Pelecanus Erythrorhynchos Research Articles

Scale-dependent population drivers inform avian management in a declining saline lake ecosystem.

Shrinking saline lakes provide irreplaceable habitat for waterbird species globally. Disentangling the effects of wetland habitat loss from other drivers of waterbird population dynamics is critical for protecting these species in the face of unprecedented changes to saline lake ecosystems, ideally through decision-making frameworks that identify effective management options and their potential outcomes. Here, we develop a framework to assess the effects of hypothesized population drivers and identify potential future outcomes of plausible management scenarios on a saline lake-reliant waterbird species. We use 36 years of monitoring data to quantify the effects of environmental conditions on the population size of a regionally important breeding colony of American white pelicans (Pelecanus erythrorhynchos) at Great Salt Lake, Utah, US, then forecast colony abundance under various management scenarios. We found that low lake levels, which allow terrestrial predators access to the colony, are probable drivers of recent colony declines. Without local management efforts, we predicted colony abundance could likely decline approximately 37.3% by 2040, although recent colony observations suggest population declines may be more extreme than predicted. Results from our population projection scenarios suggested that proactive approaches to preventing predator colony access and reversing saline lake declines are crucial for the persistence of the Great Salt Lake pelican colony. Increasing wetland habitat and preventing predator access to the colony together provided the most effective protection, increasing abundance 145.4% above projections where no management actions are taken, according to our population projection scenarios. Given the importance of water levels to the persistence of island-nesting colonial species, proactive approaches to reversing saline lake declines could likely benefit pelicans as well as other avian species reliant on these unique ecosystems.

Bayesian integrated species distribution models for hierarchical resource selection by a soaring bird

Migratory birds exhibit seasonal geographic range (hereafter, range) dynamics during the annual cycle. Few studies have examined how migratory birds select their habitats for range occupancy at the species level and space use at the individual level simultaneously. We hypothesized that environmental variables directly related to fitness components would affect the range occupancy probabilities of migrants, whereas environment variables related to movements and flights would affect the space use intensities of migrants. We built Bayesian integrated species distribution models (ISDMs) to evaluate the effects of climate conditions, wind conditions, and landcover compositions on the seasonal range dynamics of American white pelicans Pelecanus erythrorhynchos (hereafter, pelican) during summer and winter. The ISDMs estimated the summer range occupancy probabilities of pelicans with Breeding Bird Survey data, winter range occupancy probabilities with Christmas Bird Count data, and summer and winter space-use intensity rates with eBird data jointly. We evaluated the predictive performance of ISDMs using independent datasets of pelican GPS locations. Integrated species distribution models outperformed the occupancy-only models in the predictive performance of occupancy probabilities. Climate conditions had opposite effects on the range occupancy probabilities between the breeding and non-breeding grounds, whereas landcovers had relatively consistent effects on range occupancy probabilities between the seasons.

Histopathologic Features and Viral Antigen Distribution of H5N1 Highly Pathogenic Avian Influenza Virus Clade 2.3.4.4b from the 2022-2023 Outbreak in Iowa Wild Birds.

In 2022, a new epornitic of H5N1 highly pathogenic avian influenza (HPAI) virus clade 2.3.4.4b emerged in U.S. domestic poultry with high prevalence in wild bird populations. We describe pathological findings of HPAI H5N1 in nine wild birds encompassing eight different species, including Accipitriformes (red-tailed hawk, bald eagle), Cathartiforme (turkey vulture), Falconiforme (peregrine falcon), Strigiforme (one adult great-horned owl, one juvenile great-horned owl), Pelecaniforme (American white pelican), and Anseriformes (American green-winged teal, trumpeter swan). All these birds died naturally (found dead, or died in transit to or within a rehabilitation center), except for the bald eagle and American green-winged teal, which were euthanized. Gross lesions were subtle, characterized by meningeal congestion observed in the turkey vulture, bald eagle, and adult great-horned owl. Histologically, encephalitis was observed in all cases (9/9, 100%). Leukocytoclastic and fibrinoid vasculitis with necrotizing encephalitis was observed in the red-tailed hawk, great-horned owls, and American white pelican (5/9, 55.6%), and perivascular lymphohistiocytic encephalitis was seen in the turkey vulture, peregrine falcon, green-winged teal, and bald eagle (4/9, 44.4%). Coagulative necrosis or lymphohistiocytic/lymphoplasmacytic inflammation was identified in the kidney (6/8, 75%), liver (6/9, 66.7%), heart (5/9, 55.6%), and lung (2/9, 22.2%). Immunopositive signals against Influenza virus A nucleoprotein were predominantly detected within the brain (9/9, 100%), air sac (7/9, 77.8%), lung (7/9, 77.8%), kidney (6/8, 75%), heart (6/9, 66.7%), and liver (5/9, 55.6%). Additionally, other organs, such as the pancreas, spleen, intestines, gonads, and adrenals occasionally exhibited positive viral protein signals. In these organs, in addition to parenchymal cells, viral protein signals were often identified in endothelial cells. Our results suggest that the 2022-2023 HPAIV H5N1 clade 2.3.4.4b replicated systemically in all examined birds, with brain lesions being the most prevalent and associated with a subset of birds displaying clinical signs observed perimortem.

