Alien invaders—our top six!

Burmese python (Python bivittatus)

The Burmese python is one of the largest snakes in the world. In the US many pet shops sell baby Burmese pythons. But these snakes grow fast, and aren’t such cute pets after some time. People release pet snakes into the wild once they grow big and become difficult to look after at home. These snakes have become a huge problem in places like the Florida Everglades, where they have eaten up most of the wildlife. They have even been known to eat alligators!

Mesquite (Prosopis juliflora)

This is a medium-sized thorny tree with yellow flowers and pods that goats, buffaloes, and camels feed on (they also help to spread it!). It was introduced to India in the 1850s because it grew fast and could rapidly provide lots of fuelwood. Now it is an invasive plant all across the hot, dry parts of the country, and has taken over grasslands and farms. Because it spreads so fast, it is called the ‘mad babool’ in some places! But people have also figured out a use for it—in many places, people make charcoal from its wood.

Giant African snail (Achatina fulica)

The first know pair of African giant snails were brought to Kolkata by a British malacologist in the 1800s from Mauritius. (A malacologist is a scientist who studies animals like snails and oysters and even octopuses!) He presented this pair of snails to a friend to keep in his garden. Very soon, the snails had multiplied and were all over Kolkata! These large and unusual snails got carried as pets to other parts of the country and are now found in huge numbers, in places like Kerala and Assam. They are hungry creatures and chomp through crops like potatoes, spinach, bananas, and tomatoes, doing a lot of damage.

The brown tree snake (Boiga irregularis)

This snake is native to Australia and Papua New Guinea and was accidentally transported to Guam as a stowaway on ships sometime in the late 1940s or early 1950s. In Guam, there are no animals that eat the brown tree snake, but the snake has found lots of things that it can eat, like birds, rodents, and reptiles. So much so that some birds have even gone extinct on Guam, thanks to this invasive snake!

Mile-a-minute weed (Mikania micrantha)

This climber, from the American tropics, is called a “mile-a-minute” weed for good reason. It grows extremely fast, and can quickly blanket entire trees. In fact, the story goes that it was introduced to India during the 2nd World War, to camouflage airfields! It clambers all over trees in plantations and forests, very quickly smothering what is underneath.

Congress grass (Parthenium hysterophorus)

This is a small herb with tiny white flowers. It arrived in India by accident, people think, because its seeds got mixed up with wheat that was being imported for food! It is a very common plant along roadsides and in open areas. Some people are quite allergic to it.

What can you do to reduce the spread of invasive plants and animals?

  1. If you are arriving from abroad, don’t bring plants and animals back with you!
  2. Don’t buy exotic pets. And certainly don’t release exotic pets into the wild. Even tiny
    goldfish can become big and invasive.
  3. If you are planting a garden, try to use native plants. Even if you do not intend to attract
    pollinators and dispersers, be aware that colourful flowers will get pollinated and sweet
    fruit will get eaten! So help prevent accidental garden escapes via bird- and bat-mobiles.
  4. Join the SPAIS programme and report the occurrence of invasive plants and animals
    (https://indiabiodiversity.org/group/spotting_alien_invasive_species).
  5. Don’t remove creatures from where they belong and put them in places where they don’t.
This article is from issue

10.3

2016 Sep

SSHHHHHHH

SSSSHHHHHH,
WISH WASHA-WAAAAAAAAAAH,
WISH WASHA-WAAAAAAAAAAH,
WISH WASHA-WAAAA fall the waves on my shore,
SCHLOOP GLUP PA air escapes from the mud,
HSSSSSSSSSSSSSSSSSSSS,
HSSSSSSSSSSSSSSSSSSSS,
Sand drifts……………………….,
Sand drifts ……………………….,

HUSH TICA HAAAA sing the grasses in the meadow,
SWEEP SWAPA SWEEP call the birds in the trees,
SUPAAPA SIP SUPAAPA the whisper in the leaves,
A BRRRR TICA TAC… bird flies to the sky,
Mountains soar………………….,
Mountains soar………………….,

