News Article | August 31, 2016
As conservationists work to recover endangered species populations, taking individuals that are maintained and protected under human care and reintroducing them into the wild, it becomes apparent that there is a great deal to learn about the science of species recovery. In a paper published in the recent edition of the Journal of Applied Ecology, a team of wildlife experts from San Diego Zoo Global, the U.S. Geological Survey, the U.S. Fish and Wildlife Service and the University of Nevada analyzed the effect of habitat quality on the survival and dispersal of released desert tortoises. Juvenile tortoises used in this study originated from eggs produced by females housed at the Desert Tortoise Conservation Center in Las Vegas. Ages ranged from 6 months to 4 years. The tortoises were translocated and monitored for one year, using radio tracking systems. "The goals of the study were to help re-establish populations of this threatened and declining species, and to understand better what critical resources on the landscape are associated with the ability of young tortoises to survive and thrive," said Ron Swaisgood, Ph.D., director of Applied Animal Ecology at San Diego Zoo Global. Tortoises released in habitat that included appropriate vegetation, rocks and the presence of animal burrows had lower mortality rates than those released in areas where land features offered fewer options for predator avoidance. "Burrows created by small mammals represent critical components of desert tortoise ecology," said Melia Nafus, Ph.D., a researcher for San Diego Zoo Global and lead author of the study. "Supporting healthy rodent populations through habitat management may improve juvenile desert tortoise survival and recruitment." Another interesting finding of the study was that tortoises released on rocky ground were less likely to disperse away from the release site. "This finding probably relates to the tortoise's dependence on rocky substrate, as camouflage to hide from predators," said tortoise expert and co-author Todd Esque, Ph.D., from the U.S. Geological Survey. "The U.S. Fish and Wildlife Service encourages research such as this because it provides vital knowledge that informs our policy and management decisions," stated study co-author Roy Averill-Murray, who heads the service's Desert Tortoise Recovery Office. "Now, we have better information when deciding which habitats to protect for desert tortoises, and where to attempt re-establishment of desert tortoise populations with future releases." Translocation of individuals back to the wild is one of many important tools that conservation biologists use to recover endangered and threatened species. "We view these translocations as a way to learn more about animals' habitat requirements, while also assisting directly with species recovery goals," said Ron Swaisgood.
News Article | September 13, 2016
A study, by San Diego Zoo Global conservationists, released this week (Sept. 12, 2016) is shedding new light on how scientists evaluate polar bear diet and weight loss during their fasting season. On average, a polar bear loses up to 30 percent of its total body mass while fasting during the open-water season. Although some scientists previously believed land-based foods could supplement the bears' nutritional needs until the sea ice returns, a new study published in the scientific journal Physiological and Biochemical Zoology has revealed that access to terrestrial food is not sufficient to reduce the rate of body mass loss for fasting polar bears. The study—undertaken by Manitoba Sustainable Development, the University of Alberta, and Environment and Climate Change Canada—weighed polar bears that were detained in the Polar Bear Holding Facility in Churchill, Manitoba, Canada from 2009 to 2014. Polar bears were kept in this facility as part of the Polar Bear Alert Program, which aims to reduce conflict between humans and polar bears around the town of Churchill. To prevent habituation, polar bears are not fed while in the facility, which allowed for a controlled measure of their weight loss. On average, polar bears lost 2.2 pounds (1 kilogram) of mass per day—exactly the same amount as free-ranging bears measured during the ice-free season on the coastline of Hudson Bay. Scientists reported that even with land-based food opportunities, polar bears lost the same amount of weight. "Some studies have suggested that polar bears could adapt to land-based foods to offset the missing calories during a shortened hunting period on the ice," said Nicholas Pilfold, Ph. D., lead author of the study and a postdoctoral associate in Applied Animal Ecology at San Diego Zoo Global. "Yet, our results contradict this, as unfed polar bears in our study lost mass at the same rate as free-ranging bears that had access to land-based food." Researchers also estimated starvation timelines for adult males and subadults, and found that subadults were more likely to starve before their adult counterparts. "Subadult polar bears have lower fat stores, and the added energy demands associated with growth," said Pilfold, "Future reductions to on-ice hunting opportunities due to sea ice loss will affect the younger polar bears first—especially given that these bears are less-experienced hunters." Today, it is estimated that there are approximately 26,000 polar bears throughout the Arctic. The Western Hudson Bay subpopulation of polar bears is currently stable, as the length of the ice-free season has shown recent short-term stability. However, past increases in the length of the ice-free season have caused declines in the number of bears, with subadults having a higher mortality rate than adults. The current research helps to shed light on the mechanisms of past population declines, as well as to provide an indication of what may occur if sea ice declines again. For nearly a decade, San Diego Zoo Global's researchers and its U.S. and Canadian partners have focused on developing conservation strategies to boost wild populations of polar bears. At the San Diego Zoo, polar bears "collaborated" with researchers at the U.S. Geological Survey in Alaska by wearing an accelerometer collar to track their movements. The data gained from accelerometers on collared polar bears—at the Zoo and in the Arctic— will provide scientists with new insights into the bears' daily behavior, movements and energy needs, and a better understanding of the effects of climate change on polar bears. Bringing species back from the brink of extinction is the goal of San Diego Zoo Global. As a leader in conservation, the work of San Diego Zoo Global includes on-site wildlife conservation efforts (representing both plants and animals) at the San Diego Zoo, San Diego Zoo Safari Park, and San Diego Zoo Institute for Conservation Research, as well as international field programs on six continents. The work of these entities is inspiring children through the San Diego Zoo Kids network, reaching out through the internet and in children's hospitals nationwide. The work of San Diego Zoo Global is made possible by the San Diego Zoo Global Wildlife Conservancy and is supported in part by the Foundation of San Diego Zoo Global. Explore further: Arctic conditions may become critical for polar bears by end of 21st century
