Leopards get stressed. Here’s how we know – and why it matters

Leopard scat. Photo credit: Dieter Oschadleus

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The article below, written by Andrea Webster, from theUniversity of Pretoria, is republished from The Conversation Africa. It reports on a paper recently published in African Zoology that uses scats to evaluate stress levels in leopards. One of the co-authors of the paper was Pete Laver, one of the Directors of BDI.

Andrea Webster, University of Pretoria

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Leopards are versatile predators. These elusive cats can successfully occupy any habitat that supports sufficient numbers of prey species and which provides adequate cover for their ambush-style of hunting.

Leopards also adapt well to settled environments near human activity. But this often brings them into conflict with humans. In South Africa it’s been clear since the late 1980s that although protected areas play an important role in leopard conservation, most of the country’s suitable leopard habitat lies outside the boundaries of protected areas, often on private or community-owned land.

This means that leopards must navigate their way across land dedicated to human development, agriculture or mining practices. As a result, they are exposed to an array of physiological, environmental and psycho-social factors that could cause stress.

Acute stress is essential for vertebrate survival. For example, hunting an impala may be stressful in the short term, but a successful kill equates to survival. In contrast, successive or simultaneous stressors experienced over prolonged periods of time, such as constantly having to avoid human interaction, can result in chronic stress. This, in combination with other factors could affect this already vulnerable species’ long-term health and survival.

But how do you measure the stress levels within a leopard population without causing further distress? I set out to develop a method that would allow us to make a non-invasive assessment of stress levels in free-ranging leopards. It proved to be a useful approach.

My results indicate that although animals were relatively habituated at both sites, those living on the housing estate were more stressed than those in the game reserve. Pregnant females or those rearing cubs had the highest (617% higher) stress hormone levels of all the cats monitored. Overall, we found that wild male leopards showed less variation in their stress levels than females, regardless of whether they were in a protected area or not.

This method offers a new way for leopard biologists to monitor this elusive and iconic species. It can also inform the development of strategies to protect and conserve them.

Stress hormones

When we – leopards or humans – perceive a stressor, the central nervous system activates the release of hormones which act on the brain. Almost immediately, the pituitary gland releases hormones into the bloodstream and causes an almost instantaneous secretion of adrenalin. This mobilises energy which increases the heart rate and blood flow to the muscles so we have the physical means to confront the threat – or run away.

Over the next few hours, the adrenal glands release glucocorticoids – a type of steroid hormone – into the blood. These glucocorticoids (cortisol or corticosterone, depending on the species) are metabolised in the liver. After metabolism, they are then excreted via the bile into the gut and out of the body in the faeces. They can also travel via the kidneys to the bladder, to be excreted in the urine.

Previous studies have found that glucocorticoid concentrations are reliable indicators of disturbance experienced by an individual. That makes glucocorticoid metabolites very useful physiological indicators to measure stress. In this study we used scat to monitor the stress levels of free-ranging leopards.

We monitored two leopard populations. One consisted of seven known individuals living on a housing estate in Hoedspruit, a town located to the west of the Kruger National Park, South Africa’s largest wildlife reserve. The other consisted of about 27 leopards living in a protected area adjoining the park.

Applying the science

We began the study by gathering faecal samples and observational data from leopards in two captive facilities. We used the faecal material to evaluate which of five chosen enzymeimmunoassays were best suited to pick up changes in the glucocorticoid concentrations in the faeces. Enzymeimmunoassays are widely accepted analytical tools for detecting particular antigens or antibodies in biological samples.

The captive leopards were monitored to determine how long food took to move through their systems, so we knew how long we needed to wait before getting a sample. It also enabled us to determine how long after defecation the hormones remained stable enough for measuring. We then used this information to compare the glucocorticoid concentrations in the faeces of our two groups of wild leopards.

The ConversationNow that the method has been validated, we hope to use it to further examine how pregnancy, persecution outside of protected areas, levels of tourist activity and environmental factors contribute to the stress levels of this iconic African species.

Andrea Webster, PhD Candidate Mammal Research Institute Dept. Zoology and Entomology, University of Pretoria

This article was originally published on The Conversation. Read the original article.

Birding plus numbers! I absolutely love both … BDI interviews Lisl van Deventer

Lisl van Deventer has birded extensively at many exciting destinations. Before she travels, she invests a lot of time learning the key features of the birds she plans to see, and especially she tries to learn their calls. Here she is, armed with telescope and binoculars on a beach in Mozambique, close to Inhambane: “I ticked my Lesser Sand Plover lifer, in fact, there were gazillions of them amongst gazillions of other waders.” Photo credit: Anneke Vincent

BDI: Lisl, how did you become a citizen scientist? What was the catalyst that got you going?

Atlasing = Birding plus Numbers! I absolutely LOVE both!

BDI: What has been the highlight for you?

It has improved my birding skills. Because of the pentad system of the atlas atlas, I have visited off-the-beaten-track places in South Africa, seeing landscapes I would never have had a reason to go to.

BDI: How has being a citizen scientist changed your view of the world?

Meeting other atlasers and participating in the challenges (such as challenges in Greater Gauteng to turn all the pentads Green (7 checklists) and later on Blue (11 checklists)). Citizen science has taken me beyond my small world – you learn so much from other birders.

Atlasing in (poor) rural areas has been quite an eye-opener, and especially meeting some of the local people in these areas. They have a wealth of knowledge that is very useful for citizen scientists; sometimes it is simple information about the conditions of roads and at other times it is profound insights about the birds and how they are changing. It always amazes me how many locals can imitate bird calls and are curious to know the English bird names. Some locals understood details about the movement and migration of birds! It’s a huge pity some locals can’t be involved in citizen science to “tap” their knowledge. Sometimes one wishes that the voice recorder on the phone had been switched on to capture the insights. Many of these people lack their own transport and travel long distances to work means and have little time at home to do citizen science as we understand it.

The data for the very last pentad to achieve the “Four Degrees Blue” status for Greater Gauteng was submitted to the bird atlas website by Lisl on 29 June 2016

BDI: What does the term “citizen scientist” mean to you?

Volunteers collecting and contributing data for research purposes.

