SOUTH AFRICA – With less than 25,000 breeding pairs in existence today, it is an uphill battle for South Africa's African penguin. The 60% drop in their population since 2001 has put them on the International Union for Conservation of Nature's endangered species list. In some colonies, the drop in population has been as high as 80%. Competition with fisheries, oil spills, climate change, diseases and predators are all contributing factors in their dramatic decline.
To preserve this species and optimise rehabilitation efforts, epidemiologist Adam Schaefer from Florida Atlantic University in the USA joined forces with scientists Nola Parsons and Ralph Vanstreels from the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB). The facility, located near Cape Town, South Africa, receives more than 900 African penguins for rehabilitation each year. While the success rate for the overall release of these penguins back into the wild is about 75%, limited data exists on the factors that contribute to their successful rehabilitation.
To better understand how to improve the rehabilitation of African penguins, the researchers conducted a first-of-its-kind study on prognostic health indicators such as body mass, blood analysis, and infectious disease exposure. For the study, they analysed 3,657 adult African penguins that were admitted to the SANCCOB facility for rehabilitation between 2002 and 2013.
Results of the study, published in the Journal of Wildlife Diseases, provide invaluable information on the importance of minimising their rehabilitation time, treating their diseases early in the process, and controlling mosquitoes to avoid infection. The researchers found that the biggest risk factors for mortality are things that can be addressed in the first 10 days of their admission – a key finding because approximately 70% of deaths occur during this time. They also identified markers of body mass and hematologic parameters that are important criteria in the initial assessment and treatment of wildlife admitted for rehabilitation.
“Because most of the mortality of these birds occurs within the first 10 days after they are admitted, we wanted to develop more effective strategies to quickly reverse their various symptoms such as severe dehydration, hypothermia or hyperthermia, anemia, and extreme weight and muscle loss,” said Schaefer, who is a co-author of the study.
“A poor body condition may be an indication of poor food resources, physical or behavioral problems, or a combination, and is a significant predictor of survival of these seabirds during rehabilitation.”
The researchers calculated the effects of season of admission, reason for admittance, blood parasite infection status, and body mass, hematocrit, and total plasma protein upon admission in determining whether an individual penguin was likely to be released after rehabilitation.
The most frequent reasons for rehabilitation were oiling (71.2%), followed by injury (19.6%). Injured penguins had lower body mass than healthy wild adult penguins, suggesting that these birds had sub-optimal foraging success, which made them more vulnerable. Debilitation accounted for 4.3% of the admissions followed by problems with moulting – an annual process of losing and replacing their feathers – which accounted for 3.9% of admissions.
Findings from the study show that when compared with an oiled penguin, an injured penguin was 13.1 times more likely to die in rehabilitation. While oil pollution is a historical threat to the conservation of African penguins, the researchers found that on average, 93% of the oiled penguins admitted during the study period were rehabilitated successfully and released back into the wild.
“We suspect that the reason for this high success rate is because oiled penguins were often admitted in good body condition and health status," said Schaefer.
“In addition, their condition when they are oiled is physically obvious to conservation officers for collection and rehabilitation.”
The release rate for penguins admitted with injuries varied between 52% and 71% depending on the affected body part, revealing that there are still challenges in the medicine of trauma for this species. The birds that sustained chest injuries stayed at the rehabilitation centre the longest, compared to those with tail, flipper or leg injuries, which is related to the time required for feathers to regrow after an injury has healed. Also, penguins admitted to the rehabilitation centre while undergoing moult or due to arrested moult, had low release rates and were more likely to die, indicating that artificially inducing moulting (through hormonal supplementation or light-cycle manipulation, for example) could benefit the rehabilitation of these birds.
“The key is making sure that these penguins are in the right condition to be released and finding that ‘sweet spot’ where we know that they are healthy enough to be released into the wild and do well,” said Schaefer.
