The main threats to the penguins are:
The yellow-eyed penguin (hoiho) evolved in the cool coastal forest of New Zealand where it had no natural enemies. With the arrival of humans came firstly the kiore (Polynesian rat) and dogs. Later the Norway and ship rats, cats, cattle and sheep arrived. The coastal forest, home to the yellow-eyed penguin was burnt down or cut to clear the land for farming cattle and sheep.
The penguins were then forced to nest in places without shelter. Cattle and sheep trample nests and eat the shoots of native plants, preventing regeneration. Loss of habitat and predation of chicks and adults have meant a sharp decrease in numbers of yellow-eyed penguins on mainland New Zealand. Even on our offshore islands, the penguins are threatened.
On Stewart Island too, some coastal forest was burnt, and the penguin now shares its breeding grounds with feral cats, although the Trust’s work has shown that they are not a major threat. On Campbell Island, grazing animals have been removed, and pigs and rats eradicated. On the Auckland Islands, penguin numbers have been drastically reduced by grazing cattle, feral pigs and cats.
Possums, originally introduced by the early settlers, are destroying our native forests by eating the growth tips of trees. Some of these trees found along our coastline were originally nest sites for the penguins.
Predators such as mustelids (stoats, ferrets and weasels) and feral cats are one of the worst threats to the yellow-eyed penguin populations. Rabbits were brought over from Europe as pets and for sport. They thrived on the new pastureland, so it was decided to introduce ferrets, stoats and weasels to control rabbit numbers. Although these predators had a plentiful food supply in the rabbits, the numbers of rabbits continued to increase. What’s more, native birds, including hoiho and its chicks, became easy prey for these introduced predators.
Because these predators are not natural to New Zealand, for years the penguin had no need to develop defences against them. When people introduced predators, the penguins had no method of defending themselves.
Predators such as the mustelids are considered to be one of the significant factors in the decline of yellow-eyed penguin populations. Therefore action must be undertaken to minimize this.
What is the Trust doing about Predator Control?
- Sponsorship of a ‘Mustelid Workshop’
- aspects of mustelid control, techniques and field skills
- ‘Field Booklet’
- as a result of the workshop, a booklet has been produced.
- Supporting research
- assisting with funding of a research projects.
- assistance with trapping programmes e.g. Department of Conservation in North Otago areas.
- Trust reserves
- monitoring nest sites during critical times (egg laying to chick fledging)
- Supporting others
- advising on predator control techniques and resources
- providing traps on loan to private landowners undertaking predator control work on their land.
Marine food supply
Recently, hoiho (yellow-eyed penguin) has been faced with another threat in the form of a shortage of their food supply from the sea. One factor causing these shortages is the warmer water temperatures as a result of the ‘El Nino’/’La Nina’ weather pattern (the Southern Oscillation, an unusual climatic pattern which leads to lack of nutrients in coastal surface waters and reduced numbers of fish).
One of the objectives of the Yellow-eyed Penguin Trust is to create and protect onshore breeding habitats for yellow-eyed penguins. These breeding areas are generally safe from attack by dogs, as the reserve (or private) status prohibits dogs.
There is, however, a problem on our public beaches where penguins come ashore. Dog owners appreciate the freedom of romping with unleashed dogs on the open beaches. At certain times of the year, penguins (yellow-eyed, Fiordland crested, erect crested, Little Blue and Snares crested ) come ashore, either as juveniles to rest for the night or as adults to moult.
This sometimes causes problems. A penguin is irresistible to most dogs as it has a fishy smell that can be scented by dogs from a very long way off. Often well meaning dog owners only become aware of this when a penguin lies dead in a pile of feathers in the dunes. It takes only one bite to kill them.
Moulting birds and juveniles are totally defenceless. The moulting birds can’t go to sea and they are not able to drive off a dog or dogs.
The Trust, supported by the Department of Conservation and the Yellow-eyed Penguin Consultative Group and other interested parties, is trying to remedy this situation. Over the years the Trust has used the media as a means to educate beach-using dog owners about the danger their dogs present to moulting penguins. More recently, temporary laminated signs have been installed on city and other popular beaches where penguins are likely to come ashore to moult.
The latest initiative (supported by the Department of Conservation and the Yellow-eyed Penguin Consultative Group) is to seek legal protection on wildlife-sensitive beaches by requesting a change in the Clutha District Council Bylaws to prohibit dogs from the Kaimataitai Beach which bounds the Nugget Point Reserve.
This new bylaw was adopted by the Clutha District Council in November 2002. Of course there are problems policing such a bylaw, and the goodwill and cooperation of local landowners and residents is essential. As part of the consultation process, the Trust notified adjacent landowners of its intention and the reasons for this. Only one respondent strongly objected to the bylaw proposal put forward by the Trust, reasoning that it was another erosion of personal rights and freedom, and that such a rule isn’t necessary for the protection of the birds. The Trust respects the opinions put forward and will work with these to further good relations.
There is no doubt that there have been a number of birds injured and killed in this area, as adults cross Kaimataitai Beach to reach their breeding areas within the Nuggets Reserve. Similarly, the chicks at fledging come down to the water’s edge outside the boundary of the reserve, and stand around until they are ready to go to sea.
The change in the status of the land near the Nuggets Reserve will undoubtedly set a trend where more sensitive wildlife sites can be better protected by the exclusion of dogs.
There will, however, need to be some tolerance toward dog owners as they make these adjustments. Hopefully local bodies will come on board and help by creating excellent dog exercising facilities away from wildlife zones, such as the one at Rotary Park.
In the interim, the Trust will continue to work with penguin conservation interests throughout the region to overcome the problem of dog kills.