The Effects of Critical Care Nutrition on Weight Gain in African Penguin (Spheniscus demersus) Chicks

Nutritional support in malnourished animals is an essential aspect of wildlife rehabilitation; this support is especially relevant when providing lifesaving nutrition to endangered species such as the African penguin (Spheniscus demersus). This study investigated the short-term effects of a commercially available, semi-elemental, critical care diet compared with a hand-made fish formula. Twenty-one African penguin chicks were selected on admission to the Southern African Foundation for the Conservation of Costal Birds in Cape Town, South Africa, in November 2015. Initial assessment included body weight, a full clinical exam, white blood cell count, packed cell volume, and total plasma protein. Ten animals received the commercial critical care diet, whereas a control group of 11 animals were fed hand-made formula for the 2-week study period. All animals were weighed daily and blood sampling was repeated after 14 days. The median weight of both groups increased significantly over 14 days (critical care diet χ2 = 10.1, P = 0.002; control χ2 = 7.4, P = 0.006). The difference was not significant between the groups for start weight (χ2 = 0.1, P = 0.725) or end weight (χ2 = 0, P = 1.000) and was not significantly different in the change over time for either absolute numbers (χ2 = 1.7, P = 0.193) or percent gain (χ2 = 0.8, P = 0.36). The values for packed cell volume, total plasma protein, and white blood cell count increased in all animals after the 14-day study period was complete. On the basis of the results of this study, it was determined that the differing diets led to similar weight gain.

Maritime traffic trends around the southern tip of Africa - Did marine noise pollution contribute to the local penguins' collapse?

The rapid increase in seaborn trade since the 1990s has resulted in an increase in vessel-derived noise pollution, yet there is little evidence linking these activities to a decline in many marine taxa, such as seabirds. Algoa Bay, South Africa, is a marine biodiversity hotspot, providing habitats for the largest populations of endangered African Penguins (Spheniscus demersus), as well as other endangered seabirds, cetaceans and seals. The bay is situated on a major shipping route and since 2016 has hosted the first offshore ship-to-ship (STS) bunkering operations in the country, i.e. the supplying of fuel from one ship to another outside of harbours. Using Automatic Identification System (AIS) data, we estimated noise emissions from vessels as a proxy for underwater ambient noise levels within the core penguin utilisation area. Frequency of vessels using the bay doubled during our study, with numbers of bulk carriers increasing ten-fold. Ambient underwater noise levels were generally high in the bay (ca 140 dB re 1 μPa since 2015) but significantly increased by 2 dB SPL after the initiation of STS bunkering in 2016, corresponding to double the underwater noise intensity. This increase coincided with a significant and dramatic decline by 85% in penguin numbers from St Croix Island since 2016. Algoa Bay is now one of the noisiest bays in the world. This is the first study to assess the potential impact of vessel-derived underwater noise levels on a seabird population. Penguins, like marine mammal species, are known to be sensitive to marine noise pollution and urgent management interventions are required to mitigate this recent disturbance, to preserve the remaining stronghold of the African penguin and the marine mammals' populations sharing the penguins' habitat.

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.