Adult survival declines as African Penguin population plummets

25th August 2014

The African Penguin population is in freefall, with adult survival rates over the last decade desperately low. Urgent management action is required to secure both the prey requirements and future of one of Africa’s most charismatic seabirds.

Richard B Sherley
Animal Demography Unit and Marine Research Institute, University of Cape Town, South Africa

Linked IBIS paper
Age-specific survival and movement among major African Penguin Spheniscus demersus colonies. Sherley, R.B., Abadi, F., Ludynia, K., Barham, B.J., Clark, A.E. & Altwegg, R.

Globally, seabirds are in trouble. With 28% of species listed as globally threatened by the IUCN, no other similarly sized group of birds has a poorer conservation status. Seabirds are susceptible to a wide range of anthropogenic pressures, but some of the most substantial threats they face stem from the deterioration of their marine environment through unsustainable fishing practices and climate change.

Penguins may be particularly sensitive to changes in the oceans that they inhabit compared to flying seabirds, because they must swim to find their food (Boersma 2008). The African Penguin Spheniscus demersus, endemic to South Africa and Namibia, has decreased by more than 90% since the 1930s. In South Africa numbers have dropped by more than 10% a year since 2004, resulting in the species being up-listed to Endangered in 2010. Off the Namibian coast, heavy commercial fishing collapsed the stocks of sardine Sardinops sagax and anchovy Engraulis encrasicolus (the penguins’ main prey) in the 1960s and 1970s. The stocks have never recovered and today penguins in Namibia rely on a diet of junk food (Ludynia et al. 2010).

In South Africa, large-scale changes in the marine environment (possibly linked to global climate change) have caused a change in the spawning grounds of sardine and anchovy. These fish now mostly spawn further east than they did two decades ago and are out of reach of penguin colonies on South Africa’s West Coast for much of the year. However, because many of the fish canning factories are also on the West Coast and fishing vessels, like birds, are limited in how far they can go to find fish, the result has been relatively heavy fishing pressure in areas where the fish have become scarce. This is particularly true for adult sardine, a valuable commercial fish and a key source of energy for African penguins when they need to build up body condition to breed each year (Sherley et al. 2013a).


Seabirds will often respond to a scarcity of food by skipping or abandoning breeding, opting not to re-lay after losing clutches of eggs, or reducing the amount of food brought to the chicks leading to slow growth, poor chick condition and mortality through starvation. African penguins have shown all of these responses in recent years. Over time, these behavioural responses can lead to population declines through poor breeding success and juvenile survival, but they usually allow adult seabirds to buffer periods of poor food availability. Although their body condition may fall below a critical threshold needed for breeding, in long-lived animals like seabirds, adult survival is rarely compromised except in cases of extreme food shortage.

Our work, published this week in IBIS (Sherley et al. 2014), demonstrates that this is exactly what has happened with African penguins breeding in South Africa’s Western Cape. Over the course of our study period (1994/95 to 2011/12), we noted substantial decreases in adult survival as the availability of adult sardine decreased on the West Coast. At what was formerly the largest colony, Dassen Island, adult survival dropped from around 80% per year in the late 1990s and early 2000s to a low of 43% in 2007/08 (Figure 1) and a similar decline was noted at nearby Robben Island. During this period, heavy fishing pressure persisted in areas with low fish abundance because of the distribution of land-based processing plants, leading to sardine exploitation rates between 2004 and 2007 which were more than double the long-term average.
Figure 1. Time-dependent survival estimates (and 95% confidence intervals) for adult African Penguins from Dassen Island, Western Cape between 1994/95 and 2011/12.

These poor adult survival rates indicate that the population is unsustainable and are, in a large part, the reason for the recent dramatic decline in the number of African penguins breeding in South Africa. Ecologists working in the country have been recommending spatial management of the fishery to offset losses of penguins since 2006 and, in response to the species’ worsening conservation status, the government’s fisheries department has begun to investigate the potential benefits to penguins of spatial closures. Experimental small-scale fishing exclusions have been implemented around several breeding colonies, in the hope that this may take some pressure off of the penguins during the breeding season, allowing them to balance their energy budgets more easily.

