Injuries to jackass penguins (Spheniscus demersus): evidence for shark involvement

An analysis is presented of records of injuries and the types of injuries to jackass penguins in Algoa Bay, South Africa, over a 10-year-period. Sharks are implicated in causing most of the injuries, but other possible agents are discussed. The types of injuries were categorized and compared to the dentition of sharks known to occur in the area. Using a life-size model of a jackass penguin and preserved jaws of sharks, bites were simulated to establish the types of injury inflicted by different species. Certain injuries indicate attack by great white sharks, while others cannot be ascribed to any particular species. Most shark injuries show single jaw involvement, and range from small cuts across the feathers to the bird being cut in two. Sharks accounted for the highest number of identifiable natural causes of death, but the significance of shark attack as a mortality factor in jackass penguins is difficult to assess.     

Herpesvirus-like infection in black-footed penguins (Spheniscus demersus)

A herpesvirus-like infection is described in the black-footed penguin (Spheniscus demersus). Clinically, the infection was characterized by debilitation and respiratory distress. Histopathological lesions were confined to the respiratory tract and consisted of inflammation and syncytial cell formation with Type A intranuclear inclusions in sinuses, trachea, and mainstem bronchi. Electron microscopy demonstrated polyhedral viral particles 80-140 nm in size consistent with Herpetoviridae. The lesions resembled those seen in infectious laryngotracheitis.     

Group Size in Foraging African Penguins (Spheniscus demersus)

Diving synchrony was examined for varying group sizes of African penguins (Spheniscus demersus) travelling to their foraging grounds from their breeding islands. Groups of fewer than 12 birds always dived synchronously, whereas groups of more than 17 birds always dived asynchronously. Since travelling penguins do not dive deeply, large groups of birds can remain together irrespective of diving synchronization. Observations from boats showed that foraging penguins rarely occurred in groups of more than 17 birds. We suggest that groups of penguins that do not have synchronized dives cannot forage effectively, because foraging penguins dive deeply.     

Plasma electrolyte concentrations in captive and free‐ranging African penguins (Spheniscus demersus) maintained with and without dietary salt supplements

African penguins (Spheniscus demersus) are common display animals in North American zoos and aquariums. At present, 43 American Zoo and Aquarium Association (AZA)‐accredited institutions maintain over 700 of these birds. A survey of facilities found that only seven institutions maintain their birds in “saltwater habitats” (natural, brine, or artificial seawater systems), while the remaining institutions provide freshwater habitats. Penguins maintained in freshwater habitats commonly receive dietary salt supplements, though evidence is lacking as to the value of this practice. This study was designed to evaluate the necessity of salt supplementation in African penguins. We report the results of a randomized, 10‐month comparison of plasma electrolytes (Na, Cl, and K) between groups of 10 salt‐supplemented and nonsupplemented birds living in a freshwater environment. The results showed no significant differences between the two groups. An interfacility comparison at the same time points revealed temporal pattern differences in analyte values between the facilities; however, the absolute concentrations did not exceed clinical ranges found in healthy birds. Furthermore, single time‐point comparisons between wild and captive African penguins indicated similar sodium concentrations, while potassium and chloride concentrations varied between groups. Finally, the plasma electrolyte levels in 20 birds remained statistically unchanged after a 60‐day withdrawal from salt supplementation. This study provides experimental evidence that African penguins maintained in freshwater exhibits on a herring‐, capelin‐, and squid‐based diet do not require salt supplementation. In addition to the practical implications regarding the need for salt supplementation for captive birds, the results also have theoretical significance. They provide evidence that penguins do not need to ingest high salt concentrations to remain in electrolyte balance. In this regard, the ion regulatory mechanisms in penguins are similar to those in terrestrial mammals and birds. Zoo Biol 23:397–408, 2004. © 2004 Wiley‐Liss, Inc.     