First Documented Nesting of American White Pelicans (Pelecanus erythrorhynchos) in Ohio, USA

The discovery and documentation of a new breeding species in a defined area, such as a state, is a crucial first step in understanding the basic natural history of a species and its consequent needs for management and conservation. The American White Pelican has gradually expanded its breeding range from the prairies of North America into the Great Lakes region. While conducting a census on Herring Gulls (Larus argentatus) at least 4 nests of pelicans with either eggs or young were found. Further census showed a minimum of 12 almost fledged young. This report documents the first confirmed nesting of the American White Pelican in Ohio. This first nesting was observed in May 2023 on Turning Point Island, an artificial island in Sandusky Bay, Erie County, Ohio, in the western basin of Lake Erie. Continued nesting of pelicans in Ohio is expected in future years at this location and other suitable sites in the area. This species is likely to need future monitoring and management.

Eimeria erythrorhynchosi n. sp. (Apicomplexa: Eimeriidae) from the American white pelican Pelecanus erythrorhynchos Gmelin, 1789 (Pelecaniformes: Pelecanidae) in Toluca, Mexico

A new coccidian species, Eimeria erythrorhynchosi n. sp. (Apicomplexa: Eimeriidae) collected from the American white pelican Pelecanus erythrorhynchos Gmelin 1789, is reported from Toluca city, Mexico. Sporulated oocysts of the new species are ovoidal, 17.5–19.6 × 14.1−14.8 (18.5 × 14.5) μm, with a length/width (L/W) ratio of 1.0–1.5 (1.25); micropyle present, robust and protruding, W: 4.5–5.5, and polar body (1 or 2), L × W: 2.5 (2–3), associated with the micropyle; oocyst residuum absent. Sporocysts are ovoidal, 10.1–11.2 × 6.4−7.1 (10.7 × 6.8) μm, with a length/width (L/W) ratio of 1.0–1.6 (1.3); Stieda and sub-Stieda bodies are both present, but para-Stieda body is absent; sporocyst residuum of diffuse granules. Sporozoites are vermiform, 9.6 × 2.4 μm. The new species is the seventh species of Eimeria recorded in Pelecaniformes and the third in Pelecanidae.

Enteroparasites from the American White Pelican (Pelecanus erythrorhynchos) in Toluca Valley, Mexico.

We examined 82 fresh fecal samples from American White Pelican (Pelecanus erythrorhynchos) at San Pablo Autopan, Toluca Valley, central Mexico, December 2021 to April 2022. Eggs of Contracaecum spp. were observed in 100%, Capillaria spp. in two (2.5%), Strongyloides spp. in eight (9.7%), and coccidial oocysts in 12 (15%).