However, despite the closures having reduced the energetic costs of foraging at one colony (Pichegru et al. 2012) and encouraging results from a modelling study (Weller et al. 2014), evidence for demographic benefits has been scarce and the experimental closures may be removed at the end of 2014. Even if they remain in place, recent biologging studies have demonstrated that non-breeding and juvenile African penguins travel over hundreds of kilometres and feed in areas far from their breeding colonies (e.g. Sherley et al. 2013b). Thus, these closures as a stand-alone management action will not be adequate to reverse the rapid decline in Africa’s only endemic penguin. Rather, a suite of management measures is encouraged to mitigate the multiple factors contributing to the worrying decline of African penguins (Weller et al. 2014, Ludynia et al. 2014). Impacts on adult survival, such as those noted in our study, make it essential that government organizations rapidly implement effective fisheries management actions over large spatial scales to ensure food security for marine top predators.

References

Boersma, P. 2008. Penguins as marine sentinels. Bioscience 58: 597–607. View
Ludynia, K., Roux, J.-P., Jones, R., Kemper, J. & Underhill, L.G. 2010. Surviving off junk: low-energy prey dominates the diet of African penguins Spheniscus demersus at Mercury Island, Namibia, between 1996 and 2009. African Journal of Marine Science 32: 563–572. View
Ludynia, K., Waller, L.J., Sherley, R.B., Abadi, F., Galada, Y., Geldenhuys, D., Crawford, R.J.M., Shannon, L.J. & Jarre, A. 2014. Processes influencing the population dynamics and conservation of African penguins on Dyer Island, South Africa. African Journal of Marine Science 36: 253–267. View
Pichegru, L., Ryan, P.G., van Eeden, R., Reid, T., Gremillet, D. & Wanless, R. Industrial fishing, no-take zones and endangered penguins. Biological Conservation 156: 117–125. View
Sherley, R.B., Underhill, L.G., Barham, B.J., Barham, P.J., Coetzee, J.C., Crawford, R.J.M., Dyer, B.M., Leshoro, T.M. & Upfold L. 2013a. Influence of local and regional prey availability on breeding performance of African penguins Spheniscus demersus. Marine Ecology Progress Series 473: 291–301. View
Sherley, R.B., Ludynia, K., Lamont, T., Roux, J.-P., Crawford, R.J.M. & Underhill, L.G. 2013b. The initial journey of an endangered penguin: implications for seabird conservation. Endangered Species Research 21: 89–95. View
Sherley, R.B., Abadi, F., Ludynia, K., Barham, B.J., Clark, A.E. & Altwegg, R. 2014. Age-specific survival and movement among major African Penguin Spheniscus demersus colonies. Ibis. DOI: 10.1111/ibi.12189.
Weller, F., Cecchini, L.-A., Shannon, L., Sherley, R.B., Crawford, R.J.M., Altwegg, R., Scott, L., Stewart, T. & Jarre A. 2014. A system dynamics approach to modelling multiple drivers of the African penguin population on Robben Island, South Africa. Ecological Modelling 277: 38–56. View

About the author

Richard Sherley is a Postdoctoral Researcher with the Animal Demography Unit and Marine Research Institute at the University of Cape Town. He has conducted research on seabirds in southern Africa for the last seven years, focusing on understanding how their productivity, survival and dispersal are influenced by the anthropogenic and environmental changes occurring in their marine ecosystem. In particular, he is interested in research that applies ecological theory to create tangible conservation benefits and in understanding how the conditions that animals experience early in life may influence later fitness and impact on population dynamics.
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Photo images

TOP: African Penguin © Richard Sherley
BOTTOM: Moulting African Penguin © Davide Gaglio davygaglio.wix.com

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Marine biologists unlock the secrets of Antarctica

Among the discoveries are crabs that are able to live within the clouds of sulphur emitted by live underwater volcanoes

Peter Apps

Monday 25 August 2014

Marine biologists from across the world have produced an atlas of sea life in the Antarctic Ocean from microbes to whales, finding thousands of new species in the process. Among the discoveries were crabs that are able to live within the clouds of sulphur emitted by live underwater volcanoes and a new type of barnacle that has stems 50 times longer than its head. They also found that climate change had potentially caused changes in the breeding patterns of penguins.

