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  • [intro]

  • June was a really bad month for North Atlantic right whales.

  • Of the remaining 411 individuals, 6 died.

  • That's almost one and a half percent of the entire population gone in a month, which

  • is….

  • Alarming.

  • And mostly our fault.

  • If we can't fix what we're breaking, we're looking at the functional extinction of these

  • whales in just a few years

  • and their total disappearance not long after.

  • That would make them the first whale to go extinct as a result of commercial whaling.

  • North Atlantic right whales are already one of the most endangered whale species in the

  • world.

  • That's because they used to be incredibly popular with commercial whalers.

  • Hence the namethey were considered therightwhales to targetso they were

  • hunted to near-extinction.

  • But then, governments stepped in to protect them, and things started to look up.

  • In fact, in the early part of this century, their numbers seemed to be climbing.

  • But that all changed around 2010.

  • And the reason why is pretty clear.

  • Research published last month found that we've lost an average of 5.3 whales per year since

  • 2009—

  • and that's not counting 2019 and June's Unusual Mortality Event.

  • While researchers can't always tell the cause of death, most of the documented cases

  • have been caused by humans:

  • the whales either were hit by boats or caught in a fishing lines.

  • Of course, we'd like to see less whales die by our hands, but accidents do happen.

  • So it's important to have an idea of how many human-caused deaths a population can

  • withstand and still be sustainable.

  • That's a value called the potential biological removal or PBR.

  • And researchers have calculated it for North Atlantic Right Whales

  • , taking into account things like how many healthy whales are still around, their reproductive

  • habits, and the availability of their prey.

  • The problem is, that number is estimated to be 0.9 whales a year

  • so, in the last decade or so, we've killed more than five times that number.

  • And there's a lot we still don't know

  • like, how many of them die outside of monitored areas, or how many already have human-induced

  • injuries that will lead to their death later on.

  • For instance, there was one female that died fourteen years after being scarred by a propeller

  • because her scars were re-opened by pregnancy and became infected.

  • Plus, the numbers are a bit skewed because we're more likely to find carcasses that

  • have been struck by ships

  • those whales tend to be a little bulkier, so they float.

  • The whales that get tangled in fishing lines tend to sink, so their bodies are never found.

  • And not only are the whales dying too often, they're just not replacing their numbers.

  • There's only 90-100 adult females out there right now, and last year, they gave birth

  • to 7 new calves

  • and that was considered a good year.

  • Researchers think they're struggling to reproduce because our changing climate is

  • messing with their usual feeding and pupping grounds,

  • making conditions less favorable for the whale moms.

  • So basically, we've got a small population of whales that aren't making babies, and

  • we're not-so-slowly killing them off.

  • Both the US and Canada have implemented new laws in recent years to try to lower the number

  • of human-caused deaths.

  • Some have helped, but clearly, there's more work to do.

  • Because ultimately, if we can't stop these losses from happening, it won't be long

  • before these majestic animals disappear entirely.

  • And other whales similarly decimating by hunting will probably suffer the same fate.

  • In other newsand really, there's no good way to make this transition

  • research published in the Proceedings of the National Academy of Sciences this week showed

  • how bed bugs keep themselves from getting sexually transmitted infections.

  • And the findings might just help us keep these pests from infiltrating our bedrooms.

  • Now, these STIs aren't like insect chlamydiawe're talking about infections that

  • result from how these bugs have sex.

  • Bed bugs reproduce through traumatic insemination.

  • The male literally stabs his reproductive organ through the female's abdomen and deposits

  • sperm into her body.

  • This process can happen every week if the female has access to a blood meal.

  • You see, males generally target well-fed females because they usually lay the most eggs.

  • But that's a lot of stab wounds to deal with, which means a lot of opportunities for

  • infection.

  • But sort of luckily I guess -female bed bugs are able to buff up their immune systems right

  • before mating.

  • What the researchers wanted to figure out was what triggers them to do this.

  • Turns out, it wasn't what they expected.

  • They thought the females might learn to ramp up their immune defenses after repeated stabbings.

  • But the team took two groups of adult virgin female bed bugs and fed them as much as they

  • wanted once a week for three weeks.

  • And in the end, the ones stabbed by a glass needle to mimic traumatic insemination didn't

  • have a greater immune response.

  • Instead, every bug beefed up their immune system after eating.

  • That suggested the injuries the females receive aren't the driving factorinstead, the

  • bugs just have this built in immune response to food.

  • But, the researchers still wondered if it was the act of eating itself, or something

  • else.

  • So they took immature bed bugs and fed some of them on a consistent weekly schedule.

  • The others were fed at 5, 7, and 9 day intervals so their meals were inconsistent but averaged

  • out to the same once-per-week frequency.

  • Intriguingly, the group that ate every week ramped up their immune system way more after

  • eating than the group with the varied eating schedule.

  • And this made a big difference when they stabbed the bugs with bacteria-coated glass needles

  • to mimic the wounds inflicted by male bugs

  • those that were on a predictable feeding schedule had better survival rates.

  • So, it's not the food itself or a full belly, but the animals' anticipating that they'll

  • get food that triggers their immunological preparation for mating.

  • And that knowledge could help scientists find better pest control strategies.

  • They might be able to target female bed bugs when they're most vulnerable,

  • for example, or uncover ways to make the bugs more prone to infection.

  • And the researchers think that other insects might regulate their immune systems in similar

  • ways, too

  • so the more scientists learn about bed bugs, the better equipped they may be to fight all

  • sorts of pests.

  • Thanks for watching this episode of SciShow News!

  • And thanks especially to our longest running President of Space, SR Foxley.

  • Your continued support really makes a huge difference to us!

  • So does the support of all our patrons.

  • And if you join our patron community, you can get all kinds of exclusive rewards while

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  • You can find out more at Patreon.com/SciShow.

  • [ outro ]

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