Estimating Cause‐Specific Mortality and Survival of Juvenile Fall Chinook Salmon: An Investigation of Avian Predation across Large Spatial Scales

AbstractTo investigate the effects of piscivorous colonial waterbird predation on juvenile salmonids (smolts) and to determine what proportion of all sources of smolt mortality was due to predation, we analyzed a data set describing fall Chinook Salmon Oncorhynchus tshawytscha that were marked with PIT tags in the Columbia River, USA. We used a state‐space Bayesian model that incorporated live detections of tagged fish and recoveries of tags from dead fish to jointly estimate predation and survival over multiple river reaches and years (2008–2019). By incorporating recoveries of tags on bird colonies, the model was also able to increase the precision and spatial extent of survival estimates compared with a more traditional capture–recapture model. Results indicated that the avian predation probability (proportion of available fish consumed) varied depending on the predator species, colony location, and the fish's rearing type. Estimates of cumulative predation probability ranged annually from 0.066 (95% credible interval = 0.049–0.089) to 0.283 (0.210–0.419), and predation accounted for 7.3% (4.3–11.9%) to 29.1% (19.7–40.2%) of all sources of smolt mortality during out‐migration to Bonneville Dam. Probabilities of predation on wild smolts were significantly higher than those for hatchery smolts in most river reaches and years. Predation probabilities were the highest for colonies of American white pelicans Pelecanus erythrorhynchos and double‐crested cormorants Nannopterum auritum, which were located near where wild smolts rear and congregate. Estimates of predation by Caspian terns Hydroprogne caspia, California gulls Larus californicus, and ring‐billed gulls L. delawarensis were often <0.03 of available smolts annually. Collectively, results indicated that the cumulative effects of predation on Chinook Salmon smolts were substantial in some but not all river reaches and years. Future models that consider biological and environmental factors influencing smolt susceptibility to avian predation may provide a more holistic understanding of the degree to which predation limits fish survival.

Natural West Nile Virus Infections in Captive Raised American White Pelicans (Pelecanus erythrorhynchos).

A presumptive natural West Nile virus outbreak occurred in 23 of 27 captive American White Pelicans (Pelecanus erythrorhynchos) located in Starkville, Mississippi. Twenty-one birds were confirmed positive through either reverse transcriptase PCR, immunohistochemistry (IHC) or complement fixation serological testing. Two additional birds were presumed positive by histological changes typically ascribed to West Nile virus. Two of the 23 infected pelicans had been previously implanted with a temperature monitor and served as case studies. These birds began showing clinical signs in July on day 27 and 30 post-placement, preceded by a reduction in food intake one day prior in both cases. Initial clinical signs observed in both birds included wing droop and lethargy and within 72 hours both birds displayed increased agitation and aggression during feeding. Here we detail the progression of disease caused by West Nile virus in two cases.

Copper Toxicity to the Ghost Rams‐Horn Snail Biomphalaria havanensis

AbstractAvian piscivores cause direct economic losses to the aquaculture industry through predation, as well as indirect losses through transmission of digenetic trematodes. Bolbophorus damnificus is a trematode parasite associated with significant losses in catfish aquaculture. The complex life cycle involves the American white pelican Pelecanus erythrorhynchos, planorbid snails, and ictalurid catfish. With no approved therapeutics for B. damnificus in catfish Ictalurus spp. and federal protections on American white pelican, management is restricted to controlling snail hosts. Two snail species, marsh rams‐horn snail Planorbella trivolvis and ghost rams‐horn snail Biomphalaria havanensis, are common inhabitants of commercial catfish ponds and known to transmit B. damnificus. Previous work evaluated copper sulfate toxicity on marsh rams‐horn snails; however, data are lacking for ghost rams‐horn snails. Herein, laboratory‐reared adults of ghost rams‐horn snails and marsh rams‐horn snails were exposed to copper concentrations ranging from 0.16 to 3.38 mg/L Cu to evaluate 24‐, 48‐, and 72‐h acute toxicity. Additionally, sequential low‐dose treatments ranging from 0.1 to 0.8 mg/L Cu were evaluated on eggs, juveniles, and adults of ghost rams‐horn snails as a potentially safer treatment regime for ponds. Acute toxicity was similar between snail species for all exposure times. A 72‐h exposure produced an LC50 of 0.10 and 0.37 mg/L Cu for ghost rams‐horn snails and marsh rams‐horn snails, respectively. The LC50 values increased to 1.1 mg/L Cu for both species with 48‐h exposure. However, in the multiple low‐dose study, a single dose of 0.4 or 0.8 mg/L Cu was lethal to all adult snails after 1 week, as was 0.2 mg/L Cu after two doses. Four doses of 0.1 mg/L Cu or greater killed all ghost rams‐horn snail juveniles. Results indicate that marsh rams‐horn snails and ghost rams‐horn snails have similar sensitivity to copper, and multiple low‐dose treatments were effective against all life stages of ghost rams‐horn snails. These data indicate that copper can be an effective treatment for snail control in commercial catfish ponds.

