Meet the Kaka: The Kea’s Lesser-known Cousin
This is an article I wrote which appeared in the November 2007 issue of Parrots magazine.
Meet the Kaka: The Kea’s Lesser-known Cousin
Last post, I wrote about my experiences watching keas (Nestor notabilis) on a recent trip I took to New Zealand. Keas are well-known among parrot fanciers for their remarkable intelligence, intense curiosity, and extremely destructive behavior. I was absolutely thrilled to have been able to see some in the wild. I was also able to see groups of another similar parrot that lives in New Zealand: The kākā (Nestor meridionalis). The kaka is not as well-known as the kea and they are extremely rare in aviculture or zoos outside of New Zealand. So, allow me to introduce you to this handsome, little-known parrot.
Introducing the Kaka
Kakas occur in forests in New Zealand. Their name comes from the Maori and Polynesian word for parrot. “Kaka” is also part of the Maori names for other New Zealand parrots: the kakarikis (little parrots) and the kakapo (ground parrot). The kea and the kaka are close evolutionary relatives, and they are only distantly related to other parrot species. Their closest relative is the kakapo, a heavy, flightless, green parrot.
Prior to the 1800s, there were actually three species in the genus Nestor, with the third one being the Norfolk Island Kaka (Nestor productus). This bird occurred on the Norfolk and Phillip Islands, which are about 1000 km northwest of Auckland, New Zealand. The last one died in captivity in London in 1851, although the species was likely wiped out in the wild before then. Norfolk Island Kakas were not afraid of people and were hunted widely for food by European settlers. Others were trapped as pets. Another Nestor species related to the kaka occurred on the Chatham Islands, about 800 km east of Christchurch, New Zealand, but this parrot is only known from fossils and the date is went extinct is unknown.
Norfolk Island Kakas looked very similar to the New Zealand Kakas. The kakas on New Zealand are mainly brown with red-tipped feathers on the belly and the back of the neck, scarlet feathers under the wing and white feathers on the top of the head. They resemble keas somewhat, but are a bit smaller, are brown instead of olive, and their upper mandibles are heavier and broader. The Norfolk Island Kaka differed from mainland kaka in that they were slightly smaller, their cheeks were orange, their chests were yellow and the tops of their heads were brown. They were undoubtedly very beautiful birds. All that is left of the species are a few skins housed in natural history museums. Additionally, the National Museum of Natural History in Amsterdam has two whole specimens, and there are 3D images of them on their website (http://ip30.eti.uva.nl/naturalis/detail?lang=uk&id=51) that can be rotated using a mouse.
Unlike the kea, which occurs only on the South Island, the kaka occurs on both main islands and Stewart Island, along with a few other small off-shore islands. There are two kaka subspecies: The South Island Kaka (N. m. meridionalis) and the North Island Kaka (N. m. septentrionalis). The South Island variety is a bit larger than its North Island counterpart. Both tend to exist at larger densities on off-shore islands where they occur than on the mainland, where populations have decreased since European settlement due to the introduction of non-native predators, such as cats and stoats. Many of New Zealand’s native birds are not afraid of mammals and have no defense strategies to deal with them because they evolved in isolation from mammalian predators. In many areas of New Zealand, introduced predators have decimated native bird populations.
Meeting Wild Kakas: North Island
The first wild kakas I met were living at a wildlife sanctuary on the North Island. I went to Wellington after a conference I attended, with the intention of visiting Kapiti Island. This island, only eight kilometers from the mainland, serves as a sanctuary for several very rare bird species, because introduced predators have been eliminated from it. Parrot species found there include Red-fronted and Yellow-fronted Kakariki and North Island Kaka. Other very rare birds found there include the Takahe, a large, flightless, blue and green rail, and the Kokako, a member of the New Zealand wattle bird family. Less than 200 Takahe, and about 400-500 pairs of Kokako remain. Because it’s easier to keep alien predators off of islands than off of mainland sites, many populations of very rare species live primarily on smaller islands, rather than on either of the two main islands. However, some mainland sites manage to maintain populations of rare native birds by implementing predator-control programs. For example, the Kaori Wildlife Sanctuary in Wellington has a large, predator-proof fence around it to protect native birds including kaka and kakariki.
