Search Results (8)

Global biodiversity is in rapid decline, and many seabird species have disproportionally poorer conservation statuses than terrestrial birds. A good understanding of population dynamics is necessary for successful conservation efforts, making noninvasive, cost-effective monitoring tools essential. Here, we set out to investigate whether passive acoustic monitoring (PAM) could be used to estimate the number of animals within a set area of an African penguin (Spheniscus demersus) colony in South Africa. We were able to automate the detection of ecstatic display songs (EDSs) in our recordings, thus facilitating the handling of large datasets. This allowed us to show that calling rate increased with wind speed and humidity but decreased with temperature, and to highlight apparent abundance variations between nesting habitat types. We then showed that the number of EDSs in our recordings positively correlated with the number of callers counted during visual observations, indicating that the density could be estimated based on calling rate. Our observations suggest that increasing temperatures may adversely impact penguin calling behaviour, with potential negative consequences for population dynamics, suggesting the importance of effective conservation measures. Crucially, this study shows that PAM could be successfully used to monitor this endangered species’ populations with minimal disturbance. Full article

Penguins, like most birds, are considered monomorphic species. Cloacal endoscopy, laparoscopy, or molecular sex verification are used to determine sex in such animals. Our aim in this study was to investigate whether sex recognition can be performed in penguins by a non-invasive method using the shape of the bill. For this purpose, sex and population differences in penguins were investigated by geometric morphometric methods using photos of the bill in the dorsal and lateral views. Fifty-four African penguins (Spheniscus demersus) were taken for the study. Principal component analysis was applied to reveal the shape variations of the bill. Principal components were extracted for each bill projection. PC1 explained 37.06% of the total variation in the dorsal view, while PC1 for the lateral view explained 31.4% of the total variation. Canonical variance analysis was performed to reveal the differences between groups. The lateral view was more effective in revealing the differences between the groups and between the sexes. For the dorsal view, Procrustes distances values between any group were not statistically significant. The maxillary rostrum in female penguins was higher, while, in males, the mandibular rostrum was higher. The females’ bills were narrower than in males. Centroid size in males was on average larger than in females. Significant differences in bill shape between populations were also found. Using geometric morphometric methods, sex analysis can be conducted with less equipment and less stress on the birds. However, the environmental factors that cause bill variation in birds should be examined in more detail. Better knowledge of the effects of environmental factors on bill variation is important for geometric morphometric methods to give more accurate results in sex and population analyses. Full article

Swimming is an important behavior for all penguin species. However, zoo-housed penguins typically do not swim as often as their wild counterparts, which may have consequences for their health and welfare. In an effort to increase the swimming time of the African penguin (Spheniscus demersus) population at Lincoln Park Zoo in Chicago, IL, USA (21 adults: 13 males, 8 females), we introduced a commercially available bubble curtain to the outdoor pool within the penguins’ habitat. The bubble curtain pushes pressurized air out through a hose fitted with small holes to create a stream of bubbles that generate water movement, which could entice penguins to swim. Over the course of 2 months, the penguins were exposed to a series of alternating conditions characterized by the bubble curtain being off or on for 2-week periods. A total of 228 swimming bouts were observed during this study. The bubble curtain did not increase the amount of time the penguins spent swimming, nor the maximum number of penguins in the pool during swim bouts. Rather, the penguins spent more time swimming when the bubble curtain was turned off, and the number of penguins in the pool during swim bouts was consistent across experimental phases. Additionally, we found that penguins swam the most when air temperatures were between 31 and 40 °F (approximately −1 to −4 °C). Unexpectedly, at least three individual penguins swam overnight between the hours of midnight and 6:00, highlighting the value of monitoring animals during entire 24 h periods. Collectively, this study provides detailed information about the swimming behavior of a zoo-housed African penguin population, and indicates that a bubble curtain was ineffective at stimulating swimming. Full article

An understanding of the microbial communities in African penguins (Spheniscus demersus) could provide valuable information for saving this endangered species. The objective of this study was to investigate the composition, diversity and sex-related differences in the intestinal microbiota of captive African penguins. Fecal samples were collected from 21 captive adult African penguins reared in the same conditions at Shanghai Zoo. The results show that Proteobacteria, Actinobacteria and Firmicutes were the predominant bacteria in the intestinal microbiota of the captive African penguins. No difference was found in microbial diversity between female and male African penguins, as shown by their similar alpha and beta diversities. However, a notable sex-related difference was found between their microbial compositions. Female African penguins have a higher abundance of Pseudomonas and a lower abundance of Kocuria than males. A functional prediction indicates that the “mRNA surveillance pathway”, “Polyketide sugar unit biosynthesis”, “Wnt signaling pathway”, “Lysosome” and “Cell cycle” pathways were significantly enriched in the microbiota of female African penguins. In conclusion, the present study indicates that the compositions and predicted functions of the intestinal microbiota are significantly different between the sexes. Our data suggest that the intestinal microbiota of female African penguins are more unstable than the intestinal microbiota of males in captivity. Full article

