Jaguar - Panthera onca

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Jaguars fight

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A stochastic model of jaguar abundance in the Peruvian Amazon under climate variation scenarios

The jaguar (Panthera onca) is the dominant predator in Central and South America, but is now considered near‐threatened. Estimating jaguar population size is difficult, due to uncertainty in the underlying dynamical processes as well as highly variable and sparse data. We develop a stochastic temporal model of jaguar abundance in the Peruvian Amazon, taking into account prey availability, under various climate change scenarios. The model is calibrated against existing data sets and an elicitation study in Pacaya Samiria. In order to account for uncertainty and variability, we construct a population of models over four key parameters, namely three scaling parameters for aquatic, small land, and large land animals and a hunting index. We then use this population of models to construct probabilistic evaluations of jaguar populations under various climate change scenarios characterized by increasingly severe flood and drought events and discuss the implications on jaguar numbers. Results imply that jaguar populations exhibit some robustness to extreme drought and flood, but that repeated exposure to these events over short periods can result in rapid decline. However, jaguar numbers could return to stability—albeit at lower numbers—if there are periods of benign climate patterns and other relevant factors are conducive.

onlinelibrary.wiley.com/doi/10.1002/ece3.6740

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Cubs feeding on a bull their mother killed (Silveira et al., 2008).


Another cow killed by a female jaguar. This one was old and weakened (image source).


Video of a female jaguar feeding on a cow. Apparently she indeed killed this cow (link).


Another cow killed by a jaguar. Unfortunately, the jaguar was then killed in retaliation (link).


This cow survived an attack by a jaguar.


Mature zebu bulls are rarely killed by jaguars, so the cats tend to target calves and females. And zebu bulls are far less formidable than water buffalo, which will actually attack and can kill jaguars with their horns and weight. Accordingly, jaguars avoid water buffalo too (Brooke, 2020; original link).

"Since cattle are preferred, it is important to note that the primary breed is Zebu. Zebu cattle descended from stock from India and are gray, red, or white in color; have loose skin; large, floppy ears; and are easily identified by their hump. They are ideally suited for the Pantanal since they are both heat tolerant and parasite- and disease-resistant. Jaguars rarely killed mature bulls because it was too great a risk physically so they tend to prey on young calves (<1year old and <174kg) and females (Cavalcanti, 2008)."

"Other animals that jaguars avoid are Zebu bulls and water buffaloes. There are an estimated 5000 wild water buffaloes living in the entire Pantanal and these animals can weigh up to 560kg (Alho et al., 2011). These animals were at one time domesticated but now live a feral existence (Fig. 5.5). They have learned to defend themselves by forming a circle around the vulnerable young. Male buffaloes will actually advance on the jaguar and charge at them. They can gore a jaguar or cause damage by wielding their enormous body weight. Water buffaloes are a far more formidable opponent than a bull Zebu."



In order to reduce jaguar predation on domestic cattle – and therefore killings of jaguars by farmers in retaliation – cattle ranchers and conservationists in South America have come up with the idea of keeping aggressive, horned San Martinero (a breed of cattle) to fend off jaguars. Zebu cattle just flee when confronted by jaguars (link).

"Conservationists and cattle ranchers in South America have teamed up to breed ‘super-cows’ that fend off attacks from jaguars and pumas. Fighting back isn’t what most people expect from highly domesticated, and supposedly docile, creatures like cows. But these criollo (cree-oh-yo) cattle, as they’re called, have two things going for them that most cows don’t.

First, they’re the descendants of livestock brought over during colonial rule from Portugal and the Andalucian region of Spain – prime bullfighting regions that today breed bulls from ancient stocks specifically for their aggression in the ring.

Second, they’ve co-existed with jaguars and pumas for centuries now, ever since conquistadors and missionaries came to the continent. Over time, feral populations of Spanish and Portuguese cattle evolved to survive varied, and typically harsh conditions throughout Central and South America. Local farmers bred them to enhance certain traits further, creating at least two dozen criollo ecotypes adapted to specific conditions.

In the Llanos region of Colombia, that means the local criollo cattle - known as San Martinero - can withstand the annual flooding of the savannah around the Orinoco River and the predictable drought that follows. The breed also retains what conservation biologist Esteban Payán calls 'anti-predator traits'. “We had been hearing from ranchers anecdotes of San Martinero cattle that defended themselves from jaguars and pumas,” Payán says. “And we started looking into that, and apparently it’s true.”

...

Traditionally, ranchers in the Llanos relied on San Martinero cattle to maintain their herds. But in the 20th century, they began switching to imported zebu (brahman) cattle from India to improve beef production. Some die-hards hung on to their San Martineros, and the Colombian Ministry of Agriculture maintained a herd for genetic research. But by the end of the 20th century only a few thousand remained. When conservationists heard San Martinero cattle could fend off jaguars, they saw an answer to one of their thorniest problems.

