Cuckolding common in nature, but rare in humans

Fathers can breath a sigh of relief. Although biologists have found cuckolding, where one male unwittingly raises the offspring of another male, is common in animal societies, it appears humans are one of the few exceptions.

A recent review published in Trends in Ecology & Evolution on 5th April claims that across modern and ancient human societies, women tended to be faithful to their partners.

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Practice Makes Perfect:
Tool-Foraging Dolphins Improve with Age

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.
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Shy Hermit Crabs Have More Luck with the Ladies

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.
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Immaculate Conception: Clonal Reproduction in Snakes
(and other animals)

Reproduction takes two, right? Well, not always. Many arthropods and microscopic animals called rotifers reproduce clonally and although it is relatively rare in vertebrates, clonal reproduction has been confirmed in several species of fish, amphibians, birds and reptiles. Known as parthenogenesis, clonal reproduction in vertebrates can occur when an offspring develops from an unfertilised egg. Parthenogenesis has never been observed to occur naturally in mammals, although it is possible to induce it artificially in the lab.
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Can Chickens Change Sex?

Not the most pervasive of suburban legends, granted, but it seems to keep popping up. It goes something like this…

Confused Farmer finds Hen is now Cock
The mature hen, Gertie, who had laid eggs the previous year, suddenly stopped, grew chin wattles and started to crow.

So, can chickens really change sex? – Short answer: NO

The Long Answer

There are a few different explanations for stories such as these, but the important point of all of them is that these apparent sex changes are merely superficial – the hen might be visually and behaviourally male, but she is still unable to fertilise another hen’s eggs. So why does the hen suddenly start crowing? Continue reading

All-Female Fish Species takes Males for a Ride

Reproduction takes two… right? This is true for most animal species, with reproduction involving the fusion of a sperm and an egg. However, one fish species has taken a different approach. The Amazon Molly is entirely female. When they are ready to reproduce, members of this species must find a male of another, related species, and mate with him. However, instead of using the sperm from this male to provide half of the genetic information for the future offspring, the female Amazon Molly merely uses the sperm as a signal to trigger embryogenesis, in a process known as gynogenesis.

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