BDI: What are you still hoping to achieve? This might be in terms of species, coverage, targets …

I am not focusing on atlasing at the moment, but rather using the knowledge that I’ve gained with the atlasing towards the BirdPix database. I am enjoying being part of the “expert panel” for BirdPix; sometimes it is a real puzzle to work out the species in the photograph.

The members of the expert panels for each section of the Virtual Museum are the hub on which the section stands or falls. Lisl’s passion is to keep the number of records in BirdPix without confirmed identifications as small as possible, preferably less than 20!!. Since she became a member of BirdPix last year, Lisl has done 6,234 identifications, and has helped relieve the pressure on the other members of the panel, one of whom has done over 19,000 identifications!

BDI: What resources have been the most helpful? (And how can they be made better?)

BirdLasser has been awesome!! Would love to have the option of sorting the species alphabetically.

BDI: How do you react to the statement that “Being a citizen scientist is good for my health, both physical and mental!”?

Definitely! Atlasing is so rewarding! Being in nature reduces the work stress I’ve built up during the week, I get my dose of Vitamin D, it connects me with similar-minded people, mentally my thinking shifts beyond my little world to birding and to positive thinking (for example, I HAVE to find a House Sparrow for this pentad, I have to find five more species for this card).

Lisl did the confirmation of the identification in BirdPix. It had already been IDed as Yellow-billed Oxpecker by Ryan Tippet, who uploaded this photo to the Virtual Museum (see http://vmus.adu.org.za/?vm=BirdPix-53804). Many of the photos uploaded to all sections of the Virtual Museum do not even have tentative identifications. The expert panels do the best they can to either make the ID or confirm it. This expert-driven system enables everyone everywhere to be a citizen scientist and to contribute to biodiversity conservation.

BDI: What do you see as the role which citizen science plays in biodiversity conservation? What is the link?

Citizen science creates awareness, the volunteers spread the word and the public becomes aware and even involved. Data collecting provides an updated map of the distribution of a species, which revises knowledge about e.g. endangered species and in turn the focus of conservation can shift to those species. Volunteers assist by collecting and submitting data with their own finances and in turn saving money for the research project. With citizen scientist spread out in all corners of a country, the area of data collection spreads out as well and data can be collecting for species with a limited range.

 

Dispatches from Rwanda

On the 20th of May I travelled to Rwanda to attend the JRS Biodiversity Foundation’s annual Partners Symposium in Kigali. The symposium is a great opportunity for the various JRS project leaders from across Africa to meet, exchange ideas, tackle problems and find solutions for biodiversity conservation in Africa.

JRS Biodiversity Foundation’s Partners Symposium in Kigali, Rwanda

The JRS Biodiversity Foundation’s vision and mission is “a world in which biodiversity knowledge substantially contributes to conserving the Earth’s biodiversity for the benefit of society and to increase access to and use of information that will lead to greater biodiversity conservation and more sustainable development in sub-Saharan Africa.” This aligns with the goals of the Animal Demography Unit. OdonataMAP, the Atlas of African Odonata, a citizen science project run by the ADU is a grantee of the JRS. We have been tasked with mainstreaming Odonata and mapping the distributions of these amazing water quality monitors across the African continent.

Title slide of my presentation for the JRS Biodiversity Foundation’s Partners Symposium

The symposium was a great opportunity for JRS trustees and grantees to come together and discuss ideas, challenges, and solutions for the various biodiversity conservation projects across Africa. These JRS funded projects cover everything from pollinator conservation to fisheries and water resource management, water quality monitoring, and how to build better partnerships between scientists, policy makers and local communities across Africa.

Listening to Michael Murray‐Hudson (Okavango Research Institute, Botswana) presenting on “Sensitizing Audiences to the Value and Use of Biodiversity Data”

There was lots of discussion on how to improve relationships and communication between scientists and policy makers (i.e. government), but for me the crucial link is that of the citizen scientist community, without whom none of what we are trying to achieve in terms of protecting Africa’s amazing biodiversity would be possible. The citizen scientists, I believe, are the ones that have the power in their hands to drive conservation in Africa, to be ambassadors for biodiversity, to be the voice for nature and speak up for its rights. We all have our part to play in protecting wild places and spaces, not just for us and future generations, but for all the plants and animals that we share this planet with.

Some of the key themes discussed at the symposium were:

  • How to optimize data platforms for the various users of the data (i.e. how to make it more accessible and relevant)
  • How to create better lines of communication between government (policy makers), scientists and the public (local communities, citizen scientists)
  • Scientific research needs to justify conservation policies just as policies need the backing of scientific research. Governments and scientists need to work together for nature conservation and sustainable resource utilization to work!
  • Citizen science is an amazing and powerful tool, not just for collecting biodiversity data, but for creating a “connectedness” to and an awareness of nature and wildlife.
Rwandan treats! Lady Finger bananas (a diploid cultivar of the seeded banana Musa acuminate)

One of the ways members of the public can contribute to biodiversity conservation and informatics is by uploading photos of plants and animals (everything from scorpions to elephants) to the ADU Virtual Museum at http://vmus.adu.org.za. The ADU Virtual Museum provides the platform for citizen scientists to contribute to biodiversity projects. This innovative concept was developed by the Animal Demography Unit. When people hear the word museum they often think of a building filled with dusty display cases and stuffed animals. But, the Animal Demography Unit’s Virtual Museum (VM) is not gathering dust. Our “specimens”, photographic records of Africa’s biodiversity, are being used to make a difference for conservation in Africa. The VM provides the platform for citizen scientists (members of the public), or BioMAPpers, to contribute to biodiversity mapping projects. We cannot conserve Africa’s wonderful biodiversity if we don’t know where species occur. Up to date distribution maps are key for species conservation. The realm of biodiversity conservation is no longer only the responsibility of professional scientists and game rangers; everybody has their part to play in conservation! It is up to all of us to make a difference, the future of Africa’s wildlife and natural ecosystems are in our hands. So what can you do? You can snap it and map it!

Citizen science in Nigeria: BDI interviews the founder of the South West Atlas Team

Adewale Awoyemi is a young citizen scientist, who lives with birds in the Sunbird Bush, about 7 km north of the city of Ibadan in southwestern Nigeria. He is currently the manager of the AG Leventis-funded Forest Center at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria.

