Barry K. Hartup

Integrating in-situ (wild) and ex-situ (captive) conservation efforts can mitigate genetic diversity loss and help prevent extinction of endangered wild populations. The whooping crane ( Grus americana ) experienced severe population declines in the 18th century, culminating into a collapse to 16 individuals in 1941. Legal protections and conservation actions have since increased the population to approximately 840 individuals, yet the impact on genomic diversity remains unclear. We analysed the temporal dynamics of genomic erosion by sequencing a high-quality genome reference, and re-sequencing 16 historical and 37 modern genomes, including wild individuals and four generations of captive-bred individuals. Genomic demographic reconstructions reveal a steady decline, accelerating over the past 300 years with the European settlement of North America. Temporal genomic analyses show that despite demographic recovery, the species has lost 70% of its genetic diversity and has increased their inbreeding. Although the modern population bottleneck reduced the ancestral genetic load, modern populations possess more realized load than masked load, possibly resulting in a chronic loss of fitness. Integrating pedigree and genomic data, we underscore the role of breeding management in reducing recent inbreeding. Yet ongoing heterozygosity loss, load accumulation, and background inbreeding argues against the species’ downlisting from their current Endangered status on the IUCN Red List and the Endangered Species Act. The presence of private genetic variation in wild and captive populations suggests that wild-captive crosses could enhance genetic diversity and reduce the realized load. Our findings emphasize the role of genomics in informing conservation management and policy.

Pododermatitis and wing lesions are commonly reported issues in captive crane species. Regional limb perfusion has been used as a treatment for distal limb infections in several avian species, as systemic antibiotic therapy is often prolonged and unrewarding. A black-necked crane (Grus nigricollis), Siberian crane (Leucogeranus leucogeranus), and wattled crane (Bugeranus carunculatus) were treated with amikacin (5–10 mg/kg IV infusion) regional limb perfusion for cellulitis and osteomyelitis of hind limb digits and alular osteomyelitis and septic arthritis of the carpus, respectively, with a range of 1–3 treatments per case. Clinical signs of infection resolved within 10–40 days following regional limb perfusion combined with oral or parental antibiotic therapy. No side effects were observed following regional limb perfusion. This is the first report of regional limb perfusion in cranes and the first report of intravenous regional limb perfusion in a wing of an avian species.

We investigated concentrations of blood total mercury (THg) in three extant populations of endangered Whooping Crane (Grus americana). Blood THg was greater in cranes reintroduced during 2001–2008 that range in the eastern US (median = 0.31 ug/g ww) than both wild cranes in central North America (median = 0.11 ug/g ww) and from captivity (median = 0.01 ug/g ww). The median THg blood concentrations in the two free-ranging populations of Whooping Cranes were low compared to reproductive toxic thresholds suggested for other large bird species (> 4.3 ug/g ww), but a singular elevated concentration was observed in one crane (1.04 ug/g ww; 6% of samples from the reintroduced population). These results likely reflect variable dietary Hg exposure among these populations, but should prompt additional biomonitoring to discern risk of greater Hg exposure nearer to the time of breeding and potential effects on productivity.

We reviewed necropsy records of 124 Whooping Cranes (Grus americana) recovered following reintroduction of 268 individuals from 2001 to 2016 in the eastern US. Causes of death were determined in 62% (77/124) of cases facilitated by active monitoring that limited decomposition and scavenging artifact. The greatest proportions of mortality were caused by predation (0.468; 95% confidence interval 0.356–0.580; 36/77), collision with power lines or vehicles (0.260; 0.162–0.358; 20/77), and gunshot (0.169; 0.085–0.253; 13/77). Six deaths were attributed to infection (0.078; 0.018–0.138; 6/77), including bacterial and fungal etiologies. Lead analysis of 50 liver samples yielded two results with elevated concentrations (3.65 and 10.97 ppm wet weight), and 10 bone samples from partial carcasses lacking suitable liver tissue resulted in one elevated result (48.82 ppm dry weight). These data indicate that underlying subclinical or clinical lead toxicosis may be a factor in up to 5% of deaths attributed to predation or impact trauma. Brain cholinesterase activity testing indicated no exposure to organophosphate or carbamate pesticides (mean±SD=17.32±2.90 µmol/min/g, 31/71). The causes of death and potential underlying factors summarized in this study constitute the first definitive mortality survey of migratory Whooping Cranes based on a high carcass recovery rate. Causes of death by infectious etiologies remained comparatively rare in this study, and occurred as single cases with no evidence of sustained transmission among reintroduced Whooping Cranes.

