One of the most noteworthy facts about pumas (Puma concolor, mountain lions, cougars) is that their range extends from Canada to Argentina (Nielsen, Thompson, Kelly, & Lopez-Gonzalez, 2015). Unfortunately, I know very little about pumas at the northern and southern ends of their territory.
I was quite excited, then, when a reader notified me about a recent study concerning puma-livestock conflicts in Argentina.
The study, titled “Characterization of Puma-Livestock Conflicts in Rangelands of Central Argentina,” was conducted by Guerisoli et al. (2017). It is quite fascinating in that it measured the amount of livestock lost to pumas in two Argentinean counties (Villarino and Patagones), along with the number of pumas killed by ranchers.
This allowed the researchers to see if the levels of puma hunting matched the rates of livestock depredation (attacks on livestock by wild animals).
In addition, Guerisoli et al. (2017) used both qualitative research methods – in the form of semi-structured interviews – and quantitative methods. These latter, numerical methods included: questionnaires, measuring the distances from livestock kill sites to various habitat types, financial losses incurred by ranchers, and more.
This is important, because qualitative and quantitative methods have different strengths and weaknesses. The former methods can generate rich, nuanced data about a specific topic amongst a particular population. Quantitative data, by contrast, is more reliable and generalizable across populations. While one’s choice of methods is ultimately determined by their research questions, using both qualitative and quantitative approaches (called ‘mixed-methods’ design) can help to minimize the shortcomings of relying on just one type of data.
In this case, Guerisoli et al. (2017) conducted 111 and 102 semi-structured interviews in Villarino and Patagones counties, respectively. They then backed up what the ranchers told them with their own, quantitative investigations.
At the end of their eight-year (2007-2015) data collection phase, Guerisoli et al. (2017) had learned a great deal. Their results included:
- Pumas targeted sheep much more frequently than cattle.
- Both the rates and financial impacts of depredation were higher in Villarino county that in Patagones – usually.
- Proportions of sheep lost ranged from 0.1% – 51.9% in Villarino County and 0.7% – 86.7% in Patagones (Guerisoli et al., 2017, p. 5).
- In Villarino, 67.3% of interviewees said they had previously hunted pumas. The corresponding figure was 82.5% in Patagones County (Guerisoli et al., 2017, p. 5).
- Puma hunting by ranchers appeared to be largely in response to livestock depredation in Villarino county. But in Patagones, the level of puma hunting was considerably higher than the rate of livestock losses.
- Attacks on livestock occurred most frequently near grassland habitats with scrub, and least often near forests.
As the above numbers indicate, the impacts of livestock depredation were not evenly distributed. Guerisoli et al. (2017) found that while some ranchers could easily absorb livestock losses, others lost so many animals to pumas that they could not continue ranching.
Another important finding was that most ranchers in both counties told Guerisoli et al. (2017) that controlling pumas was the best way to protect livestock. In contrast, multiple studies from North America have concluded that high rates of puma hunting can increase livestock depredation and threats to human safety (Peebles, Wielgus, Maletzke, & Swanson, 2013; Teichman, Cristescu, & Darimont, 2016).
Relatedly, Guerisoli et al. (2017) reported that humans kill large numbers of pumas in Buenos Aires province (where their study took place) and in other Patagonian provinces. Yet livestock depredation continues.
Management practices like corralling sheep at night are likely to better protect livestock than killing pumas, but rural depopulation (people leaving rural areas) could make it hard for ranchers to adopt such initiatives.
Lastly, Guerisoli et al. (2017) stressed that puma hunting is not solely motivated by livestock depredation: there are other factors involved. It is therefore crucial to work with ranchers to increase their tolerance for pumas.
This post has been a small snapshot of Guerisoli et al.’s (2017) study. Please follow the link below for their full paper.