The campus of the AP Leventis Ornithological Research Institute (APLORI), University of Jos, is one of Africa’s most important ornithological treasures. APLORI runs an MSc course, each year training a cohort of Nigerians in conservation biology (Photo credit: Sam Ivande)

BDI: How did you become a citizen scientist? What was the catalyst that got you going?

I must confess that my one-year MSc course at the AP Leventis Ornithological Research Institute (APLORI), University of Jos, Nigeria, provided the turnaround in my life! Although I studied forestry and wildlife at the undergraduate level and had basic information about biodiversity conservation, my knowledge in applied conservation biology, especially citizen science was at the barest minimum, so APLORI was the eye-opener. Immediately after completing my MSc course in September 2015, I was employed at the IITA Forest Center, Ibadan in October 2015, to supervise the AG Leventis-funded bird and forest conservation projects – one of my main duties was to raise awareness about bird and forest conservation through the Ibadan Bird Club (IBC). After the club was re-launched in February 2016, I created a Facebook Group (https://www.facebook.com/ibadanbirdclub/) for the club in order to reach a wider audience. Between then and April 2018, over 300 people registered as members and an average of 30 members attend the club’s monthly meeting – the IBC is one of the best bird clubs in Africa and the initiative is now being replicated across Nigeria, to enhance citizen science – that’s just the catalyst!

The IITA Forest Center, Ibadan, invites you to the next meeting of the Ibadan Bird Club on Saturday 28 April at 4 pm. We will meet at the Botanical Nursery before proceeding for bird walk in the IITA Forest Reserve, Ibadan (see attached). New members, including children and beginners are always welcome. We lend binoculars and membership is free!

Dr Ulf Ottosson (APLORI) came to visit me at IITA, Ibadan, to introduce the Nigerian Bird Atlas Project (NiBAP). This was immediately after the project started in January 2016. Ulf told me he wanted me to be the Ambassador of NiBAP in southwestern Nigeria. I started introducing the atlas protocol to others. After developing an understanding of the atlas protocol and carrying out some trials, I thought we could set up a small group to support NiBAP in the area. I mentioned this thought first to Dr Jacob Orimaye of the Ekiti State University, as he really supported my conservation ideals, and Dr Taiye Adeyanju of the University of Ibadan, and we named the group South West Atlas Team (SWAT). This idea has produced remarkable results (check how shaded Nigeria map is around the south west region; laugh!), which is being replicated across Nigeria and some other African countries. The group now has over 50 volunteers and goes for monthly atlasing across different states in the area. Thanks to all members as I can’t keep mentioning individual names.

The red circle shows the SWAT area in southwestern Nigeria. Considering the difficulties of transport and access, this is remarkable coverage in little more than two years.

BDI: What has been the highlight for you?

Seeing the degree of turn-out and the dedication of members of IBC and SWAT is impressive. I led SWAT for about two years as the Team Leader and handed over to another person, Ademola Ajayi, who with the support of others has sustained this initiative. This is not always easy in this kind of setting and I am still a loyal member of the team – leaders should also try to be followers – I think this is another highlight!

This team atlased in Osun State in February 2017 (Photo credit: Babajide Agboola)

BDI: How has being a citizen scientist changed your view of the world?

Being a citizen science crusader has enabled me to understand how diverse the world is, especially understanding some aspects of the ecology of other taxa apart from birds, ecosystem inter-dependence, and of course knowing places of scenic values.

… and now for some landscapes in southern Nigeria
This is part of the forest reserve at the International Institute of Tropical Agriculture (IITA) (Photo credit: Adewale Awoyemi)

BDI: What does the term “citizen scientist” mean to you?

A citizen scientist is a member of the general public (specialist or non-specialist), who collect ecological data as part of scientific projects. So you can refer to all IBC and SWAT members as citizen scientists.

BDI: What are you still hoping to achieve? This might be in terms of species, coverage, targets …

Seeing the whole of south west Nigeria atlased by SWAT members, and shaded on the coverage map is one of my strongest desires. I test hypotheses and investigate bird ecology and behaviour, but to be honest with you, I love to see or hear birds – it is so interesting, especially when done in a group. Doing science while having fun such as going for atlasing and camping in remote places or in the field, is what I refer to as “not doing boring science”. Let me give you a brief statistics: I have recorded (seen/heard) over 400 species of birds out of the over 900 species reported for Nigeria. My teacher would give me 50% of the total mark but I would rather want something better as you would also want. As the day passes, I train my ears and eyes to hear and see more birds respectively!

Part of the town of Akure, capital of Ondo State in southwestern Nigeria (Photo credit: Sam Ivande)

BDI: What resources have been the most helpful? (And how can they be made better?)

From personal experience, I think social media platforms such as Facebook and WhatsApp are a good hook on which to hang conservation messages among the youth of this generation. The BirdLasser App has been an incredible aid for me; it would be great if it covered not only birds but also other taxa, including plants.

BDI: How do you react to the statement that “Being a citizen scientist is good for my health, both physical and mental!”?

Citizen scientists are always curious about their environment, implying that they will exercise their body by moving from one place to the other, searching for information, which is good for their health – at least the fat ones will burn some calories but I don’t know what someone like me, who is very skinny, will burn – I still jump up and down, searching for birds (laugh). After observing incredible things in nature, citizen scientists will still get home and search literature to expand their understanding about what they observed in the field. This is good for their mental development.

… and finally, a bird or two. Yellow-mantled Weaver is an uncommon species in the forest at IITA. This one was recorded during a SWAT expedition (Photo credit: Bibitayo Owolabi)

BDI: What do you see as the role which citizen science plays in biodiversity conservation? What is the link?

If well verified, citizen science data are important for formulating conservation strategies. The IBC, for example, has contributed immense and constant data for bird and habitat monitoring within the IITA-Ibadan campus, which holds a 360-ha secondary rainforest which is designated an Important Bird Area.

BDI: What are the challenges you experience doing citizen science and being a citizen scientist?

