Environmental Conditions and Vehicle Disturbance Influence Stress Behaviors in a Working Harris's Hawk (Parabuteo unicinctus)

Harris's hawk (Parabuteo unicinctus) is used for pest control, as their presence can deter wild birds such as gulls. Working Harris's hawk on UK waste sites is permitted in accordance with regulations and legislation. This study investigated the general environment of a waste site compound yard where a single Harris's hawk was flown for pest control. The hawk's behaviors were evaluated in an ethogram, alongside environmental measures, and disturbance levels. Data was analyzed using Generalised Linear Latent Variable Models (GLLVM) to elucidate the effects of disturbance and environment on hawk behaviors. Results suggested cloudy conditions encouraged grooming responses that were normal and relaxed in their nature. Rain, sun and wind conditions increased recognized stress behaviors. Frequency of disturbance by construction vehicles inside the compound increased stress behaviors, such that keepers are recommended to revise welfare conditions. Increased stress behaviors by birds worked in dynamic environments like waste recycling yards could potentially elicit damaging illness such as feather breaking behavior. Reducing stress factors for Harris's hawk in industrial working yards combined with amending husbandry practices will improve welfare for the species.

Blood Vessel Topography of the Feet in Selected Species of Birds of Prey and Owls

Birds of prey and owls are susceptible to diseases of and traumatic injuries to their feet, which regularly require surgical intervention. A precise knowledge of the blood vessel topography is essential for a targeted therapy. Therefore, the metatarsal and digital vasculature was examined in eight species of birds of prey and owls. The study included contrast micro-computed tomography scans and anatomical dissections after intravascular injection of colored latex. In all examined species, the dorsal metatarsal arteries provided the main supply to the foot and their branching pattern and number differed between species. They continued distally as digital arteries. All examined species showed a basic pattern of four collaterally located digital blood vessels per toe: a prominent artery and small vein on one side and a small artery and prominent vein on the other side. Digital veins united to form common digital veins, most of which joined into a superficial, medially located metatarsal vein. This vein provided the main drainage of the foot. The detailed visualization of the topography of pedal blood vessels will help veterinary surgeons during surgical procedures. In addition, differences in the plantar arterial arch between hawks and falcons were discussed regarding their possible influence on the prevalence of pododermatitis (bumblefoot).

Changes in Environment and Management Practices Improve Foot Health in Zoo-Housed Flamingos

Foot lesions are a highly prevalent phenomenon among zoo-housed flamingos, with up to 99.8% of birds affected. These lesions are a recognized welfare concern, increasing the likelihood of bacterial infections, and even septicemia. Although several risk factors have been linked to foot lesions in flamingos (including age, climate, and substrate), there have been few studies looking at changes in foot lesions over time. This study tracked changes in foot lesions for an individual flock of Chilean Flamingos (97 birds) at Dublin Zoo, Ireland, over an 18-month period in response to a mandatory indoor housing order imposed by the Irish Government as a seasonal precautionary measure to prevent the spread of avian influenza. Using a pre-defined scoring system for four common types of foot lesions (hyperkeratosis, fissures, nodular lesions, and papillomatous growths), we show that providing unrestricted access to outdoor habitats and natural substrates (both terrestrial and aquatic) can improve the health and wellbeing of zoo-housed flamingos. This longitudinal study highlights the importance of regular foot health monitoring in flamingos, and the importance of natural aquatic substrates when managing flamingos. As many zoo-housed birds have been spending more time indoors on artificial substrates over recent years due to avian influenza housing orders, it is critical that we assess the impact of such changes in management and habitat access on bird health and welfare.

Oldest preserved umbilical scar reveals dinosaurs had 'belly buttons'

Background

In egg-laying amniotes, the developing embryo is tethered to a number of the extraembryonic membranes including the yolk sac and allantois that deliver oxygen and nutrients and remove metabolic waste products throughout embryonic development. Prior to, or soon after hatching, these membranes detach from the animal leaving a temporary or permanent umbilical scar (umbilicus) equivalent to the navel or ‘belly button’ in some placental mammals, including humans. Although ubiquitous in modern mammals and reptiles (including birds), at least early in their ontogeny, the umbilicus has not been identified in any pre-Cenozoic amniote.

Results

We report the oldest preserved umbilicus in a fossil amniote from a ~130-million-year-old early-branching ceratopsian dinosaur, Psittacosaurus. Under laser-stimulated fluorescence (LSF), the umbilicus is revealed as an elongate midline structure delimited by a row of paired scales on the abdomen. The relatively late ontogenetic stage (close to sexual maturity) estimated for the individual indicates that the umbilicus was probably retained throughout life.

