CONSERVATION OF RARE AUSTRALIAN COCKATOOS

Major Mitchell's Cockatoo

As with many species of birds and animals throughout the world, loss of habitat and competition from other more adaptive species and the general influence of Man on the fine balance of the natural world, is potentially putting them at risk of extinction.  We therefore must consider it our duty to help protect them in any way we can. One such method is by ensuring the young from established pairs are kept safe during the very important and vulnerable stages of rearing.

It was during a bush tour of New South Wales and Victoria, Australia, in the early 1990's, which was organised and directed by Ray Ackroyd, a licensed trapper, that he informed members of the Parrot Society UK, namely John Mollindinia and Tom Alston, whom were present on this particular tour, that one of the problems encountered by the Major Mitchell’s Cockatoos (Cacatua Leadbeateri), as it had been noted that not many were present, was the predation of active nesting sites by Goannas, a large monitor lizard, which would climb the tree trunk, enter the nest hole and steal the eggs or chicks, whichever happened to be present.

Goannas are a species of Monitor Lizard, the particular trouble maker being the Lace Monitor (Varanus Varius), which is the second largest of its group, growing to 2 meters in length and weighing as much as 20kg. They forage over long distances, covering up to 3 km a day feeding on insects, carrion, smaller reptiles, mammals and birds.

Major Mitchell’s Cockatoos prefer lower nesting sites than other birds and particular types of trees known as Mallee trees (this refers to the way in which they grow rather than the species), which seldom grow more than 10 metres in height. This behaviour makes them more vulnerable to attack by ground dwellers that have the ability to climb.

It was during this tour that Ray and John discussed what could be done to prevent the ‘raiding’ of the nesting sites by this method, thus helping the Major Mitchell’s survival rates. Ray came up with the idea of placing a sheet of Tin around the tree trunk below the nest hole preventing the predator reaching the nest hole. Ray agreed to trial this idea in a certain area whilst monitoring the population, particularly young birds the following season. The results came back very encouraging, with the local population figures for the Major Mitchell's increased!

Tinned Tree

A typical tree with the Tin Band around the main trunk

Whilst Ray began his trial project, John returned to the UK and proposed to the Parrot Society UK Council, that if the results were good, that we should support Ray in his activities by covering the expenses incurred as Ray lives in the Blue Mountains, near Sydney, thus lots of travelling would be required to get to the areas where the Major Mitchell's nested and often in places that had no proper road access. The Parrot Society UK (PSUK) took up this mantle and supported Ray in his activities, with immediate results.

When John Mollindinia died in 2001, the PSUK not only elected to continue to support the project but honour John as the instigator to what can be considered a great success story, by placing a plaque on an active tree, a Curly Mallee (Eucalyptus gillii), within the Tandau farm located several hundred kilometres north of Sydney. This tree is now maintained by the farm estate and still has an active pair of Major Mitchell's Cockatoos using it every season.

Ray Ackroyd at John's Tree

John Mollindinia Memorial Plaque

Ray Ackroyd at John's Tree and details written on John's memorial palque

It is estimated that since this particular tree or John’s Tree as it is more affectionately known, was tinned, over 30 chicks have been successfully raised in it.

Following the initial idea by Ray and John, the PSUK now support Ray in the ‘Tinning’ of many trees, in our continued bid to maintain the population of the Major Mitchell’s Cockatoo.

During the early part of 2013, the PSUK has learned that the South Australian government is actively supporting the conservation of rare Cockatoos, by offering land owners A$500 for every tree they tin which has been chosen as a nest site by the equally rare and challenged Red Tailed Black Cockatoo (Calyptorhynchus Banksii).  In addition the State of Victoria has requested Ray to assist in a campaign to help promote the conservation of the Major Mitchell’s Cockatoo.  This project has been awarded A$10,000 and will involve the assistance of school children reporting the location of an active nesting site of the Rare cockatoos, for which they will receive A$100.  To assist the children, Ray has written a guide, which can be seen at the end of this article.

Tempy Primary School Children Celebrating

Tempy Primary School Children Celebrating the grant award, adn who will be taking part in the spot and report a tree campaign, using Ray's guide for assistance.

