Utilizing a top predator to prioritize site protection for biodiversity conservation.

Ongoing global change makes it ever more urgent to find creative solutions for biodiversity preservation, but prioritizing sites for protection can be challenging. One shortcut lies in mapping the habitat requirements of well-established biodiversity indicators, such as top predators, to identify high-biodiversity sites. Here, we planned site protection for biodiversity conservation by developing a multi-scale species distribution model (SDM) for the raptorial Northern Goshawk (Accipiter gentilis; goshawk) breeding in an extensive megacity region of Japan. Specifically, we: (1) examined the determinants of top predator occurrence and thus of high-biodiversity value in this megacity setting, (2) identified the biodiversity hotspots, (3) validated whether they actually held higher biodiversity through an independent dataset, and (4) evaluated their current protection by environmental laws. The SDM revealed that goshawks preferred secluded sites far from roads, with abundant forest within a 100 m radius and extensive forest ecotones suitable for hunting within a 900 m radius. This multi-scale landscape configuration was independently confirmed to hold higher biodiversity, yet covered only 3.2% of the study area, with only 44.0% of these sites legally protected. Thus, a rapid biodiversity assessment mediated by a top predator quickly highlighted: (1) the poor development of biodiversity-friendly urban planning in this megacity complex, an aspect overlooked for decades of rapid urban sprawl, and (2) the extreme urgency of extending legal protection to the sites missed by the current protected area network. Exigent biodiversity indicators, such as top predators, could be employed in the early or late stages of anthropogenic impacts in order to proactively incorporate biodiversity protection into planning or flag key biodiversity relics. Our results confirm and validate the applied reliability of top predatory species as biodiversity conservation tools.

Top predators as biodiversity indicators: A meta-analysis.

Identifying efficient biodiversity indicators is a key pillar of the global conservation strategy. Top predators have been proposed as reliable biodiversity signposts, but their role is controversial. Here, we verified their performance by a meta-analysis of published studies and found solid support for their efficacy as biodiversity indicators. As to be expected for any indicator species, efficacy was stronger for biodiversity components 'ecologically closer' to the predator (i.e. broad groups that include species providing key resources, such as avian and tree diversity for a bird-eating predator that nests in trees) and declined for the diversity of components more 'ecologically remote' from the predator (e.g. butterfly diversity for a fish-eating predator). This confirmed a link between the top predatory role and biodiversity and set the context for its functionality. These results show that, on average, top predators are justified candidates as biodiversity indicators and that prioritisation of conservation action based on their occurrence is likely to provide broader ecosystem benefits. However, such role should be confirmed on a case-by-case basis, acknowledging that no indicator can portray everything, checking the compatibility of the biodiversity components linked to the predator with the established conservation objectives and ideally integrating predators with other complementary indicator groups.

Demographic modeling to fine-tune conservation targets: importance of pre-adults for the decline of an endangered raptor.

Large, long-lived species with slow life histories and protracted pre-breeding stages are particularly susceptible to declines and extinction, often for unknown causes. Here, we show how demographic modeling of a medium-sized raptor, the Red Kite Milvus milvus, can aid to refocus conservation research and attention on the most likely mechanisms driving its decline. Red Kites' survival and reproduction increased through three sequential stages for 1-2, 3-6, and 7-30 yr of age, mainly corresponding to individuals that are dispersing, attempting to gain a territory, and breeding. As typical of long-lived species, elasticities were highest for adult (≥7 yr old) survival, but this was high, with little scope for improvement. Instead, the declines were driven by an extremely low survival of pre-adults in their first years of life, which weakened the whole demographic system by nullifying the offspring contribution of adults and curtailing their replacement by recruits. For example, 27 pairs were necessary to generate a single prime age adult. Simulation of management scenarios suggested that the decline could be halted most parsimoniously by increasing pre-adult survival to the mean levels recorded for other areas, while only the synergistic, simultaneous improvement of breeding success, adult and pre-adult survival could generate a recovery. We propose three actions to attain such goals through selective supplementary feeding of both breeding and non-breeding individuals, and through mortality improvement by GPS remote-sensing devices employed as surveillance monitoring tools. Our results show how improving demographic models by using real, local vital rates rather than "best guess" vital rates can dramatically improve model realism by refocusing attention on the actual stages and mortality causes in need of manipulation, thus building precious time and resources for conservation management. These results also highlight the frequent key role of pre-adult survival for the management of long-lived species, coherent with the idea of demographic systems as integrated chains only as strong as their weakest link.

