PROGNOSTIC INDICATORS OF REHABILITATION OUTCOMES FOR ADULT AFRICAN PENGUINS (SPHENISCUS DEMERSUS)

Factors determining the number of seabirds impacted by oil spills and the success of their rehabilitation: Lessons learned from Namibia and South Africa

The coastal waters of Namibia and South Africa have an extensive history of oil spills, with 71 recorded up to 2021. Thirty-nine spills reportedly affected 83,224 seabirds, with African penguins (Spheniscus demersus; 91.0 %) and Cape gannets (Morus capensis; 8.5 %) most affected. Spills affecting seabirds were caused by unknown sources (46 %), bulk/cargo carriers (43 %), tankers (38 %) and ship-to-ship transfers (14 %). The number of penguins oiled was predicted by the breeding population size within 25 to 75 km, but not the volume of oiled spilled, the month or the year. Rehabilitation records from penguins oiled in spills since 2001 reveal that the day of admission (relative to the start of the spill) was predictive of packed cell volume, body mass, and plasma total solids, with the latter two being predictive of rehabilitation success. Our results highlight the importance of rapid monitoring at colonies to locate oiled birds in the event of spills.

A systematic review of factors affecting wildlife survival during rehabilitation and release

Millions of native animals around the world are rescued and rehabilitated each year by wildlife rehabilitators. Triage and rehabilitation protocols need to be robust and evidence-based, with outcomes consistently recorded, to promote animal welfare and better understand predictors of wildlife survival. We conducted a global systematic review and meta-analysis of 112 articles that reported survival rates of native mammals and birds during rehabilitation and after release to determine intrinsic and extrinsic factors associated with their survival. We assessed survival during rehabilitation and in the short- and long-term post-release, with the hypothesis that survival will vary as a function of species body size, diel activity pattern, trophic level and study location (region of the world). We aimed to determine the direction of effect of these factors on survival to assist in decision-making during triage and rehabilitation. Results showed that mammals and birds were equally likely to survive all stages of rehabilitation, and survival rates varied between locations. Birds in North America had the poorest survival rates post-release, particularly long-term, as did diurnal and carnivorous birds in the short-term post-release. Anthropogenic factors such as motor vehicle collisions and domestic or feral animal attack contributed to morbidity and post-release mortality in 45% (168 of 369) of instances. The reasons for rescue and associated severity of diagnosis were commonly reported to affect the likelihood of survival to release, but factors affecting survival were often species-specific, including bodyweight, age, and characteristics of the release location. Therefore, evidence-based, species-specific, and context-specific protocols need to be developed to ensure wildlife survival is maximised during rehabilitation and post-release. Such protocols are critical for enabling rapid, efficient rescue programs for wildlife following natural disasters and extreme weather events which are escalating globally, in part due to climate change.

RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY OF AFRICAN PENGUINS (SPHENISCUS DEMERSUS) UNDER MANAGED CARE IN NORTH AMERICA: 2007-2018

Currently, more than 20% (51/240) of zoos and aquariums accredited by the Association of Zoos and Aquariums house African penguins (Spheniscus demersus) in their collections. The African penguin Species Survival Plan (SSP) veterinary advisors regularly collect information from those facilities to characterize morbidity and mortality for this species and to collate preventative medicine and treatment regimens. These efforts resulted in more than 10 yr of collection of management data across the SSP, representing the care and management of more than a thousand birds. The most common morbidities reported included those of dermatologic (27%, 125/452 institutions) and musculoskeletal or neurologic (18%, 82/452 institutions) disease, while the most common causes of mortality were respiratory diseases (20%, 65/323 deaths) and systemic or multifactorial conditions (19%, 62/323 deaths). Aspergillosis cases accounted for 69% (45/65 deaths) of respiratory-related mortality and avian malaria cases comprised 31% (19/62 deaths) of mortality related to systemic diseases. Mortality was most commonly reported in geriatric birds, or those older than 15 yr of age (34%, 111/323 deaths). Reproductive related mortality was only defined in female birds, while other causes of death were more evenly distributed between sexes. Utilizing the SSP data to determine morbidity and mortality trends within this population provides important information to veterinary and animal care teams, allowing them to provide enhanced levels of care to the penguins housed at their institutions. By recognizing the most important diseases and causes of death in this species, management and healthcare resources can target conditions with the highest impact on the population.