CRACKLE HISS-SIH… temperature is rising,
SAAAAAA CCCSH… ice in the North,
PIP-PIP… the ice melts away,
CHURGLE GLAGA GLUG … so much water,
…………………. Seas riiiiise…………,
…………………. Seas riiiiise ………..,

A BRRRR TICA TAC… the last bird leaves,
HSSSSSSSSSSSSSSSSSSSS,
HSSSSSSSSSSSSSSSSSSSS,
Sand drifts …………………..,
Sand drifts …………………..,
SSHHHHHHHHHH……… ,

This article is from issue

10.3

2016 Sep

Life on the Wave of Knowledge: Integrating Fisher’s Lore and Scientific Study

Can you be an expert in fisheries without a degree in marine biology? The famous scientist Dr Robert Johannes, a marine biologist, spent much of his working life answering this question with a “Hell, yes!”

In the 1970s, Johannes spent 16 months living with local people in the islands of Palau in the Western Pacific Ocean, learning about fish from them. They taught him about the different types of fish, which reefs the fish lived on, what they ate, how they hid from predators. They also knew when different fish would arrive in their fishing grounds and when they would disappear, when they bred, and how many of the different types there were. This information he got from the fishers had been built up over generations. Later, Johannes said that those fishers taught him more in just over a year than he had learnt in 15 years using research methods he practiced at university.

What did Johannes do with this knowledge? He wrote it down and became one of the first researchers of fishers’ knowledge. Other people had lived with, and written about similar communities 50 years earlier, but their work had been lost. Johannes and others uncovered their journals and notes. He found admiration for people in traditional fishing communities and felt that their knowledge should be shared with the world.

There was a challenge. The scientific way of studying fish was very different to Johannes’ approach of spending months with the local fishers, and recording their ocean lore. Scientists believed in their academic methods, where everything could be counted and measured. The types of knowledge possessed by the fishers did not fit easily with this.

Johannes’ challenge was to bring the two approaches together. He believed we could get a complete understanding of fisheries by studying the knowledge that local fishers had built over years. This could be combined with modern science to see patterns within the broader picture.

Since those early years, experts in both approaches have been busy. Over time, the sea of information they have produced has become murky, and hard to read. In 2014, Dr. Edward Hind, a researcher in marine sustainability, embarked on a voyage of discovery, to dredge all this information and summarise its flowing tides. In his review, he describes the ebbs and flows of both research approaches and asks if they have started to come together. Much like the oceans themselves, Dr. Hind finds that the research into fishers’ knowledge has come in waves.

Wave Chart
A HISTORY OF FISHERIES RESEARCH

Wave 1:

1900 to 1970
Amateur naturalists and tradesmen traveled the seas in search of adventure and riches. They were some of the first outsiders to recognize and deliberately record the knowledge of local fishers. Their notes were lost until Johannes and his colleagues re-discovered them.

Wave 2:

1970 to 2000
Scientists were inspired by the first wave. They focused on collecting fishers’ knowledge. Some even felt this knowledge was enough on its own to manage the fisheries.

Wave 3:

2000 to present day
Largely relies on semistructured interviews, e.g. local fishers are asked to rate fish numbers as ‘good’, ‘average’ or ‘bad’, or to draw information on nautical maps. They don’t think that fishers’ knowledge is enough on its own to manage fisheries. Instead, they emphasize that it should be used in combination with conventional scientific methods.

Wave 4:

Marine biologists, practicing ‘traditional science’. They do collect data from fishers, and only things they can count or measure like how many fish were caught, and exactly where and when the fishers caught them.

Wave 5:

This is very new, just a ripple really. It seems to be trying to bring together waves 3 and 4, for example, interviewing local fishermen, and recording a variety of information from them, including things which the scientists can use like fish numbers.

Question

How can wave 5 link-local fishers, fishers’ knowledge researchers, and fisheries scientists?

So where does this leave us? Is there a calmer ocean ahead for those studying fishers’ knowledge and those studying fisheries science to sail forwards together peacefully? Perhaps they could even be in the same boat? Hind thinks that there is still a way to go before the two types of researchers truly work well together. Yes, scientists must drop any negative prejudices against fishers, but fishers’ knowledge researchers must collect information useful to the scientists. What happens next is down to the next generation of scientists.