Medial Displacement Calcaneal Osteotomy for Unilateral Adult Acquired Flatfoot: Effects of Minimally Invasive Surgery on Pain, Alignment, Functioning, and Quality of Life.

We aimed to assess the effects of medial displacement calcaneal osteotomy (MDCO) through a minimal skin incision in terms of pain, function, and alignment in patients with unilateral adult acquired flatfoot. American Orthopedic Foot and Ankle Society (AOFAS) hindfoot scale and Numeric Pain Rating Scale (NPRS) were assessed as outcomes at the baseline (T0), at 6 months (T1), and at 1 year (T2) from surgery. We analyzed data of 20 patients (7 male and 13 female), mean aged 46.6 ± 5.34 years, showed significant differences after 6 months in terms of AOFAS total score (44.30 ± 7.39 vs 96.50 ± 4.89; p = .0001), AOFAS subitems (p < .001), and pain (NPRS: 7.95 ± 1.36 vs 1.05 ± 1.05; p = .0001). At 1 year after surgery (T2), all outcome measures still significantly differ from baseline (p < 01). Therefore, percutaneous MDCO through a minimal skin incision seemed to be safe and effective in the middle and long term in reducing pain and improving function and alignment in patients with unilateral adult acquired flatfoot.

Individual improvements and selective mortality shape lifelong migratory performance.

Billions of organisms, from bacteria to humans, migrate each year and research on their migration biology is expanding rapidly through ever more sophisticated remote sensing technologies. However, little is known about how migratory performance develops through life for any organism. To date, age variation has been almost systematically simplified into a dichotomous comparison between recently born juveniles at their first migration versus adults of unknown age. These comparisons have regularly highlighted better migratory performance by adults compared with juveniles, but it is unknown whether such variation is gradual or abrupt and whether it is driven by improvements within the individual, by selective mortality of poor performers, or both. Here we exploit the opportunity offered by long-term monitoring of individuals through Global Positioning System (GPS) satellite tracking to combine within-individual and cross-sectional data on 364 migration episodes from 92 individuals of a raptorial bird, aged 1-27 years old. We show that the development of migratory behaviour follows a consistent trajectory, more gradual and prolonged than previously appreciated, and that this is promoted by both individual improvements and selective mortality, mainly operating in early life and during the pre-breeding migration. Individuals of different age used different travelling tactics and varied in their ability to exploit tailwinds or to cope with wind drift. All individuals seemed aligned along a race with their contemporary peers, whose outcome was largely determined by the ability to depart early, affecting their subsequent recruitment, reproduction and survival. Understanding how climate change and human action can affect the migration of younger animals may be the key to managing and forecasting the declines of many threatened migrants.

The population density of an urban raptor is inextricably tied to human cultural practices.

Human socio-cultural factors are recognized as fundamental drivers of urban ecological processes, but their effect on wildlife is still poorly known. In particular, human cultural aspects may differ substantially between the extensively studied urban settings of temperate regions and the poorly studied cities of the tropics, which may offer profoundly different niches for urban wildlife. Here, we report how the population levels of a scavenging raptor which breeds in the megacity of Delhi, the black kite Milvus migrans, depend on spatial variation in human subsidies, mainly in the form of philanthropic offerings of meat given for religious purposes. This tight connection with human culture, which generated the largest raptor concentration in the world, was modulated further by breeding-site availability. The latter constrained the level of resource-tracking by the kites and their potential ecosystem service, and could be used as a density-management tool. Similar ties between animal population densities, key anthropogenic resources and human beliefs may occur in thousands of cities all over the globe and may fit poorly with our current understanding of urban ecosystem functioning. For many urban animals, key resources are inextricably linked with human culture, an aspect that has been largely overlooked.

