Modern Weights and Measurements of Wild Cougars

[Balam]

A myth seems to be floating around claiming that cougars from the Araucania region of Chile "average 40 kg" in weight, thus reducing the overall average for the Patagonian ecotype. This, of course, is completely false. From the book "Puma Araucano, Vida en una Dimension Paralela" by Fernando Vigal Mugica, the morphology of cougars based on his team's capture and overall appearance is given:

*This image is copyright of its original author

"Its height and body weight fluctuate notably between the different populations of Chile and accross the Americas. These differences can be considerable even when comparing the weight or mass of specimens of a same age and sex. This is how a 3-year-old male in La Araucanía can weigh 30 kg and a specimen of Magallanes, 70 kg."

*This image is copyright of its original author

*This image is copyright of its original author

"Males are generally larger, surpassing the females in about a 40% by mass or weight. During the years of observation and study of the species, the greatest weight or mass that we were able to register was that of a five-year-old male with 60 kg of weight. The rest of the specimens never exceeded 50 kg. However, we have heard testimonies from people who in the past hunted 80 kg specimens in the Araucanía. For our part, during a field trip in the course of this investigation we managed to make eye contact with a specimen that, according to our calculations, may well have weighed 80 kg or more."

*This image is copyright of its original author

"In contrast, other scholars indicate that the skulls of pumas show growth up to a certain stage of their life, being that of females up to 5 or 6 years of age, while, in the males, this growth can manifest up to 7 or 9 years of life. According to our studies based on morphometric measurements recorded in catches and recaptures of adult animals, we can conclude that both males and females not only register growth in their skull throughout their life, but also in their mass and morphometric measurements general."

From this initial excerpt, it is noted that the accurate body mass of adult males should stabilize at around 7 years of age, the heaviest male captured by them weighed 60 kg and was estimated as being 5 years old, the older lesser sized males are not given age estimations, but it is very likely that these were young adults yet to reach their full-size potential as one male mentioned by them to have weighed 30 kg was estimated as a 3-year-old, still a sub-adult. He then proceeds to speak of an adult male from that same area they estimated as being 80 kg or more in body mass.

Then from the paper: PUMA CONCOLOR COMO AMENAZA PARA GANADEROS DE CAUTÍN, REGIÓN DE LA ARAUCANÍA, Y EVALUACIÓN DE PERROS PROTECTORES DE REBAÑO COMO HERRAMIENTA DE MITIGACIÓN DEL CONFLICTO. By Christian Sepulveda Cabrera, the following data is given:

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"Data of the Metrenco veterinary clinic that receives pumas captured by the SAG of Region IX and investigations by Vidal and Sanderson (2012) of pumas in Araucanía indicate that Juvenile males weigh around 36 kg, while adult females weigh between 24 and 30 kg."

Once again, the low values for the weights of males are indicative of juvenile (i.e. sub-adult) individuals, and therefore cannot be taken as an accurate outlook on cougars from that area. The author does allude that cougars from the rainforest of southern Chile (Araucania) are smaller than those from the open areas of the Patagonia, but this is due to the smaller prey biomass and prey availability found here, as the largest native prey is the pudu, the world's smallest deer, which seldomly surpasses 10 kg in weight. Feral hogs may be present in this area as well which would allow some males, as the 80+ kg estimated aforementioned before, to reach sizes comparable to those of surrounding areas.

That same paper also references the exceptional weight claimed for some males of reaching sizes of 120 kg, this claim comes from Iriarte and is eachoed in the study: REVISIÓN ACTUALIZADA SOBRE LA BIODIVERSIDAD Y CONSERVACIÓN DE LOS FELINOS SILVESTRES DE CHILE:

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"However, molecular studies (Culver et al., 2000; Johnson et al., 2005) suggest a phylogeographic division of 6 subspecies, finding a subspecies (P. concolor puma) in our country. High degrees of gene flow reported in different molecular studies (Culver et al., 2000) suggest that the total number of subspecies could be lower. According to the subdivision ancient, 4 subspecies of the 32 described in America would be recognized: Puma concolor incarum that it is distributed from the south of Ecuador and Peru to the north of Chile (AricaParinacota, Tarapacá and Antofagasta regions), from sea level to 5,200 meters; P. c. cougar what it occupies the central zone, especially mountain range, between Coquimbo (30 ° S) and Valdivia (40 ° S); P. c. araucana, which is the smallest and inhabits between the Araucanía and Los Lagos Regions, extending in Argentina through the southwest of Neuquén and west of Río Negro; finally, P. c. patagonica that lives in steppe areas of the Aysén and Magallanes Regions. This last subspecies is the largest on a continental level, with specimens exceeding 120 kilos (Parera, 2002; Iriarte, 2008; Iriarte & Jaksic, 2012)."

The claims of 120 kg should be taken with a grain of salt as we don't have the primary source for them, but what is clear is that the largest specimens from this geographical area are capable of surpassing 100 kg in weight, being the 4th largest cats in the world, and the supposed 40 kg average does not come from adult males and is not an accurate indicator of the average size of males from that region. Reply