News Article | August 29, 2016
Wildlife trafficking is the fourth largest black market in the world (behind drugs, weapons and human trafficking) with the total trade worth $19 billion a year. The affect on the targeted animal species has been horrific. It's estimated that 100 elephants are poached every day for their tusks and more than 1,000 rhinos are killed every year for their horns, meaning both could be extinct within the next decade or two. Other animals like tigers, snakes, pangolins and turtles have suffered major population loss thanks to poaching for their skins, hides, bile and more. While there are wonderful organizations doing what they can to crack down on the poaching and selling of these animals, there are many people like you and me who want to contribute to the fight, too. Australia’s Taronga Zoo and TRAFFIC, the international wildlife trade monitoring network have created an app that lets us do our part. Called Wildlife Witness, the app lets users submit information and photos of any suspected hunting, trapping or selling of endangered animals by pinning the incident to a virtual map. The submission then gets forwarded to wildlife authorities who will investigate it. The app basically lets wildlife authorities increase the eyes and ears they have watching and listening for these crimes. Anyone who travels to Southeast Asia and Australia, where wildlife trafficking is a huge problem, can lend their senses and their smartphones to the cause. The app is being promoted in the U.S. by the San Diego Zoo Global, informing people who visit zoos about the problem and what they can do to help when they travel. "It’s an app for people to have an action component to conservation right in their back pocket," says Suzanne Hall, a research coordinator with the San Diego Zoo’s Institute for Conservation Research to FastCoExist. "We want to make everyone aware that this is out there so that when you travel you can participate in trying to put an end to wildlife crime." The app was released in May and has already had over 1,000 reports of suspicious activity that are being used by officials to create a map of trading hotspots. There has been action taken against at least 500 people thanks to tips from the app. The app actually helped authorities realize that a particular animal that they hadn't been watching out for, the robust earless monitor lizard, was becoming a popular species in the trade. The reptile is protected in its home of Malaysia. The app educates people as well as letting them make reports. There is a tab that explains the animals typically targeted and what to look out for and a way to see if other users are reporting crimes in the same area. If criminal activity is seen, users can click "Make a Report" and then choose from a drop-down list of options like endangered animals on a restaurant menu, illegal animal products in a store or the viewing of a wildlife crime in action. The report is then geo-tagged so that investigators know exactly where to go. The San Diego Zoo hopes to have a U.S. version of the app soon as well to help crack down on poaching and the trading of illegal wildlife items in the states and to help travelers keep an eye out when they're abroad. The app is available for free through the Apple App Store and the Google Play store.
News Article | September 14, 2016
The use of statistical methods to predetermine sample sizes was not necessary: in the main experiment, all healthy individuals of the world’s ‘Alalā population were tested, and all other experiments (as detailed below) likewise attempted to maximise sample sizes. Randomization procedures were used to establish the order in which subjects were observed in some experiments (as detailed below), and the order in which all video files were analysed; all videos for the assessment of inter-observer agreement were randomly selected. For some video analyses (as detailed below), scorers were hypothesis naive. ‘Alalā were studied in two captive breeding facilities operated by San Diego Zoo Global. With the species considered extinct in the wild11, 30, the world’s population consisted of 109 individuals (58 males; 51 females) in early 2013, with: 64 birds housed at the Keauhou Bird Conservation Center (KBCC), Hawai‘i Island; 44 birds at the Maui Bird Conservation Center (MBCC), Maui; and a single individual off-exhibit at San Diego Zoo Safari Park, California. The captive stock originated from a few founder individuals that had been collected from the wild since the 1970s, as described in detail elsewhere11, 29, 30, 31, 32. All birds available for testing in our study (referred to throughout by their studbook numbers) were of known ancestry, sex (determined through genetic analysis of blood samples33) and age, and had been reared in captivity (Fig. 2b). Male #67 had hatched from one of the last eggs laid by a wild pair, and three other subjects (#77, #78, #86) had temporarily lived in the wild (they had been released in the late 1990s, but were later returned to captivity30). Adult birds were kept as breeding pairs, or sometimes as singletons, and immature birds were housed in groups of up to eight individuals, to facilitate their socialization34. All aviaries at the two main facilities are multi-chambered, spacious outdoor enclosures (varying in size from ~3.0 × 6.0 × 3.7 m to 7.3 × 17.0 × 5.5 m), which are open to the elements, but have a roofed section for shelter. At the KBCC (purpose-built in 1996), the ground is covered in lava stones, with patches of live vegetation, while at the MBCC (repurposed building in use since 1986, with later extensions), some aviaries have concrete flooring. Standard fittings include a variety of branches and ropes for perching, a nesting platform, and a large water bath. All birds have access to cut vegetation (‘browse’) and sticks year-round, and pairs receive supplies of assorted nesting material during the breeding season. Enrichment protocols have changed over the years and varied slightly between facilities. Initially, all enrichment given to ‘Alalā was made of natural materials (for example, fresh browse, and logs of deadwood), but this was supplemented with artificial items (for