Integrating population connectivity into pollution assessment: Overwintering mixing reveals flame retardant contamination in breeding areas in a migratory raptor.

Determining the exposure and magnitude at which various pollutants are differentially assimilated at the breeding and non-breeding grounds of migratory wildlife is challenging. Here, the possibility of applying the migratory connectivity framework to understanding contamination in birds is illustrated by considering flame retardants in inviable eggs of a migratory raptor, the black kite (Milvus migrans). The occurrence and concentration of legacy and emerging compounds in eggs from the southeastern peri-urban area of Madrid city, central Spain, were compared with those from Doñana National Park in southern Spain. A much higher occurrence and concentration of multiple polybrominated diphenyl ethers and Dechlorane 602 were found in Madrid than Doñana, but the opposite patterns were found for Dechlorane Plus. Individuals from these and other breeding areas in western Europe showed a strong intermixing pattern over widespread wintering areas in Africa, as assessed by ringing recoveries and movements tracked by satellite devices. This diffuse migratory connectivity reveals breeding areas as the main contamination grounds. High contamination burdens sequestered in eggs point to rapid assimilation of these compounds before laying, associated with important emission sources in Madrid, especially landfills of partially incinerated urban refuse, and other anthropogenic operations. Diet composition regarding aquatic vs. terrestrial prey, and bioaccumulation and biomagnification processes are suggested to explain differential assimilation of some compounds, especially Dechlorane Plus in Doñana, although a local emission source polluting this area cannot be ruled out. Insight from the migratory connectivity framework can help to disentangle large-scale patterns of contaminant uptake and refocus attention on key regions and potential causes of chemical hazards in declining migratory species and human populations.

Lifetime variation in feather corticosterone levels in a long-lived raptor.

In long-lived animals, the challenges that threaten individual homeostasis, and the way they are dealt with, are expected to vary in an age-related manner, encompassing the progressive selection of superior phenotypes and the acquisition and improvement of key skills (e.g. foraging, breeding and fighting abilities). Since exposure to homeostatic challenges typically elevates circulating glucocorticoid (GC) levels in vertebrates (modulating the behavioural and physiological responses that mediate allostasis), we may expect concomitant age-related changes in these hormones. Here, we investigated whether the level of corticosterone (the main avian GC) deposited in feathers during regular moult reflected the expected lifelong progression of energetic challenges in a long-lived raptor, the black kite (Milvus migrans). Feather corticosterone values were highest in the youngest birds, gradually declined to reach minimum levels in prime age, 7- to 11-year-old birds, and then increased again slightly among the oldest, senescent birds (≥12 years old). This pattern mirrored the age-related changes in reproductive success and survival rates previously reported for this population, suggesting that feather corticosterone levels captured the most vulnerable and challenging periods experienced by these birds as they proceeded through life. Moreover, feather corticosterone levels were negatively related to body size, suggesting that larger birds either experienced fewer homeostatic challenges, or were better able to cope with them. Feather corticosterone measures thus provided a valuable snapshot of how allostatic loads vary along the life of individuals, supporting the idea of a tight, long-term link between cumulative physiological responses to ecological challenges and demographic performance.

Mini-Invasive Treatment for Brachymetatarsia of the Fourth Ray in Females: Percutaneous Osteotomy With Mini-Burr and External Fixation-A Case Series.

