Cable ties probably won’t stop magpie attacks – here are a few things to try instead

Stylish? No. Effective? Probably not.
Tony Wills/Wikimedia Commons, CC BY

Every spring in Australia is heralded by reports of magpies swooping at people. While it is of little comfort to those at the receiving end of a surprise attack, such events are actually quite rare when one considers the number of magpies across Australia, and the fact that they love to share our urban habitat with us.

According to one estimate, fewer than 10% of magpies swoop, and even fewer of these do so consistently. It is almost always males that swoop, and they only do so when they have chicks in the nest. Once the chicks are out the males seem to calm down; presumably they perceive nest-bound chicks as most vulnerable.

Swooping behaviour also seems to vary across Australia – at least according to Magpie Alert!, a website on which the public can report magpie attacks. Many more swoops have been reported in the eastern states than in Western Australia, and fewest of all in Tasmania.

But regardless of their relative rarity, being the target of a swooping attack by a magpie can be frightening. It has resulted in injuries and, tragically this week, the death of a 76-year-old cyclist in Wollongong.

What can we do to avoid ending up on the receiving end? Is any of the advice meted out each year on avoiding attacks actually worthwhile, or backed by evidence? As with just about everything involving biology, the answer is “it depends”.

Some magpies never attack pedestrians but go for cyclists; others do the opposite. And some hold a deep animus against posties on bikes, and reserve their fury solely for them. Even more astonishingly, some magpies seem to really have it in for particular people, and will preferentially attack them.

Although Australian magpies are not related to true crows, they do share similar levels of intelligence. US researchers have shown that American crows recognise people who have trapped them to band them, give alarm calls when they next see them, and even pass on that information to untrapped birds who also sound the alarm when they see trappers.

It seems likely that Australian magpies do the same, effectively holding a grudge against particular people. Unfortunate posties, travelling the same route each day and meeting the same magpies, seem to end up on the naughty list through no fault of their own.

Cyclists do seem to invoke more extreme reactions than pedestrians, judging by the fact that magpies appear to pursue cyclists farther. It therefore stands to reason that the best response to a swooping attack while cycling would be to get off and push your bike.

You will of course be wearing a bike helmet, and as magpies swoop from behind, this will offer protection against its sharp beak.

Sadly it seems that the classic tactic of attaching cable ties to your helmet does little to deter a determined magpie, beyond the fact that some strategic placing can help keep them away from your ears. Ditto the idea of painting eyes on the back of your helmet or hat.

More reassuringly, however, magpies really only swoop in the vicinity of their nest, so once you have moved away you should be safe. If you become aware of swooping attacks in a certain area the best thing is to avoid it – even just crossing the road should be sufficient.

If you can’t do that, at least wear a hat and sunglasses; these will help reduce the chance of a determined magpie pecking a sensitive area. Turning to face magpies may also help – many birds do not appreciate being stared at, and as magpies prefer to swoop from behind, this may be a good tactic if you find yourself cornered in a park.

If you have magpies in your garden, perhaps the most appealing way of avoiding attacks is to become their best friend. Given that magpies have long memories, a few judicious offerings of mince or similar tidbits throughout the year can help you befriend them, making them much more amenable to your presence come spring.

But don’t overfeed them – it’s just a friendly bribe, not a full-blown dependency.

If all else fails, simply console yourself with the fact that swooping season only lasts a few weeks. For the rest of the year magpies are peaceful urban nighbours who delight us with their distinctive song.

Bear that in mind, and we can hopefully reach a détente with our feathered (and occasionally flustered) friends. In the meantime, if you are unlucky enough to be swooped, remember to help others avoid the same fate by posting the details to Magpie Alert!.

Bill Bateman, Associate professor, Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

FactFile: the facts on shark bites and shark numbers

File 20180226 140181 un3yf6.jpg?ixlib=rb 1.1 — The CSIRO has provided new estimates of population sizes for White Sharks in Australian waters.
Fiona Ayerst/Shutterstock

Jane Williamson, Macquarie University and Vincent Raoult, University of Newcastle

Are there more sharks in Australian waters than there used to be, and are interactions between humans and shark increasing? Some Australian politicians have claimed that to be the case.

Let’s look at the research.

The most reputable source for shark incident data in Australia is the Australian Shark Attack file, which is collated at Sydney’s Taronga Zoo.

The map below, created by The Conversation using data from the Australian Shark Attack File, shows incidents between sharks and humans in Australia between 1997 and 2017.

You can use the filter buttons in the map to explore the data by year, season, the type of injury, the type of shark involved, the type of incident – or a combination of all the filters. Press the ‘show all’ button to reset the search.

https://cdn.theconversation.com/infographics/243/f87e27e72eb6545d5422e204b9894dedaad0f92f/site/index.html

The number of recorded encounters between sharks and humans in Australia increased modestly between 1997 and 2017, but the reason for this is unclear. Over those two decades, the Australian population increased by 33%, but that alone doesn’t explain the increase in recorded shark encounters.

