STUDY CONFIRMS THAT PAINTING EYES ON COW BUTTS HELPS WARD OFF PREDATORSTHERE'S NO SILVER BULLET, BUT "EYE-COW" TECHNIQUE IS ONE AVAILABLE TOOL FOR FARMERS.
Jennifer Ouellette - 8/18/2020, 8:43 PM
Cattle herds in the Okavango delta region in Botswana are plagued by attacks by lions and other predators, prompting farmers to retaliate by killing the predators. An alternative nonlethal technique involves painting eyes on the butts of cattle to trick ambush predators like lions into thinking they've been spotted by their intended prey. It's called the "Eye-Cow Project," and a recent paper published in the journal Communications Biology provides some solid empirical evidence for the practice. There are now practical guides for using the "eye-cow" technique available in both English and Setswana, so farmers can try it out for themselves.
Neil Jordan, a conservation biologist at the University of New South Wales in Australia, came up with the idea several years ago while he was doing field work in Botswana. Local farmers killed a pair of lionesses in retaliation for preying on their herds of cattle, and Jordan wanted to come up with a non-lethal alternative. The African lion population has dropped significantly from more than 100,000 in the 1990s to somewhere between 23,000 and 39,000 in 2016—much of it due to retaliation killings.
Jordan knew that butterfly wings sporting eye-like patterns are known to ward off preying birds and are also found in certain fish, mollusks, amphibians and birds, although such patterns had not been observed in mammals. He also discovered that woodcutters in Indian forests have been known to wear masks on the backs of their heads to discourage any tigers hunting for prey. He had observed a lion stalking an impala and noticed the predator gave up the chase when the prey spotted it. Lions are ambush hunters, Jordan reasoned, and he decided to test his "detection hypothesis" that painting eyes on the butts of cows would discourage predatory behavior from the local lion population.
The Botswana Predator Conservation Trust (BPCT) agreed to work with Jordan on the project, along with a local farmer, for a ten-week pilot study. Jordan and the farmer painted eyes on one-third of a herd of 62 cattle and took a head count when the cattle returned to the fold each night to see how many had survived. Only three cows were killed during that period, none of which had painted eyes on their butts. All the painted cows survived.
Granted, it was a small sample size, but those results were encouraging enough to convince Jordan to conduct a more ambitious study over the last four years. His team worked with local farmers in the Okavango delta region, painting the cattle in 14 herds (a total of 2,061 animals). They used acrylic paint (black and white or yellow), applied with foam stencils in the shapes of the inner and outer "eye." The colors were chosen "because of their highly contrasting and aposematic features, common in natural anti-predator signaling settings," the authors wrote.
Roughly one-third of the cattle in each herd got the eye patterns, one-third got simple cross-marks, and one-third weren't painted at all. The results confirmed Jordan's preliminary findings. Cattle with the painted eyes on their rumps were significantly more likely to survive than those cattle that had crosses painted on their butts and those that weren't painted at all. But the authors were surprised to find that even the painted crosses offered some survival advantage over the unpainted cattle. Over the course of the four-year study, 15 (out of 835) unpainted and four (out of 543) cross-painted cattle were killed by lions; none of the 683 cattle with painted eyes were killed.
“To our knowledge, our research is the first time eyespots have been shown to deter large mammalian predators,” said co-author Cameron Radford, a graduate student at the University of South Wales. “Previous work on mammal responses to eye patterns has generally supported the detection hypothesis. We think this may suggest the presence of an inherent response to eyes that could be exploited to modify behavior in practical situations, such as to prevent human-wildlife conflicts, and reduce criminal activity in humans.”
There are a couple of caveats. First, Jordan acknowledged that there were always unmarked cattle in the herd for their experiments as controls—what he termed "proverbial sacrificial lambs." It's not clear whether applying painted eyes to cow butts would be as effective if all the cows in the herd were painted. He suggests that farmers apply the marks to the most valuable cattle in the herd as the best approach until future research can be done. Second, there is the question of habituation: whether predators will eventually become accustomed to the painted eyes and learn to ignore it as a deterrent.
“Protecting livestock from wild carnivores—and carnivores themselves—is an important and complex issue that likely requires the application of a suite of tools, including practical and social interventions," said Jordan. “The eye-cow technique is one of a number of tools that can prevent carnivore-livestock conflict. No single tool is likely to be a silver bullet. Indeed, we need to do much better than a silver bullet if we are to ensure the successful coexistence of livestock and large carnivores. But we’re hoping this simple, low-cost, non-lethal approach could reduce the costs of coexistence for those farmers bearing the brunt.”
DOI: Communications Biology, 2020. 10.1038/s42003-020-01156-0 (About DOIs).
Sharks are visual predators that predominately use the element of surprise when attacking (Strong,1996), usually attacking from behind and beneath its prey (Tricas and McCosker 1984). Strong(1996) found sharks were initially attracted to their prey with sense of smell but appeared to use vision the closer it approached.
A shark’s vision is well developed and more elaborate than most fishes (Gilbert, 1963), having duplex retinas containing both rod and cone photoreceptors (Gruber & Cohen, 1985) indicating they have high visual capabilities and ability to see colour.