example, food hidden inside dog toys, or wrapped in newspaper) from 2008 at the KBCC (and at the latest from 1999 onwards at the MBCC); a human-imprinted male (#35) was given artificial items as early as 2000. Food items were hidden in holes and crevices in wooden logs, or tossed into water baths, intermittently since at least 1997, and about once or twice a week since 2004, at the KBCC (since 1999 at the MBCC), and baited PVC tubes were presented from late 2012 onwards (since 2007 at MBCC). While this enrichment provided opportunities for tool use, in the vast majority of cases bait could also be obtained by bill alone, in contrast to the extraction tasks of our formal behavioural assay (see below). Importantly, to the best of our knowledge, the use of tools to extract hidden food was never demonstrated to birds at either facility. We conducted a species-wide assay of tool-use competence, using a standardized food-extraction task set (see below). Following pilot experiments with two subjects (female #94, and her son #134) in August 2012 and January 2013, we tested all healthy birds in both facilities between 23 January and 27 February 2013. With five birds excluded from experiments a priori for medical reasons, and one male tested later in the year (#67; tool use confirmed on 31 August 2013), our final sample comprised 104 subjects, which was over 95% of the world’s ‘Alalā population at the time (see Fig. 2b). As we effectively tested an entire species, it was not necessary to use inferential statistics to support findings. The experimental set-up consisted of (Extended Data Fig. 2a): a Koa Acacia koa log containing four drilled holes and two crevices, each baited with a quarter of a neonate mouse (or other preferred food in early trials at KBCC); 12 sticks of varying lengths as potential tools scattered in front of the log; and assorted native plant materials (KBCC), or two dead branched stems (MBCC; native materials not readily available), from which tools could be manufactured, wedged firmly into a wooden board to stand upright (for further details, see Extended Data Fig. 2a). The four different types of extraction task were designed to resemble foraging problems New Caledonian crows regularly solve with tools in the wild2, 4, 23. At both facilities, we used the same two near-identical logs to run trials in parallel. Encouraged by earlier anecdotal observations during routine enrichment sessions (Supplementary Video 4), we usually also placed a piece of mouse head in the aviary’s water bath, to see whether the subject(s) would fish it out with a stick; this complementary task proved useful, as it often attracted birds’ attention, and confirmed tool-use behaviour in one female (#95) that failed to engage with the main log set-up. Trials were scheduled to last for ~1.0–1.5 h, but were terminated earlier on a few occasions at the start of the study, while the test protocol was being established (n = 6 trials), or when all bait had been extracted (n = 24), cameras failed (n = 2) or due to experimenter error (n = 1). Food bowls were usually removed shortly before trials commenced, but birds sometimes found food scraps in their aviaries, and always had ad libitum access to water. An experimenter placed the fully-baited experimental log and the board with plant materials on the ground, before scattering the sticks underneath a large cotton sheet, out of view of the subject(s). Before the experimenter removed the sheet and left the aviary, several small food items were conspicuously placed on top of the log, to encourage approach and exploration of the set-up, and the water bath was baited (see above). At the KBCC, birds could be filmed with experimenter-operated video cameras through tinted or one-way-mirror observation windows, while at the MBCC, all trials had to be filmed with static video cameras hidden inside a rainproof box, placed ~1.5–3.0 m away from the experimental set-up. Subjects were temporarily isolated for individual testing (n = 83 birds), but we also ran some trials with pairs early on in the study (n = 3 birds) and some with larger groups where isolation was impossible owing to aviary layout (n = 18 birds). For logistical and ethical reasons, birds remained in visual contact with other ‘Alalā in adjacent chambers even when tested individually. Subjects that did not show tool-related behaviours in their first trial were re-tested for varying amounts of time (Fig. 2f). Immature ‘Alalā are usually housed in groups (see above); to examine experimentally how social context affects the expression of tool behaviour, we tested a sample of birds in their second and third year of life, both in their usual housing group and individually (Fig. 2e). Video footage from experimental trials was scored in randomized order by the same observer (B.C.K.) using Solomon Coder software35, and a subsample of 10 trials was re-scored by a second observer (S.S.) to estimate inter-observer agreement (Cohen’s κ for ‘extraction type’ [tool/bill/not-extracted] = 0.97, n = 70 cases; correlation coefficient r for ‘time spent probing with a tool’ = 0.99, P < 0.0001, n = 38 probing bouts); all analyses are based on the original data. Two main types of data were generated by our standardized behavioural assay. First, we used trials to establish whether or not birds used tools, irrespective of deployment context and extraction success (see Fig. 2b, f). Second, for those birds that did use tools, we examined aspects of tool handling, modification (and possible manufacture) and deployment, and quantified the speed with which they extracted bait from the log’s holes and crevices (see Fig. 2g; trials included only when birds had been tested individually). Formal species comparisons are pending, but when extracting meat from vertical holes, ‘Alalā’s performance (n = 52 birds that probed; 63% of attempted extractions successful; cumulative probing time until extraction (median, range): 26.8 s, 3.2–215.6 s; see top-left panel of Fig. 2g) is broadly comparable to that of New Caledonian crows (more difficult, deeper and narrower holes3: n = 15; 49%; 42.3 s, 5.8–161.6 s; unpublished data). Visual-field measurements require that subjects’ heads are held completely still for ~30–45 min9. While such temporary restraint is tolerated well by most birds, it cannot currently be used with ‘Alalā, given the species’ critical conservation status. As the width of the binocular field is determined to a large degree by lateral eye-movement amplitude (correlation, r = 0.82, P = 0.02, n = 7 Corvus spp.; data from table 1 in ref. 9), we opportunistically assessed, during behavioural trials and when handling subjects for routine health checks, how much birds can rotate their eyes forward during full