Brachymetatarsia is a rare disease defined by metatarsal shortening and characterized by aesthetic dissatisfaction with or without pain. The aim of our study was to evaluate the outcomes of fourth ray brachymetatarsia treated with percutaneous osteotomy using a mini-burr and gradual lengthening with external fixation. A total of 7 females were recruited for the study; 6 (85.71%) of whom had a bilateral deformity, for a total of 13 feet affected by fourth ray brachymetatarsia. Percutaneous diaphysis osteotomy with a mini-burr followed by metatarsal elongation was performed. Metatarsal lengthening was measured as the difference between the preoperative and postoperative length at external fixator removal. The American Orthopaedic Foot and Ankle Society lesser toe metatarsophalangeal-interphalangeal score, patient satisfaction, restoration of Leliévre parabola, and treatment time were evaluated. Numerical data are reported as the mean ± standard deviation and 95% confidence intervals. The Mann-Whitney U test was used to compare the changes in the AOFAS score with a level of significance of p < .05. The mean metatarsal lengthening was 17.46 ± 4.89 (95% confidence interval [CI] 14.8 to 20.12) mm and the mean treatment time was 99.23 ± 8.53 (95% CI 94.59 to 103.87) days. The mean American Orthopaedic Foot and Ankle Society lesser toe metatarsophalangeal-interphalangeal score improved significantly from 76.38 ± 2.66 (95% CI 74.77 to 78.03) preoperatively to 86.46 ± 1.45 (95% CI 84.85 to 88.07) postoperatively (p < .01). In 12 of 13 feet (92.31%), the Leliévre parabola was restored, and the patients were satisfied with the clinical outcomes. The results of our study demonstrate that percutaneous osteotomy with the mini-burr and external fixation is an effective treatment for lengthening of fourth ray brachymetatarsia. Furthermore, we found good clinical and functional outcomes, high patient satisfaction, and a similar duration of treatment compared with other gradual lengthening procedures.

Role of lateral soft tissues release in percutaneous hallux valgus correction: A medium term retrospective study.

BACKGROUND: In the field of minimally invasive surgery (MIS) for the treatment of hallux valgus (HV), different techniques have begun to emerge in the literature concerning the distal osteotomy of the first metatarsal bone, the synthesis or not of the metatarsal head, the possible association with lateral soft tissues release (LSTR) and osteotomy of the base of the first phalanx. AIM: To evaluate the role of LSTR on percutaneous HV correction, evaluating functional and radiographical results. METHODS: From January 2012 to May 2016 a total of 396 patients with mild to moderate symptomatic HV treated with the MIS technique were included in this retrospective study. The technique provides no internal fixation (WOS). Patients were divided into the LSTR group and no LSTR group (LSTR N). This surgical procedure (LSTR) was reserved for insufficient HV angle (HVA) correction during fluoroscopic control. Patients were evaluated at each follow-up by two other authors after appropriate training by senior authors (first practitioners). Clinical evaluation was performed before surgery, 6 mo after surgery, and 48 mo follow-up. American Orthopaedic Foot and Ankle Society (AOFAS) and visual analog scale (VAS) score was used to evaluate pain and function, and complications were recorded. In addition, the incidence of relapses and the degree of joint range of motion (ROM) with the association with the LSTR (capsule, adductor tendon, phalanx-sesamoid ligament, and the deep transverse metatarsal ligament) were evaluated. Radiological parameters included HVA and intermetatarsal angle (IMA). Patient satisfaction was assessed. Student t-test and Fisher exact test were used to assess statistical analysis. RESULTS: From our study it is clear that no differences in term of HVA, VAS, IMA correction, rate of complications, and AOFAS score were found between groups, while a significant improvement of the same variables was found in each group between pre and postoperative values. A significant improvement in ROM at 6 mo (P = 0.018) and 48 mo (P = 0.02) of follow-up was found in LSTR N group. Complications were rare in both groups. CONCLUSION: LSTR procedure on percutaneous HV correction seems to increase postoperative joint stiffness with a comparable incidence of relapse and a low incidence of complications.

Hardship at birth alters the impact of climate change on a long-lived predator.

Climate change is increasing the frequency of extreme events, such as droughts or hurricanes, with substantial impacts on human and wildlife communities. Extreme events can affect individuals through two pathways: by altering the fitness of adults encountering a current extreme, and by affecting the development of individuals born during a natal extreme, a largely overlooked process. Here, we show that the impact of natal drought on an avian predator overrode the effect of current drought for decades, so that individuals born during drought were disadvantaged throughout life. Incorporation of natal effects caused a 40% decline in forecasted population size and a 21% shortening of time to extinction. These results imply that climate change may erode populations more quickly and severely than currently appreciated, suggesting the urgency to incorporate "penalties" for natal legacies in the analytical toolkit of impact forecasts. Similar double impacts may apply to other drivers of global change.