Evaluation of potential variables contributing to the development and duration of plantar lesions in a population of aquarium-maintained African penguins (Spheniscus demersus)

Bumblefoot (pododermatitis), often described as the most significant environmental disease of captive penguins, is commonly due to excessive pressure or trauma on the plantar surface of the avian foot, resulting in inflammation or necrosis and causing severe swelling, abrasions, or cracks in the skin. Although not formally evaluated in penguins, contributing factors for bumblefoot are thought to be similar to those initiating the condition in raptors and poultry. These factors include substrate, body weight, and lack of exercise. The primary purpose of this retrospective study was to evaluate variables potentially contributing to the development and duration of plantar lesions in aquarium-maintained African penguins (Spheniscus demersus), including sex, weight, age, season, exhibit activity, and territory substrate. Results indicate that males develop significantly more plantar lesions than females. Penguins weighing between 3.51 and 4.0 kg develop plantar lesions significantly more often than penguins weighing between 2.5 and 3.5 kg, and because male African penguins ordinarily weigh significantly more than females, weight is likely a contributing factor in the development of lesions in males compared with females. Significantly more plantar lesions were observed in penguins standing for greater than 50% of their time on exhibit than swimming. Penguins occupying smooth concrete territories developed more plantar lesions compared with penguins occupying grate territories. Recommendations for minimizing bumblefoot in African penguins include training penguins for monthly foot examinations for early detection of plantar lesions predisposing for the disease, encouraging swimming activity, and replacing smooth surfaces on exhibit with surfaces providing variable degrees of pressure and texture on the feet.     

Identification of land predators of African Penguins Spheniscus demersus through post-mortem examination

The African Penguin Spheniscus demersus is an endangered seabird endemic to southern Africa, and killing sprees by terrestrial predators have been one of the main threats for its mainland colonies. The methods employed to manage predators may differ depending on the species involved, therefore the implementation of strategies to limit the impacts of predation relies on the correct identification of the culprit predator. We report and quantify the lesions seen in African Penguins killed by four species of terrestrial predators: Caracal Caracal caracal (52 kills), Leopard Panthera pardus (27 kills), Domestic Dog Canis lupus familiaris (10 kills), and Cape Grey Mongoose Galerella pulverulenta (4 kills). We discuss patterns of necropsy findings that can be used to identify the predator species involved. Traditional forensic methods are useful tools to direct species-specific management actions for the conservation of the African Penguin and other seabirds so that effective mitigating measures can be deployed quickly to prevent further losses. It should be borne in mind, however, that the age, size and previous hunting experience of the predator are likely to influence the pattern of lesions that will be observed, and not all carcasses will have hallmark lesions or recognisable bite marks.     

Growth of Jackass penguin chicks (Spheniscus demersus) hand reared on different diets

Jackass penguin chicks from the age of about 10 days were hand reared on different diets: mullet Liza richardsoni , anchovy Engraulis capensis and squid Loligo reynaudi , until they fledged. The weight of food fed and the daily weight increment of the chicks was measured. Excreta were collected every 5–6 days and analysed to establish metabolized energy and metabolic efficiency. Culmen measurements were taken regularly and plotted against age. The age, weight and sum of food fed up to fledging was compared between diets as well as with field data. Compensatory growth was exhibited when stunted chicks on a relatively poor diet had their diet changed to a relatively better diet.     

Behavioral sex differences and activity patterns of captive humboldt penguins (Spheniscus humboldti)

Three female and two male captive Humboldt penguins (Spheniscus humboldti) were observed in an enclosed exhibit over a period of 10 months to examine behavioral sex differences and to establish whether captive Humboldt penguins exhibit behavioral activity patterns. There were no statistically significant differences between the behaviors of males and females in six categories: resting, self-maintenance, locomoting, lack of visibility, agonistic behaviors, or pair-directed behaviors. Although not statistically significant, the pair-directed activities of bowing and ecstatic displaying were found to have potential use for sexual identification. Females bowing to males accounted for 77% of the observed bows. Further, males were observed performing 68% of the observed ecstatic displays, while females performed only 32%. Four behavioral phases were defined: molting, proximity, nesting, and “other.” Statistically significant behavioral differences occurred between the four phases for all ethogram behaviors with the exception of agonistic and pair-directed behaviors. Although housed under natural daylight and in an exhibit simulating their habitat in the wild, the captive birds failed to demonstrate a breeding season but bred throughout the study. However, this may have been influenced by one or more of the following factors: a ready supply of food; an air-filtered, temperature-controlled atmosphere; and the presence of an adequate number of nesting sites.     