convergence (see Extended Data Fig. 1b and Supplementary Video 5). To gain insights into possible genetic predispositions15, 16, 36, we studied the development of object-oriented behaviour in seven juvenile ‘Alalā that had been bred and puppet-reared37 at the KBCC in 2012 (hatch dates between 20 June and 16 July). Subjects were housed in two mixed-parentage groups (offspring of five different pairs) of three (Group A: subjects #206, #207, #208) and four birds (Group B: #200, #201, #204, #205), respectively. Following the facility’s standard procedures, birds were transferred from fledgling aviaries (~2.0 × 1.8 × 2.3 m) to large outdoor aviaries after they had acquired basic flight skills, at 61–69 days old. From 15 September onwards, the groups were housed in adjacent aviary chambers (each ~3.0 × 12.0 × 5.5 m), with visual contact through a wire-mesh partition, but they never saw adults during the full duration of our study. Furthermore, all staff were briefed never to use ‘tools’ (of any kind) in front of subjects, both during formal observation sessions and in all other contexts, including general husbandry activities (owing to an oversight, large metal tongs were used on a few occasions, to scrape old food from logs). As subjects were co-housed in groups, individuals that only expressed tool use later in the experiment could potentially have learned from those that used tools earlier (see Fig. 3c). This means that only the very first tool behaviour expressed in either of the two experimental groups was certain to be an independent ‘discovery’15, 19. We collected two main data sets. First, we employed a standard focal-bird observation protocol15, 16, 17 to document the natural development of object-oriented behaviour. Up to three days per week (usually on Tuesday, Thursday and Saturday), we conducted a morning (between ~6:30–11:00 h) and an afternoon (~12:00–16:00 h) session, aiming to collect ~5 min of video footage per subject (that is, 3 × 2 sessions × 5 min = 30 min, per subject per week). To avoid biases, the order in which groups were observed, and the order in which subjects were observed within sessions, was pseudo-randomized, and session start times were varied slightly within the above-mentioned time windows. Second, once per week (usually on Fridays), we conducted a ‘probe trial’ to assess subjects’ tool-use competence. We presented each group for ~15–20 min with a wooden platform, containing food-baited vertical holes and crevices (Extended Data Fig. 2b). The rationale of our study design was to monitor the development of the subjects’ tool-related behaviour (see Fig. 3c) with minimal environmental ‘scaffolding’; note that, in contrast, the New Caledonian crows raised in an earlier study had ad libitum access to extraction tasks15, 16. Platforms were initially baited with waxworms and cereal treats, but from 5 October 2012 onwards, we switched to mouse heads, neonate mice, and bright-red ‘Ōhelo Vaccinium reticulatum berries38. By January 2013, subjects in both groups showed keen interest in the hidden food, and often handled objects near the platform. For two reasons, however, their tool-use attempts largely failed: they sourced inappropriate materials as tools (for example, decaying pieces of fern), and even when suitable sticks were found, they struggled to extract food from tasks. We addressed these problems by providing sticks of assorted length (6 of 10–15 cm; 6 of 20–25 cm), loosely placed in the centre of the platform (sticks were never handled in view of the birds, and never pre-inserted into tasks), and by adding horizontal holes and crevices from which food was presumably easier to extract. These changes implemented, we concluded our experiment by providing birds with abundant opportunities to practice their tool-use skills (see entries ①–③ in Fig. 3c; trial length extended to ~30 min), with: a week of almost daily platform trials (23–29 January 2013; pooled data shown as ①); two re-test trials about a week later (4 and 6 February 2013; pooled data shown as ②); and another 1.5 weeks of exposure to the platform and a range of other extraction tasks without observation (8–18 February 2013), followed by a final platform trial on 20 February 2013 (entry ③). For reference, when protocols were altered on 23 January 2013, subjects were 151–181 days post fledging. Following standard protocols, subjects received near-daily aviary enrichment (sometimes immediately prior to observation sessions), including a variety of food items that required processing but were accessible by bill alone. The exception to this were baited opaque PVC tubes, which were presented on a single day in weeks 11, 12, 16, 19 and 24 (with week 1 commencing on 3 September 2012), to assess how birds’ tool-related performance on this task compared to that expressed during formal probe trials with the more demanding platform-mounted set-up (see above). These sessions were not included in focal-bird analyses shown in Fig. 3a, but some object insertions were documented slightly ahead of formal platform probe trials (Fig. 3c). Videos from all observation sessions were scored with JWatcher software39 in randomized order by two hypothesis-naive observers (S.W. and Caitlin Higgott), who achieved very high inter-observer agreement for a subsample of three sessions (correlation coefficients for handling rates for the object categories shown in Fig. 3a, r = 0.96–0.99, all P < 0.0001, n = 10 scores for each test); sessions for post-fledging weeks 3–5 (data from fledgling aviaries included) were scored with a particularly detailed scheme, with some behaviours coded as states, rather than as events, for time-budget analyses (weekly sample sizes were 3, 5 and 7 birds, respectively; Fig. 3d). We wrote code in R40 for extracting data from raw JWatcher output files, to calculate either object-handling rates (Fig. 3a; data for ‘sticks’ and ‘stones’ analysed with simple correlations) or time budgets (Fig. 3d; calculated for the time focal subjects were in view). Except for cross-species comparisons (see below), we plotted temporal data by calendar week (Fig. 3a, c), rather than by bird age or time since fledging, because the development of the younger birds in Group A may have been accelerated through observing the older members of Group B in the adjacent aviary chamber. In videos of probe trials, we scored which behavioural actions subjects performed near or on the platform, ranging from merely approaching the set-up to successfully using tools to extract bait (action types are numbered in the panels of Fig. 3c, and descriptions are provided in Extended Data Table 1). For cross-species comparisons, we extracted data on the development of object-oriented behaviour in New Caledonian crows and common