Compensation for wind drift during raptor migration improves with age through mortality selection.

Each year, billions of flying and swimming migrants negotiate the challenging displacement imposed by travelling through a flowing medium. However, little is known about how the ability to cope with drift improves through life and what mechanisms drive its development. We examined 3,140 days of migration by 90 GPS-tagged raptorial black kites (Milvus migrans) aged 1-27 years to show that the ability to compensate for lateral drift develops gradually through many more years than previously appreciated. Drift negotiation was under strong selective pressure, with inferior navigators subject to increased mortality. This progressively selected for adults able to compensate for current cross flows and for previously accumulated drift in a flexible, context-dependent and risk-dependent manner. Displacements accumulated en route carried over to shape the wintering distribution of the population. For many migrants, migratory journeys by younger individuals represent concentrated episodes of trait selection that shape adult populations and mediate their adaptation to climate change.

Fungal signatures of oral disease reflect environmental degradation in a facultative avian scavenger.

Degradation of natural ecosystems increases the risk of infections in wildlife due to microbiota dysbiosis. However, little is known about its influence on the development of fungal communities in predators and facultative avian scavengers. We evaluated the incidence of oral disease in wild nestling black kites (Milvus migrans) under contrasting environmental degradation conditions, and explored their oral fungal patterns using molecular methods and multivariate analysis. Oral lesions were found in 36.8% of the 38 nestlings examined in an anthropogenically altered habitat (southeastern Madrid, Spain), but in none of the 105 nestlings examined in a well-conserved natural area (Doñana National Park, Spain). In a subsample of 48 black kites, the composition of the oral fungal community differed among symptomatic nestlings from Madrid (SM) and asymptomatic nestlings from Madrid (AM) and Doñana (AD). Opportunistic fungal pathogens (e.g., Fusarium incarnatum-equiseti species complex, Mucor spp., Rhizopus oryzae) were more prevalent in SM and AM than in AD. Hierarchical clustering and principal component analyses revealed that fungal patterns were distinct between both study areas, and that anthropogenic and natural environmental factors had a greater impact on them than oral disease. Fungal signatures associated with anthropogenic and natural stresses harbored some taxa that could be used to flag oral infection (F. incarnatum-equiseti species complex and Alternaria), indicate environmental degradation (Alternaria) or provide protective benefits in degraded environments (Trichoderma, Epicoccum nigrum and Sordaria). Co-occurrence associations between potentially beneficial and pathogenic fungi were typical of AM and AD, hinting at a possible role in host health. This study shows that early-life exposure to highly degraded environments induces a shift towards a higher prevalence of pathogenic species in the oral cavity of black kites, favoring oral disease. Furthermore, our findings suggest potential ecological applications of the monitoring of oral mycobiome as a bioindication of oral disease and environmental degradation.

Coping with uncertainty: breeding adjustments to an unpredictable environment in an opportunistic raptor.

No environment is truly constant in time. As a result, animals have evolved multiple adjustments to cope with such fluctuations. However, the allocation of effort to costly activities that imply long-term commitments, such as breeding, may be extremely challenging when future resources change constantly and unpredictably, a context that has received little investigation. To fill this gap, we studied the breeding response by a wetland-dependent raptor, the black kite Milvus migrans, to within and between-years fluctuations in resource availability (inundation levels). The breeding performance of the population was decomposed into reproductive components expressed in a sequence of successive tasks along the breeding cycle (e.g. timing of laying, clutch size, hatching success, brood reduction). Variation in each component was related to resource levels observed at different key dates of the season in order to test whether and when population-level reproduction was adjusted to available resources. Along a 22-year time-series, inundation levels fluctuated unpredictably within and among years, and mostly affected the later components of kites' reproduction, such as hatching success and the incidence of brood reduction, which were the main determinants of the population yearly breeding output. Results were consistent with multiple adjustments to cope with uncertainty. As the season progressed and resources became easier to assess, a bet-hedging waiting strategy based on a conservatively small, invariant and asynchronous clutch gave way to real-time resource-tracking mechanisms mediated by progressive adjustments to current prey availability, so that population-level breeding rates were determined and tuned to resources rather late in the season. Such adjustments were the likely outcome of the interaction between parental tactics and environmental constraints. Behavioural flexibility, such as dietary opportunism, probably promoted further resistance to resource oscillations. Given that all ecosystems show some degree of unpredictability, resource-tracking adjustments, such as the ones depicted here, are likely to be commonplace in most communities.