Correcting for the growth in human population in Australia, the data show that between 1997 and 2017:

incidents resulting in injury increased by 1.59%
incidents without injury increased by 0.36%, and
fatalities increased by 0.07%.

Encounters between humans and sharks are extremely variable over time, and difficult to predict. The increases in recorded incidents between 1997 and 2017 are relatively small, and may be explained by factors not related to shark populations – such as increases in the reporting of shark encounters, or increasing beach use.

https://cdn.theconversation.com/infographics/159/62c30e6dedecffbbeb4e059c8ab0e573d756f61b/site/index.html

Are there more sharks off the Australian coast?

White Sharks (formerly Great White Sharks) are recorded as being responsible for 28 of the 36 fatal shark encounters in Australian waters between 1997 and 2017, and are the primary target of shark mitigation strategies of the Western Australian, New South Wales and Queensland governments.

So, has there been an increase in the number of White Sharks in Australian waters?

Estimating population numbers in the marine environment is difficult, especially for long-lived migratory species like White Sharks.

However, there is no evidence that White Sharks numbers are on the rise, either in Western Australia or along the Eastern coast. Despite targeted conservation efforts, the available research show stable or slightly declining numbers in these populations.

There are two distinct populations of White Sharks off Australian coasts – one to the west, and another to the east of Bass Strait, which separates Tasmania from mainland Australia. The eastern population includes New Zealand White Sharks.

Recent work by the CSIRO through the National Environmental Science Program’s Marine Biodiversity Hub using innovative DNA analysis has provided us with the most detailed and reliable estimates of population size we have for this species.

The CSIRO study shows there has been a slight decline in adult White Shark populations since the year 2000.

Current adult abundance for the eastern Australasian population is estimated at 750, with an uncertainty range of 470 to 1,030. The southern-western adult population is roughly double the size, estimated at 1,460, with an uncertainty range of 760 to 2,250.

Including the available information about juvenile White Sharks, estimates of total size for the eastern population in 2017 was 5,460, with an uncertainty range of 2,909 to 12,802.

It’s difficult to detect population trends with White Sharks because of the length of time it takes juveniles to reach maturity – around 15 years. As protection of White Sharks began in the late 1990s, any changes in abundance would only be starting to appear in current populations.

How else can we measure White Shark populations?

The traditional way of measuring shark and fish populations is by examining catches in commercial fisheries over long time periods. By correcting for the level of fishing effort – which is done by looking at things like the number of nets, hooks and tows deployed by fishermen – scientists can assume that changes in the “catchability” of sharks is related to their abundance.

But due to the relative rarity of catches of White Sharks by fishing vessels, this approach is less reliable for this species than the more recent genetic studies conducted by the CSIRO and outlined above.

Western Australia has a detailed measure of White Shark numbers assessed by catch data. A report published by the Western Australian Department of Fisheries in 2016 attempted to model changes in the southern-western Australian White Shark population since the late 1930s. The authors outlined four different plausible scenarios, none of which suggested a continuous increase in the number of White Sharks.

In New South Wales, there has been a cluster of shark bites in recent years. Data from the NSW Shark Meshing (Bather Protection) Program, managed by the NSW Department of Primary Industries, show a recent increase in White Sharks caught in nets placed near ocean beaches.

But when it comes to thinking about shark populations, we should not assume that these two facts are related. It’s important to remember that just because two things may correlate, it doesn’t mean that one caused the other.

These patterns could mean that the animals are coming closer to shore, rather than a population increase (or decrease).

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Shark and human interactions: what factors are at play?

A 2016 paper examined six global shark bite “hotspots” – the United States, South Africa, Australia, Brazil, Reunion Island and the Bahamas – and concluded that when it comes to encounters between sharks and humans, there are a range of causes at play.

These include:

rises in human population
habitat destruction/modification
changes in water quality
climate change
changing weather patterns, and
the distribution/abundance of prey.

The authors also noted that shark encounters appear to happen in clusters. For example, 2009 saw a spike in shark encounters off the New South Wales coast. This coincided with an increase in beach attendance and beach rescues during what was an unusually warm summer for south-east Australia.

A 2011 paper highlighted the popularity of water sports as a factor contributing to increased human-shark encounters. More people are taking part in water sports, and improvements in wetsuit technology mean that people are in the water for longer throughout the year.

However, there is limited information on the number of people who use Australian beaches, so this explanation needs to be further studied.

It’s vital that any strategies put in place to reduce the number of unprovoked encounters between humans and sharks in Australian waters are carefully considered, and based on the best available research.

Jane Williamson, Associate Professor in Marine Ecology, Macquarie University and Vincent Raoult, Postdoctoral fellow, University of Newcastle

This article was originally published on The Conversation. Read the original article.