Safety issues in the field, verification of data collected and lack of essential equipment are some of the challenges facing citizen science in Nigeria. We advise our citizen scientists that they should go to the field with proper identification card and at least a bird buddy. It is also better if a group contains at least one ornithologist, which is always the case with SWAT. The equipment challenge is being addressed by organizations such as the AG Leventis Foundation and NiBAP, which now provide equipment and guidebooks for members and organize how-to-get-started workshops.

Yellow-throated Longclaws are common in grassland and cultivated open areas, relishing grasshoppers and beetles (Photo credit: Olufemi Olubodun)

A citizen science champion in Vanrhynsdorp

Salome Willemse lives in Vanrhynsdorp in the northwestern corner of the Western Cape, just south of one of South Africa’s most important centres of plant endemism, the Knersvlakte. For many years, the chief characteristic of this area was that it was a gap in all citizen science projects. Salome has been the catalyst that is leading the charge in filling that gap.

We wanted to get to know Salome a little better, so we asked her a few questions. Here responses below provide great insight from this citizen science champion.

BDI: How did you become a citizen scientist? What got you going?

I attended a birding course done by Anton Odendaal in 2013. Soon afterwards I realised that there is little data available for the Namaqualand region and subsequently started the Namaqua Bird Club. As I ventured deeper into the world of birding, I learned about SABAP2. We held a Citizen Scientist Day in Vredendal in 2015 and that day I realised that one individual can make a difference.

The Citizen Scientist Day initiated a series of BioBashes – each one started with a social event in Salome’s home (Photo credit: Les Underhill)

BDI: What has been the highlight for you?

Turning Namaqualand “green”, in other words getting at least full protocol checklists for all the pentads in the northwestern corner of the Western Cape, and also beyond, into the adjacent part of the Northern Cape.

The left map shows the bird atlas coverage in 2015, and how much greener it became as a result of Salome’s initiatives

BDI: How has being a citizen scientist changed your view of the world?

The Namaqua BioBashes were the first bashes where data on other taxa were recorded via VMus. Doing other taxa like scorpions and spiders has changed my whole life. I use to be petrified of spiders and now I respect their place in this world. I guess what I want to say is that getting to learn other species makes you understand and respect them. It makes one realise that we are all part of a cycle.

On another level I have made friends with like-minded people whom I now call my best friends.

BDI: What does the term “citizen scientist” mean to you?

Observing nature and learning so much about species

In the Virtual Museum, there are only two records of dragonflies from quarter degree grid cell 2414BC in the Namib Desert. Both records are Salome’s. This is a Long Skimmer (see http://vmus.adu.org.za/?vm=OdonataMAP-22965). The nearest record of a Long Skimmer to this one is about 150 km inland! (Photo credit: Salome Willemse)

BDI: What are you still hoping to achieve? This might be in terms of species, coverage, targets …

Turning the whole of Namaqualand green … And the Northern Cape

BDI: What resources have been the most helpful? (And how can they be made better?)

BirdLasser has been a wonderful tool that has turned atlassing into fun. And then also a dedicated person like Prof Les Underhill who keeps the interest going with social media.

BDI: How do you react to the statement that “Being a citizen scientist is good for my health, both physical and mental!”?

Amen

Salome has just twitched the Rufous-tailed Scrub-robin at Zeekoeivlei (Photo credit: Zenobia van Dyk)

BDI: What do you see as the role which citizen science plays in biodiversity conservation? What is the link?

Scientists themselves cannot be everywhere. We as citizen scientists can take a picture of a species and submit it. Being in the field and observing nature you often get to see really strange behaviour. If you are able to capture these moments other people can learn from that.

Thank you, Salome, for your efforts in this precious part of South Africa – keep up the excellent work!

Why studying African birds’ varied migration patterns is so important

A white-throated swallow, one of several intra-African migratory birds. Photo credit: MartinMaritz/Shutterstock

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Les Underhill recently published this piece in The Conversation (the original article can be found here).

Les Underhill, University of Cape Town

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Bird migration comes in many flavours – and, as with ice cream, “vanilla” is the one people are most familiar with.

This is the process of flying from the northern hemisphere to the southern hemisphere, leaving the northern autumn and entering the southern spring; then making the return journey from autumn to spring. That sounds like a lifestyle to be envied: perpetual summer. But it’s not easily achieved. Birds must make the trip of thousands of kilometres using their energy and muscles; they have to deal with headwinds and storms.

Each year on the second weekend of May scientists, conservationists and bird lovers mark World Migratory Bird Day. In 2018, there’s a change to the calendar: the event will be marked twice, now also on the second Saturday in October. The organisers hope this will draw attention to migratory bird habits beyond the more studied and better resourced northern hemisphere.

This is an important step in recognising that there are hundreds of variations on the basic “flavour” of migration. Judging from attendance at international conferences, about three-quarters of ornithologists live and do research in the areas which were under the ice sheets of Europe and North America tens of thousands of years ago. So birds’ search for perpetual summer is what’s been most intensely studied.

Our knowledge of migration between Europe and Africa, and between North and South America, then, is good – but nowhere near complete. In an era of global climate change and development, scientists have realised that this knowledge is not static. It’s dynamic, and constantly shifting. The weak link in understanding vanilla migration is a knowledge of where each species spends the non-breeding season at the southern end of migration.

Vanilla migrants

Most bird species have been around for a long time, and have been through many ice ages. The most recent, known as the Pleistocene Epoch, ended around 12 000 years ago.

At the worst of this epoch – about 20 000 years ago – most of Europe north of about Spain and Italy was so cold and miserable that it was uninhabitable by birds throughout the year. Then gradually Europe’s climate became better for birds, but only in spring and summer.

It was precisely this strong seasonality which made the new territory so attractive. For most bird species, breeding occurs when there is a spike in food abundance. In the new territory, the thaw in spring was accompanied by a burst in plant growth. This was quickly followed by an abundance of caterpillars and other insects to feed on the plants, and to provide a reliable source of food for nestlings.

So as the permanent ice sheets across Europe and elsewhere retreated, the areas left behind became attractive breeding places. Once they’d bred, birds would escape to warmer places further south. The pattern that is recognised so well today was established.

But what about other forms of bird migration?

Different patterns

There are many species that migrate within the continent of Africa, appropriately known as “intra-African migrants”.

