It has become something of an annual tradition that I produce an advent calendar each year with facts, interesting links and videos. Consider it a little festive treat for your brain :) Here is your 2016 advent calendar – check out the doors that are already open, and come back each day for a new treat!
Great-tailed grackles are very flexible, quickly learning to associate new cues with food, but new research suggests this doesn’t help them innovate to solve new problems.
What do those cute little baby sea turtles do after their epic sprint to the water? Until very recently, we simply didn’t know. Nobody had been able to study the movement of juvenile sea turtles in natural conditions – they were simply too small and too difficult to track. But a new study reveals for the first time just what the young turtles have been up to in the Pacific ocean – and it shows that they are just as determined and tenacious as they were on land, fighting strong currents to reach their preferred feeding grounds.
A group of bottlenose dolphins in Shark Bay, Western Australia, use a clever trick to access prey on the sea floor – they cover their beaks with marine sponges to protect themselves from sharp rocks as they search for food. 30 years after the behaviour was first reported, scientists have now found that individuals improve with practice, peaking just when it matters most.
If you ever owned a pet stick insect as a child, you might have noticed them swaying back and forth at the end of a twig, but until recently, nobody knew what this strange behaviour was for.
For male elephant seals, the fight to secure a mate can be vicious, even deadly. So they try everything they can to avoid it. This is a pattern biologists see again and again – across the animal kingdom, males have evolved to use signals to assess each other’s prowess and avert costly physical confrontations. In most cases, these signals are honest – they accurately convey an individual’s size, strength or dominance. But new research shows this is not the case for Elephant seals, which have evolved a more sophisticated system.
New research published last week describes how black widow spiders destroy their mate’s nests to deter rival males.
Nice guys finish last? Not for the hermit crab – shy males produce more sperm and are more successful with the ladies.
While we accept the individual differences in behaviour between humans without question, terming it ‘personality’, the idea personality in animals has been met with great scepticism. However, evidence for consistent behavioural differences between individuals, known as personality or behavioural syndromes, is now widespread, the question remaining is why? What is the benefit of personality? Some scientists suggest that different personalities represent different life strategies relating to risk taking and investing in the future, others suggest that personalities exist because environmental conditions are variable and different strategies fair better under different conditions.
Most birds make nests, and spend their time foraging to feed and care for their chicks. Cuckoos, on the other hand, don’t waste their time with any of that, they simply lay their eggs in another bird’s nest and let them do all the heavy lifting. This might sound like the easy option, but in fact cuckoos have made a whole lot more work for themselves trying to evade and deceive their neighbours. When cuckoos succeed in their trickery, their unsuspecting host suffers, producing fewer young that year and wasting time and energy. So, evolution has pitted host birds against cuckoos, with each side developing increasingly sophisticated techniques to try and get their own way. Host birds mob potential attackers, while cuckoos use mimicry to avoid detection, and threaten defectors with serious consequences.
Cuckoos are famous for taking advantage of their unsuspecting neighbours; laying eggs in their nest and leaving their unwitting host to raise the chicks. The world cuckold, used to refer to the husband of an adulterous wife, originates from the cuckoo bird. There are over 50 species of parasitic cuckoo in the family Cuculidae; some are generalists who will lay their eggs in any available nest, others specialise in one or a few ‘host’ species, but all are engaged in an evolutionary battle with the species they parasitise – an arms race, if you will. Species parasitised by cuckoos are at a disadvantage – in the best case they are merely wasting resources raising an unrelated chick, in the worst case the chick will hatch early and push out the other eggs in the nest, meaning that the unlucky bird in question loses an entire clutch. In each generation, therefore, natural selection will favour host birds that are able to avoid parasitism. The birds might evolve to be more discerning, for example, identifying the appearance of cuckoo eggs and removing them, or selecting nest sites that are more difficult for the cuckoos to access. Equally, in each generation the cuckoos that are most successful in deceiving and parasitising their neighbours will produce more offspring and their traits will be favoured by natural selection. Cuckoos might evolve eggs that more closely resemble those of their host, or very rapid egg incubation to ensure their chick hatches first. Ultimately, neither species wins, with evolution demanding increasingly sophisticated tactics for successful parasitism in cuckoos, and traits to thwart parasitism in the host species.