EcoLincNZ

Category: Species distributions

  • The hotspots are where it’s at if you want to spot a cat: the search for the common leopard

    The Himalayas are an almost mythical place, where mountains loom and the clouds surf down their sides before sliding into the forests below. The songs of rhesus monkeys, palm civets, and the occasional jackal sing out from the thick trees. This landscape is beautiful yet rugged. Travelling through is difficult for our human capabilities, in many cases impossible.

    Now imagine. This is the backdrop you must navigate to discover the number of big cats that live there. To top it all off, your target is the shyest and one of the rarest of them all, the inappropriately named common leopard.

    A common leopard relaxing in the sun
    (Source: Daily Pakistan: Pakistan’s common leopard endangered due to loss of habitat)

    Now, it’s not unusual that scientists doing field research are thrown into difficult situations. You might end up with dangers like Carlos Jared who innocently picked up a frog while doing fieldwork in Brazil, discovering frogs can be venomous. Or you might accidentally glue yourself to a crocodile while attaching a radio transmitter like Agata Staniewicz did (find that and more hilarious field research fails here).

    But when you’ve got a shy animal, add in an impassable landscape, plus the addition of the very real and dangerous threat of bumping into rebels which is, unfortunately, the reality in parts of Pakistan, you’ve really got your work cut out for you.

    This momentous task is one Muhammad Asad, PhD student at Lincoln University, took on as he bravely set off to northern Pakistan. Nobody had done this before and the leopard landscape was mostly unknown. But he was up for the challenge.

    The not-so-common leopard

    Leopards are found all over the world, the most widespread of all land-based carnivores. They’re incredibly adaptable, able to make their homes in all sorts of climates: from the savannas of Africa, the tropical forests of South East Asia, to the freezing mountains of far north Russia. They even make it work when humans move in.

    Their only request, being rather introverted, is that they have lots of space. They’re very territorial, protecting their home range fiercely. But honestly, a bit of peace is a reasonable request!

    Despite this incredible flexibility, common leopard populations are in decline. They’re no longer found in 63-75% of their historic range. The decline in Asia is even bigger, with an 83-87% drop! It’s no surprise that these gorgeous cats are listed as critically endangered.

    The majestic common leopard
    (Source: Daily Pakistan)

    Leopards are facing many different threats. The main ones are:

    • habitat is lost or changed,
    • trees cut down,
    • inbreeding from being cut off from one another,
    • human developments being built near their protected ranges,
    • prey disappearing,
    • poaching,
    • and human-wildlife conflict.

    Clearly, these cats need protection. So, leaving New Zealand and heading back to his native Pakistan, Muhammad took the first step to build a conservation plan; he had to figure out how many leopards there were and where they were found.

    To do this across the entire country would be too big a job. Instead, he focussed on the Gallies and Murree Forest Division in northern Pakistan, lying in the outer Himalayas. Here, leopards are protected under the law. Even so, there are often no checks for this, with hunters easily getting away with it. This is made worse by the slow and sometimes non-existent compensation programmes, programmes designed to reimburse farmers who have lost livestock to a leopard attack. The locals often resent the leopards. But it’s hard to blame them when people, including children, are occasionally attacked and killed.

    Leopards are poached frequently in Pakistan. Cubs are trapped to sell in the illegal pet trade or body parts and skin are taken for sale. Skin, claws, and teeth are sold in north Pakistan.
    (Source: Raj K Raj/Getty Images)

    Estimating the number of leopards in an area is very tricky. They have large territories with very few cats within each area. Figuring out where to look, especially when the landscape has the worst access, is the key to success.

    How to find leopards

    Muhammad and his crew began with a questionnaire survey. They asked people from local communities who lived nearby to fill these out. They asked about losses of livestock, when the attack happened, and the type of injury, for example, bite marks on the neck, missing dogs, or human casualties.

    Based on the information from the locals, they ended up with 63 different sites where they could focus the leopard hunting efforts. A much better start!

    Next, they moved into these sites, peeling their eyes for signs of poop, territorial markings (such as peeing on a tree), and tree scratches. These signs meant one thing; here be leopards.

    With this proof, they set up special cameras, known as camera traps, on either side of the trail, ready to capture the cats on the silver screen.

    They also set up cameras on 5 connecting trails which hadn’t shown any signs of leopard action. These were used to see if they could capture leopards in areas where they had left no signs. As new leopard trails were discovered, the camera traps were moved to snap those too.

