5. elokuuta 2022

Please Collect Gang-gang Feathers for Genetic Research

This project aims to better understand the population genetics of Gang-gang Cockatoos iacross their range through feather collection.

Feathers contain genetic information unique to an individual. They provide insights into the biology and ecology of birds that are otherwise challenging to sample, and in a way that is not intrusive.

By learning about the genetic variability of Gang-gangs, we can estimate their ‘effective population size’. Knowing the population size of a species, and monitoring changes to this over time, can directly inform planning and implementing conservation actions. Genetic information extracted from Gang-gang feathers may also provide insights into their habitat use, mating systems and conservation status across their range.

To see how you can help go to

https://www.environment.act.gov.au/nature-conservation/conservation-and-ecological-communities/gang-gang-cockatoo-feather-collection-project#:~:text=This%20project%20aims%20to%20better,information%20unique%20to%20an%20individual.

Lähetetty 5. elokuuta 2022 01:12 käyttäjältä michaelmulvaney michaelmulvaney | 2 kommenttia | Jätä kommentti

30. heinäkuuta 2022

Please look out for Mrs Long-beak Gang-gang in the Canberra area

We learnt a lot about Gang-gang movements from citizen science reported sightings of "Baldy" a male Gang-gang with a distinctively damaged crest, who was raising two chicks in Canberra bushland. Baldy has now nearly fully grown back his crest and is now not so distinctive. However, we have another noticeable Gang-gang for you to look out for and please report. She has a mishappen beak which looks like a very long uncut finger nail. She has been reported from South Canberra but may breed elsewhere.

https://canberra.naturemapr.org/sightings/4439813#Comments

Thanks Michael Mulvaney

Lähetetty 30. heinäkuuta 2022 21:41 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

23. heinäkuuta 2022

Summary of this season's Gang-gang tree hollow research findings

Thanks to the many of you that contributed to the Gang-gang nest hollow project. In total we have now identified 60 nests (52 in Canberra, 2 in Campbelltown, 2 in Wombat State forest (Vic) and one near or in Moruya, Cooma, Tumbarumba and East Melbourne). We continue to learn much about Gang-gang nesting ecology and behaviour. We have 5 years of good data from Canberra but would like to compare what we are finding here with that elsewhere. Gang-gang hollow checking is increasing as we approach breeding season and we ask that you keep posting sightings of where you observe Gangs-gangs looking into hollows, but particularly in remote or rural areas away from Canberra .

Highlights of last season’s research include

  • A further 25 nest hollows were identified across much of the Gang-gang's range. Hollow dimension data has been collected from most of the hollows as has fledging success rate, fledging sex ratio (0.7 females to 1male) and timing of fledging. A significant relationship was found between fledge time and altitude. Low altitude sites, such as Campbelltown (50m) may have a breeding period 2 months in advance of that at high altitude locations, like Cooma (1000m).
  • 216 of hollows, in the Canberra, Cooma and Tumbarumba areas, that were of interest to Gang-gangs were closely monitored. Of these we found:

46% empty
9% Gang-gang nest hollow
10% empty but with chewed bark
12% Brushtailed Possum
5% leaf-lined suggesting possum or perhaps Galah use
9% Flooded (Gang-gang water source)
4% Bees
3% Australian Wood Duck
3% Sulphur-crested Cockatoo
1% Galah
1% Crimson Rosella, Boobook Owl

These results possibly suggest that at least in the Canberra area hollows are not a limiting factor and that competition from other hollow nesting such as cockatoos and parrots is not a major factor. There is an on-going project in Canberra to help determine whether sites are limiting. Brushtail Possums are the major hollow competitor. The rate of predation is unknown but the project confirmed Brushtail Possums as a significant predator of eggs and chicks.

  • At least some Gang-gang pairs will prepare multiple hollows before choosing one as a nest. Gang-gangs line their nests with bark chips of a distinctive shape and size. They appear to be choosing nest hollows on the basis of climate experienced. In Canberra, in two hot, dry years, no hollow bearing dead trees were utilised while in the two most recent wet and cooler years, 6 hollow bearing dead trees were utilised. The clutches raised in the hot/dry and wet/cool years were similar (26 and 32 respectively).
  • Only about a third of previously used nest hollows are used in any one year, but if a hollow is used one year there is a 50% chance of it being used the next.
  • With the help of the ACT Government nest hollow dimensions have been measured and used to guide nest tube design. The nest tubes are currently being trialled as part of another project. With the Canberra nest hollows, the average height in a tree is 6.5m (range 2.5 - 10m). The average hollow entrance dimensions are height 22.4cm, width 15.2cm; largest breeding entrance measured is 39 x 24 cms The smallest breeding hollow entrance is 10 x 7 cms. The average floor diameter is 20cm (range 12- 33cm).
  • It is problematic to attach trackers and bands to Gang-Gangs so this has never happened. Consequently, little is known about their movement. One of our hollow observers (thanks Cath) alerted us to a male raising two chicks that had considerable crest damage and was easily recognisable. We put the call out for "Baldy" sightings and received sightings at 7 different locations. Four of these were during the breeding season. The furthest from the nest was 3.89km, where Baldy was foraging on Red Stringybark nuts, so this is the distance that we now know a Gang-gang raising chicks will at least travel to forage.
  • Baldy also made repeated visits to a residence about 700m from the nest where he fed on Sunflower seeds. Caged Gang-gangs are known to suffer infertility and other health issues when largely fed on a sunflower seed diet. The impact of sunflowers in the diet of wild birds is unknown, but the project has highlighted it as a potential issue.
Lähetetty 23. heinäkuuta 2022 00:17 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