ravens from figure 2 in ref. 17. For ‘stick’ manipulation, we only used data from untutored New Caledonian crows (2 subjects)17, and the object category ‘perch’ included all non-portable aviary fixtures. These species comparisons are for indicative purposes only (Fig. 3d), as the three studies considered varied in a range of factors, including details of subject housing, access to objects and extraction tasks, observation conditions and behavioural scoring (note considerable variation for ‘stick’ estimates for ‘Alalā), and the species in question are known to exhibit different rates of juvenile development4, 5, 8. Prior to the commencement of our study, ‘Alalā had regularly been observed using tools in both captive facilities. Staff did not consider these cases particularly noteworthy, as they were aware that the behaviour had been previously described for the congeneric New Caledonian crow. To provide context for our study, we collated information on these earlier, opportunistic observations, trying to locate written records12, 13 and conclusive photo or video evidence (Supplementary Video 4). It is worth noting that our sample of well-documented historical observations constitutes only a small fraction of the observations made by facility staff over the years. To examine the influence of environmental and/or social factors on tool-use competence, we reconstructed our subjects’ lifetime housing histories—that is, the time they had spent at different facilities, their allocation to particular aviaries and chambers, and their co-housing with other birds—using paper files and electronic spreadsheets held at the KBCC and MBCC. First, we conducted some basic checks, to see whether competence was related to being raised (first two years of life), or kept, in a particular facility (Fig. 2c). Next, we used our detailed housing data to investigate how well our study population was admixed socially, by simulating41 the flow of information—such as tool use—across birds42, 43. Using all dated housing entries in our database (n = 1,501 for 135 birds in 1996–2013), we first generated contact networks that specified which crow dyads were in potential visual contact at any given time, by sharing an aviary or occupying adjacent aviaries/chambers with a see-through wire-mesh partition (cumulative ‘co-housing matrix’ shown in Fig. 3e, left). As the expression of ‘Alalā tool behaviour is strongly age-dependent (Fig. 2d), and studies in other systems have shown that learning is often particularly effective during a ‘sensitive window’ early in life18, we considered only the subset of co-housing events in which one of the birds was adult (>2-years-old) and the other immature (<2-years-old). Our idealised simulation model assumed that, if the adult had the information at the time of co-housing, it was expressed and transmitted instantaneously to the immature. The information was never lost, so both the adult (and the immature, once old enough) could pass it on in subsequent co-housing events. We then traced (computationally) for all potential ‘innovators’ of information all possible transmission pathways through the time-ordered contact networks, identifying those reaching confirmed tool users by 2013 (grey dots in Fig. 3e, left, refer to immature recipients that were not among the confirmed tool users in 2013); the results are summarized in the ‘reachability matrix’ (Fig. 3e, right). From this matrix we computed44 the smallest number (m) of independent innovation events (rows) needed to ensure that every tool user (column) is reached. For the transmission dynamics described, m = 8. To establish a lower-bound estimate, we relaxed the transmission rules so that information could be passed between birds of all ages, yielding m = 1. Both simulations assumed highly conservatively that transmission was not only instantaneous but also deterministic (although we would expect considerable between-dyad variation in transmission probabilities due to differences in social-learning opportunities and phenotypic plasticity18, 45), but inevitably had to ignore possible pathways created by birds for which exact aviary information was unknown (16.3% of 1,501 housing entries). As explained in the main text, these analyses helped us to characterize the ‘social connectivity’ of our study population, but further behavioural experiments are required to demonstrate social learning in ‘Alalā. To examine phylogenetic relationships within the genus Corvus, we built a consensus tree (Fig. 1a) from sequence data that had previously been archived in GenBank by two independent studies6, 46 (note that C. macrorhynchos culminatus had erroneously been logged as C. culminatus in GenBank6). Where more than one sequence was available for a given species, we aligned them and produced a consensus sequence. We then aligned each region (CR, Gapdh, ND2, ND3, and ODC) separately using MAFFT47, and concatenated these alignments. For species that did not have coverage for a particular region, these regions were coded as Ns. We used this alignment to generate a consensus tree, using MrBayes48 (n = 10,000,000). Uncertainty about the specific status of some taxa affects the total number of species within the genus6, 8, 46 (for example, recent authors46 treated C. violaceus and C. minutus as distinct species, rather than as subspecies of, respectively, C. enca and C. palmarum8), but not the gross topology of the phylogenetic tree. Importantly, although more work is required to resolve the close relationships of C. moneduloides4, 6, 46, our analyses confirmed that the two tool-using species C. hawaiiensis and C. moneduloides are only very distantly related49. While our concatenation method enabled us to maximise data coverage, it complicated the estimation of divergence times; according to an earlier study, however, the last common ancestor would have lived in the mid-Miocene, ~11 million years ago (see figure 2 in ref. 46). The ‘Alalā is the only survivor of at least five species of crow that once inhabited the Hawaiian archipelago5, 26, 30. To assess variation in craniofacial features, we used previously published photos (figure 3 in ref. 26) of the fossil skulls of two extinct species (C. impluviatus, C. viriosus), and adapted (mandibles closed; flipped horizontally; re-coloured) and re-sized them for direct comparison with the portrait photo of a live ‘Alalā (adult female #94; Fig. 1f). The evolutionary history of this species assemblage remains unknown, but variation in bill morphology indicates well-differentiated foraging behaviour50, 51. The distribution of an undescribed species with “a bill modified for hammering”5 may be of particular relevance4 for understanding the evolutionary ecology of tool behaviour in ‘Alalā.