Zebu cattle flee when jaguars approach, leaving vulnerable calves behind. In contrast, San Martinero cattle stand their ground. Males and females both have pointy horns, and adults circle around calves to protect them. Bulls patrol the outer edges of the territory, and warn off predators with a distinctive whistle. According to Payán, jaguars actually learn the San Martinero whistle, and eventually avoid these herds. Payán cites other anti-predator traits as well: cows birth standing up and calves can stand almost immediately and wean quickly. “Just like wildebeest on the Serengeti,” he says."



Unrelated to cattle, but related to caimans. It appears that some jaguars have adapted to tourism boats driving caimans away from shores by adopting an interesting hunting strategy (Brooke, 2020).

"When they hunt, jaguars have adapted well. They literally herd caiman by extending their forelimbs and pushing, vegetation and all, up onto the bank. It is like the jaguar are coralling the caiman. Their adaptation has taught them to change their hunting tactics, especially within the female population. They are smaller and more nimble than 120-kg males. Interestingly, female jaguars in the Northern Pantanal act more like leopards and use trees to their advantage. Tourism boats may push the caiman away from shore (or they may move there on their own in the narrower rivers and channels), some female jaguars have an ingenious way to cope with this: launch themselves from overhanging limbs of trees right onto the back of caiman. Females such as Carly and Hunter have both been seen doing this behavior lounging on tree waiting for an opportunity. If, in the case of Carly, she launches herself from 10m above the river from her favorite tree, the force of this jump may break the caiman’s back or stun the caiman so severely that it may be very easy for the jaguar to make a successful bite to the back of the skull. They may also use the noise of the boats as a distraction in order to gain an advantage during stalking (see Fig. 5.12)."

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Reptiles as principal prey? Adaptations for durophagy and prey selection by jaguar (Panthera onca)
Everton B.P. Miranda, Jorge F.S. de Menezes, and Marcelo L. Rheingantz

We examined the evidence supporting the hypothesis that jaguars (Panthera onca) have morphological and behavioural adaptations to facilitate reptile predation. Jaguars’ head and bite features show adaptations to durophagy (consumption of hard-integumented prey) that are very unusual within the genus Panthera. These include: thick canines, well-developed head muscles and a fatal bite directed to braincase or nape. These characteristics have been previously considered an adaptation for the consumption of reptilian prey, whose thick integument poses a challenge to predation. Although causation of any trait as result of natural selection is hard to demonstrate with ecological evidence, its consequences can be suggested and predictions made. Here, through a review of the literature on jaguar predatory habits, we tallied the evidence for saurophagy against environmental characteristics correlated with jaguar predation on reptiles. We offer a new explanation for the presence of those traits, based on the selection patterns, prey abundances and main predation habits over the geographic range of the jaguar. We believe that these features allow jaguars to overcome dangerous and/or armoured prey by dispatching them rapidly through a bite to the head or nape. Reptile consumption is restricted to areas of high reptile abundance while dangerous or armoured prey is consistently preyed upon throughout the jaguar’s distribution, and selected even when their abundance is low. This questions the validity of the saurophagy hypothesis. We believe that these results are relevant to jaguar conservation and management, because some of the main prey species are severely threatened over their range, and because threatened reptiles are also consumed as prey.

Interesting info regarding the danger peccaries can pose to jaguars.

Peccaries (Tayassuidae) are social animals known for collectively attacking predators (Bissonette 1982; Kiltie and Terborgh 1983). Apart from jaguars themselves (Soares et al. 2006; Azevedo et al. 2010), they are one of the few animals known to kill jaguars (Scognamillo et al. 2003). Killing a peccary by suffocation takes time and would leave the predator vulnerable to attack by the rest of herd. On the other hand, a braincase bite would kill swiftly or, at least, severely disable the prey animal. In consequence, even if the herd attacks, the jaguar can retreat, then subsequently scavenge the corpse. Given the frequent scars and fresh wounds that jaguar show on camera-trap photographs, defensive attacks by peccary against jaguar may not be uncommon (Everton Miranda, pers. obs.).

www.tandfonline.com/doi/abs/10.1080/00222933.2016.1180717

(Full text available via Google Scholar)

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Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator

Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 per 100 km²) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same-sex adults including cooperative fishing, co-traveling, and play. Our study demonstrates that aquatic subsidies, frequently described in omnivores, can also transform the ecology and behavior of obligate carnivores.

esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3543

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When waterholes get busy, rare interactions thrive: Photographic evidence of a jaguar (Panthera onca) killing an ocelot (Leopardus pardalis)

During a camera trap survey conducted in Guatemala in the 2019 dry season, we documented a jaguar killing an ocelot at a waterhole with high mammal activity. During severe droughts, the probability of aggressive interactions between carnivores might increase when fixed, valuable resources such as water cannot be easily partitioned.

onlinelibrary.wiley.com/doi/epdf/10.1111/btp.12916

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May 21, 2021 19:00:49 GMT 5 Infinity Blade said:

Reptiles as principal prey? Adaptations for durophagy and prey selection by jaguar (Panthera onca)
Everton B.P. Miranda, Jorge F.S. de Menezes, and Marcelo L. Rheingantz

We examined the evidence supporting the hypothesis that jaguars (Panthera onca) have morphological and behavioural adaptations to facilitate reptile predation. Jaguars’ head and bite features show adaptations to durophagy (consumption of hard-integumented prey) that are very unusual within the genus Panthera. These include: thick canines, well-developed head muscles and a fatal bite directed to braincase or nape. These characteristics have been previously considered an adaptation for the consumption of reptilian prey, whose thick integument poses a challenge to predation. Although causation of any trait as result of natural selection is hard to demonstrate with ecological evidence, its consequences can be suggested and predictions made. Here, through a review of the literature on jaguar predatory habits, we tallied the evidence for saurophagy against environmental characteristics correlated with jaguar predation on reptiles. We offer a new explanation for the presence of those traits, based on the selection patterns, prey abundances and main predation habits over the geographic range of the jaguar. We believe that these features allow jaguars to overcome dangerous and/or armoured prey by dispatching them rapidly through a bite to the head or nape. Reptile consumption is restricted to areas of high reptile abundance while dangerous or armoured prey is consistently preyed upon throughout the jaguar’s distribution, and selected even when their abundance is low. This questions the validity of the saurophagy hypothesis. We believe that these results are relevant to jaguar conservation and management, because some of the main prey species are severely threatened over their range, and because threatened reptiles are also consumed as prey.

Interesting info regarding the danger peccaries can pose to jaguars.

Peccaries (Tayassuidae) are social animals known for collectively attacking predators (Bissonette 1982; Kiltie and Terborgh 1983). Apart from jaguars themselves (Soares et al. 2006; Azevedo et al. 2010), they are one of the few animals known to kill jaguars (Scognamillo et al. 2003). Killing a peccary by suffocation takes time and would leave the predator vulnerable to attack by the rest of herd. On the other hand, a braincase bite would kill swiftly or, at least, severely disable the prey animal. In consequence, even if the herd attacks, the jaguar can retreat, then subsequently scavenge the corpse. Given the frequent scars and fresh wounds that jaguar show on camera-trap photographs, defensive attacks by peccary against jaguar may not be uncommon (Everton Miranda, pers. obs.).

www.tandfonline.com/doi/abs/10.1080/00222933.2016.1180717

(Full text available via Google Scholar)

Thanks to a visual comparison by Dr. Douglass Rovinsky (link->), jaguars having thicker, more rounded canines than other Panthera is confirmed.

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Mitogenomic analysis of a late Pleistocene jaguar from North America

The jaguar (Panthera onca) is the largest living cat species native to the Americas and one of few large American carnivorans to have survived into the Holocene. However, the extent to which jaguar diversity declined during the end-Pleistocene extinction event remains unclear. For example, Pleistocene jaguar fossils from North America are notably larger than the average extant jaguar, leading to hypotheses that jaguars from this continent represent a now-extinct subspecies (Panthera onca augusta) or species (Panthera augusta). Here, we used a hybridization capture approach to recover an ancient mitochondrial genome from a large, late Pleistocene jaguar from Kingston Saltpeter Cave, Georgia, USA, which we sequenced to 26-fold coverage. We then estimated the evolutionary relationship between the ancient jaguar mitogenome and those from other extinct and living large felids, including multiple jaguars sampled across the species’ current range. The ancient mitogenome falls within the diversity of living jaguars. All sampled jaguar mitogenomes share a common mitochondrial ancestor ~400 thousand years ago, indicating that the lineage represented by the ancient specimen dispersed into North America from the south at least once during the late Pleistocene. While genomic data from additional and older specimens will continue to improve understanding of Pleistocene jaguar diversity in the Americas, our results suggest that this specimen falls within the variation of extant jaguars despite the relatively larger size and geographic location and does not represent a distinct taxon.

academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esad082/7502715?login=false&fbclid=IwAR2XEwe3yEC5MEwe_-pThLNlaU0MpqUbWUmPLY-CLMxeliFhNN6GwCGShKU