Category Archives: Science Communication

New Bird Behaviour Discovered: Exciting Discovery or Boring Fact

Posted on April 4, 2019 by | Leave a comment

We always see birds flying around, but have you actually ever paid attention to what they are doing?

Recent research into bird behaviours has yielded some interesting observations. One such observation is a behaviour that birds in Central and South America displays. This behaviour is called “coordinated misdirection.” Coordinated misdirection was first observed by Alexander Skutch in the 1950s, but it wasn’t until recently that Eric Gulson-Castillo, Harold Greeney, and Benjamin Freeman furthered the study of the behaviour.

Image of a bird resting on top of its nest. Image from https://www.maxpixel.net/static/photo/1x/Feathered-Nature-Finch-Bird-Nest-1721311.jpg

What is coordinated misdirection?

Coordinated misdirection is coordinated diversion method employed as an anti-nest predation behaviour that is performed by a pair of birds. Prior to entering the nest, the two birds would perch around the vicinity of the nest. The birds would then fly towards the nest parallel to each other. As they get to the nest, one of the bird would fly into the nest while the other would proceed to make a diversionary trajectory that catches a predator’s eyes. The birds would later reunite on a perch somewhere else. The nests of these birds are typically dome shaped or hidden in crevices on mountain sides or in trees. This is so that there is more coverage over the nest and that there is only one entrance to the nest, therefore when the birds do this behaviour the nest would be much more easily concealable.

A dome shaped nest with a bird resting on it. Image from https://www.maxpixel.net/static/photo/1x/Bird-Nests-Feathered-Bird-Swallow-1700031.jpg

 

 

Why is this important?

Birds from around the globe would often use different behaviours to distract or fool predators so that their nest would have a higher surviving chance such as the broken-wing behaviour. This behaviour is similar to coordinated misdirection since they are both distraction behaviours that the birds would display to try to lead the predators away from their nests thus allowing the eggs to have a higher survival chance.

Toucans are one of the main nest predators in the Tropics. Image from https://www.maxpixel.net/static/photo/1x/Jungle-Keel-Billed-Toucan-Costa-Rica-Forest-1080724.jpg

One disadvantage about these displays is that it would typically only be useful for predators that use their vision such as monkeys or toucans. Therefore in essence, it is completely useless for predators that uses other ways to find nests such as snakes that uses scents.

In our interview, Dr. Freeman said:

“Behaviours that birds will do to protect their eggs and babies are much broader than previously thought”

This tells us that there are still a lot more that we can study from birds and that it would take a lot more effort to understand the effects and causation of a bird’s behaviour.

Nest predation will always be a main concern for birds. Consequently as time goes by, birds will evolve even better ways to prevent nest predation.

Group 4

Gloria Chan, Riley Cox, Fan Feng, Jonathan Kraft

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Posted in Biological Sciences, Outreach Project, Science Communication

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Can We Predict the Next Mass Extinction?

Posted on March 11, 2019 by | 1 comment

Asteroid Impact that killed the dinosaurs (Source: Wikimedia Commons)

Sixty-six million years ago, a massive asteroid crashed into Earth. The explosion from the impact released energy equivalent to 100 trillion tons of TNT. The mass extinction that occurred afterwards wiped out about 80% of all species at the time, including the dinosaurs. What if there was a way to predict such a catastrophe?

Do Mass Extinctions Follow a Pattern?

In 1984, researchers Raup and Sepkoski compiled data on twelve recent extinction events. Using statistics, they analyzed the data and found that a mass extinction seemed to occur about every 26 million years. This finding led to a torrent of research as scientists sought to replicate and explain this phenomenon.

The Solar System’s Journey through the Milky Way

One of the most prominent explanations were suggested by Rampino and Stothers. They proposed this pattern had something to do with our sun’s movement within the Milky Way galaxy. Just like how the earth revolves around the sun, the sun also revolves around the centre of our spiral galaxy. As the sun orbits, it also oscillates above and below the spiral arm. The gravity within our solar system fluctuates along with this vertical movement.

