New Study: Mapping Threats to Jaguars in the Gran Chaco

Jaguar with Cubs in Bolivia’s Chaco. Image © Daniel Alarcón, used with permission.

I am happy to share another study about a region I know little about: The Gran Chaco.

The Gran Chaco is a massive plain that encompasses north-central Argentina, western Paraguay, southeast Bolivia, and a small part of Brazil. There appear to be some uncertainties about how large the Chaco is, but the general range of figures is between 800,000 – 1.1 million km2 (Prado, 1993; Romero-Muñoz et al., 2018). That is more than twice the size of California (WWF, 2018).

Female Jaguar in Kaa Iya 3. Image © Daniel Alarcón, used with permission.

Despite its vastness, the Chaco is undergoing rapid deforestation and defaunation (loss of medium and large wildlife); largely driven by the expansion of agriculture (WWF, 2018; Romero-Muñoz et al., 2018; The Nature Conservancy, 2018). The Chaco’s top predator, the jaguar (Panthera onca), is one of the creatures under threat.

Alfredo Romero-Muñoz and his colleagues set out to map the extent of the jaguar’s habitat degradation in the Gran Chaco between 1985-2013. In addition, they sought to determine whether hunting or habitat loss were most responsible for the cats’ decline in the region.

Hunting and habitat loss often intersect. When a patch of forest is cleared, for example, jaguars then have less cover and natural prey; making them more vulnerable to human hunting and conflict with people. Furthermore, the extension of roads into remote locations gives hunters access to harder-to-reach places.

However, excessive hunting can deplete an area of its large mammals before habitat loss does (Galetti & Dirzo, 2013; Jorge, Galetti Ribeiro, & Ferraz, 2013; Thoisy et al., 2016). To determine how habitat loss and hunting interact in the Chaco, Romero-Muñoz et al. (2018) mapped the expansion of both threats over the same time period (1985-2013). Theirs was the first study to do so.

To obtain their findings, the researchers amassed a large amount of data concerning: jaguar occurrences in the Chaco, predictors of key resources that determined the quality of jaguar habitat, and where people had killed jaguars. They used a machine learning approach to determine how threats to jaguars had changed over time (Romero-Muñoz et al., 2018).

It is amazing how well this jaguar’s camouflage works amidst the dry grass of the Chaco. Jaguar Bolivian Chaco. Image © Daniel Alarcón, used with permission.

Romero-Muñoz et al.’s (2018) results were both alarming and hopeful. For one, they found that jaguars had lost a huge amount of habitat between 1985-2013. Jaguar core areas – which are habitat patches with plentiful resources and low hunting pressure – declined by 33%. That comes out to 82,400 km2, or an area the size of Austria (Romero-Muñoz et al., 2018).

Habitat fragmentation also increased between 1985-2013, which makes jaguars more vulnerable to inbreeding depression and human hunting.

Concerning hunting, Romero-Muñoz et al. (2018) found that ‘sinks’ and ‘attractive sinks’ (areas where jaguars are more likely to be killed by humans) both grew by about 27% during their study period (p. 8). Most of the jaguar’s range in the Chaco consisted of sinks and attractive sinks by 2013.

Based on these results, hunting has expanded faster than habitat loss in the Chaco. By 2013, hunting impacted an area 20% larger than low resource availability – although the two threats acted together over 29% of the jaguar’s range (Romero-Muñoz et al., 2018, p. 11). But there is still time to act.

A substantial portion of jaguar core habitat remains in the Chaco, mostly close to international borders. At the same time, only 9.1% of the Chaco is formally protected. Since protected areas (especially large ones) lost proportionally less jaguar habitat than unprotected areas, this presents an opportunity.

Establishing reserves along international borders would strengthen the Chaco’s protected area network, and it could also bolster habitat connectivity in the region.

Moreover, hunting appears to be the primary threat to jaguars in the Chaco. This can be addressed. Working with local people to increase tolerance for jaguars, discouraging hunting, and expanding protected areas could all reduce the pressure on jaguars.