This article is from issue

10.2

2016 Jun

Tracking a Gentle Giant

Basking sharks can grow up to 12m in length, making them the 2nd largest species of fish in the world. This poses the question; how can we know so little about something so big?

The sight of a large dark fin slicing through the water will fill some with dread. For me it’s excitement and intrigue. Sharks have been swimming in our oceans for nearly 450 million years, but we know very little about key parts of their lives, such as where they eat, breed and travel to during their annual migrations. This information is critical to help provide protection for sharks, as many species are over-exploited and numbers are dwindling. This is where my research comes in…

I am a PhD student, studying basking sharks (Cetorhinus maximus) in UK waters, trying to uncover a little more about where these awesome creatures travel to and what they might be doing when they go there.

The answer is that even though we often see these sharks feeding at the surface in coastal waters of the UK and Ireland during the summer, from the autumn onwards they move into deeper waters, disappearing from sight, and leaving us unable to follow them. However, we are now able to attach small satellite tags onto the sharks, which take detailed information about how deep the sharks are in the water, and where in the world they are swimming. The tags then fall off the sharks after a set time, and send us all this information via satellites. This allows us to follow them, without being anywhere near them!

But first, we need to find the sharks to put the trackers on them. We head out on our boat each summer, searching until we see some sharks (which can take minutes, hours or days). We then approach very slowly so that we don’t disturb the sharks from what they were doing. In the summer, this usually means eating. Standing at the very front of the boat, we use a long pole to attach the tag to the base of the shark’s fin. The shark, unfazed, continues to swim along, feasting on the tiny zooplankton in the water.

The tags then start to collect lots of exciting data for us, so we can try and make sure this enigmatic species is well looked after for the future!

Find out more at:

https://www.exeter.ac.uk/esi/people/phd_students/doherty/

https://www.exeter.ac.uk/esi/research/baskingsharktracking/

This article is from issue

10.2

2016 Jun

It’s feeding time at the cleaner-fish cafe

common names
Common cleaner-fish
Bridled beauty
Gadfly fish
Janitor fish

scientific name
Labroides dimidiatus

distribution
Tropical and temperate waters of the Indo-Pacific ocean. A well-known species on the great barrier reef in Australia.

habitat
Coral reefs

diet
L.dimidiatus feeds on parasites and mucus which it removes from the scales, mouths and gills of other larger species of reef fish, called ‘clients’.

fact file
The relationship between L.dimidiatus and its ‘clients’ is called a mutualism. This means that both the cleaner-fish and client get something from their relationship. The cleaner-fish gets food, and their clients have their parasites removed. This improves their health and increases their chances of survival. The process also appears to feel good, perhaps like gentle tickling.

Cleaner-fish establish territories, called cleaning stations, from which they provide their services. Their clients know where these stations are, and visit them when they need a clean.

Although providing an important service for their clients, L.dimidiatus also takes the opportunity to cheat when possible, picking mucus instead of parasites from their client’s scales. Scientists think this mucus may provide the cleaner-fish with protection from ultraviolet sun rays, as well as with a nutritious meal. Even fish need to wear sun screen when the sun is fierce. However, removing the mucus doesn’t get the client fish much cleaner, so they prefer their cleaners to stick to the parasites.

client species

Spiny chromis damselfish
Acanthochromis polyacanthus
Females lay very large eggs, embryos develop slowly for damselfish, making the young very well-developed when they hatch. Both parents look after the young for a surprisingly long period once they emerge from the eggs.

Slingjaw wrasse
Epibulus insidiator
When males of this species are trying to impress the females and find a mate, they can actually change their color, becoming brighter. If disturbed from their displays, they can quickly switch back to their usual color pattern.

Black-backed wrasse
Anampses neoguinaicus
This carnivorous fish usually lives in small groups of females, and is accompanied by a single male. Black-backed wrasse is what scientists call a protogynous hermaphrodite. All individuals start off as females, but when the male in the group dies, one of the females changes her sex, becoming the dominant breeding male.