Source
Galoustian, G., Experts team up on study to save endangered African penguins [press release], 15 November 2017, Florida Atlantic University
Journal citation
Parsons, N.J., Vanstreels, R.E.T., & Schaefer, A.M. (2018). Prognostic indicators of rehabilitation outcomes for adult African penguins (Spheniscus demersus). Journal of Wildlife Diseases, 54(1), 54–65. https://doi.org/10.7589/2017-06-146
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| African penguins. Photo credit: Ralph E.T. Vanstreels, D.V.M., Ph.D |
To better understand how to improve the rehabilitation of African penguins, the researchers conducted a first-of-its-kind study on prognostic health indicators such as body mass, blood analysis, and infectious disease exposure. For the study, they analysed 3,657 adult African penguins that were admitted to the SANCCOB facility for rehabilitation between 2002 and 2013.
Results of the study, published in the Journal of Wildlife Diseases, provide invaluable information on the importance of minimising their rehabilitation time, treating their diseases early in the process, and controlling mosquitoes to avoid infection. The researchers found that the biggest risk factors for mortality are things that can be addressed in the first 10 days of their admission – a key finding because approximately 70% of deaths occur during this time. They also identified markers of body mass and hematologic parameters that are important criteria in the initial assessment and treatment of wildlife admitted for rehabilitation.
“Because most of the mortality of these birds occurs within the first 10 days after they are admitted, we wanted to develop more effective strategies to quickly reverse their various symptoms such as severe dehydration, hypothermia or hyperthermia, anemia, and extreme weight and muscle loss,” said Schaefer, who is a co-author of the study.
“A poor body condition may be an indication of poor food resources, physical or behavioral problems, or a combination, and is a significant predictor of survival of these seabirds during rehabilitation.”
The researchers calculated the effects of season of admission, reason for admittance, blood parasite infection status, and body mass, hematocrit, and total plasma protein upon admission in determining whether an individual penguin was likely to be released after rehabilitation.
The most frequent reasons for rehabilitation were oiling (71.2%), followed by injury (19.6%). Injured penguins had lower body mass than healthy wild adult penguins, suggesting that these birds had sub-optimal foraging success, which made them more vulnerable. Debilitation accounted for 4.3% of the admissions followed by problems with moulting – an annual process of losing and replacing their feathers – which accounted for 3.9% of admissions.
Findings from the study show that when compared with an oiled penguin, an injured penguin was 13.1 times more likely to die in rehabilitation. While oil pollution is a historical threat to the conservation of African penguins, the researchers found that on average, 93% of the oiled penguins admitted during the study period were rehabilitated successfully and released back into the wild.
“We suspect that the reason for this high success rate is because oiled penguins were often admitted in good body condition and health status," said Schaefer.
“In addition, their condition when they are oiled is physically obvious to conservation officers for collection and rehabilitation.”
The release rate for penguins admitted with injuries varied between 52% and 71% depending on the affected body part, revealing that there are still challenges in the medicine of trauma for this species. The birds that sustained chest injuries stayed at the rehabilitation centre the longest, compared to those with tail, flipper or leg injuries, which is related to the time required for feathers to regrow after an injury has healed. Also, penguins admitted to the rehabilitation centre while undergoing moult or due to arrested moult, had low release rates and were more likely to die, indicating that artificially inducing moulting (through hormonal supplementation or light-cycle manipulation, for example) could benefit the rehabilitation of these birds.
“The key is making sure that these penguins are in the right condition to be released and finding that ‘sweet spot’ where we know that they are healthy enough to be released into the wild and do well,” said Schaefer.
Source
Galoustian, G., Experts team up on study to save endangered African penguins [press release], 15 November 2017, Florida Atlantic University
Journal citation
Parsons, N.J., Vanstreels, R.E.T., & Schaefer, A.M. (2018). Prognostic indicators of rehabilitation outcomes for adult African penguins (Spheniscus demersus). Journal of Wildlife Diseases, 54(1), 54–65. https://doi.org/10.7589/2017-06-146
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