Sika deer are not native to Wales, or even to the UK, but have escaped from private collections or wildlife parks.
Originally from Asia, these chestnut-brown creatures have now established themselves in small pockets across the country.
Males invest an enormous amount of energy into growing their antlers, which become bigger each year. These status symbols are shed in April or May.
The mating season runs from August until October, and young are born eight months later.
Sika deer have been mating with the native red deer and the result is a declining number of pure-bred deer. Without genetic analysis it is hard to distinguish between the hybrids and the pure-breeds.
They are mostly described as solitary, but at the Teifi Marshes Nature Reserve near Cardigan there are nine or ten deer which are often seen in two groups.
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