Epaulette shark
Hemiscyllium ocellatum
This shark grows to just over a meter in length, and can be found in waters as shallow as 15cm. They can survive even when oxygen levels in the water are very low, lowering their blood pressure by 50% to maintain blood-flow to their brains.

Blunt-head parrotfish
Chlorurus microrhinos
This large and colourful fish grows up to 80cm in length, forms schools of up to 40 individuals and can live for 15 years.

eviction notice!

In December 2015, the Queensland state government gave the go ahead for the expansion of a coal port at Abbot Point. Although there are measures in place to protect the coral and the life it supports, these restrictions may not stop the damage. Adani Mining, argues that the control measures are sufficient and the expansion will create 10,000 jobs and deliver $AUD 22 billion in taxes and royalties.

Although some development work has begun, the mining projects, are currently being held up by opposition and legal challenges from groups representing aboriginal land-owners, the United Nations, and environmental groups.

This article is from issue

10.2

2016 Jun

The African black rhino

Scientific name
Diceros bicornis

{Dicero comes from the Greek words, Di = two and Ceros = horn and Bicornis from the Latin words, Bi = two and Cornis = horn}

Also called the hook-lipped rhino, it’s hook-shaped upper lip helps grasp and rip plants.

Diceros bicornis bicornis, Diceros bicornis michaeli, Diceros bicornis minor and Diceros bicornis longipes are all sub-species of the African black rhino found in the dry deserts, wet forests and Savannah grassland.

Length (head and body)
3.0 – 3.8m

Height (at shoulder)
1.4 – 1.7m

Weight
800 – 1,350kg

Larger front horn
0.5 – 1.3m

Smaller rear horn
up to 55 cm

Diet
Herbivorous

2000 BC
Rhinos engraved into rocks in Niger

Early 20th Century
Increased hunting, land clearance for agriculture & conflict due to crop damage. With the exclusion of indigenous people from many areas, and increased trophy hunting, traditional knowledge and ways of life are lost. This leads to poverty and the search for alternative livelihoods.

1930s
Population falling fast

1950s – now
Increased use of rhino horn in Chinese medicine (thought to cure rheumatism, gout, fever, typhoid and other conditions. There is little evidence for these medical benefits). Poaching is lucrative and a poacher could make more money in a day than he would otherwise earn in a year.

1980
Rhinos found in only two countries, 110 in Cameroon and 25 in Chad.

1991
50 in Cameroon and none in Chad.

1997
10 – 18 individuals remaining.

2001
5 confirmed and 3 unconfirmed sightings.

2006
Extensive survey fails to find any rhinos.

2011
Western black rhino officially declared extinct.

A look into the future

Although facing many of the same threats which caused extinction of the Western black rhino, all three of the other subspecies still survive in the wild. The numbers are increasing, conservationists are optimistic that with effort and pressure from governments and the public, the remaining black rhinos can be saved.

There are critical questions that still need to be answered. Who owns the rhinos? Should rhinos be protected, harvested for their horns or both? How do we balance the rights of people and rhinos? Is there a role for ecotourism?

Population size estimate (IUCN, 2010)

D.b.bicornis (South-Western)
1920

D.b.michaeli (Eastern)
740

D.b.minor (Southern-Central)
2220

This article is from issue

10.1

2016 Mar

India meets the UK in a new pen-pal project for Current Conservation

The pen-pal tradition, where two school children living on different continents share their daily adventures, has become much less common than it once was.

Modern technology has offered wonderful new opportunities for instant long-distance communication. In many ways, it has made distances between people seem much smaller. It is now possible, for one sitting in his bedroom in India, to have a real-time video chat with a friend in London, Hong Kong, Sydney, or Shanghai.

Traditional methods of communication, letters and brown paper parcels, are slow by comparison. They are rapidly becoming obsolete. However, traditional technologies have a tangible quality that cannot be replaced by an email.

Although email gives us instant gratification, letters allow readers to feel closer. There is much excitement in receiving a hand-written letter or ripping open, emptying, and exploring the contents of a big parcel.