Migratory Movements and Home Ranges of Geographically Distinct Wintering Populations of a Soaring Bird

Migratory soaring birds exhibit spatiotemporal variation in their circannual movements. Nevertheless, it remains uncertain how different winter environments affect the circannual movement patterns of migratory soaring birds. Here, we investigated annual movement strategies of American white pelicans Pelecanus erythrorhynchos (hereafter, pelican) from two geographically distinct wintering grounds in the Southern and Northern Gulf of Mexico (GOM). We hypothesized that hourly movement distance and home range size of a soaring bird would differ between different geographic regions because of different thermals and wind conditions and resource availability. We calculated average and maximum hourly movement distances and seasonal home ranges of GPS-tracking pelicans. We then evaluated the effects of hour of the day, seasons, two wintering regions in the Southern and Northern GOM, human footprint index, and relative pelican abundance from Christmas Bird Count data on pelican hourly movement distances and seasonal home ranges using linear mixed models and generalized linear mixed models. American white pelicans moved at greatest hourly distance near 1200 h at breeding grounds and during spring and autumn migrations. Both wintering populations in the Northern and Southern GOM exhibited similar hourly movement distances and seasonal home ranges at the shared breeding grounds and during spring and autumn migrations. However, pelicans wintering in the Southern GOM showed shorter hourly movement distances and smaller seasonal home ranges than those in the Northern GOM. Hourly movement distances and home ranges of pelicans increased with increasing human footprint index. Winter hourly movements and home ranges of pelicans differed between the Northern and Southern GOM; however, the winter difference in pelican movements did not carry over to the shared breeding grounds during summers. Therefore, exogenous factors may be the primary drivers to shape the flying patterns of migratory soaring birds.

Composition and Structure of Mixed-Species Foraging Aggregations of Waterbirds in Las Salinas, Ciénaga de Zapata, Cuba

Mixed-species foraging aggregations of waterbirds result from foraging and anti-predator behaviors, and understanding the dynamics of these aggregations is useful in planning the conservation of waterbirds species and understanding their ecological functions within the ecosystem. This paper describes the dynamics in composition and structure of mixed-species foraging aggregations during the wet and dry seasons in the lagoon system of Las Salinas, Ciénaga de Zapata, Cuba. We surveyed these aggregations monthly from 2009 to 2017. Aggregation structure was analysed through relative abundance per guild, percentage of presence, and participation weight and participation rate. Forty-two mixed-species foraging aggregations of waterbirds were observed throughout the study, with greater species richness (n = 12 species, confidence interval: 10–13) and number of individuals (n = 800 individuals, confidence interval: 565–1,055) in the wet season. During the dry season, the most prominent species in aggregation formation were Snowy Egrets (Egretta thula), American White Ibises (Eudocimus albus) and Roseate Spoonbills (Platalea ajaja), which have been identified as nuclear species in other studies. In the wet season, American White Pelicans (Pelecanus erythrorhynchos) appeared to be the nuclear species within aggregations, something that had not previously been described in mixed-species aggregations of waterbirds. Confirming these nuclear species at Las Salinas is an important next step, given that conservation efforts focused on nuclear species might benefit the maintenance and function of the entire assembly.

Avian Predation on Juvenile and Adult Lost River and Shortnose Suckers: An Updated Multi‐Predator Species Evaluation