Untapped potential of physiology, behaviour and immune markers to predict range dynamics and marginality

Linking environmental conditions to the modulators of individual fitness is necessary to predict long-term population dynamics, viability, and resilience. Functional physiological, behavioral, and reproductive markers can provide this mechanistic insight into how individuals perceive physiological, psychological, chemical, and physical environmental challenges through physiological and behavioral responses that are fitness proxies. We propose a Functional Marginality framework where relative changes in allostatic load, reproductive health, and behavior can be scaled up to evidence and establish causation of macroecological processes such as local extirpation, colonization, population dynamics, and range dynamics. To fully exploit functional traits, we need to move beyond single biomarker studies to develop an integrative approach that models the interactions between extrinsic challenges, physiological, and behavioral pathways and their modulators. In addition to providing mechanistic markers of range dynamics, this approach can also serve as a valuable conservation tool for evaluating individual- and population-level health, predicting responses to future environmental change and measuring the impact of interventions. We highlight specific studies that have used complementary biomarkers to link extrinsic challenges to population performance. These frameworks of integrated biomarkers have untapped potential to identify causes of decline, predict future changes, and mitigate against future biodiversity loss.

Non-invasive hormone monitoring as a robust method for determining adrenocortical activity in injured, emaciated and oil-contaminated African penguins undergoing rehabilitation

Anthropogenic activity is a major driver of seabird injury and mortality in the 21st century. Although most seabirds perish within the natural environment as a result of human activities, some are rescued and admitted to rehabilitation centres. Despite the considerable number of admissions, little is known regarding the physiological response seabirds have to specific admission reasons and the rehabilitation process. In this study, we aimed to determine the effect of injury, emaciation, oiling, individual removal from the natural environment and the rehabilitation process on the physiological stress response of the African penguin (Spheniscus demersus). Urofaecal samples were collected from African penguins throughout a three-stage rehabilitation process and quantified for glucocorticoid metabolites (ufGCM). The three stages included an initial ICU crate stage (Stage 1), an ICU pen stage (Stage 2) and a rehabilitation stage (Stage 3). Data were analysed using a generalised linear model in order to determine the effect of admission reason, age and rehabilitation stage (Stage 1, 2 and 3) on ufGCM levels. Although the model indicated that only Stage 1 was a significant driver of adrenocortical activity in the study population, ufGCM levels of injured and emaciated animals within Stage 1 were considerably higher than those of birds with any other admission reason across all stages. This is the first study examining the causes and effect of rehabilitation on the physiological stress response in African penguins. Enhanced care and attention should be given to rescued individuals, especially during the first stage of rehabilitation, to reduce perception of additional stressors and thus increase the chance of full recovery.