For instance, there are species which breed in South Africa in the southern summer and then head north, to elsewhere on the continent, in winter. Most swallows are in this category, notably the white-throated swallow. They leave in March-April, and are away until August-September. My fellow bird researchers and I think they migrate to countries farther north like Angola and Zambia.

Some birds fall into a second category: they are partial migrants. For example, about 80% of the Cattle Egrets in South Africa’s Gauteng province leave for warmer countries to the north each December and January. But there are always at least some Cattle Egrets throughout the province during winter. Partial migration is challenging even to recognise, because the species is continuously present throughout the year – and even harder to study.

Then there’s altitudinal migration. This is the idea that birds move downhill in winter to warmer places where there is more food. South Africa is one of the best places in the world to study altitudinal migration.

Tanya Scott, who recently completed her MSc with the Animal Demography Unit which I head at the University of Cape Town, was the first to comprehensively examine all the province’s bird species to identify altitudinal migrants. She searched for patterns that would help provide explanations for why some species undertake altitudinal migration, and others don’t. She found none. A week after her MSc was submitted, the first ever global review of altitudinal migration was published – and reached the same conclusions.

Altitudinal migration is a big puzzle. Vanilla migration is easy; all the birds do it. But developing an understanding of why some birds of a species migrate downhill after breeding and the birds in the neighbouring territory do not, is key to understanding how migration in a population starts.

There are many hypotheses about how long-distance migration started in species in which every individual migrates. These ideas can only be tested in the context of partial migration.

Understanding migration for conservation

The populations of many long-distance bird migrants are getting smaller. It is obvious that researchers can only develop effective conservation strategies for these species if we understand their spatial needs throughout their annual cycle.

The ConversationAnd many partial migrants are categorised as being “threatened” with extinction. Understanding the where, the when and the how of their movements is key to their protection. Mountains are particularly impacted by climate change, and a study of altitudinal migrants might well reveal that a disproportionate number of them are threatened.

Les Underhill, Professor, Biodiversity Informatics, University of Cape Town

This article was originally published on The Conversation. Read the original article.

Birds and barbed wire

Birds and barbed wire – by Les Underhill

Barbed wire was invented in America in the 1860s, and used to keep cattle inside of camps, or outside of crops.

Within a few decades, farmers in the old Cape Colony had found a new use for barbed wire. In 1892, a civil servant in the Colony’s Department of Agriculture designed a vermin-proof fence that utilized closely strung and interlaced strands of barbed wire. He reasoned that if this were widely adopted, it would make the extermination of jackals and other “vermin” much easier. The farmers lobbied the government, and they were even provided with financial assistance to build jackal-proof fencing. Within the first decades of the 1900s, the “Fencing Movement”, aided and abetted by Parliament through an assortment of “Fencing Acts”, had successfully transformed the natural landscapes of South Africa into a patchwork mosaic of fields and camps.

A century has passed, during which jackals and other vermin have remained as big a problem as they ever were. But the barbed wire fences remain. Some are carefully maintained and others have rotten to rust. But they have undoubted been the catalyst that, over the past century, has altered the way South Africa looks.

Barbed wire along roads takes us back to its original purpose: keeping animals inside the camps. Here, barbed wire fences are both the bird photographer’s curse and the photographer’s blessing. The barbed wire either gets in the way, or it provides a perch out in the open!

Photo credit: Les Underhill

This Southern Red Bishop is easy out on the fence line

Photo credit: Les Underhill

Take away the out-of-focus barbed wire, and this would be reasonable image of a Capped Wheatear

Photo credit: Les Underhill

These Red-eyed Doves are using the fence to soak up the early morning sun

Photo credit: Les Underhill

The fenceline and dropper are almost conspiring to hide the distinguishing feature of the Cape Longclaw

Photo credit: Les Underhill

Being flat-footed on the dropper is probably more comfortable than curled up feet on the wire for the Common Fiscal

Photo credit: Les Underhill

Cape Weaver hiding, unsuccessfully, behind the wire

Photo credit: Les Underhill

This Cape Bulbul has its right foot too close to the sharp end for comfort

Photo credit: Les Underhill

The Speckled Pigeon is too large to hide behind the wire

International Citizen Science Day in The Company’s Garden

Photo Credit: Les Underhill

International Citizen Science Day in The Company’s Garden – by Les Underhill

All but one of the thousands of people in The Company’s Garden, in the heart of Cape Town, were there to enjoy the autumn sun, and hoping for rain. I was there to celebrate International Citizen Science Day, Saturday, 14 April 2018. The sun made it easy to take photos for the Virtual Museum (http://vmus.adu.org.za).

Photo Credit: Les Underhill

The dragonflies and damselflies, taken together, are called the Odonata. The damselflies mostly fold their wings over their backs, but they are mainly associated with really clean freshwater. So it was a bit of a surprise to find a damselfly sitting on the stalks emerging from the ornamental pond in the top photo.

Photo Credit: Les Underhill

The pair of Egyptian Geese in this pond had one gosling. Probably this was the only one left of a brood; the average starting off size of a brood is eight. This brood shrinkage is not a conservation issue in The Company’s Gardens. There is no shortage of Egyptian Geese.

Photo Credit: Les Underhill

This goose parent used the fountain in the ornamental pond as lookout. Cecil John Rhodes, of Cape to Cairo ambitions, has turned his back on this Egyptian Goose. Reminders of the failure to put a railway from here to Egypt is apparently a stressful topic.

Photo Credit: Les Underhill

The war horses and soldiers of the Delville Wood Memorial have to withstand the unsavoury attentions of the Hartlaub’s Gulls. They provide a great vantage point from which they can swoop down on anyone who scatters any food.

Photo Credit: Les Underhill

The Company’s Garden has a well-maintained section of vegetables. This is the best spot for butterflies. The most abundant butterfly today was the Cabbage White. This is South Africa’s only invasive alien butterfly. It was first recorded in Sea Point, Cape Town, in 1996, and has already expanded its range as far as the Eastern Cape.

Photo Credit: Les Underhill

This African Monarch was still flying in spite of large fractions of its wing area having worn away.