AbstractPrevious research suggests that predation by piscivorous colonial waterbirds may negatively influence the survival of Lost River Suckers (LRS) Deltistes luxatus and Shortnose Suckers (SNS) Chasmistes brevirostris in the Upper Klamath Basin (UKB), USA. However, estimates of predation from past studies, which were based on suckers with PIT tags, represent minimum estimates of sucker mortality because analyses did not account for the proportion of tags that were consumed by birds and deposited beyond their breeding colony. To address this uncertainty, we fed PIT‐tagged suckers to American white pelicans Pelecanus erythrorhynchos to estimate deposition probabilities. A hierarchical Bayesian model was then used to estimate predation rates (percentage of available tagged fish that were consumed) on juvenile suckers that were released as part of the Sucker Assisted Rearing Program (SARP) and on wild juvenile and adult LRS and SNS during 2009–2020. Pelican deposition probabilities were estimated to be 0.47 (95% credible interval = 0.36–0.60), indicating that for every 100 tags consumed, 47 tags on average were deposited on breeding colonies by birds. Deposition‐corrected estimates of predation rates were approximately two times greater than those previously reported and ranged annually from 4.3% (95% credible interval = 2.9–6.7%) to 8.5% (6.3–12.7%) on SARP juvenile suckers, from 4.3% (0.9–13.2%) to 10.5% (3.8–24.5%) on wild juvenile suckers, and from 0.1% (<0.1–0.3%) to 7.2% (2.8–16.4%) on adult suckers, depending on species and location. Results suggest that predation by colonial waterbirds, although not the original cause of sucker declines, was a substantial source of sucker mortality in some years. Future studies should consider models that jointly estimate both predation and survival and models that include environmental factors that potentially influence sucker susceptibility to avian predators in the UKB.

Seasonal Habitat Selection by American White Pelicans

Resource utilization strategies of avian migrants are a major concern for conservation and management. Understanding seasonal habitat selection by migratory birds helps us explain the ongoing continental declines of migratory bird populations. Our objective was to compare the second-order and third-order habitat selection by the American White Pelican (Pelecanus erythrorhynchos; hereafter pelican) between the breeding and non-breeding grounds. We tested the Lack hypothesis that habitat selection by migratory birds is stronger on the breeding grounds than on the non-breeding grounds. We used random-effect Dirichlet-multinomial models to estimate the second-order habitat selection between the seasons with the GPS locations of 32 tracked pelicans. We used Gaussian Markov random field models to estimate the third-order habitat selection by pelicans at the breeding and non-breeding grounds, accounting for spatial autocorrelation. Pelicans strongly selected waterbodies and wetlands at both non-breeding and breeding grounds, tracking their foraging habitats between the seasons at the home range level. However, pelicans exhibited seasonal differences in the strength of the third-order selection of wetlands and waterbodies with foraging habitat selection being stronger at the breeding grounds than at the non-breeding grounds, supporting the Lack hypothesis.

Seasonal variation and tracking of climate niche of a migratory bird

Migratory birds inhabit different areas during breeding and non-breeding seasons. Depending on the time of the year, they may utilize different resources available in seasonal habitats, but also are subjected to changing climate regimes during their annual life cycle. Migratory birds may adopt ecological niche tracking to cope with different environmental conditions between breeding and non-breeding grounds. The American White Pelican ( Pelecanus erythrorhynchos , hereafter ‘AWPE’) is a short-distance migrant between the Gulf of Mexico coastal regions (non-breeding grounds) and the Northern Great Plains (breeding grounds) of Canada and the US. The American White Pelican is a piscivore, feeding on fish, crayfish, and salamanders in inland freshwater wetlands. Cold, icy winter weather conditions substantially reduce and limit food resource availability at the breeding grounds during winters. Thus, we hypothesize that AWPEs would migrate between the breeding and non-breeding grounds to track climatic conditions that allow easier availability of resources. However, the niche tracking strategies have not been tested in AWPEs mainly due to the lack of reliable tracking data. Our objectives were to test whether the niche tracking or niche switching hypothesis would better explain seasonal variations in ecological niche overlap of AWPEs using the GPS locations of 19 tracked migrating birds, which had GPS locations at both breeding and non-breeding grounds. We estimated overlap of climate niche to test for seasonal niche tracking behaviors at both individual and population levels. Our results indicate that six out of 13 GPS-tracked AWPE individuals tracked climatic niche during the annual migration cycle. The analysis of the combined data of all 19 tracked AWPEs demonstrated that AWPEs tracked seasonal climate niche at the population level. Cold winter temperatures below zero (℃) may freeze the water surface of wetlands and shallow waterbodies, preventing AWPEs from acquiring sufficient food. The coupling of winter food resources with winter climatic conditions may result in climate niche tracking. Variation in climate niche tracking among individuals may offer ecological plasticity for AWPEs to cope with climatic changes. • Migratory birds may either track or switch ecological niche during the annual cycle. • American white pelicans are short-distance migratory birds. • American white pelicans tracked climate niche at individual and population levels. • Climate niche tracking may make American white pelicans vulnerable to warming.

