Survival of the Fittest

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Do you remember these owlets from the blog post on 29th April?

Survival of the Fittest blog post image Owlets

Because Tawny Owls lay their eggs over a period of several days, the hatching is also staggered. This means that there is always a difference in the size of the chicks in the nest, the larger and more active individuals invariably getting more food from the parents than their smaller, weaker siblings. As a result, it is rare for all the chicks that hatch from a clutch to survive unless there is an abundance of food. Often the youngest chicks starve, or are sometimes even eaten by their siblings. This may seem cruel but this method of rearing of young ensures that, whatever the food availability, some offspring will always survive and produce further offspring. If all the young were fed equally there would be a chance that all might starve in years of poor food supply. So when the box was re-visited yesterday, it was no surprise that there was only one large healthy chick.

Survival of the Fittest blog post image Healthy owlet

This was ringed and then carefully returned to the nest box.

Survival of the Fittest blog post image Owlet

The moth trap was set last night and produced 41 moths of 7 different species (Early Grey, Hebrew Character, Common Quaker, Powdered Quaker, Twin-spotted Quaker, Clouded Drab and Small Quaker.