very much hope for the takins of the Earth.
Comizzoli P.,Center for Species Survival |
Songsasen N.,Smithsonians National Zoological Park |
Wildt D.E.,Center for Species Survival
Cancer Treatment and Research | Year: 2010
Sustaining viable populations of any wildlife species requires a combination of adequate habitat protection and a good understanding of environmental and biological factors (including reproductive mechanisms) that ensure species survival. Thousands of species are under threat of extinction due to habitat loss/degradation, over-exploitation, pollution, disease, alien species invasions and urban sprawl. This has served as incentive for intensive management of animal populations, both ex situ (in captivity) and in situ (living in nature). Assisted reproductive technologies developed for addressing human infertility and enhancing livestock production have shown encouraging promise in a few wildlife species. However, species-specific physiological variations and a lack of fundamental knowledge have limited how these tools can be used to help rapidly re-build endangered species numbers. Despite limitations, there is enormous potential in applying human-related fertility preservation strategies to wild animals, especially approaches that could assist managing or 'rescuing' the genomes of genetically valuable individuals. Indeed, one of the highest priorities in wildlife ex situ management is sustaining all existing genetic diversity to (1) preserve heterozygosity to avoid inbreeding depression and (2) ensure species integrity and the persistence of genomic adaptability to environmental changes. There are components of the rapidly emerging field of oncofertility in women that are highly compatible with preserving valuable genomes of individuals or populations of threatened wildlife. Strategies associated with ovarian tissue cryopreservation and follicle in vitro culture are especially attractive for protecting and extending fertility for wild females. Given adequate attention and more basic studies, we predict that these approaches could assist in the intensive and practical management of gene diversity in endangered species. © 2010 Springer Science+Business Media, LLC. Source
Terrell K.A.,Center for Species Survival |
Quintero R.P.,Smithsonian Conservation Biology Institute |
Murray S.,Smithsonian Conservation Biology Institute |
Kleopfer J.D.,801 John Tyler Highway |
And 4 more authors.
Journal of Experimental Biology | Year: 2013
Ectothermic species living in temperate regions can experience rapid and potentially stressful changes in body temperature driven by abrupt weather changes. Yet, among amphibians, the physiological impacts of short-term temperature variation are largely unknown. Using an ex situ population of Cryptobranchus alleganiensis, an aquatic North American salamander, we tested the hypothesis that naturally occurring periods of temperature variation negatively impact amphibian health, either through direct effects on immune function or by increasing physiological stress. We exposed captive salamanders to repeated cycles of temperature fluctuations recorded in the population's natal stream and evaluated behavioral and physiological responses, including plasma complement activity (i.e. bacteria killing) against Pseudomonas aeruginosa, Escherichia coli and Aeromonas hydrophila. The best-fit model (ΔAICc=0, wi=0.9992) revealed 70% greater P. aeruginosa killing after exposure to variable temperatures and no evidence of thermal acclimation. The same model predicted 50% increased E. coli killing, but had weaker support (ΔAICc=1.8, wi=0.2882). In contrast, plasma defenses were ineffective against A. hydrophila, and other health indicators (leukocyte ratios, growth rates and behavioral patterns) were maintained at baseline values. Our data suggest that amphibians can tolerate, and even benefit from, natural patterns of rapid warming/cooling. Specifically, temperature variation can elicit increased activity of the innate immune system. This immune response may be adaptive in an unpredictable environment, and is undetectable by conventional health indicators (and hence considered cryptic). Our findings highlight the need to consider naturalistic patterns of temperature variation when predicting species' susceptibility to climate change. © 2013. Published by The Company of Biologists Ltd. Source