Unfortunately, the boats to Kapiti Island did not sail during the few days I was in the area. That was disappointing, but the trip was by no means a total bust and still turned out quite well. I managed to see a flock of free-living kakas and several other very rare bird species by heading north to the Pukaha Mount Bruce Wildlife Centre. This wildlife centre is completely devoted to the conservation of native New Zealand wildlife, and has an information centre including audio-visual displays, several large aviaries containing native birds, a Tuatara display, walkways through restored native forests, a kiwi house, a shop and a café. The center has bred rare kokakos for release into the wild on offshore islands and in the forest around the centre. North Island Brown Kiwis have also been released into the forest, where predator-control programs increase their chances of surviving and breeding. Other very rare birds bred there include the Campbell Island Teal (of which only 20 survive in the wild), and the Shore Plover (of which only 200 birds exist).
The centre also runs a kaka recovery program. After having been absent from the area for 50 years, kaka are now back in the forest around the centre and free-living flocks can be seen from the walkways through there. Wild kaka transported from Kapiti Island and captive-bred kakas were released into the forest in 1996. Other captive-bred kakas were released in following years. This kaka conservation project has been successful so far, because the birds have successfully raised several chicks in the wild and the population is increasing. To give the kakas a better chance at raising young, biologists put some predator-proof nesting boxes out for the kaka.
The wild kakas weren’t too difficult to find,because, like most parrots, they have a loud call. Since they call while they fly, I could easily spot birds flying solo or in pairs over the trees. However, several of the birds I spotted were resting in the trees, or preening, since it was mid-day – siesta time for parrots. The kakas blend in well with their surroundings so seeing the quiet, inactive ones took some effort. Other kakas were chewing the bark and twigs off of the trees. Many of the trees in the forest showed evidence of kaka-induced damage. However, unlike keas, which are often found near human settlements, kakas limit most of their destruction to trees. While some individuals will visit backyard bird feeders, most kakas stay in forests away from towns and cities.
Since many of the free-living kaka around the wildlife centre were captive bred, they are offered supplementary food at a feeding station each day at three in the afternoon. When I approached the feeding station before feeding time, several kakas started to follow me, hoping I had their food. They weren’t afraid of me, but they didn’t approach me too close, either. They were very interesting to watch and photograph and would go about their normal activities while I followed them with a camera or spied on them with binoculars, like a parrot paparazzo. The kakas were quite chatty, but they weren’t quite as loud at the keas I saw.
At three, workers at the centre added some corn and nuts to the parrot feeder. The parrots all rushed in to grab the best bits. Most preferred to grab a bit of food and dart off to a tree to eat it in peace. Those who stuck around the feeder tried to steal food from each other constantly. Often, one bird would approach another to take a nut or piece of corn, and the bird with the food would wind up dropping it to the ground. They were rather messy eaters and got crumbs and bits of corn all over the ground. Larger pieces of food that wound up on the ground were eventually cleaned up by the kakas, and songbirds and blackbirds would take the smaller pieces. Kakas usually stay off the ground, but not if there’s a good piece of food down there.
Before they are released, captive-bred kakas are given access to a similar feeder so they are used to eating from it. Staff can also monitor the birds from the feeders, and the feeder gives the public a great opportunity to view a free-living flock of wild parrots. From watching the kaka throughout the day, it seems that most do forage just fine on wild food as well. It was very nice to see, first hand, such great results from a parrot conservation project.
Wild Kaka Dietary Habits
Wild kakas eat a variety of food. Somewhat like lories, their tongues are bristled, which helps them lick up nectar. In the process of feeding on nectar, they help pollinate a lot of flowers. Some kaka will visit special bird feeders stocked with a sweet liquid, like big hummingbird feeders with a place for the birds to perch. Kakas also eat berries, seeds, tree sap, honeydew and some invertebrates. They will often dig grubs from rotting logs, and they can easily peel bark off of trees with their strong beaks to get the sap. They do not feed on the ground as often as keas do, and in fact, look a bit awkward skipping along on the ground. Kakas are forest birds and spend most of their time in trees. They are very acrobatic, and many can eat while hanging upside down by one foot.
Play Behavior in the Kaka vs. the Kea
Overall, kakas are somewhat less exploratory and playful than their mountain cousins, the keas. However, as is the case with most parrot species, young kakas will spend some time playing. Diamond and Bond (2004) studied the play behavior of both kakas and keas, and compared the play-styles of the two species. This represents one of a very small number of formal studies done on parrot play.