Large- and Small-Scale Climate Influences Spring Migration Departure Probability of American White Pelicans

Endogenous (e.g., age and sex) and exogenous (e.g., climate and resource availability) factors influence avian migration phenology. However, little is known regarding the migration ecology of birds at the non-breeding grounds, including the American white pelican (Pelecanus erythrorhynchos). We used Global Positioning System transmitters to track the movements and migration of 51 pelicans from 2002 to 2012. We used the Kaplan–Meier model to estimate pelican spring migration probabilities to quantify partial migration with 94 spring migration events and used the Cox proportional hazards model to evaluate the effects of the North Atlantic Oscillation index (NAOI), Southern Oscillation Index (SOI), and spring daily precipitation on the propensity of pelican spring migration departures. Increases in the NAOI and SOI enhanced the propensity of pelican spring departure. The propensity of spring departure was also positively related to daily precipitation. Male pelicans have greater spring migration probabilities than female pelicans. Spring migration departure probabilities of adult pelicans are greater than those of immature pelicans. Therefore, both large-scale and local climatic conditions affect pelican spring departure probabilities. Advanced migratory phenology of pelicans caused by climate changes with warming temperature and increased precipitation may result in the mismatch of pelican spring arrival with food resource availability of breeding grounds and subsequent pelican population declines.

Conflicts among protected native birds and valuable sport fishes: potential pelican predation effects

Reservoirs are examples of novel ecosystems that have developed into popular sport fisheries; these systems are also becoming seasonal refuges for migratory birds, including the piscivorous American white pelican ( Pelecanus erythrorhynchos). We (1) investigated the proportion of cutthroat trout ( Oncorhynchus clarkii utah) and other species consumed by pelicans, (2) compared whether pelicans have an adverse effect on cutthroat trout spawning movement, and (3) determined the importance of pelican predation relative to other sources of fish mortality in Strawberry Reservoir, Utah, USA. Pelican diet samples consisted of >85% Utah sucker ( Catostomus ardens), 6% Utah chub ( Gila atraria), and 3% cutthroat trout. Based on bioenergetics, we estimated that pelicans consumed 384–3020 individual cutthroat trout (0.17%–1.3% of population), in contrast to 14 166–27 196 nongame sucker and chub. Bird-related mortality rate ranged from 1% to 6% for stocked, PIT (passive integrated transponder)-tagged adult cutthroat trout and from 4% to 16% for subadult cutthroat trout. Based on these results, any management action taken to control pelican predation would need to be weighed against the benefits of nongame fish removal and the protected status of pelicans.

Evaluating Target Levels of American White Pelican Abundance to Achieve Management Objectives for Adfluvial Yellowstone Cutthroat Trout

AbstractRecent declines in abundance of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in the upper Blackfoot River drainage in Idaho coincided with establishment of a nearby nesting colony and increased abundance of American white pelicans Pelecanus erythrorhynchos (hereafter, “pelicans”). Published pelican predation rates have been estimated to be as high as 70% on Yellowstone Cutthroat Trout in the Blackfoot River. Consequently, the Idaho Department of Fish and Game established management objectives for pelicans of less than 350 breeding pairs or 700 adults. However, a thorough assessment has not been conducted to evaluate if the pelican abundance objective would reduce predation to an extent that would allow Yellowstone Cutthroat Trout to recover to levels that meet minimum objectives for abundance. A Bayesian state‐space model that integrated survival and abundance data was used in this study to evaluate the effects of local pelican abundance on survival, abundance, and population growth rate of Yellowstone Cutthroat Trout. Survival of both juvenile and adfluvial adult Yellowstone Cutthroat Trout decreased as pelican abundance increased, and there was a positive relationship between survival of both life stages and population growth rate. If the current management objective for abundance of 700 breeding pelicans was met, the probability of meeting or exceeding the Yellowstone Cutthroat Trout objective was 0.44 and declined substantially as simulated pelican abundance increased beyond 700. Results of this study suggest that if pelican abundance can be maintained at or below the current management objective, there is a reasonable chance of meeting the management objective for Yellowstone Cutthroat Trout.