News Article | November 27, 2016
The future looks grim for the rhinoceros. Just 29,000 rhinos now exist in the wild, down from half a million at the beginning of the 20th century. Look closer, and the numbers become even more disheartening. The western black rhino was officially declared extinct in 2011. Three of the five remaining species aren't far behind: Just 58 to 61 Javan rhinos and fewer than 100 Sumatran rhinos now live in the wild. Armed guards in Kenya constantly protect the last three northern white rhinos on the planet. The animals' most lethal predators are human, attracted to the big business of rhino horn. And it is big business. By most estimates, rhino horn can fetch as much as $60,000 per kilo, or about $27,000 a pound. That makes it more valuable by weight than gold or cocaine. The chief markets are in Asia, where traditional medicine has used the horn for centuries to treat everything from fevers and convulsions to rheumatism and food poisoning. But demand for the horn has skyrocketed in just the past 10 years, primarily in Vietnam. Now the world's biggest consumer of rhino horn, the country's swelling well-to-do class prizes it as a status symbol of wealth and power, and a miracle cure for cancer. As a result, poaching has surged to "unprecedented levels," Save the Rhino International (SRI) says on its website. In South Africa alone, poachers slaughtered almost 3,400 rhinos over three years -- a rate of one animal every eight hours -- according to SRI. If the pace continues, rhinos could be wiped from the wild within the next decade. That could have far-reaching consequences because the rhinoceros is what scientists call an umbrella species. Protect it, and you protect the other species sharing its habitat. Rhinoceros survival matters -- and conservationists are turning to science and technology to save it. Several companies, including Ceratotech, Rhinoceros Horn LLC and Pembient, believe they have the solution for stopping illegal rhino horn traffic: Give consumers lab-grown alternatives at a fraction of the price, crowding the real thing out of the market. Pembient is the most prominent company in this space. Its approach relies on 3D bioprinting -- basically adding rhino DNA to synthetic keratin, then creating a sort of keratin ink that can run through a 3D printer. The company says its bioprinted material is genetically identical to real horn. Co-founder and CEO Matthew Markus thinks Pembient can do more good by flooding the market with lab-grown horn than traditional conservation efforts can. "When you show up in a country and say you can't use tiger bone, rhinoceros horn, pangolin scales and so on, that's a tough sell," says Markus. "We like to say Pembient is founded on the belief that animals are precious and traditions are important. I see value in both, while it seems most conservationists don't." Conservationists don't just see things differently. Over the past two years, more than a dozen organizations have written articles, published position papers or filed petitions against the sale of synthetic horn. This past February, WildAid and the Center for Biological Diversity petitioned the US Department of the Interior to ban the import, export and sale of bioengineered horn. Nearly all say fakes will just make things worse -- stimulating demand for real horn and reinforcing the myth that it can cure cancer. "What Pembient does is validate the untruth that there's any medical value to rhino horn," says CeCe Sieffert, deputy director of the International Rhino Foundation (IRF). "Having something created as a supplement or replacement says there is value." Thomas Snitch, previously executive officer of the UN Wildlife Enforcement Monitoring System and professor at the University of Maryland's Institute for Advanced Computer Studies, believes black marketers would just sell synthetic horn as the real thing. "The criminal syndicates would like to kill every rhino on the planet and control every rhino horn left in existence," he says. "Then a horn will have an infinite value. They will buy up the Pembient horn and sell it for tens of millions." This year, researchers with San Diego Zoo Global and the Leibniz Institute for Zoo and Wildlife Research, in Berlin, revealed they're working on an absolute last-ditch effort -- building rhinoceroses from scratch using stem cell technology. Here's how it would work. A team from the San Diego Zoo would induce stem cells from the three remaining northern white rhinos -- which are too old to breed -- into sperm and egg cells. The team will also use frozen sperm and other cells taken from 10 other northern white rhinos before they died. The scientists will then use IVF to fertilize the egg and implant the resulting embryo in a surrogate southern white rhino. "Only two embryos have ever been created," says Sieffert. "One grew to two cells and one grew to three cells but weren't viable after that. A rhino's a lot more than three cells. The technology just isn't there." In 2015, the UK nonprofit organization Protect announced it would help save rhinos by installing cameras in their horns. This system, called RAPID (Real-time Anti-Poaching Intelligence Device), would comprise the camera, a GPS collar and a heart-rate monitor. A suddenly rapid heart rate would tell the system to switch on the camera, sound an alarm and dispatch an anti-poaching team. It sounds great in theory. It also raised quite a few questions: How long would the power last? What if the rhino damaged anything? Could poachers steal or destroy the camera? Protect seems to have backed away from the idea. At the time of this writing, the organization had removed any mention of RAPID from its website and YouTube channel. And its chief architect, Paul O'Donoghue of the University of Chester, in England, didn't respond to requests for comment. Snitch took a more feasible approach. Using GPS trackers, satellite imagery and analytics software, his team created models predicting the movements of rhinos, rangers and poachers in South Africa's Olifants West Reserve. "We now have 11 months of data on every patrol route, every animal seen, every anomaly the rangers spotted," says Snitch. "I now have an organic model of how the reserve breathes, how people and animals move, so I know when and where to target poachers." But not everything has to be state of the art. Simple trickery can work, too. "I put $12 fake CCTV cameras with motion and blinking lights up in a number of trees -- along with a couple of real cameras," says Snitch, now director of federal relations at Bowling Green State University in Ohio. "The poachers think I have the fence line covered. In the area we are currently operating, we have cut poaching by 87 percent." He's also using the nature to aid efforts to supply technology in the field, an ingenious combination that relies on a firm understanding of the way the local environment works. "I am working on building beehives in Zambia equipped with solar panels, radio repeaters and a video camera on a telescopic