Photo Credit: Les Underhill

Here is a younger and more vibrantly coloured African Monarch.

Photo Credit: Les Underhill

Outside of suburbia, the Garden Acraea, occurs mainly in forest and woodland. It has moved into the suburbs on a large scale, because its favourite host plant on which its caterpillars feed is the Wild Peach Kiggelaria Africana, and these are grown in many gardens.

Photo Credit: Les Underhill

Another species that originally was a forest inhabitant is the Hadeda. This noisy bird has made itself at home in the suburbs, and in The Company’s Garden it happily feeds in the beds while people walk by on the adjacent footpaths.

Photo Credit: Les Underhill

This Grey Squirrel is another introduced alien, which seems to have The Company’s Garden as the epicentre of its Cape Town distribution. Here is one, of hundreds, and it is feeding on an acorn, from an introduced oak tree. So far, there is nothing unusual about all of this.

Photo Credit: Les Underhill

But the squirrel moves off looking like a rabbit. Somehow, it is coping with life minus its bushy tail.

All these photographs will be uploaded to the Virtual Museum. They will be valuable in two ways. They will confirm the continued existence of each species in this locality. And especially for the butterflies, and for the damselfly, these records will provide information on the time of the year when they are in flight. As we move through April, and the weather in Cape Town gets cooler, we anticipate seeing fewer and fewer of these two groups of insects.

BDIgest Saturday, 14 April 2018

Predation risk and plasticity in vigilance behaviour headline our pick of recent research this week. We continue the predation risk theme with an example of climate-mediated changes in predation risk. We look at an overview of the relationship between ecosystem services and population abundance – it is not as clear-cut as one might think. We also have a fascinating paper about co-evolution of a pathogen and its host species. We end off the peer-reviewed section with a thought-provoking piece – an ecological warning to humankind. This week, as a bonus, we have included two articles from popular literature that cover research topics that could be of interest … the scientific paper is dead; the AMOC is running amok. Pieter Cronje is our featured conservation artist this week, with “Tiger Tragedy”. Sign up below if you would prefer to receive this digest as an email.

 

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Cheetah with a hare kill. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)

Cheetahs strategise to deal with cheaters

Cheetahs are sometimes considered the weaklings in their guild, often losing kills (kleptoparasitism) or losing cubs (predation) to larger carnivores like lion and spotted hyaena. A recent study published in Behavioral Ecology and Sociobiology shows how cheetahs in the Serengeti National Park exhibit plasticity in their vigilance and foraging behaviours. Hilborn et al. (2018) draw on a long-term dataset (35 years) and a huge number of observation hours in the field to show how cheetahs balance their predation risk and food intake. Essentially, animals that are at risk of kleptoparasitism but not cub predation (male coalitions and single adult females) reduce vigilance and eat quickly. However, females that have cubs, increase vigilance, delay their own feeding, and spend longer handling the kill – thus allowing these mothers to expend more effort detecting potential predators and allowing their cubs to feed.

DOI: 10.1007/s00265-018-2481-y

Ed: Full disclosure – I know the authors and was privileged to be able to spend some time in the field with them. This is a fascinating ecosystem, and this long-term project has produced some remarkable ecological insights.

Lead author, Anne Hilborn, in the field. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Authors, Anne Hilborn and Marcella Kelly. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
After pushing the field vehicle out for the umpteenth time. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Cheetah mother with cubs. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Kleptoparasitism. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Kleptoparasitism writ large. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Food coma. Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)
Photo credit: Pete Laver 2003 (CC BY-NC-SA 2.0)

 

 

 

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Orange-fin anemonefish (Amphiprion chrysopterus). Public domain: US National Park Service.

Finding Nemo and his cousins just became easier … a tale of cascades, multiple symbioses, climate change, and predation risk

One of the fall-outs of climate change is ocean warming, which is some areas is causing mass bleaching of anemones and corals. Corals and anemones depend upon an algal symbiosis, whereby algal symbionts, zooxanthellae, photosynthesise and provide nutrients to the host organism (which may additionally feed on zooplankton). Many corals kept in the dark (so that their zooxanthellae cannot photosynthesise) but kept with a plentiful supply of zooplankton, will begin to die unless the zooxanthellae return to photosynthesis. Increases in ocean temperature are believed to result in the loss of these zooxanthellae.

In Proceedings of the Royal Society B, recently, and in Nature Communications last year, we find a pair of studies looking at the metabolic and physiological costs of this coral and anemone bleaching on its symbiont, the orange-fin anemonefish (Amphiprion chrysopterus). As with other clownfish and anemonefish, this relationship forms part of a service-service mutualism (anemones provide protection to anemonefish from their predators and vice versa) with a possible service-resource component (waste ammonia from the fish may feed the zooxanthellae).

The two papers show firstly that anemonefish exhibit higher stress hormone (cortisol) levels and lower reproductive hormone (ketotestosterone and estradiol) levels during bleaching events. Further, this is linked to a fitness effect, whereby bleaching events are associated with less spawning, lower egg production, and higher egg mortality.

The authors conclude: “Why anemonefish should exhibit a stress response to host bleaching is not known, but may be in response to a perceived increased risk of predation either from the shrinking of the anemone, or a reduced neurotoxicity of venom from bleached anemones. Alternatively their increased conspicuousness might lead to increased harassment from heterospecifics.”

The more recent paper adds a layer of complexity to this issue, by showing that the anemonefish from bleached anemones had higher standard metabolic rates (SMRs) than anemonefish from unbleached anemones, even though both groups did not differ in their activity levels.

Metabolic costs:
DOI: 10.1098/rspb.2018.0282

Stress hormones:
DOI: doi:10.1038/s41467-017-00565-w

Ed: Similar outcomes have been found for other animals that recently, due to climate change, find their perceived predation risk changing. For example, the snowshoe hare may be shifting its geographic range in relation to the snow-pack (see here). The hares in some areas exhibit a seasonal moult to a white winter coat which provides camouflage against the snow background. Populations that cannot adapt quickly enough to changing snowfall patterns in a warming climate might suffer fitness consequences (getting nabbed by predators due to a colour mis-match, e.g. here) or physiological consequences (as seen in the anemonefish above). Some populations of hares have, however, already developed some plastic moult strategies to prevent this mis-match (again here).