Conclusions

Unlike most extant reptiles and birds that lose this scar within days to weeks after hatching, the umbilicus of Psittacosaurus persisted at least until sexual maturity, similar to some lizards and crocodylians with which it shares the closest morphological resemblance. This discovery is the oldest record of an amniote umbilicus and the first in a non-avian dinosaur. However, given the variability of this structure in extant reptilian analogues, a persistent umbilical scar may not have been present in all non-avian dinosaurs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01329-9.

Surviving the Urban Jungle: Anthropogenic Threats, Wildlife-Conflicts, and Management Recommendations for African Crowned Eagles

Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to humans and domestic animals’ safety, which generate the need for management and removal strategies. These issues become especially challenging when humans and wildlife coexist close to one another, for example, in urban landscapes. African Crowned Eagles (Stephanoaetus coronatus) are powerful forest raptors that breed within the metropolitan green-space system of Durban and Pietermaritzburg, South Africa. Negative human-wildlife interactions can occur because eagles occasionally predate on pets, such as cats (Felis catus) and small dogs (Canis lupus familiaris), and provisioning domestic stock to nest sites has previously been quantified. Here, wildlife management becomes critical, usually aimed at reducing or eliminating causes of economic or social harm, but have to be balanced against conservation goals regarding threatened species. In this study, we (i) identified causes of harm or loss of Crowned Eagles because of injuries (n = 53 incidents; 31 mortalities); and (ii) describe interactions with negative perceptions to human livelihoods, particularly concerning predation on pets and livestock. Anthropogenic causes of mortality were more likely to be reported than remote natural deaths, which provides important opportunities for mitigation measures. Most avoidable are electrocution on utility poles, persecution via gunshot wounds and poisoning (targeted or secondary), while collisions with anthropogenic structures, such as glass panes, vehicles and fence wires, are more challenging to mitigate. Out of 44 verified Crowned Eagle vs. pets and livestock conflicts, we documented 19 dog attacks (2012–2020), with detrimental impacts on social perception and acceptance of urban eagles. Pet and livestock conflicts were primarily associated with juveniles and immature eagles (83%). Of these, 19% occurred during September alone, which marks the end of the post-fledging dependency period; 70% occurred outside the breeding season. We provide management recommendations regarding various categories of Crowned Eagle human-wildlife interactions. For example, activities such as rehabilitation and falconry can coordinate to achieve a high standard of public support and conservation outcomes for Crowned Eagles. Finally, we discuss using different management intervention strategies, including rehabilitation, falconry, re-wildling processes, and lethal control of specific “problem” individuals toward achieving the goal of sustainable, healthy Crowned Eagle populations that coexist with humans in urban landscapes.

Successful, Full-Thickness Skin Graft in a Bald Eagle (Haliaeetus leucocephalus)

A subadult, male bald eagle (Haliaeetus leucocephalus) was evaluated after being found unable to fly, with large eschars on the dorsal head and right stifle. Because of the appearance and location, the lesions were believed to be caused by an electrical injury. Treatment included oral antibiotics, nonsteroidal anti-inflammatory drugs, pain medication, surgical debridement of the eschars, and trephining of the affected inner table of the cranium. A full-thickness skin graft was performed to expedite wound healing and minimize holding time. After 6 weeks, the bird had new feather growth on its dorsal head and was released. This is the first report, to our knowledge, of a nonmesh, full-thickness skin graft in an avian species. Full-thickness skin grafts should be considered as a surgical option in juvenile or adult avian patients with large dorsal head wounds.

Management of Severe Frostbite in a Grey-Headed Parrot (Poicephalus fuscicollis suahelicus)

An approximately 5-year-old female grey-headed parrot (Poicephalus fuscicollis suahelicus) was evaluated after exposure to outdoor temperatures below -20°C (-4°F) for approximately 22 hours. Severe frostbite affecting multiple digits, as well as dehydration and a depressed attitude, were diagnosed. Treatment included oral antibiotics, antifungals, nonsteroidal anti-inflammatories (NSAIDs), pentoxifylline, and topical aloe vera. Surgical amputation of the affected toes was not performed. Mild to moderate pododermatitis over the intertarsal joints developed because of a shift in weight bearing after the loss of most digits. Within 5 months after initial presentation, all frost-damaged toes had self-amputated, and the bird was able to function independently with no limitations in mobility.