    Sampling locations of the camera-traps survey in Gallies Forest (Ayubuia National Park, surrounding Reserved Forest and Guzara Forest), and Murree Forest (Protected, Reserved and Municipal Forest). Country map (top left – green). Study area showing different city boundaries (middle left).
    (Source: From paper)

    A leopard can’t change its spots – a handy identification tool

    You may have heard the proverb that a leopard can’t change its spots. This is supposed to teach us that we all stay true to our nature, even if we pretend we’re different. But it turns out when it comes to leopards it’s 100% true! The coat of a leopard is as unique as our fingerprints. Incredibly useful when you’re a scientist trying to tell the difference between two cats in a grainy photo!

    Their gorgeous spots are a bit like the shape of a rose, giving them the name ‘rosettes’. This means that by matching up the images of the rosettes you can figure out if it’s the same cat. The best place to match things up is on either side of their back legs or the top of their tail.

    Example of an individual being identified using the rosettes on the tail
    (Source: From paper)

    This is trickier than it sounds. The rosettes change shape as the leopard moves. And it can look different depending on the angle it is to the camera. But still, it’s a pretty helpful method to avoid double-counting cats. Double counting would give you a very different population size! You can find out more information on leopard identification techniques here.

    Example of when the spots don’t match up.
    (Source: From paper)

    So, how many are there?

    In 2017 Muhammad estimated there were between 16-24 common leopards in the Gallies and Murree Forest Division. This went down to 7-12 in 2018.

    However, they don’t think the population dropped. In 2018 they got fewer clear images making it harder for them to identify the cats. They think the real number could be closer to 12-18, meaning its range overlaps with the 2017 estimate.

    But, this might not be the case. In 2018, Pakistan was suffering from a drought. Perhaps the leopards had been forced to move out of their territories to look for food. So far there hasn’t been any research on leopard movements in relation to strange weather. This would be an interesting thing for someone to look into (are there any leopard enthusiasts up for the task?).

    Or perhaps this drop is real. Poaching and unreported killings are still huge in Pakistan. Plus, Muhammed and his team did find signs of hunting. So the reason could in fact be nefarious.

    Regardless of the reason, Muhammad estimated there to be 8-12 leopards and 3.5-6.5 leopards per 100 km2 in the Gallies and Murree Forest Division. They also confirmed they lived in the Swat, Dir, and Margalla Hills, even though locals as well as wildlife departments thought they had disappeared.

    These estimates are not 100% accurate. But the team is pretty confident that they are close to the true number. All in all, a great success.

    Mother common leopard and her cub.
    (Source: Daily Pakistan)

    What next?

    Now there’s a basic understanding of how many leopards there are and where they like to hang out, we can start to protect them.

    With this information, we can:

    • Use the leopard hotspots to keep an eye on the population trends and demographic changes over time.
    • Decide on the most important conservation areas. Special attention should be given to the corridors that join areas together to protect the long-term health of the leopard populations.

    For example, Muhammad discovered that 70% of leopards killed for revenge in the Guzara Forest happened outside of the Reserve area, close to the village, and in winter. That tells us we should focus the conservation efforts on the hotspots in the Guzara Forest surrounding the Reserved Forest so that human-leopard conflicts can be reduced.

    There’s still a lot of work ahead for the common leopard in Pakistan. But with Muhammad on the case, their future is looking a little brighter.

    You can read Muhammad’s research in full here: The Un-Common Leopard: presence, distribution and abundance in Gallies and Murree Forest Division, Northern Pakistan

    This article was prepared by Master of International Nature Conservation student Kat Douglas as part of the ECOL608 Research Methods in Ecology course.

    Full citation: Asad M, Waseem M, Ross JG, Paterson AM (2019). The Un-Common Leopard: presence, distribution and abundance in Gallies and Murree Forest Division, Northern Pakistan. Nature Conservation 37. 53-80. https://doi.org/10.3897/natureconservation.37.32748

  • The big, bold, redbacks of Buckland

    “No, Mr Baggins has gone away. Went this morning, and my Sam went with him: anyway, all his stuff went. Yes, sold out and gone, I teller. Why? Why’s none of my business, or yours. Where to? That ain’t no secret. He’s moved to Bucklebury or some such place, way done yonder. Yes it is – a tidy way. I’ve never been so far myself; they’re queer folks in Buckland. No, I can’t give no message. Good night to you!” JRR Tolkien – The Fellowship of the Ring

    One of the greatest illustrations of Tolkien’s work, IMHO, The Gaffer and the Black Rider by Stephen Hickman.

    I’ve always liked this passage where old Gaffer Gamgee is talking, unbeknown, to a nazghul. It is an important story point but delivered in the type of conversation that you could hear all over the world. ‘Those people that live 20 – 30 km away are just so different and weird!‘ Are the people of Buckland really so different to the good, honest folk of the Shire? If so, how did this happen by simply crossing a river?