mast," he says. "Honey to sell, better crop pollination, power to charge cell phones and lights at night, better ranger communications and the elephants stay away from village gardens -- reducing animal/human conflict. Elephants are deathly afraid of bees. All for $600 a hive. No one is going to steal my beehive." Saving the rhinoceros involves more than stopping poachers before they kill. We also have to show local communities they can gain more from the rhino's survival than they can by killing it, says IRF's Sieffert. "That can happen with ecotourism, through hiring rangers, paying local communities," she says. "We have one group in Indonesia that we pay to gather food for the animals in the sanctuary. In Tanzania, communities can create what's called communal conservancies and then sell concessions to tourism companies. That community-based conservation is a critical link in wildlife conservation." Then there's the issue of combating the illegal traffic. Both Sieffert and Snitch praise sniffer dogs, like those trained by the African Wildlife Foundation (AWF), for their role in that. Over two months, the AWF's Conservation Canine Programme trains dogs and handlers to be sent to key export hubs, such as Tanzania's port of Dar es Salaam. Sniffer dogs can detect even the smallest amounts of rhino horn dust with a 90 percent accuracy rate, the AWF claims. The first training class of eight dogs and 14 handlers -- rangers from Tanzania's Wildlife Division and the Kenya Wildlife Service -- graduated last year. Time may be running out for the rhinoceros. Greed powered by uninformed demand could wipe out rhinos in the wild in the next 20 years. But that's not stopping people from trying to save them. Last-gasp moonshots, like reconstructing one rhino species from stem cells, may yield advances to save others. GPS trackers, cameras and motion sensors could catch poachers before they can kill. Cancer breakthroughs might quash demand for the horn. There's a good chance it won't be any one answer for saving the rhino, but a combination of many. "We are excited to work with technology companies, and we hope that we can find a solution to this confounding crisis," Sieffert says. "No idea is too crazy to just throw out there and see if it actually works." About 29,000 rhinos still live in the wild. Ideas, anyone? This story appears in the winter 2016 edition of CNET Magazine. For other magazine stories, click here.
News Article | December 29, 2016
Wildlife experts are looking into the death of three endangered Hawaiian crows that were recently released into the wild as part of conservation efforts. The Department of Lands and Natural Resources (DNLR) in Hawaii reported on Monday, Dec. 26, that three of the five ʻalalās (Corvus hawaiiensis) that were reintroduced into the Pu'u Maka'ala Natural Area Reserve on Dec. 14 were found dead last week. The Hawaiian crows were part of a breeding program that was supposed to repopulate the islands with the endangered species. ʻAlalās have long been extinct in the wild and are only bred in captivity. Before discovering the dead ʻalalās, officials said the birds were even spotted doing well and eating from feeders located around the area. It is still unknown what exactly caused the death of the Hawaiian crows. Animal experts are set to perform necropsies on the dead birds to find out more. "We were prepared for that possibility," John Vetter, a wildlife biologist at the DLNR, said. "The initial days of release are always the most difficult stage of any release program, and the level of uncertainty is also highest with the first release cohort." Since 2002, populations of ʻalalās have been missing in the wilderness of Hawaii. While attempts were made to reintroduce captive-bred Hawaiian crows into the wild during the 1990s, many of the birds suffered from high mortality rates because of predation and disease. The DNLR launched the 'alala breeding program in cooperation with the U.S. Fish and Wildlife Service and the non-profit organization San Diego Zoo Global. The Hawaiian crows are part of several bird reintroduction efforts that San Diego Zoo Global has been doing over the past few years. Christina Simmons, a spokeswoman for the conservation group, said performing full necropsies on the dead 'alalas could take a few weeks to finish. There is also a chance that experts won't be able to find a definitive answer as to what exactly killed the birds. Bryce Masuda, manager of the bird conservation program, said the loss of the three 'alalas is difficulty for everyone involved in the breeding and reintroduction of the endangered birds into the wild. He said that condolences for the loss of the Hawaiian crows have come from different parts of the world. The two remaining 'alalas have now been returned to an outdoor aviary. Vetter said this is to ensure the safety of the endangered birds while they await the result of the necropsies. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | April 21, 2016
Polar bears in the Arctic Basin are now forced to swim longer distances as sea ice in the region continues to retreat faster, marking an evidence of climate change's "fingerprint," a new study in Canada revealed. Past research has shown that swimming is a costly activity for polar bears in terms of their body's energy expenditure. With that, a team of scientists led by Nicholas Pilfold sought out to understand polar bears' swimming behavior. The researchers found that polar bears are swimming more frequently and in longer distances as a result of the changes in the location and quantity of summer sea ice. This, in turn, is caused by climate change. Pilfold and his colleagues tracked populations of polar bears in Hudson Bay and the Beaufort Sea through satellite-linked telemetry. Factors such as swimming frequency were different between individual polar bears, depending on body size, sex, age, and the region's geographic features. In 2012, the same year in which the quantity of Arctic sea ice dropped to a record-low, about 69 percent of the telemetry-tracked female polar bears in the Beaufort Sea had swam more than 50 kilometers or 31 miles at least once, the team found. Female polar bears with young cubs often swam less to prevent submersion of their youngsters in frigid waters, while single subadults swam as often as lone adults, researchers said. The longest recorded swim ever in the research was done by a subadult female polar bear, travelling for more than 687 kilometers or 427 miles over the course of nine days in 2011. The female polar bear lost 22 percent of her body weight. Her cub died along the way. "These bears are going for days without stopping," said Pilford. Pilfold, a postdoc fellow at San Diego Zoo Global, also found that swimming occurred more frequently in the Beaufort Sea than in Hudson Bay. Biologist Andrew Derocher, a co-author of the study, said more and more polar bears are caught in places that they just can't stay. The ice they are on keeps breaking up, the floes are too small, and the animals have to swim longer distances to find better habitat. What's more, the polar bear population in the Beaufort Sea has dropped to more than 50 percent in the past decade, Derocher said. Although the study did not find any direct link to the population decline, Derocher and the team were unable to track survival of any cubs who may have been with female polar bears. The study, which is a collaboration that involved experts from Environment and Climate Change Canada (ECCC) and the University of Alberta, is published in the journal Ecography. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | September 15, 2016