Viability and discrimination of avian peripheral blood mononuclear cells and thrombocytes intended for improvement of wound healing in birds

Birds often suffer from skin injuries of different aetiology. Platelet-rich plasma (PRP) is successfully used for improvement of wound healing in humans and in some mammalian species (e.g. horses, dogs and cats), but experience with its application in avian patients has not yet been published. Therefore, the aim of this study was to test a quick method for the counting of isolated avian platelets and mononuclear leukocytes and to find an appropriate carrier for their application to the wounds of birds. It seems that flow cytometry can be used for the quick counting of isolated cells and the discrimination of thrombocytes, lymphocytes and eventually monocytes or debris. Of the tested gels and sponges routinely used for improvement of wound healing, a gelatin sponge (Gelaspon®) providing the highest numbers and viability of isolated cells proved to be the best carrier.

Advancement flap as a novel treatment for a pododermatitis lesion in a red-tailed hawk (Buteo jamaicensis)

Pododermatitis is a pathologic condition commonly reported in captive raptors and characterized by swelling, excoriation, ulceration, cellulitis, or abscessation of the plantar aspect of the foot. Its cause can be multifactorial, often involving abnormal weight bearing or poor sanitation, and medical and surgical techniques, in addition to environmental alterations, are hallmarks of treatment. In this case, a single pedicle advancement flap was used to treat chronic, nonresponsive grade V/VII pododermatitis of the right metatarsal pad in a red-tailed hawk (Buteo jamaicensis). The advancement flap was formed by using the interdigital skin between digits 3 and 4. The double layer of skin was incised and separated, and the leading edge of the flap was then advanced over the defect and secured with simple interrupted subcutaneous and skin sutures. The foot was bandaged after surgery to take pressure off the surgical site. At 58 days after the surgery, the hawk was deemed medically sound with no signs of pododermatitis and was released to a wildlife rehabilitator. The use of a single pedicle advancement flap has not previously been reported for the treatment of pododermatitis.

Application of a single vascularised skin flap in eastern imperial eagle with skin defects

Skin defects are a frequent problem in avian clinical practice. They require rapid and effective therapy due to the absence of available skin around the skin defects and desiccation of the surrounding tissue. Within the period of one year, between March 2010 and April 2011, several specimens of eastern imperial eagle (Aquila heliaca) were treated at the Clinic of Exotic and Free-Living Animals of the University of Veterinary Medicine and Pharmacy in Košice. Three of them (cases 1, 2 and 3) had damaged skin on their limbs. The skin defects presented in these patients required surgical treatment by a vascularised skin flap. Acceptance of the skin flap on the entire recipient site was seen in all three patients. Complete healing, as well as functioning of the damaged sites were observed within two months from the surgery. Using surgical treatment in case of extensive skin damages, as well as skin damages in hardly accessible locations, helps to prevent a number of complications associated with the management of the treatment of open wounds. The given method appears suitable also due to a better cosmetic effect and lower degree of stress to the patients.

Management of select bacterial and parasitic conditions of raptors

Raptors are susceptible to a broad array of established and emerging bacterial and parasitic diseases, including babesiosis, chlamydiosis, clostridiosis, coccidiosis, cryptosporidiosis, malaria, mycobacteriosis, pasteurellosis, salmonellosis, trichomoniasis, and pododermatitis. Many of these conditions are opportunistic and can be easily managed or averted with proper preventive measures related to captive management, husbandry and diet, and veterinary care. Once infected, treatment must be prompt, appropriate, and judicious. This article examines the significance, diagnosis, management, and prevention of select bacterial and parasitic pathogens of raptors.

Emergency care of raptors

Raptors may present with a variety of conditions, such as trauma, debilitation, and disease, that necessitate emergency care. Emergency treatment should prioritize stabilization of the patient. Diagnostic testing should be delayed until feasible based on patient status. This article reviews emergency medicine in raptors, including appropriate handling and restraint, hospitalization, triage and patient assessment, sample collection, supportive care, and common emergency presentations.

Wound management in nonpsittacine birds

Although nonpsittacine avian species comprise many different groups of birds, basic medical and surgical principles common to wound management in many vertebrate species are still applicable. This article will delve into examination and wound assessment along with therapeutic stabilization of wounded nonpsittacine birds. An overview of common case presentations that lead to a necessity for wound care are included, and may focus on one particular avian group, but the information can be used on a variety of avian species.

Wound healing and management in psittacine birds

Psittacines and other companion avian species often develop wounds requiring some form of medical or surgical therapy. Advancing technology in the field of wound care and management continues to evolve for use by the veterinary clinician. Although not all wounds can be successfully treated, many can be reduced and minimized with therapy. Consideration of the overall health, management, and nutrition of the avian patient will also aid in wound management. The avian patient with normal immune function and optimal nutrition will have improved wound healing compared with an immunocompromized or malnourished patient. The duration of treatment and potential stress of the wound-management program should also be taken into consideration when selecting a treatment program for the avian patient.