Spider monkey home ranges: A comparison of radio telemetry and direct observation

The ranging patterns of two male and five female spider monkeys (Ateles geoffroyi) were studied with the use of radio telemetry in Santa Rosa National Park, Costa Rica. The average size of a spider monkey home range was 62.4 hectares; however, range size varied with sex, and, for females, with the presence of a dependent infant. The probability of encountering a radio-collared spider monkey in a three-hour search using radio telemetry (0.91) was much greater than using a visual search (0.20), and telemetric data resulted in a larger estimate of mean home range size than did observational data, when all subjects were compared. However, the difference appeared to be owing to the presence of male ranges in the telemetric, but not the observational, data. When the size of home ranges derived from radio-tracking data for adult females was compared to size of ranges for adult females derived from observations, the results were not significantly different. Adult males had larger home ranges than adult females, thus lending support to the hypothesis that males have adapted to the dispersion of females by occupying a large home range that overlaps the ranges of several adult females. The smallest home ranges were occupied by low-weight females with dependent infants, perhaps reflecting social and energetic constraints.     

Behavior and adrenal physiology of Magellanic penguins (Spheniscus magellanicus) serving as ambassador animals

Ambassador animals are part of many zoo programs, but studies assessing their impact on these animals are relatively rare. This study validated an excrement glucocorticoid metabolite (GCM) assay for Magellanic penguins and used GCM measures in conjunction with behavioral observations to evaluate individual responses to participation in an ambassador animal program. Excrement samples and behavioral observations were collected daily from each bird during two phases, 1 week during which it participated in a twice-daily ambassador program and 1 week in which it did not. We found no differences in GCMs between phases or in comparisons between penguins with 5 or 10 years of program experience. GCM also did not show significant individual variation and did not increase over time during the program phase. There were no significant correlations between bird experience and behavior frequencies, nor GCM concentrations and behavior, across birds. We observed significant positive correlations between the penguins' engagement with novel objects during programs and their unguided approach to guests. Our results suggest that there is no adverse physiological effect of program participation on these penguins, that behavioral and physiological responses may be decoupled, and that choice and control can increase desired behaviors behavior during ambassador programs.     

Hematology and plasma chemistry values in free-ranging Humboldt penguins (Spheniscus humboldti) in Chile

To establish baseline hematologic and plasma biochemistry values in free-ranging Humboldt penguins (Spheniscus humboldti), heparinized blood samples were collected from 51 apparently healthy, adult Humboldt penguins residing at two colonies off the Chilean coast. Thirty samples were collected in April, 1992, from penguins inhabiting the Ex-islote de los Pájaros Niños in Algarrobo, Chile. In September, 1992, 21 samples were collected from birds inhabiting Isla de Cachagua, Chile. Hematologic values measured include packed cell volume, leucocyte count, leucocyte differential, and the presence of blood parasites. Plasma biochemistry values measured include glucose, blood urea nitrogen, creatinine, uric acid, calcium, inorganic phosphorous, sodium, potassium, chloride, total protein, albumin, globulin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, and creatine kinase. Only the mean values for chloride and for the number of eosinophils differed significantly between the two sample groups. No blood parasites were seen. © 1995 Wiley-Liss, Inc.     

Pond Use by Captive African Penguins (Spheniscus demersus) in an Immersive Exhibit Adjacent to Human Bathers

Nonhuman animals in zoos are exposed to a continuous human presence, which affects their behaviors and welfare. However, little is known about what role the “visitor effect” has on penguins in captivity. The African penguin (Spheniscus demersus) is an endangered species commonly housed in zoos worldwide. The aim of this study was to evaluate whether the abundance of human bathers could reduce the average time spent in the water of a colony of African penguins housed in an exhibit where their pond habitat was adjacent to a swimming pool. Observations were carried out on 7 penguins in the summer of 2009. Data were collected during 3 time periods (Time 1 [T1] = opening of the swimming season, Time 2 [T2] = core of the season, Time 3 [T3] = late season) of 14 days each. The human disturbance caused by bathers strongly reduced the pond use by penguins at T1 and T2, especially when there were large numbers of visitors. However, at T3, we observed that the overall use of the pond by penguins increased, and the average duration of their diving was no longer dependent on the number of visitors.     

Assessment of microsatellite and SNP markers for parentage assignment in ex situ African Penguin (Spheniscus demersus) populations

Captive management of ex situ populations of endangered species is traditionally based on pedigree information derived from studbook data. However, molecular methods could provide a powerful set of complementary tools to verify studbook records and also contribute to improving the understanding of the genetic status of captive populations. Here, we compare the utility of single nucleotide polymorphisms (SNPs) and microsatellites (MS) and two analytical methods for assigning parentage in ten families of captive African penguins held in South African facilities. We found that SNPs performed better than microsatellites under both analytical frameworks, but a combination of all markers was most informative. A subset of combined SNP (n = 14) and MS loci (n = 10) provided robust assessments of parentage. Captive or supportive breeding programs will play an important role in future African penguin conservation efforts as a source of individuals for reintroduction. Cooperation among these captive facilities is essential to facilitate this process and improve management. This study provided us with a useful set of SNP and MS markers for parentage and relatedness testing among these captive populations. Further assessment of the utility of these markers over multiple (>3) generations and the incorporation of a larger variety of relationships among individuals (e.g., half‐siblings or cousins) is strongly suggested.     

