Tag: predation

Man’s best friend could be a jaguar’s next meal: A case study from the Mexican Caribbean

Events of jaguars predating on and attacking dogs are poorly documented throughout the Americas. Researchers from Mexico and Germany report in detail jaguar attacks on 20 dogs at a tourist site in the Mexican Caribbean. In addition, they describe an initiative proposed by locals as well as national and international NGOs to prevent human-jaguar conflicts due to pet predation. The study was published in the open-access journal Neotropical Biology and Conservation.

Mahahual is a small fishing village in the Mexican Caribbean that receives a large number of tourists every year. Over the past 15 years, its population has increased rapidly, and, as a result, people have started to settle in areas away from the main center of the village, sometimes encroaching on jaguar habitats. As most of those people keep guard dogs on their properties, jaguars have taken advantage of this situation by wandering near people’s houses at night, and sometimes those dogs end up as a night-time snack for the big cats.

A jaguar is photographed wandering around houses looking for dogs. Photo by Víctor Rosales

Unlike jaguar attacks on livestock, attacks and predation on other domestic species such as dogs have only been documented anecdotally (through interviews or from remains found in faeces). Such attacks can indeed lead to pet predation conflict, which can ultimately have a negative impact on the jaguar populations. Attachment to pets may lead humans to start killing the big cats, which is of particular concern for an endangered species like the jaguar. Furthermore, it is possible that a wide range of pathogens may be transmitted from dogs to jaguars, further threatening the health of jaguar populations in Mahahual.

A dog injured as a result of a jaguar attack in Mahahual, Quintana Roo, Mexico. Photo by Víctor Rosales

This is why a multidisciplinary team made up of veterinarians, conservationists, locals, NGOs (Aak Mahahual A.C. and International Fund for Animal Welfare (IFAW)) and researchers (El Colegio de la Frontera Sur and Universidad Tecnológica de Calakmul), led by Dr Jonathan Pérez Flores, began investigating the occurrence of jaguar predation and attacks on dogs at the Mexican Caribbean tourist site from almost 10 years ago. Their research was just published in the open-access journal Neotropical Biology and Conservation.

According to their report, the behaviour of Mahahual’s jaguars resembles that of Indian leopards, which have already turned dogs into an important component of their diet, preferring them over livestock. Jaguars and leopards usually attack from a blindside, biting the dogs on the neck or head to avoid counterattacks. Similarly to leopards, jaguars attack at night and kill more dogs during the dry season. This is likely due to the fact that it’s easier for jaguars to hunt dogs than their natural prey: armadillo, lowland paca, brocket deer, white-tailed deer. Furthermore, the latter are less available during the dry season.

One of the night houses built by the people of Mahahual, Aak Mahahual A.C. and International Fund for Animal Welfare (IFAW). Photo by Francisco Rubén Castañeda

In 2017, the people of Mahahual partnered with Aak Mahahual A.C. and IFAW to build protective night houses made of wood and wire mesh meant to keep dogs safe at night. So far, they’ve built 38 such houses to prevent jaguar attacks. Sterilisation and vaccination campaigns have also been intensified since late 2020 to prevent the transmission of diseases between the two species.

Thanks to this study, we now have a better understanding of the adaptability and persistence of jaguars in human-dominated landscapes and the impact of dog predation by jaguars. However, the authors call for more research in the area to help paint the full picture.

Research article:
Carral-García M, Buenrostro I, Weissenberger H, Rosales V, Pérez-Flores J (2021) Dog predation by jaguars in a tourist town on the Mexican Caribbean. Neotropical Biology and Conservation 16(4): 461-474. https://doi.org/10.3897/neotropical.16.e68973

Cave fights for food: voracious spiders vs assassin bugs

Killing and eating of potential competitors has rarely been documented in the zoological literature, even though this type of interaction can affect population dynamics. In a recent publication in the open-access journal Subterranean Biology, Brazilian scientists presented their notes regarding the predation of an assassin bug by a spider in Neotropical caves. Underground, where food resources are scarce, such events might be possible as a result of ecological pressures imposed by the hostile environment, hypothesise the researchers.

Killing and eating of potential competitors, also known as intraguild predation, is a rare event that occurs only in specific situations such as severe scarcity of food resources, resulting in the competition between predators.

A recent paper in the open-access journal Subterranean Biology examines the case of a wandering spider species (Enoploctenus cyclotorax) seen to prey upon assassin bugs (Zelurus diasi) in a limestone cave in Brazil.

Even though such type of ecological interaction is uncommon, it is potentially important since it may decrease the competition between apex predators and thus, affect their population dynamics. Zelurus and Enoploctenus are voracious predators with a wide distribution in caves and epigean environment. Both of them have similar diets. In normal conditions, spiders reject assassin bugs as potential prey, so intraguild predation cases occur only in very specific situations.

From the perspective of the participants, intraguild predation is a dangerous strategy because the prey is also a predator, armed and capable to kill. However, in caves, this could be a very useful behaviour since food resources are scarce and have low density.

“This may be an important factor, maintaining the species in that challenging environment”, concludes lead author of the study Dr. Leopoldo Ferreira de Oliveira Bernardi.