The project was the first of this magnitude since the publication of the Antactic Map Folio Series 45 years ago. Dr Katrin Linse, an expert in Antarctic molluscs at the British Antartic Survey, told The Independent: “Since 1969 there has been no update but lots of science done in that period and lots of species discovered. “We had knowledge of 3,000 or 4,000 species when this process began, but now we know of more like 9,000 -- so it has hugely increased the number of known species.”

She added: “A lot of nations came together and put a lot of information together and specialists were chosen to analyse the data and when you do that you suddenly start to see changes.” The atlas, published this week by the Scientific Committee on Antarctic Research, follows four years work by leading oceanographers and biologists compiling everything they know about ocean species including microbes, fish, mammals and birds. Dr Linse added: “Now if we observe distribution changes or breeding areas, we can say for sure if it represents a change rather than just a year that is different for some reason.”

Claude De Broyer, of the Royal Belgian Institute of Natural Sciences, said: “The data and expert opinions in the atlas will help inform conservation policy, including the debate over whether or not to establish marine protected areas in the open ocean.”

The atlas also gives scientists the ability to predict what effect climate change could have on the distribution of key species, using sophisticated environmental models coupled with the existing species distribution data. The book was a remarkable example of international co-operation. It was produced using data from 147 scientists from 91 different academic institutions in 22 countries.
Huw Griffiths, author and editor of the British Antarctic Survey, said: “The book is unique and contains an amazing collection of information and photos. “It’s been an enormous international effort and will serve as a legacy to the dedicated team of scientists who have contributed to it. “The atlas is a must-read for anyone interested in the animals living at the end of the Earth.”

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Little penguins forage together: 40% of studied penguins synchronized underwater movements while foraging

Date: August 13, 2014

Most little penguins may search for food in groups, and even synchronize their movements during foraging trips, according to a study published August 13, 2014 in the open-access journal PLOS ONE by Maud Berlincourt and John Arnould from Deakin University in Australia. 

Little penguins are the smallest penguin species and they live exclusively in southern Australia, New Zealand, and the Chatham Islands, but spend most of their lives at sea in search of food. Not much is known about group foraging behavior in seabirds due to the difficulty in observing their remote feeding grounds.

Scientists aiming to better understand this behavior used GPS-derived location and diving data to track at-sea foraging associations of little penguins during breeding season. Researchers gathered 84 separate foraging tracks and then categorized individual penguin associations into one of three groups: not associating with other penguins; associating when departing from or returning to the colony; or at sea when traveling or diving, including synchronized dives.

The authors found that ~ 70% of little penguins' foraging tracks were in association with other penguins, ~ 50% of individuals dove while associating with other penguins, and ~ 40% exhibited synchronous diving. These behaviors suggest little penguins forage in groups, may synchronize their underwater movements, and potentially cooperate to concentrate their small-schooling prey.

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Story Source:
The above story is based on materials provided by PLOS. Note: Materials may be edited for content and length.

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Journal Reference:

1. Maud Berlincourt, John P. Y. Arnould. At-Sea Associations in Foraging Little Penguins. PLoS ONE, 2014; 9 (8): e105065 DOI: 10.1371/journal.pone.0105065

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PLOS. "Little penguins forage together: 40% of studied penguins synchronized underwater movements while foraging." ScienceDaily. ScienceDaily, 13 August 2014. <www.sciencedaily.com/releases/2014/08/140813174225.htm>.

Penguins Act As Coalmine-Canaries for the Southern Ocean

August 13, 2014 

Conservation This Week

Miners used to bring caged canaries down into the mines with them. The notion was that if toxic gases like methane or carbon monoxide leaked into the mine, then the canaries would die before the humans, giving the miners a chance to escape. The idea of a sentinel species is the same. Sentinels are groups of animals who are particularly or uniquely sensitive to changes to their ecosystem. If a sentinel species begins to suffer, it might mean that the broader ecosystem is under attack as well, sometimes giving us a brief window of opportunity to try to address the problem. In some ways, penguins are a sentinel species for southern ocean ecosystems.