One of the best ways to help jaguars in the Chaco, like this mother and her cubs, is to establish more protected areas along international borders. Jaguar Bolivian Chaco with Cubs 3. Image © Daniel Alarcón, used with permission.

In summary, Romero-Muñoz et al. (2018) learned that jaguars are faring worse in the Chaco than previously thought; areas with low resource availability and high hunting pressure both expanded considerably between 1985-2013. Luckily, all is not lost. By quickly establishing protected areas along international borders and reducing hunting, the Chaco’s jaguars can still be saved.

Click Here for Romero-Muñoz et al.’s New Study about Jaguars in the Gran Chaco

23 Thoughts

  1. I used to think it was funny how jaguars and other big cats have spots because up close, it seems to stand out but far away and in their natural habitat, they blend in. And they should make it illegal to hunt jaguars, the poor things.

    Liked by 1 person

    1. I used to wonder about their spots too, but when you see images of jaguars and leopards in the wild it’s incredible how well they blend in. It is illegal to hunt jaguars in much of their range, but there’s little enforcement for such rules. That’s one of the reasons we have to increase people’s tolerance for jaguars, so that they freely choose not to kill them.

      Liked by 1 person

        1. Education is part of the answer, but simply giving people information isn’t always enough to significantly alter their behavior. We also need to establish strong working relationships with ranchers and other people who live with jaguars, and help alleviate some of the difficulties that come with living near big cats.

          Liked by 1 person

          1. Yeah of course! I just hope that everything will work out and these big cats begin to increase in numbers again. I was so shocked about the fact there are only about 90 Amur leopards left.

            Liked by 1 person

          2. I remember that! I was shocked! It’s still a very low number but at least it is going up – shows that conservation and animal protection programmes work.

            Liked by 1 person

        1. I know, right? Could you imagine if someone cut down the vast majority of the ancient, majestic forests in the eastern US? Oh, wait…

          Digs at colonialism aside, deforestation absolutely needs to be slowed in the tropics. There are just so many unique forms of life there that, once lost, might never return. I won’t tell other countries not to use their resources at all, but it’s always good to plan for the future.


          1. It’s the perfect day to throw shade on colonialism. It’s Colombus Day! 😂

            I think Jamaica has been doing pretty good with protecting our resources. What we really need to work on is pollution. Jamaicans litter like it’s nobody’s business.


  2. Sad to see people wanting to harm such a beautiful species! I hope we never give up on our efforts as wildlife conservationists to save them! More power to you!


    Liked by 1 person

    1. Oh, we’re certainly not going to stop trying to conserve species like jaguars. It is sad to see people wanting to kill jaguars – from our standpoint. However, not everyone has the same perspective as us, and part of our job as wildlife conservationists is to try to understand other peoples’ viewpoints. From there, we can begin working with people to increase their tolerance for species like jaguars.

      Liked by 1 person

  3. I’m never giving up hope that one day people will have the life altering revelation that hunting wildlife is wrong, and it should be stopped immediately.

    I just want to have a world full of happy animals with the freedom to roam about freely in the wild.

    Liked by 1 person

    1. Well, I’m not opposed to ALL hunting, just that which is excessive and needless. If people genuinely need to hunt for food, then that’s one thing. Even though it’s morally distasteful, some sport hunting can provide at least short-term benefits for conservation. It needs to be well-regulated according to the best science though, and it seems like many times that’s not the case.

      I’m also incredibly uncomfortable with the notion that it’s illegal for people in Africa to kill endangered wildlife, but rich white people are celebrated for doing the same thing. That’s the definition of colonialism. As long as conservationists keep reinforcing the power structures that are tearing the world apart, we’ll never truly succeed.

      Liked by 1 person

      1. Yeah I totally see your point.

        Oh you can say that again it’s very double standard and unfortunate that sometimes the rules only apply to colour and the depths of ones pocket.

        The headlines here have been very disheartening… the Maasai Mara river is on its death bed due to human encroachment on the water towers that feed the river, we previously lost 13 rhinos out of carelessness while translocating them, it’s just mayhem

        Liked by 1 person

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