上海动物园圈养斑嘴环企鹅种群统计学与遗传学分析

根据1984—2017年上海动物园圈养斑嘴环企鹅Spheniscus demersus数据,应用Sparks 1.6和PMx 1.0进行数据整理、统计学和遗传学分析。结果显示,该种群数量呈增长状态,但也存在如下问题:(1)种群中未知性别比例过高,占46.25%;(2)种群年龄结构不合理,0~4岁及7~8岁个体数量不足,育龄个体中未知性别的数量较多;(3)雌雄个体0~1岁、10~13岁的死亡率偏高,曲霉菌病是致死的主要原因;(4)参与繁殖的奠基者数量(9只)和潜在奠基者数量(1只)少,分属2个家系,且后代数和贡献值明显不均衡,种群的平均亲缘关系值为0.097 2,种群的平均近亲繁殖系数为0.099 5,存在近亲繁殖现象;(5)虽然现有种群保留了野生个体90.28%的基因多样性,但未来丢失也较快。因此,为了建立健康的斑嘴环企鹅种群,应尽快引进新的血统,开展性别鉴定工作,采取预防为主、防治结合的方式降低曲霉菌病的致病率;采用各种技术如人工授精技术提高企鹅受精率,为繁殖个体,尤其是后代数量过少的奠基者个体提供均等的繁殖机会,从而加强上海动物园圈养斑嘴环企鹅的种群管理。     

Trans-species polymorphism of the Mhc class II DRB-like gene in banded penguins (genus Spheniscus)

The Major Histocompatibility Complex (Mhc) class II DRB locus of vertebrates is highly polymorphic and some alleles may be shared between closely related species as a result of balancing selection in association with resistance to parasites. In this study, we developed a new set of PCR primers to amplify, clone, and sequence overlapping portions of the Mhc class II DRB-like gene from the 5′UTR end to intron 3, including exons 1, 2, and 3 and introns 1 and 2 in four species (20 Humboldt, six African, five Magellanic, and three Galapagos penguins) of penguin from the genus Spheniscus (Sphe). Analysis of gene sequence variation by the neighbor-joining method of 21 Sphe sequences and 20 previously published sequences from four other penguin species revealed overlapping clades within the Sphe species, but species-specific clades for the other penguin species. The overlap of the DRB-like gene sequence variants between the four Sphe species suggests that, despite their allopatric distribution, the Sphe species are closely related and that some shared DRB1 alleles may have undergone a trans-species inheritance because of balancing selection and/or recent rapid speciation. The new primers and PCR assays that we have developed for the identification of the DRB1 DNA and protein sequence variations appear to be useful for the characterization of the molecular evolution of the gene in closely related Penguin species and might be helpful for the assessment of the genetic health and the management of the conservation and captivity of these endangered species. The nucleotide sequence and amino acid sequence data reported in this paper have been submitted to the DDBJ database and have been assigned the accession numbers AB301478, AB301944–AB301950, AB302087–AB302090, AB302190–AB302192, AB302843, AB302844, and AB303942–AB303945.     

Plasmodium relictum as a cause of avian malaria in wild-caught magellanic penguins (Spheniscus magellanicus)