What if you combined the two, making the most of the digital realm’s ability to connect people instantly, and sharing physical objects from friends in far-flung places? This new Current Conservation project promises much joy for students by resurrecting the pen-pal tradition and taking the best that old and new postal methods offer.

11-13-year-olds from two schools, one in Cornwall UK, and another near Bangalore India, will establish the first trial partnership. The students will explore ‘a year in the life of a tree’. Working together and independently, children from both schools will observe a particular tree.

They will collect, illustrate and share stories about the tree and its many visitors. The documentation could be a painting, a collection of leaves, lists of bird species seen among the branches, or anything else that has captivated their imagination. What species live in the tree? What do its flowers look like? When does it fruit? What sound do its fluttering leaves make when you sit beneath its branches on a breezy day? The schools will then exchange their natural diaries, and maintain a record of the sights and sounds they see and hear from their windows, and their counterpart’s windows, a continent away.

Current Conservation will document this partnership, and display some of the exchanged experiences. The pen-pal project will bridge the gap between the technological and natural worlds.

If your school wishes to participate in the pen-pal project, please write to us at :
matthew.creasey@gmail.com (U.K), or hiremath@atree.org (India).

We look forward to hearing from you!

This article is from issue

10.1

2016 Mar

A Day in the Life of a Raptor Ecologist: Baby Birds with a Powerful Bite

George Swan, a PhD student at Exeter University, UK, recounts his daily climbing adventures with buzzard chicks!

My research involves climbing up to nests of common buzzards (Buteo buteo), to collect data on how often the parents bring food to the chicks, and what sort of prey they prefer. Young birds with big beaks – they give me plenty to think about.

I start my day by going through my calendar and making a list of all the nests I need to visit. I visit nests when the chicks are 18-25 days old and install tiny cameras that film the parents every time they bring food to the chicks.

This age range is the perfect period when chicks are large enough to control their temperature but small enough to be handled easily.

I avoid visiting nests in bad weather as I don’t want to disturb the chicks when they are already cold. This means that on sunny days in late spring, I have to be super organized! With my target nests selected, I load the truck with all my climbing and camera gear and head out.

Once I’ve reached a nest, it usually takes 45 minutes to complete everything I need to do. I start by firing a weight attached to some string over a strong branch high up in the tree using a huge catapult. When the weight drops down the other side, I attach my climbing rope and pull it up and over. Then I hoist myself up the rope, climb to the nest, install the camera and assemble a recording box at the base of the tree. I try and climb three nests before lunch, and then another two or three in the afternoon.

Such work can be physically demanding, it is a struggle to climb more than six nests in a day. By dark, I am back at the storeroom where I clean all the gear, check the weather for the next day and get ready to start all over again.

This article is from issue

10.1

2016 Mar

The Bull, the Bear, and the Bumbley Bee!

The bull, the bear and the bumbley bee,
Sat in the shade of a Gulmohar tree,
Said one to the two, and two to the three,
What lives do we lead, persecuted or free?

I live in the forest, eat termites and ants,
I sleep in my den through the heat of the day,
But I can be grumpy if woken too early,
Surprised or disturbed and I don’t like to play.

Should I be chased for not being cheerful?
Don’t you feel the same when woken too soon?
I’m happy to share the forests and grassland,
I’ll come out at night, by the light of the moon.

Some of my cousins have freedom to wander,
To graze in green pastures, no shackles, no chains,
One brother I have in the Banni,
Fed on crops grown in sweet summer rains.

How different for those in cities and towns,
More buildings built, more green fields lost,
A cow in town must scavenge on garbage,
The city grows bigger, the cow pays the cost.

You both talk of freedom, of cities, of forests,
Loved or revered, you both have your place,
I live here too, am I not important?
I’m so very small and take up little space.

Without me no honey, no flowers, no blossom,
No food for birds, no flutter-byes bright,
I’m sorry to sting, but when we are threatened,
To defend my sisters I’m willing to fight.