Seabirds in general are useful indicators of ecosystem health because they are so dependent on having suitable habitats for breeding and on finding sufficient amounts of prey. Penguins in particular reflect local (or regional) conditions perhaps better than any other group of seabirds. That’s according to Head of Conservation Biology at the British Antarctic Survey Phil N. Trathan and colleagues, who reasoned that understanding the threats to penguins might allow us a better understanding of the Southern Oceans more generally.

Seabirds are the most threatened group of birds, and after albatrosses, penguins are the second most threatened group of all the seabirds. Some seabirds can travel quite far to find food; if there isn’t enough nearby, they can fly a little farther, and are therefore better able to withstand certain pressures. But penguins – all 18 species of them – tend to stick close to home. Penguin populations can therefore reflect both natural, seasonal variations in the health of the ecosystems within several hundred kilometers of their colonies, as well as the more artificial changes brought about by human activities.

In general, the regions with the most cumulative impacts from human activities are in the northern hemisphere. That makes sense, since proportionally, more humans live in the northern hemisphere. But that doesn’t mean that the southern hemisphere in unaffected by human activity. The Southern Oceans, however, are less studied. If researchers can figure out the factors that cause penguin populations to suffer, then they might be able to determine what factors are threatening the Southern Oceans more generally. For Trathan’s team, penguins might as well be canaries.

The Southern Ocean, highlighted in blue.

They found that penguin populations are in some ways resilient and, if given sufficient habitat and food, can recover from historic threats like hunting (for oil and feathers) and egg harvesting. Given the threats we aren’t equipped to mitigate in the near- or medium-terms like climate change, infectious disease transmission, and toxic algal blooms, Trathan argues that it is more important that we address those stressors over which we do have control.

The threats from habitat degradation, invasive species, oil pollution, plastic pollution, fisheries bycatch, and competition with fisheries over their prey sources, represent major concerns and “require concerted action to mitigate future population declines for many species.” In other words, the ability for penguins to survive global pressures like climate change and ocean acidification will depend on our ability to protect their prey, to protect their breeding grounds, and to eliminate the pollution from the waters in which they swim. “A risk averse or precautionary approach to the conservation of penguins would thus take immediate action to off-set these impacts,” writes Trathan.

The best solution identified by Trathan’s group is the establishment of marine protected areas (MPAs) both in sovereign waters and on the high seas. Because penguins have different spatial needs as they age, most existing MPAs are inadequate to protect penguins throughout their lifespan. Despite the challenge of coordinating local, national, and international conservation efforts, protecting penguins would also have a positive effect on the other species who share their ecosystems, including fish and marine mammals.

MPAs alone won’t get the job done, however, which is why Trathan and colleagues say that other, flexible, creative approaches will be required to supplement them. Coastal breeding habitats should be protected, especially since penguins have such extreme site fidelity. Introduced or invasive species need to be strictly controlled. Shipping lanes ought to be routed away from critical penguin resting, transit, and foraging areas. “Concerted action to conserve penguin populations today,” they write, “will be essential to facilitate populations that are robust and resilient to climate change impacts in the future.” 

– Jason G. Goldman | 13 August 2014


Source: Trathan P.N., García-Borboroglu P., Boersma D., Bost C.A., Crawford R.J.M., Crossin G.T., Cuthbert R.J., Dann P., Davis L.S. & DE LA Puente S. et al. (2014). Pollution, Habitat Loss, Fishing, and Climate Change as Critical Threats to Penguins., Conservation biology : the journal of the Society for Conservation Biology, PMID: http://www.ncbi.nlm.nih.gov/pubmed/25102756
 
Header image: Rockhopper penguin, Patagonia, Argentina via shutterstock.com; Southern ocean graphic via Connormah/Wikimedia commons

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Giant fossil penguin features on coin

Wednesday, 6 August 2014

Professor Ewan Fordyce proudly holds the 2014 collectable coin with his discovery – a Kairuku penguin – depicted on it. Photo: Sharron Bennett.

