Katipo - Population Decline

Population Decline

The katipo is an endangered species and has recently become threatened with extinction. It is estimated that there are only a few thousand katipo left in about 50 areas in the North Island and eight in the South Island. A number of reasons have contributed to its decline; the major factors appear to be loss of habitat and declining quality of the remaining habitat. Human interference with their natural habitat has been occurring for over a century following European settlement. Coastal dune modification resulting from agriculture, forestry, or urban development along with recreational activities like the use of beach buggies, off road vehicles, beach horse riding and driftwood collection have destroyed or changed areas where katipo lives. The introduction of many invasive exotic plants has also contributed to the decline of suitable habitat.

Foreign spiders have colonised areas where suitable habitat remains. The major coloniser is the South African spider Steatoda capensis. It was first reported in the 1990s and may have displaced the katipo along the west coast of the North Island from Wellington to Wanganui. Although both the katipo and S. capensis have been found sharing the same dune systems or even co-existing under the same piece of driftwood suggesting that the two species can co-exist in similar habitats. It is possible that the displacement of the katipo by S. capensis is due to its ability to recolonise areas from which the katipo had been displaced after storms or other dune modifications. Furthermore S. capensis breeds year-round, produces more offspring and lives in a greater range of habitats which leads to greater pressure on the katipo. S. capensis also belongs to the family Theridiidae and shares many of the katipo's features. It is of similar size, shape, general coloration, it lacks the red stripe on its back, but may have some red, orange or yellow on its abdomen, as well as the general location where katipos are found. Due to these similarities it is commonly known in New Zealand as the ‘false katipo’.

In June 2010 the katipo was given full protection under the Wildlife Act to assist conservation efforts. Previously, it had no protection under the Act.