Raptor breeding sites indicate high plant biodiversity in urban ecosystems.

Preserving biodiversity in urban ecosystems has become an urgent conservation priority, given the rapid upsurge in global urbanization. As woody plants play essential ecological roles and provide psychological benefits to human city dwellers, their preservation is of particular interest to conservation scientists. However, considering that extensive censuses of woody plants are resource-intensive, a key accomplishment is to find reliable conservation proxies that can be quickly used to locate biologically diverse areas. Here, we test the idea that sites occupied by apex predators can indicate high overall biodiversity, including high diversity of woody plants. To this end, we surveyed woody plant species within 500 m of Northern Goshawk (Accipiter gentilis) breeding sites in urban ecosystems of Japan and compared them with non-breeding control sites without goshawks. We found that goshawks successfully identified and signposted high levels of richness, abundance, and diversity of woody plants. Our findings show that sites occupied by top predatory species could be exploited as conservation proxies for high plant diversity. Due to their exigent ecological requirements, we would expect apex predators to be tied to high biodiversity levels in many other urban ecosystems worldwide.

Simultaneous analysis of multiple PCR amplicons enhances capillary SSCP discrimination of MHC alleles.

Major histocompatibility complex (MHC) genotyping still remains one of the most challenging issues for evolutionary ecologists. To date, none of the proposed methods have proven to be perfect, and all provide both important pros and cons. Although denaturing capillary electrophoresis has become a popular alternative, allele identification commonly relies upon conformational polymorphisms of two single-stranded DNA molecules at the most. Using the MHC class II (beta chain, exon 2) of the black kite (Aves: Accipitridae) as our model system, we show that the simultaneous analysis of overlapping PCR amplicons from the same target region substantially enhances allele discrimination. To cover this aim, we designed a multiplex PCR capable to generate four differentially sized and labeled amplicons from the same allele. Informative peaks to assist allele calling then fourfold those generated by the analysis of single PCR amplicons. Our approach proved successful to differentiate all the alleles (N=13) isolated from eight unrelated birds at a single optimal run temperature and electrophoretic conditions. In particular, we emphasize that this approach may constitute a straightforward and cost-effective alternative for the genotyping of single or duplicated MHC genes displaying low to moderate sets of divergent alleles.

Reproductive endocrinology of wild, long-lived raptors.

The last decades have witnessed a surge of studies analyzing the role of sex hormones on the behavior and ecology of wild bird populations, allowing a more integrated view of the evolution of avian physiology and life histories. Despite a marked progress, field studies show a considerable bias towards research on specific phylogenetic groups, neglecting a significant fraction of the class Aves. Here we analysed changes in the circulating levels of sex steroids in relation to reproductive behaviour in wild black kites (Milvus migrans), a long-lived and socially monogamous Accipitridae raptor. Males and females displayed a single seasonal peak of circulating testosterone (males) and estradiol (females) during pre-laying and laying. Absolute male testosterone levels were low even at the seasonal maximum and remained below detection limits in females. The latter results supports the idea that avian species establishing long-term pair bonds require lower amounts of circulating androgens for reproduction. Circulating progesterone showed a single seasonal peak in females and males, but their timing (during Incubation and Post-brooding respectively) did not overlap. The fact that females black kites perform the majority of incubation and males provide the majority of care to fledglings suggests that progesterone is involved in the expression of parental behaviors.

Preliminary Experience With a Minimally Invasive Technique for Hallux Valgus Correction With No Fixation.