Play in the kaka is limited to young birds, while it is found in both adult and young keas. Keas will also play in groups of three or more birds, while kakas generally will not. Both species engage in rough play-fighting, but keas are much more aggressive about it than kakas. For example, kakas will use their powerful beaks to nip at each other in play, but they don’t seem to put enough pressure into their bites to make their opponent feel much. However, when a kea bites a playmate, the bird being bit will sometimes pull away like he’s been hurt, although playing keas rarely make each other bleed. Perhaps this difference is due to the fact that kakas have bigger, heavier beaks than keas. If the kakas put any pressure on another bird with their beaks, they would likely cause a serious injury.
Playful keas or kakas will jump on or push their opponents with their feet. Both species sometimes initiate play sessions by cocking their heads to the side, although this move is far more exaggerated in kakas. This behaviour seems to be the equivalent of the “play bow” in dogs, where the dog places his front feet on the ground while his rear stays up in the air. These behaviors let the animals around know that the following behavior is in play and is not to be taken as aggression. Like caiques or lories, keas and kakas also approach potential play partners by hopping.
Keas will play with objects, while kakas generally do not. What could account for that difference? In general, object play is found most often in generalist species like keas that do a lot of exploring. Crows and their relatives also fit this description, and like keas, are among the most behaviorally flexible of all birds. Adult kakas, despite being large-brained, intelligent birds, are more afraid of new objects and situations than keas tend to be. Kaka diets also include a smaller range of items than the typical kea diet. For example, kakas do not eat other birds or mammals like keas do. Perhaps its harsher environment means that the kea must accept a larger variety of food sources than the kaka. In turn, keas must be bolder and more exploratory to locate a greater variety of foods. Keas also stick around their parents for a longer time than kakas do, perhaps because it takes them longer to learn to find and eat the huge variety of foods they need.
South Island Kakas
After spending a few days on the North Island, I headed back to the South Island and eventually made my way to Stewart Island, which is a one hour ferry ride from the South Coast. Some introduced predators do exist on the island, although stoats – extremely efficient bird predators – are absent. As a result, the island is rich in birdlife and is a wonderful place for a bird watcher to spend a few days on. South Island Kaka, Red-fronted Kakariki and Yellow-fronted Kakariki are the parrot species present on the island. In my few days there, I saw several Red-fronted Kakariki and kaka right in Oban, the only town on the island. The kakas were not too difficult to spot at all, due to their habit of calling while in flight. They generally started calling very early in the morning, before the sun was fully up. I needed no alarm clock out there.
I saw plenty of interesting birds on Stewart Island, but the best place near Oban to see birds was undoubtedly Ulva Island. This small island, a five-minute boat ride from Oban, has been cleared of predators, and many rare birds have been reintroduced there. Kakas are present, and while I only saw a few of them far up in the trees while I was there, I saw plenty of evidence of their activity in the form of tree damage. Many trees had places where bark had been stripped off by kaka.
Unfortunately, I saw no kiwis, which are present on the island. Stewart Island is one of the few places were one has a decent chance of spotting a kiwi in the wild, since the kiwis there will forage in the daytime, shortly after the sun rises and before the sun sets. Most other kiwis are completely nocturnal. At any rate, I managed to see many kakariki, which were, of course, on my “must see” list. More on them and the other birds on Ulva Island next issue!
Diamond, J., and Bond, A. B. 2004. Social play in kaka (Nestor meridionalis) with comparisons to kea (Nestor notabilis). Behaviour 141: 777-778.
Habitat: Native New Zealand forest on the North Island, the South Island, and Stewart Island. They are also common on many small offshore islands, such as Kapiti Island, Little Barrier Island, Tiritiri Matangi Island, and Ulva Island.
Conservation Status: Populations have declined on the mainland since European settlement. Deforestation and the introduction of non-native predators are primarily responsible for the species declined. Introduced possums and wasps also compete with kaka for food. Overall, the species is considered vulnerable.
Breeding Habits: Kakas breed from September to March. As is the case with most parrots, they use holes in tree trucks as nests. Kakas will often enlarge the holes. The female incubates the eggs for three weeks and she only leaves the nest twice daily to be fed by the male. Chicks fledge 9-10 weeks after hatching, and they are fed for another week afterwards.
Other Habits: Outside the breeding season, they live in small, loose flocks of up to ten birds. Some kakas on islands such as Kapiti are very bold and will approach people readily.