Episode 191 – Least Tern: Twitter Mob

“..and today we’re talking about the most direct path imaginable. But more on that later…”

When you’re a little bird surrounded by larger predators, you need to have a strong support network to fend off the baddies. Just like Flik in a Bug’s Life, the least terns have realized that there is true strength in numbers. By giving much stronger opponents the business as a group, terns can turn away even the fiercest of predators. But sometimes standing your ground is the best way to survive here in Life, Death, and Taxonomy.


  • Least Terns are white, grey, and black seabirds that always wear a hat and sunglasses. 
  • By that I mean they have black on the top of their head which connects to a black bandit mask that covers their eyes and leaves a white space on their forehead.
  • They have grey on their backs and the tops of their wings, and black wing tips. 
  • The birds also have yellow feet and beaks. 
  • They stand completely horizontal.
  • In flight you can see the sharp features of their pointed wings. Their tail feathers come to two points like the rock n’ roll hand sign.
  • Chicks are fuzzy grey and white dust bunnies with black specks on their backs. 

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro!

  1. Moorhen
  2. American Kestrel
  3. Arctic Skua
  4. Whinchat


  • 50 cm (20 in)
  • How many wingspans was the longest ever flight in an airplane through a tunnel?
  • Hint: The Italian daredevil Dario Costa flew his plan through a tunnel in Istanbul achieving the record for the longest tunnel flight ever.
  • 3,460 wingspans. The tunnel was 1,730 m (5,675 feet).


  • 39–52 g (1.4–1.8 oz)
  • How many least terns go into the mass of the earth’s core?
  • Hint: They figured out the weight of the earth and its core by studying a mysterious particle from space called neutrinos. These particles are both tiny and invisible, but they crash down to and through earth all the time. It’s estimated that around 50 trillion neutrinos from the sun crash through your body at every second. They are also able to pass through the earth. They don’t interact with light and are barely touched by gravity, but huge massive objects like planets can cause them to interact with other particles. There is a place in Antarctica called the IceCube Neutrino Observatory, that can detect neutrinos that pass through the earth. Theoretically, the more massive the earth is, the fewer neutrinos will make it through. 
  • 52,337,581,200,000,000,000,000,000 (52 septillion) least turns. The core is 6 septillion pounds (2.72 septillion kg).

Fast Facts

Least terns are sea birds but they’re smaller than some of their kin on the beach.

They like to eat small baitfish, crustaceans, and they sometimes eat insects. Least terns hunt by diving into tidal water or calm water to catch small fish close to the surface.

They migrate back and forth between North and South America. They breed and nest in the spring and summer on North American coasts and head down south for fall and winter. 

They nest close to one another and just lay eggs in a small indentation in the sand. Burrowing owls, gull-billed terns, and American kestrels often disturb their nests. Other predators include cats, coyotes, bobcats, feral dogs, great blue herons, and other birds of prey. 

As a whole, least terns are of least concern when it comes to conservation. However, some subspecies are considered threatened at the state level, and the California least tern was listed as an endangered species in 1972. Their main threat is habitation loss. 

Major Fact: Ants Don’t Serve Grasshoppers

When you’re a little bird in a big world, you can’t just rely on your own chutzpah to get by – you need a crew willing to go the extra mile on your behalf.

When it comes to fight, flight, or freeze, you’d think that flight would be option number one for a bird, but terns have figured out that there’s strength in numbers.

So if you’re a predator or just an intruder, things can easily take a tern for the worst. In fact, if you even look like you could be a problem, prepare to feel the tern. Terns use a defensive tactic called mobbing to handle threats.

This mostly involves sounding an alarm and flying at and around the intruder – harassing them. So a bunch of terns will dive bomb the threat, scratching and pecking when they can (though least terns tend to avoid making contact).

Since most predators that prey on birds (like cats, dogs, owls, and raptors) rely on stealthy or speedy ambushes, having a bunch of birds cawing and flying around you can put a damper on your blitzkrieg.

A bunch of terns mobbing a target will often encourage other species of birds to join in since terns are far from the only birds to do their fair share of mobbing. 

In fact, birds with a tendency to mob will join in on the fun just because everyone else is doing it. They may not even know what the threat is.

That’s why a bunch of birds will sometimes mob a statue or a passerby or a conservative on Twitter. It’s like buying loads of toilet paper last year.

If you’ve ever seen a hawk or something being chased by five or six blackbirds, you’ve seen mobbing. But terns and other sea-faring birds like gulls and fieldfares are possibly the most effective mobsters.

And you might think that the mobsters are putting themselves in danger. Why doesn’t the much stronger animal just attack the bird’s back? Well, animals, predators included, tend to avoid fights when it comes to food (not so much when it comes to mating though) so if it looks like they may lose an eye or it’ll just be a hassle, the predator will likely just leave and find an easier target.

The real thing that sets gulls and terns apart from other mobbing birds is the common tactic of actually pooping on the predator – sometimes so much that they can’t fly anymore.

Ending: So keep a paranoid eye out for threats, stick with your tribe, and viciously attack whatever everyone else is attacking like the least tern here in LDT. But not really.