African Penguins struggle to find food at sea, contributing to a sharp drop in numbers over the years. The endangered animals also face a shore-based threat in South Africa — pet dogs.

Authorities in Cape Town say more than 40 penguins were killed this year by one or more dogs and they recently increased patrols in a penguin nesting area where people often take their dogs for a walk.

The city said Monday that the protective measures along Burgher's Walk in Simon's Town, which include requiring leashes for all dogs in the area, have been effective and that full-time patrols will continue until the end of January.

The city says the total population of African Penguins is about 2.5 percent of what it was 80 years ago.