Passage-Based Question: Western Barred Bandicoots
Landing in Australia, the British colonists weren’t much impressed with the small-bodied, slender-snooted marsupials called bandicoots. “Their muzzle, which is much too long, gives them an air exceedingly stupid,” one naturalist noted in 1805. They nicknamed one type the “zebra rat” because of its black-striped rump.
Silly-looking or not, though, the zebra rat—the smallest bandicoot, more commonly known today as the western barred bandicoot—exhibited a genius for survival in the harsh outback, where its ancestors had persisted for some 26 million years. Its births were triggered by rainfall in the bone-dry desert. It carried its breath-mint-size babies in a backward-facing pouch so mothers could forage for food and dig shallow, camouflaged shelters.
Still, these adaptations did not prepare the western barred bandicoot for the colonial-era transformation of its ecosystem, particularly the onslaught of imported British animals, from cattle and rabbits that damaged delicate desert vegetation to ravenous house cats that soon developed a taste for bandicoots. Several of the dozen-odd bandicoot species went extinct, and by the 1940s the western barred bandicoot, whose original range stretched across much of the continent, persisted only on two predator-free islands in Shark Bay, off Australia’s western coast.
“Our isolated fauna had simply not been exposed to these predators,” says Reece Pedler, an ecologist with the Wild Deserts conservation program.
Now Wild Deserts is using descendants of those few thousand island survivors, called Shark Bay bandicoots, in a new effort to seed a mainland bandicoot revival. They’ve imported 20 bandicoots to a preserve on the edge of the Strzelecki Desert, in the remote interior of New South Wales. This sanctuary is a challenging place, desolate much of the year, with one of the world’s most mercurial rainfall patterns—relentless droughts followed by sudden drenching floods.
The imported bandicoots occupy two fenced “exclosures,” cleared of invasive rabbits (courtesy of Pedler’s sheepdog) and of feral cats (which slunk off once the rabbits disappeared). A third fenced area contains the program’s Wild Training Zone, where two other rare marsupials (bilbies, a larger type of bandicoot, and mulgaras, a somewhat fearsome fuzzball known for sucking the brains out of prey) currently share terrain with controlled numbers of cats, learning to evade them. It’s unclear whether the Shark Bay bandicoots, which are perhaps even more predator-naive than their now-extinct mainland bandicoot kin, will be able to make that kind of breakthrough.
For now, though, a recent surge of rainfall has led to a bandicoot joey boom, raising the Wild Deserts population to about 100, with other sanctuaries adding to that number. There are also signs of rebirth in the landscape itself. With their constant digging, the bandicoots trap moisture and allow for seed germination so the cattle-damaged desert can restore itself.
They have a new nickname—a flattering one, this time. “We call them ecosystem engineers,” Pedler says.
Question:
Why are western barred bandicoots now called “ecosystem engineers”?
- Led to a surge and increase of rainfall.
- Grown fivefold in terms of population.
- Aided in altering an arid environment.
- Led a revival in preserving the species.
Analysis:
The passage explains that western barred bandicoots have been nicknamed “ecosystem engineers” because of their significant environmental impact. Their digging helps trap moisture and promotes seed germination, aiding in the restoration of the cattle-damaged desert. This transformation of the arid environment is the reason for their new flattering nickname.
Evaluation of Options:
- Option 1: Incorrect. While there was a recent surge in rainfall, the passage does not link this to the bandicoots.
- Option 2: Incorrect. The nickname is not related to the population growth but their environmental contributions.
- Option 3: Correct. Their digging alters the environment by trapping moisture and aiding seed germination, helping restore the desert.
- Option 4: Incorrect. The nickname is not about species revival but about their role in environmental restoration.
(. . .) There are three other common drivers for carnivore-human attacks, some of which are more preventable than others. Natural aggression-based conflicts – such as those involving females protecting their young or animals protecting a food source – can often be avoided as long as people stay away from those animals and their food.
Carnivores that recognise humans as a means to get food, are a different story. As they become more reliant on human food they might find at campsites or in rubbish bins, they become less avoidant of humans. Losing that instinctive fear response puts them into more situations where they could get into an altercation with a human, which often results in that bear being put down by humans. “A fed bear is a dead bear,” says Servheen, referring to a common saying among biologists and conservationists.
Predatory or predation-related attacks are quite rare, only accounting for 17% of attacks in North America since 1955. They occur when a carnivore views a human as prey and hunts it like it would any other animal it uses for food. (. . .)
Then there are animal attacks provoked by people taking pictures with them or feeding them in natural settings such as national parks which often end with animals being euthanised out of precaution. “Eventually, that animal becomes habituated to people, and [then] bad things happen to the animal. And the folks who initially wanted to make that connection don’t necessarily realise that,” says Christine Wilkinson, a postdoctoral researcher at UC Berkeley, California, who’s been studying coyote-human conflicts.
After conducting countless postmortems on all types of carnivore-human attacks spanning 75 years, Penteriani’s team believes 50% could have been avoided if humans reacted differently. A 2017 study co-authored by Penteriani found that engaging in risky behaviour around large carnivores increases the likelihood of an attack.