    There is a question around invasive species whether the individuals that arrive in a new area are just a random selection of the individuals (and their traits) that live in their home area or whether they represent a group of individuals with consistent and particular traits that make them more likely to have successfully invaded the new area.

    For example, all humans in Aotearoa/New Zealand have arrived from outside these shores over the last 1000 years. Were the people that made their way here more bold and explorative than the rest who stayed behind? Or were they no different than their neighbours who stayed at home? Maybe they just simply had the opportunity to go?

    These ideas are important in thinking about why invasive species are successful at establishing or not. If any old random subset of the population can turn up then they are less often going to successful at establishing (they may not be fit-for-purpose!) compared to if they arrive with skills that allow them to survive better in a new environment (or even to survive the journey).

    Being large might help give invasive individuals an advantage over native species. Likewise, producing more offspring, growing faster, being bold, exploring more, dispersing sooner, having a broader diet, could all help with invading and establishing.

    What about our Bucklanders?

    “Long ago Gorhendad Oldbuck, head of the Oldbuck family, one of the oldest in the Marish or indeed in the Shire [has had high evolutionary fitness over many generations], had crossed the river [successfully able to disperse relative to other hobbits and to explore more], which was the original boundary of the land eastwards. He built (and excavated) Brandy Hall, changed his name to Brandybuck, and settled down to become master of what was virtually a small independent country. His family grew and grew [high fecundity in offspring production], and after his days, continued to grow, until Brandy Hall occupied the whole of the low hill, and had three large front-doors, many side-doors, and about a hundred windows. The Brandybucks and their numerous dependants then began to burrow, and later to build, all round about … The people in the Marish were friendly with the Bucklanders … But most of the folk of the old Shire regarded the Bucklanders as peculiar, half foreigners as it were [suggests a slightly different distribution of traits compared to the parent population].Though, as a matter of fact, they were not very different from the other hobbits of the Four Farthings. Except in one point: they were fond of boats, and some of them could swim [bold and innovative behaviours].” JRR Tolkien- The Fellowship of the Ring

    Captive redback with web. Image by Adrian Paterson.

    We are also told elsewhere that the Brandybucks and Tooks (another bold lineage of hobbits) are generally taller than average Shire hobbits. Tolkien, as I have said in many other places (taxonomy of orcs and hobbits, evolutionary biology ideas, burrow architecture, mammal pest management, fire and ecosystems), was rather accurate when it came to integrating biology into his writing. Did he get it right here?

    To test this invasion idea you need a species that is well-studied in it’s native range as well as in its colonising range. You also need to be able to measure all of those traits. Spiders fit the bill nicely. They’re small and have short generations, are easy to fit into small experimental set ups, and some are venomous and, therefore, well studied. Enter the redback spider (Latrodectus hasselti), invasive in Japan and New Zealand and well studied in its Australian homeland.

    Cor Vink, New Zealand’s leading arachnologist, joined a group based in Toronto, Canada headed by Monica Mowery, to look at individuals from these three areas. They measured the size of individuals (bigger is usually better in interactions with competitors), their egg sac production (producing more young may give you more opportunities for at least some surviving), and length of generation times in captive populations (shorter allows for faster replacement, longer allows for larger more long-lived individuals).

    A redback – amazing photo from the talented Bryce McQuillan

    They measured the behaviour of the redbacks, such as frequency of cannibalism (you never know when a snack might come in handy!). Also, individual spiders were placed in a new environment and the speeds at which they started spinning webs (exploration) or moving after being exposed to a puff of wind (boldness) were measured. Spiders were also placed into a warm arena with a small simulated breeze to see whether they would balloon (effectively float away in the wind) or rappel (climb using their web silk) away from the start point (dispersal).

    The outcomes from this work were published in Biological Invasions. Redbacks from the invasive populations showed more dispersal behaviour than the home populations. They also tended to be larger in size, more cannibalistic, and produced more offspring. Interestingly, the redbacks in Japan and New Zealand did not seem to be more bold or explorative than in Aussie. Overall though, the invasive populations looked and acted differently to the source population.

    It appears that populations that successfully disperse and establish in new areas might do so because they are settled by individuals with useful traits that differ a little from the source population. This may help us to figure out which species potentially pose the most invasive threats.

    What about those strange Bucklanders? The Gaffer was mostly right. They are a bit different. Bucklanders are a population that managed to successfully disperse to an isolated area. Bucklanders are larger and more fecund. Tolkien does not record whether the Bucklanders tended to be more cannibalistic than hobbits in the Shire, but that would be a prediction!

    We can certainly sympathise with the Gaffer’s concerns about his Sam going to live among them.