A team of researchers and conservationists has found that the critically endangered Hawaiian crow is highly proficient in using tools for foraging food. The Hawaiian crow, commonly known as 'Alalā, is one of very few birds that use tools for foraging in the wild. However, 'Alalā is not the only crow variety with such skills — the New Caledonian crow that lives in a remote South Pacific island of the same name has amazed the researchers with its exemplary skills in using tools. The New Caledonian crow is proficient in using sticks to winkle out worms and insects from deadwood and other vegetation. Researchers were confused for a long time now that among 40 species of crows and ravens in the world only one species possessed such foraging skills. Dr. Christian Rutz, from the University of St. Andrews in the UK said that there is an intriguing possibility that a number of crow species efficient in using tools are yet to be discovered. The unusually straight bills of the New Caledonian crow species made researchers wonder if it is a special adaption of the bird to hold tools just like the opposable thumb in people. The eagerness to find crow species that are capable of handling tools took the researchers close to 'Alalā, which is now unfortunately extinct in the wild. However, the endangered bird variety is taken into captivity for breeding lately. Bryce Masuda, the study co-leader and program manager of San Diego Zoo Global's Hawaii Endangered Bird Conservation Program, said that the captive-reared birds will be released later this year in the Hawaiian island to re-establish the bird population in the wild. Masuda added that though his team has at times noticed 'Alalā using stick tools at their breeding center they did not give much of a thought about it. Masuda, who was excited about St. Andrews researchers' call for a collaborative study on tool handling skills of 'Alalā in captivity, readily agreed to the research. Masuda noted that 104 of 109 'Alalā species alive at the time were keenly observed and it was found that the majority of the said birds in captivity used tools spontaneously. "Using tools comes naturally to 'Alalā," said Rutz. "These birds had no specific training prior to our study, yet most of them were incredibly skilled at handling stick tools, and even swiftly extracted bait from demanding tasks." Rutz also noted that the Hawaiian crow is similar to the New Caledonian species that is under study for 10 years now. The study is published in the journal Nature on Sept. 14. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | April 20, 2016
A study undertaken by scientists from the University of Alberta and Environment and Climate Change Canada to understand swimming behavior in polar bears is showing an increase in this behavior related to changes in the amount and location of summer sea ice. Lead author Nicholas Pilfold, now a postdoctoral fellow at San Diego Zoo Global, said "the pattern of long-distance swimming by polar bears in the Beaufort Sea shows the fingerprint of climate change. Swims are occurring more often, in association with sea ice melting faster and moving farther from shore in the summer." The study, published in a recent issue of the journal Ecography, was accomplished using satellite-linked telemetry-tracked populations of polar bears in the Beaufort Sea and Hudson Bay. Results of the study show an increase in swimming associated with reduced ice, due to climate change. In 2012, the year in which Arctic sea ice hit a record low, 69 percent of the tracked adult females in the Beaufort Sea swam more than 31 miles (50 kilometers) at least once. "Recent studies indicate that swimming may be energetically costly to polar bears," said Nicholas Pilfold. "Given the continued trend of sea ice loss, we recognize that an increased frequency in the need to engage in this behavior may have serious implications for populations of polar bears living around the Arctic Basin." Swimming frequency and other movement factors varied between individual bears and showed differences dependent on age, sex, body size and geographic features of the region. Swims occurred more frequently in the Beaufort Sea than in Hudson Bay. Researchers noted that females with young cubs tended to swim less to avoid submersion of youngsters in cold waters, while lone subadults swam as frequently as lone adults. The longest recorded swim in the study was by a subadult female that traveled over 249 miles (400 kilometers) in nine days. Explore further: Polar bears 'spotted swimming with cubs on back'
News Article | March 22, 2016
A study published in the journal Global Ecology and Conservation may help field conservationists better understand the potential for human activities to disturb endangered giant pandas in native habitats. Using pandas located at the San Diego Zoo, conservation scientists worked with animal care specialists to determine pandas' range of hearing sensitivity, discovering that they can detect sound into the ultrasonic range. Because giant pandas depend in large part on information transmitted through vocalizations for reproductive success, noise from human activities in or near forest areas could be disruptive. "An understanding of a species' hearing provides a foundation for developing estimates of noise disturbance," said Megan Owen, associate director of giant panda conservation, San Diego Zoo Global. "For the giant panda, vocalizations are typically emitted in proximity to conspecifics (members of the same species), however the ability to discriminate between fine-scale differences in vocalizations is important for successful reproduction; and so, a thorough understanding of acoustic ecology is merited in order to estimate the potential for disturbance. "In order to learn about panda hearing, researchers at the San Diego Zoo worked with giant pandas to teach them to respond, if they could hear sounds at a particular pitch and loudness, thus communicating their ability to hear across the acoustic spectrum," Owen said. "Through this study, the pandas at the San Diego Zoo have made a significant contribution to our understanding of what may be affecting panda reproduction in habitats in China," said Ron Swaisgood, director of applied animal ecology, San Diego Zoo Global. "It is only because of the strong relationship that animal care staff have with the bears at the Zoo that we have been able to gather this information."