When predating, sharks undertake a risk assessment before attacking its prey (Lima and Dill, 1989; Martin et al., 2005) and it’s at this point where “Shark eyes” is designed to assist watermen.
“Shark Eyes” is intended to signal the approaching predator that it has been detected, effectively saying “I’ve seen you” and thereby altering the shark’s predatory behaviour.
“Shark Eyes” therefore aims to alter the sharks risk assessment and deter the shark from attacking. By taking away the element of surprise, the shark has a reduced chance of successfully capturing its prey. For example, an adult white shark is usually not agile enough to capture a fleeing, darting seal hence it generally attacks its prey by surprise (Tricas and McCosker, 1984). Similarly, Strong (1996) observed in numerous occasions that fur seals and sea lions easily avoided white sharks, suggesting that once the shark was visually detected, the change of capture of the seal prey drop considerably. Once a shark sees the “Shark eyes” and realises it has been detected, it may now be optimal for the shark to abandon its attack.
As described by Martin et al., (2005) the stages of predatory behaviour by a white shark involves a “Gather Info” stage before deciding to “Strike” or “Abort” an attack. It’s at this “Gather Info” stage that “Shark Eyes” aims to influence the sharks risk assessment, altering the shark’s behaviour to “Abort”.
1. Sharks have high visual capabilities.
It is well known that sharks have superior senses. Research of late has discovered that this includes their vision – and they do in fact have high visual capabilities. Sharks have been found to detect surface prey visually (Strong, 1996) having high visual capabilities (Gruber & Cohen, 1985).
Sharks are ambush predators, relying heavily on the element of surprise to capture prey (Strong, 1996). Sharks employ predatory tactics which involve a risk assessment before attacking it’s prey (Lima & Dill, 1989). “Shark Eyes” aims to alter the sharks initial risk assessment thereby altering its “strike” behaviour to an “abort” behaviour (Martin et al., 2005).
Shark Eyes is unlike any of the sharks natural prey and is designed to mimic that of a human eye. Hours of Research has gone into designing a set of eyes that we know sharks can see. Science is unsure as to whether sharks can see colour or not though many scientists believe they can, they do know they can see contrast. Shark Eyes – the design of the eye – achieves depth of field through contrast.
2. Shark Eyes eliminates the predatory element of surprise.
When the element of surprise is gone, sharks often abandon their attack.
Sharks are ambush predators just like lions and Tigers. Like most land apex predators, shark predation relies heavily on the element of surprise. We know and have witnessed sharks change their behaviour and become more cautious once eye contact has been made.
Shark Eyes is designed to mimic human eye contact, making the shark feel like it has been spotted, taking away their element of surprise. This has the potential to change the behaviour of the shark and prevent an attack.
3. Mimicry / Eyespots
Shark Eyes is simply copying what nature is already doing.
Mimicry / Eyespots are scientifically proven as a successful defence mechanism seen often in nature. Land and water animals are known to adapt to mimic large false eyes mostly on their rears to fend off predators. Mimicry is seen in birds, butterflies, moths, cats, caterpillars, fish and more.
Humans have successfully used mimicry as a line of defence in India. Face masks were applied to the back of the locals heads to protect them from tigers. It reduced the amount of attacks.
Sharks are visual predators that predominately use the element of surprise when attacking (Strong,1996), usually attacking from behind and beneath its prey (Tricas and McCosker 1984). Strong(1996) found sharks were initially attracted to their prey with sense of smell but appeared to use vision the closer it approached.
A shark’s vision is well developed and more elaborate than most fishes (Gilbert, 1963), having duplex retinas containing both rod and cone photoreceptors (Gruber & Cohen, 1985) indicating they have high visual capabilities and ability to see colour.
When predating, sharks undertake a risk assessment before attacking its prey (Lima and Dill, 1989; Martin et al., 2005) and it’s at this point where “Shark eyes” is designed to assist watermen.
“Shark Eyes” is intended to signal the approaching predator that it has been detected, effectively saying “I’ve seen you” and thereby altering the shark’s predatory behaviour.
“Shark Eyes” therefore aims to alter the sharks risk assessment and deter the shark from attacking. By taking away the element of surprise, the shark has a reduced chance of successfully capturing its prey. For example, an adult white shark is usually not agile enough to capture a fleeing, darting seal hence it generally attacks its prey by surprise (Tricas and McCosker, 1984). Similarly, Strong (1996) observed in numerous occasions that fur seals and sea lions easily avoided white sharks, suggesting that once the shark was visually detected, the change of capture of the seal prey drop considerably. Once a shark sees the “Shark eyes” and realises it has been detected, it may now be optimal for the shark to abandon its attack.
As described by Martin et al., (2005) the stages of predatory behaviour by a white shark involves a “Gather Info” stage before deciding to “Strike” or “Abort” an attack. It’s at this “Gather Info” stage that “Shark Eyes” aims to influence the sharks risk assessment, altering the shark’s behaviour to “Abort”.