A Novel Automated Method for Point-Based Change Detection Increases Estimation Accuracy of Breeding Pairs in Waterbird Colonies

The number of breeding pairs is an essential indicator for assessing waterbird colony status. Accurate estimates require distinguishing stationary adults (likely to be breeders on nests) from nonstationary adults (likely to be loafing or foraging breeders or non-breeders). High-resolution multi-temporal aerial imagery obtained from manned aircraft, satellites, or unmanned aircraft systems (UAS) can be analyzed to determine bird movements and derive estimates of the number of stationary adults, which corresponds to the number of active nests, and thereby breeding pairs. Automated detection of stationary objects, such as nesting waterbirds, can be complicated by small positional changes of objects, either because of image co-registration errors or because the object slightly shifts position. A non-parametric, point-based approach was developed to distinguish stationary birds from moving birds using sequences of either two or three consecutive remotely-sensed images. This approach was tested with simulated data and during a case study of nesting American White Pelicans (Pelecanus erythrorhynchos). In both cases, the non-parametric point-based approach had higher accuracy than other established methods such as ground counts. Using two consecutive images had higher sensitivity (correct classification of stationary birds) while using three consecutive images had higher specificity (correct classification of nonstationary birds). This novel, multi-temporal nearest-neighbor method is most useful when positional shifts of stationary animals is low between consecutive images.

Giant panda behaviour recognition using images

Monitoring giant panda (Ailuropoda melanoleuca) behaviour is critical for their conservation and understanding their health conditions. Currently, captive giant panda behaviour is usually monitored by their caregivers. In previous studies, researchers observed panda behaviours for short time spans over a period. However, both caregivers and researchers cannot monitor them 24-h using traditional methods of observation. In other words, animal behaviour data are difficult to collect over long periods and are prone to errors when recorded manually. Some researchers have used wearable devices such as accelerometer ear tags and collar-mounted units with a global position system (GPS) receiver and contactless devices such as depth cameras and video cameras for understanding behaviour of other animals such as primates and American white pelicans. However, the giant panda, an icon of endangered species conservation, is almost completely neglected in these studies. To monitor giant panda behaviour effectively, a fully automated giant panda behaviour recognition method based on Faster R–CNN and two modified ResNet was created. The Faster R–CNN network was able to detect panda bodies and panda faces in images. One of the modified ResNet was trained to classify their behaviour into five classes, walking, sitting, resting, climbing, and eating and the other to recognise whether the panda’s eyes and mouth were opened or closed. Experiments were conducted on 10,804 images collected from over 218 pandas in various environments and illumination conditions. The experimental results were very encouraging and achieved an overall accuracy of 90% for the five panda behaviours and an overall accuracy of 84% for the subtle panda facial motions. The proposed method provides an effective way to monitor giant panda behaviour in captivity.

A Physiologically Based Oiling Model (PBOM) to Predict Thermoregulatory Response in Birds

When birds are exposed to oil, their ability to thermoregulate is impaired as a result of damage to the insulative properties of their feathers. If an oiled bird is unable to maintain thermal homeostasis, hypothermia and death can follow rapidly. Physiological responses to oiling depend on several variables including environmental conditions (e.g., ambient air and water temperatures), life history of bird species (e.g., body size and habitat selection), and foraging strategies (e.g., divers, surface feeders, shorebirds). The most widely used approach to assess the effect of spilled oil on birds is the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Type A Natural Resource Damage Assessment (NRDA) Model for Coastal and Marine Environments. This approach addresses body size and time spent in a hypothetical slick but lacks the flexibility to assess other variables related to physiological response. We developed a dynamic physiologically based oiling model (PBOM) for birds to address this need. The PBOM has been validated against empirical data from a dose-response study in which common eiders were exposed to Statfjord A crude oil. The PBOM can be used to predict time to hypothermia for birds of differing body size and habitat preferences, in environments ranging from Arctic to subtropical. The model presently includes 5 representative bird species: common eider, spotted sandpiper, great blue heron, dovekie, and American white pelican, but could be adapted to represent almost any bird. Environ Toxicol Chem 2021;40:251-260. © 2020 SETAC.