Eleven penguin chicks have hatched at Chester Zoo – the most to hatch during “hatching season” at the zoo for more than 10 years.

The new arrivals are from the highly threatened Humboldt species of penguins. Of the world’s 17 penguin species, they are now among the most at risk.

Parental duties are shared by penguins, with both mum and dad playing an active role in helping with the care of the youngsters.

Keepers say they are “delighted” to report that each of the chicks has been nurtured beyond the delicate first 40 days of life and, to help them keep track of the new chicks, a different naming theme is selected each year.

Previous topics have included NHS heroes, brands of crisps, chocolate bars and British Olympic athletes.

This year, the chicks are being named after plants, with Nettle, Thistle, Dandelion, Tulip and Daffodil among the confirmed names so far.

Humboldt penguins are becoming increasingly rare and are now listed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN).

Found on the rocky coastal shores of Peru and Chile, the penguins face threats from climate change, over-fishing of their natural food sources, and rising acidity and temperature levels in the oceans – all causing the penguins to search further from their nests for fish which increases their vulnerability.