BACKGROUND: Percutaneous operative techniques for hallux valgus (HV) correction are less damaging to soft tissues and the first metatarsophalangeal joint, and they carry a lower risk of wound complications. We report our preliminary results using a percutaneous technique that allowed correction of the deformity without internal fixation. METHODS: One hundred ninety-five consecutive patients with isolated symptomatic HV were surgically treated using a percutaneous technique without any form of internal fixation, with a mean follow-up of 34.6 months. The American Orthopaedic Foot & Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale score was used for clinical assessment. Radiographic evaluation included pre- and postoperative assessment of the hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), and sesamoid position in weightbearing radiographs. RESULTS: According to the AOFAS score, the patients improved from a preoperative median of 54.7 to 89.6 at 2 years' follow-up (P = .002). Patients were satisfied or very satisfied in 94% of cases at the latest follow-up. A mean radiographic correction of the HVA of 15.5 degrees, of the IMA of 5.4 degrees, and of the DMAA of 5.4 degrees was achieved. The AOFAS global score and every individual parameter improved significantly between pretreatment and latest follow-up (P > .01). A total of 19 (9.7%) complications were reported. CONCLUSION: This percutaneous technique, which did not use any form of internal fixation described, produced durable results for the correction of HV, reliably correcting the deformity and resulting in significant improvement in function and decrease of pain. LEVEL OF EVIDENCE: Level IV, retrospective case series.

GPS-telemetry unveils the regular high-elevation crossing of the Himalayas by a migratory raptor: implications for definition of a "Central Asian Flyway".

Remote technologies are producing leapfrog advances in identifying the routes and connectivity of migratory species, which are still unknown for hundreds of taxa, especially Asian ones. Here, we used GPS-telemetry to uncover the migration routes and breeding areas of the massive population of migratory Black-eared kites wintering around the megacity of Delhi-India, which hosts the largest raptor concentration of the world. Kites migrated for 3300-4800 km along a narrow corridor, crossing the Himalayas at extremely high elevations (up to > 6500 m a.s.l.) by the K2 of the Karakoram Range and travelled long periods at elevations above 3500 m. They then crossed/circumvented the Taklamakan Desert and Tian Shan Range to reach their unknown breeding quarters at the intersection between Kazakhstan, Russia, China and Mongolia. Route configuration seemed to be shaped by dominant wind support and barrier avoidance. Wintering ranges were smaller than breeding ranges and concentrated around Delhi, likely in response to massive human food-subsidies. Our results illustrate that high-elevation crossings by soaring migrants may be more common than previously appreciated and suggest the delineation of a hitherto poorly-appreciated "Central Asian Flyway", which must funnel hundreds of thousands of migrants from central Asia into the Indian subcontinent via multiple modes of the Himalayan crossing.

Overland and oversea migration of white storks through the water barriers of the straits of Gibraltar.

Soaring landbirds typically exploit atmospheric uplift as they fly overland, displaying a highly effective energy-saving locomotion. However, large water bodies lack thermal updrafts, potentially becoming ecological barriers that hamper migration. Here we assessed the effects of a sea surface on the migratory performance of GPS-tagged white storks (Ciconia ciconia) before, during and after they crossed the straits of Gibraltar. Oversea movements involved only flapping and gliding and were faster, traversed in straighter, descending trajectories and resulted in higher movement-related energy expenditure levels than overland, supporting the water barrier hypothesis. Overland movements at both sides of the sea straits resulted in tortuous routes and ascending trajectories with pre-crossing flights showing higher elevations and more tortuous routes than post-crossing, thus supporting the barrier negotiation hypothesis. Individual positions at both ends of the sea narrow were predicted by zonal winds and storks´ location at entry in the European hinterland, and birds did not show compensational movements overland in anticipation to subsequent wind displacements oversea. The length of the water narrow at departure shore, the elevation therein and the winds on route affected major components of sea crossing performance (such as distances and times overwater, minimum elevations, climb angles, speeds and energy expenditure), supporting the departure position and oversea winds hypotheses. In summary, our study provides a prime example at high temporal resolution of how birds adjust their behavior and physiology as they interact with the changing conditions of the travelling medium, reallocating resources and modifying their movement to overcome an ecological barrier.