Studying and Saving Species in the Anthropocene

Guest post by Helen O'Neill

The world is changing.  Areas that were once remote are becoming ever more accessible; even the world’s few remaining areas of wilderness are increasingly human-dominated. The global human population’s ever growing effects on the environment has led many people to start referring to our current period in history as the Anthropocene.

Habitat loss and fragmentation are the leading threats to global biodiversity. As areas where wild species once thrived disappear and remaining parcels of wilderness become rarer and more isolated, wildlife is often forced into closer contact with local human populations.  Whilst protected areas are undoubtedly important refuges for many threatened species, human-dominated landscapes are nevertheless likely to be key for the future of conservation. 

Large carnivore populations in Europe provide tangible evidence of the importance of human-dominated landscapes to conservation. Just a few decades ago, across the continent populations of brown bears (Ursus arctos), grey wolves (Canis lupus) and Eurasian lynx (Lynx lynx) had undergone massive declines as a result of habitat loss in combination with human persecution. However, over recent years these carnivore populations have had a resurgence. Changes in legislation providing the species with greater protection from persecution, along with the establishment of nature reserves, has led to populations of all three species remaining steady and even increasing across Europe. Whilst the increase in protected areas has been of great importance for these carnivore species, the majority of their populations still live outside of protected areas.  =It is likely thanks to the recognition of the importance of these non-protected, and human-dominated, areas to carnivore conservation and the interventions that have focused on them, which has resulted in carnivore population recoveries.

Collaring Zuri. Photo contributed by Helen O'Neill.

My research focuses on how African wild dogs and cheetah live in a human-dominated landscape in Laikipia County in Northern Kenya, and how geographical features such as fences affect them.  Both wild dogs and cheetah have suffered from extensive habitat loss and fragmentation across Africa, with wild dogs now found in just 7% of their former range and cheetah 11%. They are the widest-ranging species within the African large carnivore guild; with individuals and groups from both species having been recorded having home-ranges of more than 2000 sq km. This wanderlust means they need large areas of carnivore-friendly land to survive. As with European carnivore populations, very few protected areas are large enough to support viable populations of cheetah or wild dogs on their own, meaning that habitat loss and fragmentation are still very real threats to their survival.

When you talk about habitat loss and fragmentation people's first thoughts are usually of vast swathes of tropical forests being cut down, leaving only small stands of trees, however such images don’t tell the full story. Fragmentation is caused by any feature that prevents animals moving from one area of habitat to another. Increases in fragmentation mean that connections between habitat patches are lost and can result in serious consequences for the species affected, ranging from animals no longer having access to the resources they need to survive or, in the longer-term, inbreeding. 

For many human-dominated landscapes amongst the key causes of fragmentation are fences. This kind of fragmentation is much less obvious than a vast swathe of deforestation as there may well be areas of apparently prime habitat on each side of the fence.  Nonetheless fences can have important impacts on the connectivity of an area - after all preventing movement between different areas is literally their raison d'etre.

In order to look at how wild dogs and cheetah live in and move through their landscape, I use data collected by GPS collars, which my colleagues and I fit to our study animals.  These collars record the animal’s location at pre-programmed times throughout the day, enabling me to see how they interact with different features within the landscape. It is perhaps not surprising that I have found that fences have important impacts on our study animals but what has been interesting is the extent to which the design of the fence affects how much the wild dogs and cheetah are affected by them. Whilst some fences have significant effects, others appear to have little or no effect at all.

Laikipia is an area of huge conservation significance. Living alongside a large and growing human population there are high wildlife densities and vital populations of several globally threatened species. Laikipia is already a human-dominated landscape as is only likely to become more so over the coming years. However, whilst it is undoubtedly important to take into account the effects of different socio-economic and cultural factors, it is nevertheless encouraging to look to carnivore populations throughout the European mainland and see them persisting, and even thriving, in human-dominated landscapes there.

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Helen O'Neill is a PhD candidate at Zoological Society London, and her research focuses on cheetah and African wild dogs living in a human-dominated landscape in Northern Kenya.  You can find more about her research here or reach out to her on Twitter @hmk_oneill.

Large mammals aren’t getting enough attention (for once)

Guest Post by Dani Rabaiotti 

Large mammals get an awful lot of attention. People love a fluffy, charismatic, animal, and their large size often makes them comparatively easier to study, and an awful lot of time, effort and money goes into conserving charismatic large mammals. As a result, there are systematic biases towards large mammals in conservation research, in the media, across social media (guilty), and in the amount of money raised both through charities and grants. Whilst most people think of large African megafauna when they hear large mammals, they are actually making a comeback in Europe: numbers of wolves, bears, and lynx are increasing across most of the continent and, in some areas, these animals are even expanding their ranges.

This leads me onto one area of research where…possibly (hear me out here!)…large mammals might be overlooked. A lot of the focus on climate change response research has been into reptiles and amphibians, which have physiological traits that mean their behaviour and/or breeding is directly dependant on temperature, or species like corals, which have been identified as most at risk. Low down on the list of climate change impact studies are large mammals. A fairly large number of correlative studies have been done, where researchers look at where species live now and what the climatic conditions are, and use it to project where they could live under climate change. Far fewer studies have looked at the mechanisms by which large mammals might be affected by temperature changes.

African Wild Dog. Photo contributed by Dani Rabaiotti.

It could be argued, however, that large mammals may be disproportionately at risk. Due to their size, large mammals need a lot of resources and as a result generally need big territories to survive. Large mammals are disproportionately threatened compared to small mammals, in part due to global habitat loss, but also because they are more likely to come into conflict with humans, and be persecuted as a result: think large carnivores eating livestock or elephants eating crops. This also means that, as the climate warms, many species have no-where to move to (many plants and animals will move to cooler areas to avoid rising temperatures). In my study species, the African wild dog, for example, it has already been extirpated from over 90 percent of its former range through habitat loss and human conflict – there is no other ‘range’ for it to shift to. On top of this, large mammals take a really long time to reproduce, meaning that if they need to adapt to climate change, it has to be through behaviour and not evolution.

Because of this, it is really important that we understand the responses of large mammals to changes in temperature. This can be challenging as, unlike many smaller species, you can’t stick an elephant in a lab and heat it up to see what happens. The fields of herpetology, fisheries research, and, to a slightly lesser extend ornithology, have done some great work into how the physiology, behaviour and breeding habits of various species are impacted by climate change. These can be used to gain a mechanistic (that is, the mechanism behind how climate change might effect a species in future) understanding of climate change impacts, and allows the building of more detailed, mechanistic models that don’t just rely on correlation. However, there are far fewer papers of this kind on large mammals.

The good news is we already have a lot of data on large mammals, and where data is missing there are a lot of long-term projects out there. It would be a shame to pour money into conserving large mammals in an area that may be too hot for them to survive in the future, when it may be better directed elsewhere. It would be tragic if the large mammal conservation successes in Europe were lessened by an oversight in research. It is important that people start looking at past datasets, and collecting new datasets with questions on temperature impacts in mind. This would help ensure the future of these species that people know and love so well.

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Dani Rabaiotti is a PhD student studying the impact of climate change on African wild dogs at the Zoological Society of London and UCL.  You can find more about her research here or reach out to her on Twitter @DaniRabaiotti.