 

The ‘tinning’ procedure – we are now looking into a more aesthetic clear plastic solution – is also being adopted by other conservation groups to help other species who’s nests are also being predated by Goannas, Feral Cats, foxes etc.

Plastic version of trunk protection

Ray Ackroyd has written a guide fto help the school children involved in the 'spotting' project 

NESTING OF MAJOR MITCHELL'S COCKATOOS IN THE WILD

Do Major Mitchell's cockatoos mate for life?

Yes they do and can nest together for up to 50 years.

If one bird dies or gets killed does the remaining bird seek out a new mate?

Yes

What type of tree do Major Mitchell's nest in?

Dry gum trees and Cypress Pine that is alive or dry.

What time of year to Major Mitchell's go to nest?

Late August to early September.

Do they pick out a special tree?

Yes they do: usually on a sand ridge or in open country away from other trees.  They like to be able to see what is going on around them. It iss a precautionary thing so that they can identify any predators including mankind.

Do Major Mitchell's Cockatoos nest in big trees?

Not really. Some may pick out a dry Cypress Pine tree that has no top or a broken limb that has left a hollow. Some trees are small and nests that are 5 metres from the ground are common.

Do Major Mitchell's like a special entrance to their nests?

Yes they do.  Major Mitchell’s like an entrance to their nest that is shaped like an upturned canoe.

* Note – it is important to know that when looking for nests.

Do Major Mitchell's take long to prepare their nesting site?

No they don't. Both birds go into the nest chamber and pare off small chips of wood to form a soft base to lay their clutch of eggs. This usually takes only a few days to prepare.

How far down from the entrance do Major Mitchell's lay their clutch of eggs?

That can vary but usually about ½ a metre.

How many eggs do Major Mitchell's lay each year?

Depending on the season. If it’s a good year with lots of herbage on the ground they will lay up to four eggs. However the norm is three eggs.

How long is the incubation period or how long does it take to hatch from egg to chick?

28 days.

Who sits on the eggs?

They take turns. The Cock may sit during the day and the Hen at night or vice versa.

Is it easy to find the nest of Major Mitchell's Cockatoos?

No it isn’t easy. They are very secretive birds when nesting and can hear footsteps approaching a long way from the nest tree.

When is the best time to find a Major Mitchell's Nest?

When they are on eggs or have small young. Before or after that time is difficult.

Note- It is important to note that Major Mitchell’s return to the same nest site every year and will continue to do that unless the tree is lost to fire or habitat-loss through logging.

How can I study a nest once I have found it?

Walk slowly toward the tree and identify the nest entrance. You must walk very quietly or he or she will leave the nest and not return until you have gone. The best way to study a nest is to build a hide just away from the tree and wait and watch.  At no time should you disturb the nesting procedure.

If Major Mitchell's lose their nesting tree because of fire or land clearings do they leave that area?

No they don't. Usually they try and select a new nest site in the same area. It may not be the same type of tree, so if a nest is lost look for the new site and it should be found within a half kilometre.

How long do the young stay in the nest?

Approximately seven weeks. When the parents want the fledged babies to leave the nest they will encourage their young to climb up to the nest entrance and feed them there. This is an extremely dangerous time, when predators will attack the young and the parent birds become very aware of that.

Are Major Mitchell's Cockatoos reliable breeders?

Most certainly. Almost all Major Mitchell’s return to the same tree every year. Usually around mid August.

What is the average clutch size of nesting Major Mitchell's?

Average: 2.5 some raise 2, most raise 3 and 4 is not unusual.

How far do Major Mitchell's Cockatoos fly from their nesting site in the off season?

Up to 300 kilometres.

How long do the baby birds stay with the parents after leaving the nest?

Approximately six weeks then they join together into a small flock.

How long before young birds can breed themselves?

Three years.

If Major Mitchell's are such good and reliable breeders in the wild, why then isn't the overall population increasing?

Good question.

 

Are baby Major Mitchell's noisy feeders when being fed in the nest and can that noise be heard from a distance?