 

 

 

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At your service … for now

It is well established that biodiversity is associated with ecosystem services – certain species and community assemblages provide services (sometime unique to that taxon). However, it isn’t immediately clear how declines in population numbers of those species would affect the provision of the services they provide. The simplest a priori assumption might be that the relationships are both positive and linear. Gaston et al. (2018) provide a good overview of this issue in the journal BioScience. They use birds as an example taxonomic group to show that although population abundance and ecosystem service provision are usually positively related, this is not always true, and the forms of the positive relationships may seldom be linear.

DOI: 10.1093/biosci/biy005

Ed: This paper illustrates an important point – we might assume in many cases that the abundance of a species (or population) is linearly and positively related to the services the species (or population) provides, BUT, that relationship may be non-linear and thus include inflection or tipping points.

 

 

 

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Variable harlequin frog (Atelopus varius). Photo credit: Brian Gratwicke (CC BY 2.0)

Some froggin’ good news

Amphibians have generally had a rough time as humans have degraded habitat and polluted air and water with toxins and endocrine disruptors. To make matters worse, many amphibian species have suffered dramatic declines in the last two decades, linked to chytrid fungus epidemics. Batrachochytrium dendrobatidis is the fungal pathogen believed to cause chytridiomycosis in amphibian hosts.

Voyles et al. (2018) recently gave us some good news from Panama where they looked at detection of frog species and pathogen and host attributes nearly 10 years apart. The initial data were collected during outbreaks (epidemic or epizootic events) around 2004. Twelve riparian frog species had either been driven to critically-low population levels or had putatively been extirpated by chytridiomycosis. Ten years later, nine of those species appeared to be recovering, even after a period of no detection during the outbreaks.

Typically, it isn’t a good idea for pathogens to wipe out their hosts because they would get wiped out with them. Thus, diseases typically shift from initial epizootic (epidemic or outbreak) phases where hosts suffer high morbidity and mortality to enzootic (endemic) phases where morbidity and especially mortality are greatly reduced. It is not yet well-established how this transition occurs … through attenuation of the pathogen (i.e. its pathogenicity is reduced) or through improved host defenses or decreased host susceptibility. Voyles et al. (2018) show that in this case, Batrachochytrium dendrobatidis is no less pathogenic now than it was ten years prior at the height of the outbreak in Panama. Instead, some of the amphibian hosts appear to have more effective defenses.

DOI: 10.1126/science.aao4806

Ed: This is a really fascinating study and offers some hope for amphibian assemblages that have been ravaged by chytrid fungus. On the issue of co-evolution of a pathogen and its host, this study provides a great entry point, and opens up so many new questions. It would be great to compare this co-evolving system which has a single pathogen and multiple host species, with a system that has a single pathogen with high host specificity (perhaps just a single host species). In the former system, it may well be the case that multiple host species provide reservoirs for the pathogen – i.e. some insurance against obliterating its host. The latter system of a single host species offers less insurance, and I would suspect that pathogenicity might evolve quicker than host defenses to prevent a catastrophic host population crash. 

 

 

 

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We need to have a talk …

At the end of 2017 a sizeable portion of the world’s scientific community published a frank warning to humanity (Ripple et al., 2017). This letter had over 15,000 academic signatories from 184 countries. This letter marked the 25th anniversary of the last time such a warning was made – then by more than 1,700 signatories (including most living Nobel laureates in the sciences). Recently, BioScience published some follow-up letters (here, here, and here) and a response from Ripple et al. (2017) (response).

Ripple et al. (2017) summarised broad environmental trends since the previous warning was issued. For the most part those trends have continued unabated, suggesting that, in general, the first warning was not heeded. The only success has been in stabilising the stratospheric ozone layer. They provided 13 potential steps that humanity could take to make the transition to sustainability: 1) prioritising connected, well-funded and well-managed in situ conservation in reserves; 2) halting habitat conversion; 3) restoring habitat on a large scale, particularly forests; 4) re-wilding areas, including re-introducing top predators; 5) enforcing strong policies to prevent poaching, exploitation, and trade of threatened species; 6) reducing humanity’s food waste; 7) promoting dietary shifts to mostly plant-based diets; 8) reducing human fertility rates by increasing access to education and family-planning services; 9) increasing education about, engagement with, and appreciation of nature; 10) redirecting investing and purchasing choices to promote positive environmental change; 11) promoting green technologies and renewable energy production while phasing out reliance on fossil fuel-derived energy; 12) reforming economies to reduce inequality, and to price in environmental externalities; 13) determining and striving for a sustainable long-term human population size.

The follow-up letters briefly address three additional steps to be taken: 14) transitioning economies away from a growth model (the underlying premise is that the finite resources of the planet cannot sustain infinite growth); 15) developing a new global ethic (in which we are part of the biosphere, it is part of us, and morality includes environmental concerns); 16) moving more forcefully as scientists into the realms of policy-making and politics.

And so … the conversation continues …

DOI: 10.1093/biosci/bix125 (2017 letter)
DOI: 10.1093/biosci/biy006 (2018 follow-up – economic growth)
DOI: 10.1093/biosci/biy007 (2018 follow-up – new global ethic)
DOI: 10.1093/biosci/biy008 (2018 follow-up – political power)
DOI: 10.1093/biosci/biy009 (2018 response to all)

Ed: This series of letters is sobering and somewhat depressing. A lot of the recommended steps would appear to be beyond our individual control as they fall into either POLICY or THE MARKET. We should remember though that in most cases, policy and the market are the collective outcomes of a multitude of individual behaviours and decisions (e.g. votes, or purchases). Some of our most effective lobbying may be to lobby the people directly around us – friends, family, colleagues, neighbours – people who at the very least might give us the chance to be heard.

 

 

 

Popular literature

 

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Are scientific papers obsolete?

The Atlantic produced an interesting article about scientific papers and how they may be obsolete in the digital age. The article focuses heavily on the idea of creating computational essays instead – digital files that include data, algorithms, traditional text, and interactive components. Two competing models are introduced – a pay-to-play version from Stephen Wolfram, and an open-source alternative, Jupyter.