Biochemical and trace element analyses of blood from wild Whooping Cranes (Grus americana) were performed to assess the health of the only self-sustaining, migratory population in North America. Juvenile cranes (n=31) approximately 49–70 d-old were sampled at Wood Buffalo National Park, Northwest Territories, Canada, in midsummer from 2010 to 2012. Archived serum (n=24) and whole blood (n=31) samples from captive juvenile cranes were selected as age-matched controls. Reference values were calculated for serum biochemical analytes and trace elements in whole blood from the captive juvenile Whooping Cranes reared under controlled conditions and with known health histories. Several statistical differences among blood biochemical and trace element values of the wild and captive juveniles were identified and were likely attributable to dietary differences between the populations.

Juvenile whooping cranes (Grus americana) raised for wild release were found to have an increased incidence of rib fractures at fledging in 2017 compared with the previous 16 years. Serum analysis showed 30-day-old juveniles in 2017 (n = 12) had significantly lower 25-hydroxyvitamin D3 and significantly higher parathyroid hormone concentrations than juveniles in 2010 (n = 6) with no history of rib fractures. Increased serum parathyroid hormone concentrations in the 2017 juveniles persisted to fledging age. Review of dietary and environmental management revealed that juveniles in 2017 were provided a commercial diet with a lower, and perhaps suboptimal, calcium:phosphorus ratio and experienced reduced time outdoors in the first month after hatch, presumably resulting in less ultraviolet B radiation exposure. Mild hyperparathyroidism in precocial whooping cranes may result when dietary constraints and/or outdoor access is compromised and manifest as rib fractures in the absence of traumatic injury.

To investigate the pharmacokinetics of the nonsteroidal anti-inflammatory drug (NSAID) piroxicam in cranes, three brolgas (Antigone rubicunda) were administered piroxicam as a single oral dose at 0.5 mg/kg and 1.0 mg/kg during separate trials. Serial blood samples were collected for quantification of piroxicam in plasma. Piroxicam was readily absorbed at both dosages, and no adverse effects were observed. Plasma concentrations peaked at 3.67 hr with a concentration of 4.00 μg/ml for the lower dosage, and at 0.83 hr at 8.77 μg/ml for the higher dosage. Piroxicam may exhibit linear kinetics and dose proportionality in brolgas, but will require further study. Mean peak plasma concentrations in brolgas were comparable to concentrations demonstrated to be analgesic in humans. To the authors' knowledge, this study represents the first pharmacokinetic investigation of piroxicam in an avian species.

This paper presents veterinary management strategies and diagnostic findings in the reintroduction of the endangered whooping crane (Grus americana). Between 2005 and 2010, 63 (27 male, 36 female) hatchling whooping cranes were assigned to a reintroduction project involving autumn release of costume-reared chicks in Wisconsin. Veterinary care included preventive measures and comprehensive pre-release evaluations to improve fitness and reduce translocation of potential disease agents to native habitats. A total of 44 clinically normal birds were released (70% of assigned individuals). Cases of morbidity were classified according to primary body system affected. Musculoskeletal disorders were described in 57 birds (90%); five birds were removed from the project prior to release (8%), all for abnormalities that prevented normal function. Fourteen birds died or were euthanized prior to release (22%); pre-release mortality was attributed to developmental abnormality, predation, trauma or infectious disease. Chronic respiratory aspergillosis, diagnosed in seven birds (11%), was the most common infectious disease of concern. Predation and trauma were primary causes of post-release mortality; no evidence of infectious disease of captive origin was detected in the study population by the end of 2010. The assessment of data accumulated by this project helped to outline successful health management strategies, as well as identify and mitigate ongoing risks to captive whooping cranes that impede reintroduction efforts and achieving management goals for species recovery. Zoo Biol. 32:600–607, 2013.

This study investigated the ecology of hematozoan parasites in two eastern populations of House Finch (Carpodacus mexicanus). Blood smears were obtained from birds captured in Georgia during 2001-2003 (n = 757) and New York during 2001 (n = 282) and evaluated for the presence of hematozoans. Low-density infections of Haemoproteus fringillae and Plasmodium relictum were confirmed at each location. Infections were observed year-round in Georgia, but primarily between June and November in New York. Overall, hematozoa were more prevalent in House Finches from Georgia than New York (P </= 0.01). The prevalence of infection was similar between finches of different age, sex, and reproductive status in Georgia. The low density of the infections observed suggests there is limited influence on host mortality.