In what is thought to be a first for an Otago researcher, Geology’s Professor Ewan Fordyce has had one of his research findings emblazoned on a collectable coin issued recently by New Zealand Post.
A Kairuku penguin is depicted on the 2014 New Zealand Annual Coin. The extinct species of giant penguin was named by Professor Fordyce and a team working from the Department of Geology in 2012.

Professor Fordyce says he was “very delighted” when contacted by New Zealand Post earlier this year with the proposal and request to use the image of a Kairuku on the coin.

"It's nice to see Otago research recognised in this way."

“It's nice to see Otago research recognised in this way. Actually, the fossils can be a bit personal, if they are unusual like the Kairuku penguins (in this case, well preserved and big), and if we can remember the original discovery.”

The first discovery of Kairuku remains involved 27-million-year-old fossilised bones spotted “by chance” by Professor Fordyce in 1977. An account of the fossil’s discovery and significance can be found here.

He plans to keep his own copy of the coin at hand, bringing it out now and then to share with those who might really appreciate it from a scientific perspective – the occasional visiting paleospheniscologist (fossil penguin researcher).

Just 1500 of the commemorative coins were minted in the series produced annually by New Zealand Post to highlight endangered native species.

About Kairuku penguins:

The giant penguins are taller than any species of penguin known to have lived in New Zealand. They are thought to have lived about 27 million years ago and probably became extinct somewhere between 24 and 25 million years ago.

These penguins were much taller and heavier than their modern counterparts. When standing, they were 1.3 metres tall and stretched out to an impressive 1.5 metres when swimming. Their weight is estimated to have been at least 60 kilograms. The Kairuku has unusual proportions, with a long beak, long flippers, a slender body and short, thick legs and feet compared with modern penguins. This body type and beak suggest that they were divers that speared or snapped at their food.

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Risks to penguin populations analyzed

Date:

August 6, 2014

Source:

British Antarctic Survey

Summary:

A major study of all penguin populations suggests the birds are at continuing risk from habitat degradation. Scientists recommend the adoption of measures to mitigate against a range of effects including; food scarcity (where fisheries compete for the same resources), being caught in fishing nets, oil pollution and climate change.

King penguins.

Credit: Pete Bucktrout, BAS

A major study of all penguin species suggests the birds are at continuing risk from habitat degradation. Writing in the journal, Conservation Biology, scientists recommend the adoption of measures to mitigate against a range of effects including; food scarcity (where fisheries compete for the same resources), being caught in fishing nets, oil pollution and climate change. This could include the establishment of marine protected areas, although the authors acknowledge this might not always be practical. A number of other ecologically based management methods could also be implemented.

Populations of many penguin species have declined substantially over the past two decades. In 2013, eleven species were listed as 'threatened' by the International Union for Conservation of Nature (IUCN), two as 'near threatened' and five as 'of least concern'. In order to understand how they might respond to further human impacts on the world's oceans the scientists examined all eighteen species, looking at different factors where human activity might interfere with their populations. Forty-nine scientists contributed to the overall process.

They considered all the main issues affecting penguin populations including; terrestrial habitat degradation, marine pollution, fisheries bycatch and resource competition, environmental variability, climate change and toxic algal poisoning and disease. The group concludes that habitat loss, pollution, and fishing remain the primary concerns. They report that the future resilience of penguin populations to climate change impacts will almost certainly depend upon addressing current threats to existing habitat degradation on land and at sea.

The group of scientists recommends that the protection of penguin habitats is crucial for their future survival. This could be in the form of appropriately scaled marine reserves, including some in the High Seas, in areas beyond national jurisdiction.

Dr Phil Trathan, Head of Conservation Biology at the British Antarctic Survey and the lead author of the study, said: "Penguins and humans often compete for the same food, and some of our other actions also impinge upon penguins. Our research highlights some of the issues of conservation and how we might protect biodiversity and the functioning of marine ecosystems. "Whilst it is possible to design and implement large-scale marine conservation reserves it is not always practical or politically feasible. However, there are other ecosystem-based management methods that can help maintain biodiversity and a healthy ecosystem. For example, the use of spatial zoning to reduce the overlap of fisheries, oil rigs and shipping lanes with areas of the ocean used by penguins; the use of appropriate fishing methods to reduce the accidental bycatch of penguins and other species; and, the use of ecologically based fisheries harvesting rules to limit the allowable catches taken by fishermen, particularly where they target species that are also food for penguins."
 