The scientists suggest that probably prey scarcity has left little choice for spiders, and that’s why they ended up using unconventional type of prey in their diet.

Intraguild predation between female Enoploctenus cyclotorax and adult Zelurus diasi observed during the study.
Credit: Leopoldo Ferreira de Oliveira Bernardi
License: CC-BY 4.0

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Original source:

Bernardi LFO, Sperandei VF, Audino LD, Sena CH, Alves JA (2020) Notes on the predation of an assassin bug by a spider in a Neotropical cave. Subterranean Biology 33: 17-22. https://doi.org/10.3897/subtbiol.33.48292

Two fish a day keep the mantid coming back to prey: The 1st fishing praying mantis

Commonly known to predate on insects, praying mantises have occasionally been observed to feed on vertebrates, including small birds, lizards, frogs, newts, mice, snakes and turtles. Mostly, such records have either not been scientifically validated or have occurred under induced and human-manipulated circumstances.

Nevertheless, no scientific data of mantises preying on fish existed until the recent study of Roberto Battiston, Musei del Canal di Brenta, Rajesh Puttaswamaiah, Bat Conservation India Trust, and Nayak Manjunath, published in the open access Journal of Orthoptera Research.

Last year, the team observed an adult male hunting and devouring guppies in a pond located in a private roof garden in Karnataka, India. Curiously enough, the predator came back five days in a row and caught a total of nine fish (a minimum of two a day). To reach its prey, the insect would walk on the leaves of water lilies and water cabbage growing on the surface of the pond.

*The artificial pond with the praying mantis sitting on a leaf visible to the right.*

Apart from being a curious first-of-its-kind, the observation raises three new discussion points worthy of further study, point out the researchers.

Firstly, the fact that praying mantises hunt on vertebrates outside cages in labs confirms that a single invertebrate species is indeed capable of having an impact on a whole ecosystem. In this case, a mantis preys on guppies which, in their turn, feed on aquatic insects.

*The mantis eating a guppy starting from the tail, while the fish is still alive and breathing in the water.*

Secondly, the discovery questions previous knowledge about the visual abilities of mantises. While the structure of their eyes clearly indicates that they have evolved to prey in daylight, the studied male specimen proved to be an excellent hunter in the dark. The insect managed to catch all nine fish either at sunset or late at night.

Besides visual, mantises might have evolved impressive learning abilities too. The researchers speculate that the observed repetitive behaviour might have been the result of personal experience, utilised to navigate the specimen. Sophisticated cognitive skills, on the other hand, might have allowed the mantis to develop its hunting strategies.

“Remembering the prey’s abundance in a particular site, in relation to their ease of capture and their nutritional content, could be one important factor of this choice and indirectly influence the individual predator’s fitness,” comment the scientists. “This should be investigated in further studies.”

Original source:

Battiston R, Puttaswamaiah R, Manjunath N (2018) The fishing mantid: predation on fish as a new adaptive strategy for praying mantids (Insecta: Mantodea). Journal of Orthoptera Research27(2): 155-158. https://doi.org/10.3897/jor.27.28067

First description and video of a rainbow boa preying on a vampire bat in a cave in Ecuador

While snakes are well-known enemies to bats, their preying on the winged mammals has hardly been recorded. Furthermore, no bat as big and heavy as the common vampire, has been described being killed and eaten prior to the present study, published in the open access journal Subterranean Biology.

The study, where scientists, led by Sarah Martin-Solano, Universidad de las Fuerzas Armadas, ESPE, Ecuador, record a rainbow boa catching the bat, is the first known such case to have taken place on a cave’s floor. The documented observation serves to confirm that snakes do predate on bats in caves, and is also the first such case known from Ecuador.

Apart from the detailed description, the scientists also provide a film, showing almost in full the event of a rainbow boa catching, killing and swallowing an adult female common vampire bat.

The predation has been observed in a 450-metre-long cave in Tena, Ecuador. There, an adult female common vampire bat, one of the three bat species to feed exclusively on blood, was seen to fly into the cave right over the boa’s head and its waiting open jaws, raised some 30-35 centimetres above the ground.

The approximately 140-centimetre-long snake snatched the bat by the head and immediately brought it down to the floor. Having been strangled by the boa, the bat appeared to give up its resistance about two minutes later, although the predator did not let it go for another seven minutes. Once assured the mammal is dead, the snake started trying different positions from which to fit the bat in its mouth. However, this seemed particularly difficult due to the mammal’s size and the stiffness of its shoulder joints.

Eventually, the rainbow boa began constricting the body once again. Then, starting from the head, the snake managed to swallow the whole bat in 4 minutes and 50 seconds, with the predation measured to last about 25 minutes in total.

In conclusion, the authors suggest that more research needs to be undertaken, so that scientists can find out how common is for snakes to prey on bats in caves.

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Original source:

Martin-Solano S, Toulkeridis T, Addison A, Pozo-Rivera WE (2016) Predation of Desmodus rotundus Geoffroy, 1810 (Phyllostomidae, Chiroptera) by Epicrates cenchria (Linnaeus, 1758) (Boidae, Reptilia) in an Ecuadorian Cave. Subterranean Biology 19: 41-50. doi:10.3897/subtbiol.19.8731