Effects of petroleum exposure on birds: A review

Birds are vulnerable to petroleum pollution, and exposure has a range of negative effects resulting from plumage fouling, systemic toxicity, and embryotoxicity. Recent research has not been synthesized since Leighton's 1993 review despite the continued discharge of conventional petroleum, including high-volume oil spills and chronic oil pollution, as well as the emergence of understudied unconventional crude oil types. To address this, we reviewed the individual-level effects of crude oil and refined fuel exposure in avifauna with peer-reviewed articles published 1993-2020 to provide a critical synthesis of the state of the science. We also sought to answer how unconventional crude petroleum effects compare with conventional crude oil. Relevant knowledge gaps and research challenges were identified. The resulting review examines avian exposure to petroleum and synthesizes advances regarding the physical effects of oil hydrocarbons on feather structure and function, as well the toxic effects of inhaled or ingested oil, embryotoxicity, and how exposure affects broader scale endpoints related to behavior, reproduction, and survival. Another outcome of the review was the knowledge gaps and challenges identified. The first finding was a paucity of oil ingestion rate estimates in birds. Characterizing environmentally realistic exposure and ingestion rates is a higher research priority than additional conventional oral dosing experiments. Second, there is an absence of toxicity data for unconventional crude petroleum. Although the effects of air and water contamination in the Canadian oil sands region have received attention, toxicity data for direct exposure to unrefined bitumen produced there in high volumes and other such unconventional oil types are needed. Third, we encountered barriers to the interpretation, replication, broad relevance, and comparability of studies. We therefore propose best practices and promising technological advancements for researchers. This review consolidates our understanding of petroleum's effects on birds and points a way forward for researchers and resource managers.

Hematology and Blood Chemistry Reference Values of Captive Adult Black-Faced Ibis (Theristicus melanopis melanopis)

Hematology and blood chemistry reference values in wildlife animals are considered a key element to evaluate their health and welfare status. The incidence of birds rescued is increasing, thus, rehabilitation centers worldwide need valid reference values to improve medical care for wild individuals. The objective of this study was to obtain the reference values of the adult black-faced ibis (Theristicus melanopis). Blood was taken from adult rehabilitated birds and analyzed to obtain red and white line values such as hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), heterophils, lymphocytes, monocytes, eosinophils and basophils. Values for blood glucose, proteins, albumin, globulin, calcium, phosphorus, blood urea nitrogen (BUN), creatinine, alkaline phosphatase, aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and albumin:globulin (A/G) ratio were also obtained. The results were similar to others reported for species of the Threskiornithidae family (bald, glossy and Puna ibises), but showed higher values for white blood cells (WBC), heterophils, monocytes and heterophil-lymphocyte (H/L) ratio, but lower values for basophils and eosinophils. Moreover, higher values in albumin, BUN and CPK were observed. This is the first report of the hematology references values for the black-faced ibis showing differences to other closely related species. The results may be of use in rescue and rehabilitation centers for animal welfare and health assessments of the black-faced ibis.

FACTORS AFFECTING ABNORMAL MOLTING IN THE MANAGED AFRICAN PENGUIN (SPHENISCUS DEMERSUS) POPULATION IN NORTH AMERICA

Abnormal molting, including partial or incomplete molt, arrested molt cycle, or inappropriate frequency of molt, is a primary concern for the managed African penguin (Spheniscus demersus) population and is documented across institutions. To identify factors associated with increased odds of abnormal molts and characterize intervention opportunities, a comprehensive survey evaluating numerous husbandry and medical parameters was created. Survey results represent 45 North American African penguin holding facilities and 736 unique animals. Of these individuals, 135 (18.3%) demonstrated an abnormal molt over the 5-yr study period (2012-2017). Increased odds ratios for abnormal molt included biologic (age, sex, etc.), geographic (elevation, latitude), and husbandry (exhibit design, diet, etc.) variables. The mean age of affected animals was 15.2 yr (1-45 yr, n = 135) compared with 9.92 yr (4 mo-38 yr, n = 601) for unaffected animals. In addition, although statistically insignificant, males were overrepresented in the affected cohort compared with a near even distribution among unaffected animals. Identified factors with increased odds for abnormal molting included advanced age and facilities using freshwater pools. Normally molting penguins were more commonly found with saltwater pool access and natural lighting exposure. Anecdotal medical intervention attempts are discussed, although further research is needed to define their use. Of attempted interventions, subcutaneous 5.4-mg melatonin implants placed in anticipation of environmental molting cues showed the most promise at inducing catastrophic molt, with 14 of 17 (82.3%) of affected individuals molting normally following this treatment. Survey analysis indicated that abnormal molt is a complex, multifactorial process, and modifiable factors that may predispose animals to abnormally molt exist. Addressing these factors in future exhibit design may mitigate the prevalence of this condition. Despite these efforts, it is likely that medical interventions will be required to aid in the treatment of abnormal molting in this species.