 

 

 

7

Don’t you dare touch that thermostat

Scientific American discusses the Atlantic Meridional Overturning Circulation (AMOC), which plays a vital role in how heat gets distributed around the planet. Previously, in this digest, we have looked at climate oscillations such as El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and the North Atlantic Oscillation (NAO) (see here). AMOC could have even bigger impacts on humankind, and it appears that there is now evidence that AMOC is undergoing some change – specifically a slowing down of the currents. The links between climate change, melting Arctic ice, resulting changes in water density in the North Atlantic, and ultimately changes to AMOC, all make for grim but important reading.

 

 

 

 

 

Conservation Art this week

 

A new prison uniform … striped, and orange?

The featured conservation artist this week is Pieter Cronje. He is a human rights lawyer with a master’s degree in Human Rights Law, with Environmental Law as one of his subjects. He was born In Oudtshoorn, South Africa. He started drawing and painting when he was in high school. He also studied history of art and spent many hours at the arts faculty of the University of the North West in Potchefstroom while he was doing his military service. As a human rights lawyer he has traveled to many countries which have both serious human rights issues and environmental issues. Environmental issues were always part of his inspiration and are depicted in many of his paintings. Pieter’s contribution to the Virtual Museum has been massive; he has submitted 27,000 records from 22 countries.

“Tiger tragedy” 2017 by Pieter Cronje. Oil on stretched canvas, 46 cm x 46 cm
“Tiger tragedy” 2017. Oil on stretched canvas, 46 cm x 46 cm.
Pieter says: “During 2017, I had the opportunity to train police in Punjab, India, on how to respond to violence against women. The police invited me to visit a nature reserve (Tiger Reserve) in what they refer to as Kipling country. This is the area of India which inspired the English author Rudyard Kipling to write the Jungle Book. They originally took me to a zoo to see tigers which really saddened and frustrated me. After some discussion they agreed to take me to see the real thing. After one night on the train I was fortunate to see three tigers in the wild. Unfortunately, most of the tigers nowadays are in cages. This picture shows the fear and majesty of the tiger kept in a broken cage. Sadly, this is a highly threatened species in high demand from Chinese traditional healers for tiger bones. They also use the skins for a dancing ceremony in Tibet, although the Dalai Lama requested the local Tibetan people not to use tiger skins. The tradition was taken over by the Chinese staying in Tibet as a sign of power and wealth. Also represented is the Emperor of India Butterfly, also known as Kaiser-I-Hind, Teinopalpus imperialis, is also a highly endangered species due to habitat destruction and butterfly collectors.”
Pieter says: “As a human rights lawyer, I also always challenge people about the destruction of the earth and the decline of species and what they can do about it. I work with law enforcement agencies all over the world and focus on human rights related issues such as human trafficking and domestic violence; but I also talk about the environment to my learners and this is always an important part of every workshop to law enforcement officials. For the past few years my paintings have become a social commentary after my visits to some of these places.”
Have a look at a selection of Pieter’s paintings by visiting https://www.facebook.com/pietercronjeart/.

 

 

 

 

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Thanks,
Pete Laver
Editor, BDIgest
pnlaver(at)gmail(dot)com

 

 

 

 

Biodiversity and Development Institute

Paardeberg site report – 2018/04/07

By Les Underhill. Photo credits: Les Underhill & Dieter Oschadleus

Team BDI explored the northwest corner of the Paardeberg on Saturday 7 April 2018. We visited the part of this mountain range which is closest to Malmesbury. Technically, the Paardeberg is a series of granite plutons – dome-shaped hills. It was called the Paardeberg because, when discovered, it had been inhabited by quaggas, which to the early settlers were horselike. This is a fascinating area, and one we plan to revisit.

We joined an expedition led by Arnold van der Westhuizen to check two camera traps. Leopard scats had been reported here recently, and the cameras had been set up in the hope of confirming the presence of this seldom-seen animal. We found leopard scats and uploaded them to MammalMAP: http://vmus.adu.org.za/?vm=MammalMAP-24172

On the foothills of the Paardeberg, the main crop is grapes, but there was no water in the farm dams for irrigation this summer, and there was no harvest in the higher lying vineyards. Above the agricultural areas is a band of renosterveld. Go a little higher, and the proportion of plants which are proteas, ericas and restios increases, and renosterveld gives way to fynbos.

The camera traps had taken a total of 44 photos. All of them turned out to be baboons, and some were caught in some unusual poses! Maybe a leopard or two would help create a “landscape of fear” for the baboons.

Cape Black-Eye
Cape Black-Eye

At the end of long, dry, drought summer, biodiversity was scarce. This was one of only two butterflies we saw. It is a Cape Black-eye Leptomyrina lara (http://vmus.adu.org.za/?vm=LepiMAP-645342) This is a species that frequently rests on bare ground, and did so for us. The Cape Black-eye occurs mainly in the more arid western half of South Africa, in Lesotho and it also occurs northwards into Namibia. This is the sixth record of the species in the Paardeberg, and the others have also been within a few kilometres of this spot.

Crimson-speckled Footman

The Crimson Speckled Footman Utetheisa pulchella is a moth that flies in the daytime (http://vmus.adu.org.za/?vm=LepiMAP-645342). It looks like a white butterfly in flight; but when it is settled the red and black pattern on the white wings makes it instantly recognisable. These moths are unpalatable to birds; the bold wing colours serve as warning to predators: “I am toxic”, or, in technical terms, “I have a condition called aposematism.” The Crimson Speckled Footman has a wide distribution across Africa and southern Asia. The South African distribution map should show an almost continuous range.

We didn’t see any mammals, not even a baboon, but we did find this porcupine quill and submitted it to the MammalMAP section of the Virtual Museum (http://vmus.adu.org.za/?vm=MammalMAP-24182).

Two species scorpions were found. This one is Uroplectes carinatus (http://vmus.adu.org.za/?vm=ScorpionMAP-3161). The scorpions don’t yet have English “common” names, like the birds, butterflies and dragonflies do. The identity of the second species is still being debated by the specialists (http://vmus.adu.org.za/?vm=ScorpionMAP-3160).

We are grateful to Arnold van der Westhuizen for being our guide.