Two of the most common risky behaviours are parents leaving their children to play outside unattended and walking an unleashed dog, according to the study. Wilkinson says 66% of coyote attacks involve a dog. “[People] end up in a situation where their dog is being chased, or their dog chases a coyote, or maybe they’re walking their dog near a den that’s marked, and the coyote wants to escort them away,” says Wilkinson.
Experts believe climate change also plays a part in the escalation of human-carnivore conflicts, but the correlation still needs to be ironed out. “As finite resources become scarcer, carnivores and people are coming into more frequent contact, which means that more conflict could occur,” says Jen Miller, international programme specialist for the US Fish & Wildlife Service. For example, she says, there was an uptick in lion attacks in western India during a drought when lions and people were relying on the same water sources.
(. . .) The likelihood of human-carnivore conflicts appears to be higher in areas of low-income countries dominated by vast rural landscapes and farmland, according to Penteriani’s research. “There are a lot of working landscapes in the Global South that are really heterogeneous, that are interspersed with carnivore habitats, forests and savannahs, which creates a lot more opportunity for these encounters, just statistically,” says Wilkinson.
Question 17: According to the passage, what is a significant factor that contributes to the habituation of carnivores to human presence?
Detailed Solution:
The correct answer is 3. The reduction in carnivores’ instinctive fear response, resulting from their reliance upon human-provided food.
Explanation:
- Option 1: While climate change is mentioned as a factor in increased conflicts, it is not the primary driver for habituation as described in the passage.
- Option 2: Natural aggression-based conflicts are mentioned, but they do not directly contribute to habituation of carnivores to human presence.
- Option 3: Correct. The passage explicitly states that as carnivores rely more on human food sources, they lose their instinctive fear of humans, leading to habituation and increased conflicts.
- Option 4: Predatory attacks are rare and are not described as a factor contributing to habituation in the passage.
Thus, Option 3 is the most accurate answer based on the information provided.
(. . .) There are three other common drivers for carnivore-human attacks, some of which are more preventable than others. Natural aggression-based conflicts – such as those involving females protecting their young or animals protecting a food source – can often be avoided as long as people stay away from those animals and their food.
Carnivores that recognise humans as a means to get food, are a different story. As they become more reliant on human food they might find at campsites or in rubbish bins, they become less avoidant of humans. Losing that instinctive fear response puts them into more situations where they could get into an altercation with a human, which often results in that bear being put down by humans. “A fed bear is a dead bear,” says Servheen, referring to a common saying among biologists and conservationists. Predatory or predation-related attacks are quite rare, only accounting for 17% of attacks in North America since 1955. They occur when a carnivore views a human as prey and hunts it like it would any other animal it uses for food. (. . .)Then there are animal attacks provoked by people taking pictures with them or feeding them in natural settings such as national parks which often end with animals being euthanised out of precaution. “Eventually, that animal becomes habituated to people, and [then] bad things happen to the animal. And the folks who initially wanted to make that connection don’t necessarily realise that,” says Christine Wilkinson, a postdoctoral researcher at UC Berkeley, California, who’s been studying coyote-human conflicts.
After conducting countless postmortems on all types of carnivore-human attacks spanning 75 years, Penteriani’s team believes 50% could have been avoided if humans reacted differently. A 2017 study co-authored by Penteriani found that engaging in risky behaviour around large carnivores increases the likelihood of an attack.
Two of the most common risky behaviours are parents leaving their children to play outside unattended and walking an unleashed dog, according to the study. Wilkinson says 66% of coyote attacks involve a dog. “[People] end up in a situation where their dog is being chased, or their dog chases a coyote, or maybe they’re walking their dog near a den that’s marked, and the coyote wants to escort them away,” says Wilkinson.
Experts believe climate change also plays a part in the escalation of human-carnivore conflicts, but the correlation still needs to be ironed out. “As finite resources become scarcer, carnivores and people are coming into more frequent contact, which means that more conflict could occur,” says Jen Miller, international programme specialist for the US Fish & Wildlife Service. For example, she says, there was an uptick in lion attacks in western India during a drought when lions and people were relying on the same water sources.
(. . .) The likelihood of human-carnivore conflicts appears to be higher in areas of low-income countries dominated by vast rural landscapes and farmland, according to Penteriani’s research. “There are a lot of working landscapes in the Global South that are really heterogeneous, that are interspersed with carnivore habitats, forests and savannahs, which creates a lot more opportunity for these encounters, just statistically,” says Wilkinson.
Question 16: Which of the following statements, if false, would be inconsistent with the concerns raised in the passage regarding the drivers of carnivore-human conflicts?
Solution:
The passage highlights climate change as a significant factor in escalating human-carnivore conflicts, suggesting that resources scarcity drives these interactions. If climate change had negligible effects, as stated in Option 4, it would contradict the concerns raised. Other options align with the passage: carnivores lose fear of humans (Option 1), risky human behaviors impact incidents (Option 2), and predatory attacks are rare (Option 3). Thus, the correct answer is: Option 4.