Good question! Yes they are noisy feeders and that is to their detriment.The major predators are Goannas which each year kill large numbers of baby Major Mitchell's and in the early part of the season also take the eggs.Goannas bite into and suck out the contents of the eggs.If the Hen Cockatoo lays a second clutch, the Goanna will usually return for a second time.It is important to note that Goannas know that Major Mitchell's return to the same nest each year so immediately they come out of hibernation they do the yearly rounds of the nests.

Other predators at the nests are feral cats, possums and foxes, once the baby Major Mitchell's leave the nest and at this early age are unsure of predators.

Is it possible to prevent predators from attacking the nests of Major Mitchell's Cockatoos?

Most certainly:The most effective method of preventing predators from climbing nest trees is to attach a collar around the tree with the base of the collar one metre from the ground.

What is the collar made of?

Smooth galvanized tin or heavy duty plastic.Both need to be one metre wide and can be cut to size and nailed around the tree.

This method has proven to be fully successful.The tin or clear plastic is very slippery and doesn’t allow the predator to climb the tree.

Research has shown that where Major Mitchell's nesting trees were collared up, not one nest was lost to predators.

Very successful deterrent to protect nests, who thought of that?

During October 1990 an elderly English birdman from the English Parrot Society (sic = PSUK), Mr John Mollindinia, conducted a study on Major Mitchell's Cockatoos in Western NSW.This study clearly indicated that almost 80% of these Cockatoos’ nests were taken by predators that climbed the nest trees from the ground.

On his return to England following his study he indicated to the English Parrot Society (PSUK) that it should fund a trial project to protect the nesting trees of the Major Mitchell’s Cockatoos in Western NSW.

That could be achieved by placing a smooth tin or plastic collar around the trunk of each nest tree making it impossible for predators to climb to the nest.

That trial project set the benchmark for tinning trees to species such as Major Mitchell's or Glossy Black Cockatoos to mention just a few.

Since that time a new heavy duty flat plastic is now available and has proven to be an upgrade on tin. Also clear plastic does not stand out and makes it almost impossible for any person to identify the nest tree.  The English Parrot Society (PSUK) is very proud of being able to fund a project to protect one of Australia's most outstanding Cockatoos.  The fund has been ongoing for many years thanks to Mr Mollindinia. The Parrot Society attached a plaque at the base of a Major Mitchell's nesting tree in honour of the late John Mollindinia for his outstanding work.

So how can we find the nests to collar them up and how do we inform the landowners?

Firstly you have to search for the nests when the Major Mitchell's are on eggs or very early young. Following that time they are difficult to find at the nest site. A good pair of binoculars is essential as well as getting out of bed early! Try to get to an elevated spot and watch for the white birds. Once you find a nest you must remember where it is so you can return and collar the tree, provided the landowner agrees.

How do we get this message across to landowners whose properties are the habitat of Major Mitchell’s?

Any coverage by local newspapers and other media is good value. Let them know how important this issue is. Take pictures of any tree protection you are doing and give talks at school meetings.

What about Major Mitchell's Cockatoo nest trees in national parks? Do the managers protect breeding trees?

Most state national parks have their own management strategy.

There is evidence that some parks are constructing artificial nest sites at great expense. Whether these additional nests will attract Major Mitchell's Cockatoos is yet to be clarified.

At this time I do not know of any tree that hosts the nest of Major Mitchell's Cockatoo being protected by way of collars, either tin or plastic in national parks, but it works!

How do you tell the difference between the Cock and Hen Major Mitchell's Cockatoos?

Both birds are the same size:

Cock - has black eye and not as much yellow in the comb (feather crest) as the hen.

Hen - has pink/brown eye and more yellow in comb.

How do you tell the difference between the Eastern race of Major Mitchell's Cockatoo and the Western race called Mollis?

Mollis has a longer crest and upon maturity, ie 3 years, has a comb without yellow.

Do Major Mitchell's Cockatoos fly at great heights when travelling?

No they don't. Major Mitchell's, no matter how far they are going, do not fly at great heights.

In essence Major Mitchell's fly just above tree height and in fact sometimes between trees. I believe the reason is because they are white and are slow flyers compared to other cockatoos. The tree line allows them to identify hawks or eagles that may attack them and escape into that tree line as a form of protection.