The scientists believe their work will be of benefit to other studies of animal species, not just in the southern hemisphere, but the northern one too, where human impacts on the environment is even greater.

All 18 species of penguin were studied; Emperor and Adelie (Antarctica), King, Chinstrap, Gentoo, Macaroni, Royal, Southern Rockhopper, Northern Rockhopper (Sub-Antarctic), Little, Fiordland, Snares, Erect-crested, Yellow-eyed (Oceania), and African, Magellanic, Humboldt and Galapágos (Africa and South America).

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Story Source:
The above story is based on materials provided by British Antarctic Survey. Note: Materials may be edited for content and length.

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Journal Reference:

1. Phil Trathan, Pablo García-Borboroglu, Dee Boersma, Charles-André Bost, Robert Crawford, Glenn Crossin, Richard Cuthbert, Peter Dann, Lloyd Spencer Davis, Santiago De La Puente, Ursula Ellenberg, Heather Lynch, Thomas Mattern, Klemens Pϋtz, Philip Seddon, Wayne Trivelpiece and Barbara Wienecke. Pollution, Habitat Loss, Fishing and Climate Change as Critical Threats to Penguins. Conservation Biology, 2014 (in press)

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British Antarctic Survey. "Risks to penguin populations analyzed." ScienceDaily. ScienceDaily, 6 August 2014. <www.sciencedaily.com/releases/2014/08/140806102808.htm>.

Extinct mega penguin was tallest and heaviest ever

• 16:16 01 August 2014 by Jeff Hecht

Forget emperor penguins, say hello to the colossus penguin. Newly unearthed fossils have revealed that Antarctica was once home to the biggest species of penguin ever discovered. It was 2 metres long and weighed a hefty 115 kilograms.

Palaeeudyptes klekowskii lived 37 to 40 million years ago. This was "a wonderful time for penguins, when 10 to 14 species lived together along the Antarctic coast", says Carolina Acosta Hospitaleche of the La Plata Museum in Argentina.

She has been excavating fossil deposits on Seymour Island, off the Antarctic peninsula. This was a warmer region 40 million years ago, with a climate like that of present-day Tierra del Fuego, the islands at the southern tip of South America.

The site has yielded thousands of penguin bones. Earlier this year, Acosta Hospitaleche reported the most complete P. klekowskii skeleton yet, although it contained only about a dozen bones, mostly from the wings and feet (Geobios, DOI: 10.1016/j.geobios.2014.03.003).

Now she has uncovered two bigger bones. One is part of a wing, and the other is a tarsometatarsus, formed by the fusion of ankle and foot bones. The tarsometatarsus measures a record 9.1 centimetres. Based on the relative sizes of bones in penguin skeletons, Acosta Hospitaleche estimates P. klekowskii was 2.01 meters long from beak tip to toes.

Its height will have been somewhat less than its length owing to the way penguins stand. But it was nevertheless larger than any known penguin.

Emperor penguins can weigh 46 kilograms and reach lengths of 1.36 metres, 0.2 metres above their standing height. Another extinct penguin used to hold the height record, at around 1.5 metres tall.

P. klekowskii's tarsometatarsus "is the longest foot bone I've ever seen. This is definitely a big penguin," says Dan Ksepka at the Bruce Museum in Greenwich, Connecticut. However, he cautions that the estimate of its length is uncertain because giant penguins had skeletons "very differently proportioned than living penguins."

Larger penguins can dive deeper and stay underwater longer than smaller ones. A giant like P. klekowski could have stayed down for 40 minutes, giving it more time to hunt fish, says Acosta Hospitaleche.

Journal reference: Comptes Rendus Palevol, DOI: 10.1016/j.crpv.2014.03.008

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