The bee, the bull and the snuffly bear,
Were common but now are increasingly rare,
So ask one another would not it be fair,
To live and let live in the country we share?

This article is from issue

10.1

2016 Mar

Conserving diversity: biological and institutional

Most people love nature, and marvel at its incredible diversity. Even an ecosystem patch as small as a tiny pond can contain hundreds of different kinds of species, with complex life systems working at multiple levels, that have evolved over millennia. We admire this complexity, are amazed by it, and deeply appreciate the need to save it. Witness for instance the ongoing discussion in the Indian media about the crisis of the fast disappearing tiger, India’s flagship conservation species, and the depleting diversity of the dry tropical forest habitats where it has a large home range.

It is quite surprising to observe the almost total lack of similar awareness of the incredible institutional diversity that exists across the world, and the deep connections between this kind of institutional diversity, and the conservation of biological diversity. From Africa to Alaska and India to Iceland, traditional tribes and local communities have developed complex, multi-level, astonishingly detailed and varied systems of rules and norms that have enabled them to conserve and sustainably use the natural resources with which their lives are so intricately interwoven. Some of these institutions have a documented existence of time scales spanning several centuries. From forest-specific rules that include a ban on the killing of specific species during the breeding season, to complex multi- level irrigation systems that specify when downstream and upstream farmer groups engage in maintenance activities, to spatially and temporally varying guidelines for pastoral grazing communities that move across hundreds of kilometers and many ecological regimes, these communities have developed innovative, complex and constantly adapting approaches to deal with the varying challenges that they face while nested in a certain ecology.

For those who have interacted with local communities governing ecological commons in any part of the world, it is easy to see that the “natural” environment in these contexts in fact exists as an interconnected social-ecological system. Social and institutional rules are modified in response to ecological condition, while at the same time acting as a major force shaping ecosystem change. Yet, many policy makers, governments and administrators, conservation agencies, and even the average city dweller, tend to be unaware of the vast history, heritage, learning – and potential-of community institutions.

Elinor Ostrom’s pioneering work has done much to change this situation, but there is still a long way to go. As the articles in this special issue indicate, her research has made a substantial case for governments to involve local communities in conservation, by providing a substantial body of evidence that affirms the capacity of local communities to sustainably manage natural resources. In Latin America, Asia and Africa, governments have initiated policies of decentralization that attempt to return some degree of control over forests and other local resources to communities. Yet, Ostrom’s reasoning is far from prescriptive or naïve—she clearly warns of the dangers inherent
in rapid decentralization without effective controls, and lays out a clear set of principles that indicate conditions under which communities are likely to be successful managers of common resources. She cautions that a large part of the reasons why communities are successful is that they have the freedom to craft diverse rules that apply to their local context, and to modify these rules based on their real life learnings, and in response to changes in the condition of the natural resource over time. Unfortunately, many governmental, regional and international policies—even those aimed at engaging with local communities—fail because they tend to be prescriptive, assuming that one approach to conservation, with a few simple rules (such as the need to raise money for more guns and more guards) will always work. She also argues eloquently for the need for polycentric institutions—those with multiple levels of administration and decision making, national and local, government and community—working in synergy for better management at all appropriate scales. Thus her work does not pit community against state, but asks for better and closer engagements between these two sets of actors, with greater trust, and opportunities for participation at an equal footing.

Since the award of the Nobel Prize, broader awareness of her influential ideas has increased, and this is a good sign for the future of the world, and its indigenous peoples. Elinor Ostrom’s indefatigable energy has taken her across the globe several times over, traveling to meet with policy makers, governments and think tanks and explain to them the main message of her work, without losing out on the essential details of complexity, adaptiveness and change. It is a hard task, but one made more accessible by the energy and spirit with which she delivers her message. It is also a goal made more feasible by the rich body of resources she has developed over decades in the form of colleagues, networks, postdocs and students, who now engage with similar issues across the world, expanding on these ideas in a range of local contexts. This special section brings to you a glimpse of the work—theoretical and applied—inspired by Ostrom’s principles of the commons—in different parts of the world.