Avian malaria (Plasmodium relictum) caused significant mortality in wild-caught Magellanic penguins (Spheniscus magellanicus) in 1986 at the Blank Park Zoo in Des Moines, Iowa (USA). In early winter, wild birds were captured off the southern coast of Chile and flown to Detroit, Michigan for a 38 day quarantine. After quarantine, 18 birds were dispersed to Lansing, Michigan, six to a facility in Maine, and 46 to Des Moines, Iowa. Upon arrival in Des Moines, several penguins became weak and inactive, had to be force-fed, and died after 2 days. Gross lesions at postmortem included splenomegaly, hepatomegaly, and pulmonary edema. Histopathological examination revealed numerous intraendothelial schizonts in spleen, lung, liver, heart and kidney. Schizonts were generally 16 to 28 micron by 11 to 16 micron and contained merozoites of two distinct sized (macromerozoites, nuclei 1.0 micron; micromerozoites, nuclei 0.5 micron). Based on the morphology of the abundant exoerythrocytic forms, a tentative diagnosis of avian malaria (Plasmodium sp.) was made. Subsequent transmission electron microscopic examination of schizonts in formalized tissue revealed merozoites with tear-shaped rhoptries. Antimalarial therapy was initiated early but deaths continued for 5 mo. Mortality, which eventually totaled 83%, occurred in three distinct waves, each separated by a hiatus of approximately 1 mo. Despite examinations of repeated blood smears, intraerythrocytic Plasmodium relictum was not detected until late in the outbreak. Diagnosis was based on morphologic characteristics including schizonts with eight to 12 merozoites/segmenter and round gametocytes that displaced and turned the infected erythrocyte nucleus. In addition to malaria, penguins showed evidence of aspergillosis, bacterial enteritis (Escherichia coli; Proteus sp.; and Edwardsiella sp.), and helminthiasis (Contracaecum sp. and Tetrabothrius sp.). Based on gross and histological lesions, disease prevalence in this group of penguins was malaria 58%, aspergillosis 61%, enteritis 60%, helminthiasis 26%. Epidemiologic investigation including group transport history, disease prevalence in co-quarantined birds not sent to Des Moines and climatological data implicated Des Moines as the likely site for initial exposure, although information is not conclusive. Stress and concurrent disease certainly contributed to the severe mortality in this group of penguins infected with P. relictum.     

Fibre types in primary ‘flight’ muscles of the African Penguin (Spheniscus demersus)

The African penguin (Spheniscus demersus) is an endangered seabird that resides on the temperate southern coast of Africa. Like all penguins it is flightless, instead using its specialized wings for underwater locomotion termed ‘aquatic flight’. While musculature and locomotion of the large Antarctic penguins have been well studied, smaller penguins show different biochemical and behavioural adaptations to their habitats. We used histochemical and immunohistochemical methods to characterize fibre type composition of the African penguin primary flight muscles, the pectoralis and supracoracoideus. We hypothesized the pectoralis would contain predominantly fast oxidative–glycolytic (FOG) fibres, with mainly aerobic subtypes. As the supracoracoideus and pectoralis both power thrust, we further hypothesized these muscles would have a similar fibre type complement. Our results supported these hypotheses, also showing an unexpected slow fibre population in the deep parts of pectoralis and supracoracoideus. The latissimus dorsi was also examined as it may contribute to thrust generation during aquatic flight, and in other avian species typically contains definitive fibre types. Unique among birds studied to date, the African penguin anterior latissimus dorsi was found to consist mainly of fast fibres. This study shows the African penguin has specialized flight musculature distinct from other birds, including large Antarctic penguins.     

Circulating nutrient concentrations in free-ranging Humboldt penguins (Spheniscus humboldti) in Punta San Juan,Peru

Free-ranging Humboldt penguin (HP, Spheniscus humboldti) populations are under pressure from resource competition with industrial fisheries, habitat loss, and El Niño Southern Oscillation events. Foraging patterns for this top marine predator change during periods of aberrant oceanographic conditions and scarce fish stock numbers. These radical dietary fluctuations can lead to poor fertility, early embryonic death, poor hatchability, suppressed immune function, high chick mortality, and illness. To understand the variability of nutrient status in reproductive seasons, we measured select circulating nutrient concentrations (fat-soluble vitamins A, D, E, and carotenoids, fatty acids, amino acids, minerals, and electrolytes) of 105 HP at Punta San Juan, Peru during the first reproductive seasons of 2007 and 2008. We determined significant differences in nutrient status between sexes, years of sampling, and reproductive stages. Males (4.5 ± 0.38 kg) weighed more than females (4.0 ± 0.29 kg) and exhibited higher concentrations of vitamin A (0.71 ± 0.11 vs. 0.61 ± 0.12 µg/ml) and docosahexaenoic acid (6.70 ± 1.61 vs. 5.65 ± 1.59%). Males also displayed lower concentrations of β-carotene (0.01 ± 0.01 vs. 0.012 ± 0.001 µg/ml) and phosphorus (3.43 ± 0.83 vs. 4.40 ± 1.66 mg/dl). Comparison between the 2 years showed most circulating amino acid concentrations were higher in 2007. Significant differences in circulating amino acids and vitamins were also noted between different reproductive stages. These results demonstrate concentrations of nutrients can vary due to the physiological state of the animal, as well as the overall dynamics of their marine ecosystem habitat.