Determinants of external and blood parasite load in African penguins (Spheniscus demersus) admitted for rehabilitation

We investigate the factors associated with the occurrence and abundance of external and blood parasites in African penguins (Spheniscus demersus), an endangered seabird that breeds exclusively on the coasts of Namibia and South Africa. External parasites were collected using the dust-ruffling method from 171 African Penguins admitted at a rehabilitation facility in the Western Cape, South Africa. Additionally, blood smears were obtained upon admission and weekly during rehabilitation and examined for blood parasites. Fleas Parapsyllus longicornis humboldti, ticks Ornithodoros capensis and lice Austrogoniodes demersus were recovered from 93, 63 and 40%, respectively, of the penguins upon admission to the centre. Rescue location and age group were identified as significant determinants of flea abundance, whereas month of admission was a significant determinant of tick abundance. Blood parasites were also common on admission, with Babesia being the most frequent (46% prevalence) whereas Borrelia was recorded sporadically (1.2%) and Plasmodium was recorded once. The prevalence and abundance of ticks on admission was positively associated with Babesia infection on admission. Our findings demonstrate the variability and contributing factor of parasite infections in an endangered species of penguin, and highlight the need for additional research on the parasite-host dynamics involving these potential disease vectors.

Empirical Primaquine Treatment of Avian Babesiosis in Seabirds

Babesia species are tickborne hemoprotozoans. Although experiments have shown that primaquine is highly effective in the treatment of Babesia species infections in mammals, this drug has not been widely used for the treatment of avian babesiosis. Consequently, the treatment of this disease for avian patients has traditionally relied on an empirically established imidocarb treatment. In this study, the authors examined the efficacy of primaquine as a treatment alternative for avian babesiosis (Babesia peircei and Babesia ugwidiensis) in seabirds. Retrospective analysis was performed on the medical records and blood smears of 446 B peircei-positive African penguins (Spheniscus demersus) and 41 B ugwidiensis-positive Cape cormorants (Phalacrocorax capensis) admitted for rehabilitation at the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB, Cape Town, South Africa). Treatment with primaquine (1 mg/kg PO q24h for 10 days) was effective in rapidly and markedly decreasing the proportion of Babesia-positive blood smears in African penguins and Cape cormorants. No regurgitation, loss of appetite, or any other signs after administration of primaquine were observed during the study period. The use of primaquine can be a particularly advantageous treatment alternative for avian babesiosis in circumstances in which it is not possible to determine confidently whether the intraerythrocytic inclusions seen in blood smears correspond to Babesia or Plasmodium or in cases in which there is a coinfection by Babesia and Plasmodium.

PROGNOSTIC INDICATORS OF IMMATURE REHABILITATED AFRICAN PENGUINS (SPHENISCUS DEMERSUS) IN SOUTH AFRICA

The Southern African Foundation for the Conservation of Coastal Birds (Cape Town, South Africa) regularly receives African Penguins (Spheniscus demersus) for rehabilitation. The impact of life history and clinical parameters at admission of 3,975 chicks, 1,687 blues (chicks without downy plumage that are about to fledge or have recently fledged), and 850 fledged juveniles admitted over a 12 yr period (2002-13) were assessed in relation to rehabilitation outcomes using multivariate analysis. Younger chicks were more likely to die during rehabilitation compared with older chicks, and chicks admitted because they had been abandoned by their parents were more likely to die than those admitted preemptively (chicks that were removed when rangers considered their nests were in high-risk areas). Blues admitted because of injury and juveniles admitted because of debilitation, injury, and molt were more likely to die or be euthanized relative to the reference category oiling. Plasmodium infection contributed to natural death for all age groups and to the decision to euthanize chicks, whereas Borrelia infection contributed to both natural death and the decision to euthanize blues. Babesia infection was associated with decreased odds of euthanasia among juveniles. Low hematocrit at admission contributed to natural death of chicks and blues and euthanasia of blues. Low total plasma protein, on the other hand, contributed to natural death in chicks, blues, and juveniles, whereas high total plasma protein had a protective effect against natural death in chicks. These results indicate a need to focus on prevention and early intervention among compromised immature penguins in order to increase the rehabilitation success for this endangered species.