The challenge for our future is to apply these principles for effective management in a world impacted by urbanization, climate change and deforestation, where the scale and intensity of environmental and ecological problems are changing before our very eyes. Treating people as part of the solution, rather than just part of the problem, will have to constitute the way forward. The area of work initiated by Elinor Ostrom and her network of colleagues will provide a critical component in searching for new solutions to the emerging crisis.

This article is from issue

4.3

2010 Sep

Culture and Conservation

Folklore about the Tonkean Macaque (Macaca tonkeana) might be the reason behind an indigenous group in Indonesia tolerating this crop-raiding species, reports a new study in the journal Oryx.

Erin P Riley, a primatologist at the San Diego state university, conducted semi-structured interviews among the To Lindu, an ethnic group indigenous to highlands in Lore Lindu National Park in Indonesia to understand how these people conceptualize the Tonkean Macaque, a species which frequently raids their crops. Through a qualitative analysis of the data, she identified three main themes which characterized to Lindu’s folklore about the macaques.
01. Macaques were biologically similar and related to humans;
02. Macaques should be treated well even when they raid crops because otherwise they will do much worse things
03. Macaques act as guardians of Lindu adat or customary law.

These biological, cultural and ecological links to the Tonkean Macaque envisioned by the To Lindu has resulted in a taboo that prevents them from harming this crop-raiding species. Riley, uses this case study, to highlight the importance of including traditional knowledge and beliefs in conservation efforts but also adds the caveat that cultural reasons for conservation are probably context-specific and might not apply for a different species or even for the same species in another area. Moreover, people’s beliefs are not fixed and might change in response to external influences. For example, even among the To Lindu, another taboo against the felling of strangler figs is slowly vanishing seemingly in response to the rise of Christianity among its people. Given the tenuous nature of cultural reasons for conservation, it is therefore important that a suite of values, including ecological and economic benefits are used in justifying the conservation of a particular species.

Further reading
Riley EP. 2010. The importance of human–macaque folklore for conservation in Lore Lindu National Park, Sulawesi, Indonesia. Oryx 44(2) 235–240.

This article is from issue

4.1

2010 Mar

Joining the dots

Conservation research has traditionally focused on understanding how human-induced disturbances such as pollution and hunting directly affect wild species, leading to their extinctions. Little is known about how these extinctions might in turn influence other species living in the area. One would guess that these influences will be important because species are connected to other species in myriad ways – as food, as predators, as competitors for the same resource and as partners in mutually beneficial relationships. Ulrich Brose, in this conceptual paper, argues that visualizing species as nodes in a network might help us understand these secondary effects of species extinctions.

Take for example a simple food chain involving an eagle, a snake and a frog. The snake feeds on the frog and in turn is fed on by the eagle. Now suppose these snakes are hunted for their skin and over time become extinct, what might happen to the eagles and the frogs? What might also happen to the insects which the frogs eat and the other creatures that the eagles eat? Building ecological networks of these relationships will help us predict the answers to these questions.

Ecological networks are representations of the pair wise relationships between species in an area. While initially, these networks were almost entirely used in the context of food webs such as in the example describe above, more recently, other kinds of relationships such as competition and positive interactions (for e.g. between plants and their pollinators) have also been investigated. This paper highlights two particularly important uses of network building in the context of conservation:
01. To identify and prioritise for conservation, species whose extinction will have strong secondary effects on other members of the community.
02. To understand what features of communities make them vulnerable or resilient to disturbance. For example, it has been shown in numerous studies that the greater the number of ties between species in a community, the less susceptible it is to disturbance.

In spite of a great deal of research into the impacts of humans on species and biodiversity over the last few decades, global extinction rates are currently at an all-time high. This paper makes the case that this is due to a lack of attention to species interactions and that the next big step in conservation research will be to understand these interactions using ecological networks.

Further reading

Brose U. 2010. Improving nature conservancy strategies by ecological network theory. Basic and Applied Ecology 11(1): p. 1-5.

Hari Sridhar is a PhD student at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India. Mail at hari@ces.iisc.ernet.in

This article is from issue

4.1

2010 Mar