The sun’s orbit around Milky Way (Source: Wikimedia Commons)

According to Rampino and Stothers, the changes in gravity has an important impact on the Oort Cloud, a cluster of asteroids in the outer reaches of our solar system. When the sun is located right within the galaxy arm, the gravity from this densely packed region disturbs the Oort Cloud. As a result, Oort Cloud comets are deflected into the inner solar system, where any one of them can crash onto Earth, potentially causing a mass extinction similar to the one that killed the dinosaurs.

Oort Cloud (Source: Wikimedia Commons)

Counterargument

Equally many scientists have also criticized the existence of the 26-million-year pattern. For example, in his study, John Alroy claimed that the proposed pattern did not agree with data documenting mass extinctions of marine animals. In addition, Bailer-Jones pointed out flaws in Raup and Sepkoski’s statistics. She wrote that there were extinction events in the data that Raup and Sepkoski had omitted from the calculations. Furthermore, she noted the dates of the extinction events were uncertain, which Raup and Sepkoski did not account for. As a result, Bailer-Jones felt that Raup and Sepkoski’s calculations were not significant enough to draw such bold conclusions. Instead, she felt there’s more evidence that mass extinctions are sporadic, caused by multiple factors, including climate change.

Conclusion

The idea that mass extinctions occur at a predictable rate is both terrifying and fascinating. However, scientists are still debating whether such a pattern really exists. In the meantime, we can focus on other causes of mass extinctions. Specifically, ones we can control. Asides from meteor impacts, global warming  is also a major cause of mass extinctions and there’s not need to predict that our planet is warming at an unprecedented rate.

-Written by Helen Hu

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Posted in Issues in Science, Science Communication

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Do We Have to Sleep This Much?

Posted on March 10, 2019 by | 2 comments

Sleep is a universal behavior for many species on earth. Almost all mammals spend a fair amount of time sleeping every day. Adult humans, specifically, normally spend eight hours per day sleeping, and most of us will sleep over 175,000 hours in our lifetimes. Imagine how much more we could have achieved if we don’t have to sleep. Therefore, it is pretty intuitive to ask the question, do we need this much sleep? This famous study of sleep reduction may give the answer.

howstuffworks.com

Average Daily Sleep Totals of Different Animals (credit: @HowStuffWorks)

 

In 1977, Freidman et al. conducted a long experiment based on a gradual sleep reduction. During the study, participants were asked to gradually reduce their nightly sleep until they reached 6.5 hours per night. Then, the participants were asked to reduce their nightly sleep further until they no longer desired to reduce their sleep. The shortest duration of sleep was maintained by the participants for one month, and for the following two months, a sleep duration of 30 more minutes was allowed for each participant. The health of participants were recorded throughout the experiment.

Sleep Reduction/Deprivation (credit: smallbusiness.uk)

 

After sleep reduction for such a long period of time, we would expect to see a reduction in participants’ physical and psychological health. However, contradict to our common sense, although all of the participants display an increase in daytime sleepiness after they have reduced their sleep below 6 hours per night, there was actually no change in their mood, physical healthy or performance on tasks of vigilance or memory. Overall, their daytime activities were not influenced by the long-term sleep reduction.

 

The most interesting part of this study is probably that multiple participants reported daytime discomforts and reduced performances at work or school, although their performance was not actually influenced based on objective/physical measures. For example, some participants felt more distracted, depressed and sick (symptoms like having a cold) during sleep reduction, but when they were asked to perform tasks that require attention and efficiency, there was no noticeable change.

https://www.123rf.com/photo_82257239_stock-vector-sick-woman-sitting-at-home-and-big-set-of-cold-influenza-treatment-elements-flat-vector-illustration.html

Feeling Sick (credit: Aleksandra Sabelskaia)

 

Return to our original doubt, do we have to sleep as much as we do now? Based on this famous example, if subjective feelings were set aside, the answer is probably no. Sleep reduction only has a minimal impact on one’s performance during daytime, probably because that sleep deprivation increases the efficiency of sleep as recent researches have shown. However, more profound influences of sleep reduction and the physiological basis behind may need more studies for us to safely reduce the amount of sleep.

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Posted in Biological Sciences, Science Communication, Science in the News, Uncategorized

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