Captive husbandry and veterinary care of seabirds during the MV Rena oil spill response

Abstract ContextSeabirds were the most common taxa captured alive as part of the oiled wildlife response to the grounding of the container vessel MV Rena in the Bay of Plenty, New Zealand. AimsTo describe the management of seabirds during the spill response, to outline the common problems encountered and to make recommendations for future responses. MethodsSeabirds were collected from 7 October 2011 to 14 January 2012. They were stabilised and underwent pretreatment, washing and rinsing procedures to remove oil, followed by swimming physiotherapy to restore waterproofing and long-term housing in outdoor aviaries. The birds were released in batches close to the original sites of capture once the wild habitat was cleaned. Key results428 live seabirds were admitted. There were two temporal peaks in admissions associated with the ship grounding and when the ship broke up. The majority of live birds were little penguins (Eudyptula minor; 394/428, 92%). Most seabirds admitted (393/428, 91.8%) were contaminated with heavy fuel oil, with the remainder (35/428, 8.2%) found unoiled but starving and/or exhausted or with injuries. Little penguins had lower mortality during rehabilitation (28/394, 7.1%) than other seabird species combined (27/34, 79.4%). Seabirds in poorer body condition on arrival had higher mortality, and unoiled birds were also more likely to die than oiled birds. In oiled little penguins, the degree of oiling on the plumage ranged from 1 to 100%, but mortality was not significantly associated with the degree of oiling (P=0.887). Pododermatitis affected 66% of little penguins. The most common causes of death (n=45) included weakness, anaemia and hypothermia in oiled seabirds (16/45, 35.6%), and starvation and weakness in unoiled seabirds (14/45, 31.1%). ConclusionsTotal survival to release was 87.1%, primarily influenced by the species involved and the body condition of the birds on arrival. Unoiled seabirds had higher mortality rates than oiled seabirds. ImplicationsOiled wildlife can be rehabilitated with good success, even when heavily oiled, or to a lesser extent, when found in poor body condition. More work is needed to refine species-specific rehabilitation protocols for seabirds, especially for those being admitted in emaciated body condition.

From incubation to release: Hand-rearing as a tool for the conservation of the endangered African penguin

The African penguin (Spheniscus demersus) population is estimated at 25,000 breeding pairs, approximately 5% of that at the start of the 20th century, and the species is currently classified as Endangered. In the last two decades, the hand-rearing of penguin chicks that were abandoned by their parents due to oil spills or other circumstances has become a valuable conservation tool to limit mortality and to bolster the population at specific colonies. We summarize and evaluate the techniques employed by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) to incubate and hand-rear African penguin eggs and chicks. From 2012 to 2016, a total of 694 eggs and 2819 chicks were received by SANCCOB’s Chick Rearing Unit. It was estimated that 13% of the eggs were infertile, and 81% of the fertile eggs hatched successfully. The overall release rate for chicks was 77%, with a higher release rate for chicks that were pre-emptively removed (93%) followed by chicks that had been abandoned by their parents (78%), chicks admitted due to avian pox lesions (61%), chicks that hatched from artificially-incubated eggs (57%), and chicks admitted due to injuries or deformities (25%). Rescuing and hand-rearing eggs and chicks has been a successful strategy for African penguins, and might be also applicable for the conservation of other threatened seabird species whose population are critically low or during natural or anthropogenic events that could have disastrous population impacts (e.g. oil spills, disease outbreaks, catastrophic weather events, strong El Niño years, etc.).