Description and Ecology
The northern brown kiwi (apteryx mantelli) are flightless birds with only vestigial wings and no external tail. They exhibit brown spiky feathers, short legs, and claws. Kiwi are endemic to New Zealand and are known to have existed for nearly 65 million years. There are five species of kiwi, each being genetically and geographically distinct. The northern brown kiwi inhabit the North Island.
Kiwi are nocturnal and rest in hollow logs or under thick vegetation during the day. They are widespread among forests and farmland. More often heard than seen, males produce a high pitch whistle, while females produce a slow and low pitch cry. They make loud cries at night, mainly the first two hours after dark.
Their nostrils are located at the end of their ivory bills, which measure between 65-155mm. The bill is used for food rather than defense. Their diet consists of small invertebrates, fruit, and leaves.
Adult kiwi form strong pair bonds and are extremely territorial. Depending on the species, territory spans from 2-100ha and life expectancy ranges from 25-50 years.
Geographic and Population Changes
The historic range of kiwi across New Zealand was more extensive than today. The northern brown kiwi once extended into southern Northland, Mt Pirongia and Mt Hikurangi; however, the species has not inhabited that range since 1970. The current geographic distribution of kiwi remains unchanged in areas. The species experiences remnant populations along with translocated populations to new island habitats.
The total population was around 35,000 individuals in 1996, but has since decreased across the North Island. Although only one fifth of the population are under species management, they are increasing in proportion to the assumed decline in the unmanaged populations. Recent data indicates a 5.8% decline for brown kiwi. Kiwi hybrids can be found on the island.
Listing Status
Following a taxonomic change that split the species in to apteryx rowi and apteryx mantelli, the IUCN red list classified the northern brown kiwi as endangered in 2014
Causes of Decline
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| Maori, the indigenous Polynesian people of New Zealand |
Kiwi have been in decline for more than 700 years since the arrival of Maori to New Zealand. The presence of humans induced species decline with habitat loss from deforestation, predation by dogs , and resource competition with kiore, a Polynesian rat.
Europeans arrived in the mid 1800s and further accelerated the species decline with more efficient methods of deforestation. Kiwi habitat loss is minimal today, but the species continues to decline due to predation by stoats. The predators pose a problem to kiwi populations with a faster decline in Northland. The high rates of mortality from predation are not offset by the high productivity of kiwis.
Main Threats
Recovery Plan
The northern brown kiwi are currently managed under the third plan implemented for all five species of kiwi. The focus changes with each iteration. The first plan from 1991 prioritized research, while the second plan sought to raise awareness for the species' endangered status. By doing so, the second plan helped involve the public in the conservation efforts. The current plan builds on the efforts of the previous two.
The current recovery plan follows a ten year term from 2008-2018 and has four main goals to ensure kiwi protection over their current habitat range.
- highest priority to prevent extinction of any kiwi
- maintain intraspecific genetic variation and distribution
- manage within and restore to their natural range
- gain maximum benefits from the surrounding ecosystem
Long Term Goal
Recovery Plan-Period Goals
1. Management
To double the wild populations of rowi and Hasst tokoeka
To halt the overall decline of the great spotted kiwi, tokoeka and brown kiwi
To minimize the loss of distribution and genetic diversity in the wild for all species
To increase the wild population of the little spotted kiwi by 50%
2. Community Relations and Engagement
To increase and sustain community-led projects for all species across New Zealand
To double corporate sponsorship funding
3. Research and Innovation
To clarify kiwi taxonomy and provide information to manage genetic diversity
To undertake population modeling for all species
To undertake or support research for pest management and monitoring
How Can You help?
Donate to local organizations like "Kiwis for kiwi" for kiwi protection and habitat conservation.
Stay informed - click here to read reports and publications about kiwi
If you visit New Zealand
report sick, injured, or dead kiwi to the Department of Conservation (DoC)
minimize the threat of pets
be cautious of kiwi
Other Resources
Smithsonian's National Zoo & Conservation Biology Institute
Department of Conservation - Help Kiwi
Video: National Geographic on Kiwi (2 min)
Video: Kiwi Hatching at the Smithsonian
Works Cited
A95142721.en.
New Zealand Birds Online. www.nzbirdsonline.org.nz/species/north-island-brown-kiwi
It was interesting to learn that this bird has been around for 65 million years. It's also interesting to discover that there are kiwi hybrids out there.
ReplyDelete-Marina Enriquez
ReplyDeleteThis was an interesting bird species that I did not know existed. I hope the conservation efforts manage to minimize the predation threats posed to Kiwis.
ReplyDelete- Kyla Cooper
DeleteI have heard of this bird species before, but did not know much about it so I enjoyed learning more about the Kiwi. The threats were interesting to read about, especially the fact that males are more at risk and the effect that has on the species.
ReplyDelete-lauren Danna
I had never heard of this species before and it was interesting to read about. We learned about invasive species in lecture, but it is so disheartening to read other examples, such as this, where the Polynesian rat has caused the decline of this species.
ReplyDelete-Anna Donaldson