The known host range of circoviruses is continuously expanding because of more intensive diagnostic activities and advanced sequencing tools. Recently, a new circovirus (penguin circovirus (PenCV)) was identified in the guano and cloacal samples collected from Adélie penguins (Pygoscelis adeliae) and chinstrap penguins (Pygoscelis antarcticus) in Antarctica. Although the virus was detected in several asymptomatic subjects, a potential association with feather disease was speculated. To investigate the occurrence and implications of PenCV in other penguin species located outside of Antarctica, a broad survey was undertaken in African penguins (Spheniscus demersus) on two islands off the southern Namibian coast. For this purpose, specific molecular biology assays were developed and validated. None of the 151 blood samples tested positive for PenCV. Several reasons could explain the lack of PenCV positive samples. African penguins and Pygoscelis species are separated by approximately 6000 km, so there is almost no opportunity for transmission. Similarly, host susceptibility to PenCV might be penguin genus-specific. Overall, the present study found no evidence of PenCV in African penguin colonies in Namibia. Further dedicated studies are required to assess the relevance of PenCV among different penguin species. Full article

Avian malaria is a worldwide distributed, vector-born disease of birds caused by parasites of the order Haemosporida. There is a lack of knowledge about the presence and pathogenetic role of Haemosporida in Psittacidae. Here we report a case of avian malaria infection in lovebirds (Agapornis roseicollis), with the genetic characterization of the Plasmodium species involved. The birds were hosted in a zoo located in Italy, where avian malaria cases in African penguins (Spheniscus demersus) were already reported. Animals (n = 11) were submitted for necropsy after sudden death and were subjected to further analyses including histopathology, bacteriology, and PCR for the research of haemosporidians. Clinical history, gross lesions and histopathological observation of schizonts, together with positive PCR results for Plasmodium spp., demonstrated that avian malaria was the cause of death for one animal and the possible cause of death for the other nine. The sequences obtained were compared using BLAST and analyzed for similarity to sequences available at the MalAvi database. Genetic analyses demonstrated a 100% nucleotide identity to Plasmodium matutinum LINN1 for all the obtained sequences. To our knowledge, this is the first report describing avian malaria in lovebirds. Full article

Aeromonas hydrophila was isolated from an African black-footed penguin (Spheniscus demersus) that died while in zoo captivity. At necropsy, the virulence of A. hydrophila appeared to be enhanced by stress, so was assessed in the presence of in vitro and in vivo stressors and serial passaging in mice. Virulence genes from the isolate were amplified by PCR. In vitro assays were conducted to test the hemolytic activity, cytotoxicity, and effect of stress hormones on A. hydrophila virulence. In vivo assays were conducted to test the stress effect on mortality of A. hydrophila-infected mice and virulence in mice. Two virulence genes coding for hemolysin (ahh1) and aerolysin (aerA) were detected, and the cytotoxic potential of the isolate was demonstrated in baby hamster kidney and Vero cells. Some or all mice inoculated with A. hydrophila and exposed to stress hormones (epinephrine and norepinephrine) or low temperature died, while mice inoculated with A. hydrophila and exposed to fasting or agitation stressors or no stressors survived. We concluded that stress can be fatal in mice experimentally infected with A. hydrophila and that serial passaging in mice dramatically enhances the virulence of A. hydrophila. Full article

Animal ambassador programs are increasingly prevalent in zoos, yet few studies have investigated their impact on animal welfare. We assessed the effects of an ambassador program on the behavior of a colony (N = 15) of zoo-housed African penguins (Spheniscus demersus) and evaluated whether individual characteristics were predictive of participation. Behavioral data were collected for 16 weeks and included 43 “penguin encounters”, during which zoo visitors entered a designated portion of the penguins’ enclosure. When comparing colony behavior following encounters to behavior during a matched control period lacking an encounter, we found no significant difference between affiliative or aggressive behaviors, suggesting that the encounters did not disrupt interactions in the colony. The same was true when comparing behavior preceding the encounter to a matched control period, indicating that any anticipatory period was similarly non-disruptive. Space use during encounters suggested comfort near visitors. We also measured penguin temperament on the shy-bold continuum by recording the birds’ response to novel objects and found that penguins’ temperament, sex, and age were predictive of participation. We concluded that this program had a neutral or positive impact on penguin welfare and considered the findings in relation to aspects of the ambassador program that provided penguins with control over their involvement. Full article