21. tammikuuta 2022

Citizen Science rescues Gang-gang chicks

One of the advantages of citizens monitoring the activity at Gang-gang nest hollows is that chicks that fall out of the hollow can be placed back before they are predated by cats, foxes or birds like the Australian Raven. About a week prior to fledging gang-gang parents will entice chicks to the entrance of their usually 50cm deep hollow by only feeding them there. Sometimes the structure of the hollow entrance make it precarious for the Gang-gang chicks to perch there. This is exacerbated at feeding times where beak to beak contact by a parent can be quite forceful. Thus chicks occasionally fall or are knocked off their hollow rim perch prior to their wings being fully developed. We also suspect that extreme heat and/or smoke leads to a greater number of premature nest departures. On four occasions tree hollow watchers have discovered fallen chicks at the base of nest trees. At one site Government authorities didn’t allow a tree to be climbed but at the three locations where chicks could be replaced they have been quickly cared for by parent birds and successfully fledged. This includes one chick that spent a night at a local vets, separated from parents, but on reunion was immediately cared for by the parents. An added bonus of our study, and also guidance as to what to do if you come across a fallen chick.

To recap if you find a chick on the ground, best to put back into the hollow as soon as possible. If it can’t be put in the hollow place up as high as you can away from predators and with some leaf or branch protection from the elements. Don’t remove unless you absolutely have to.

Lähetetty 21. tammikuuta 2022 23:07 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

20. joulukuuta 2021

Hollow occupancy suggests Brushtail Possums may be a greater concern than nesting bird competitors

Over the last three years citizens have made over 500 image based reports of Gang-gang activity at tree hollows. Thank you, to all those who reported sightings. Trees with multiple records or where Gang-gangs were observed entering or leaving hollows were prioritised for checking. The occupancy of hollows during this Gang-gang breeding season was initially checked by visible observation and if no activity was observed then with a pole camera. To date, one Hundred and ninety hollows of known Gang-gang interest were checked in the Canberra area, fifteen at Cooma and four at Tumbarumba.

The following are the initial results

1 Hollows empty – 109 (52%)

  1. Gang-gang nest hollow – 22 (11%) note two nests seem to be no longer active
  2. Flooded (hollow a likely water source) - 19 (9%)
  3. Brushtail Possum in hollow - 18 (9%)
  4. Hollow lined with many gum-leaves suggesting possum use - 12 (6%)
  5. Now a bee-hive -6 (3%)
  6. Galah nest hollow – 6(3%)
  7. Wood-duck eggs or eggshell in hollow 5 (2%) – woodducks have an earlier breeding season and sometimes woodducks and Gang-gangs can use the same hollow within a year
  8. Sulphur-crested Cockatoo nest hollow 4 (2%)
  9. Crimson Rosella nest hollow 1
  10. Rainbow Lorikeet nest hollow 1
  11. Kookaburra nest hollow 1
  12. Boobook Owl roost/nest hollow 1

At least eight of the empty hollows were known Gang-gang nest hollows in previous years. At least three previous nest hollows were flooded this season. Over half of the hollows in which Gang-gangs were observed entering, leaving, chewing bark around or looking into, were empty. Galahs, Sulphur Crested Cockatoos, Rainbow lorikeets and Corellas have all been suspected as being significant competitors of Gang-gangs for nesting hollows, but between them they only occupied 5% of the inspected hollows.

Brushtail possums were observed in 9% of the hollows, with evidence of possum use found in a further 6% of hollows. No Gang-gang nests were found in trees in which Brush-tail Possums were observed but on a few occasions Gangs-gangs were found nesting in the same tree as Sulphur Crested Cockatoos.

Once completed and nest images checked the results will be subject to further analysis, but your work is already providing valuable insights. It is hoped that the Canberra results (were the Gang-gang population is steady) will be compared to that of areas where they have suffered significant and drastic declines – so please keep those tree hollow activity records flowing in.

Lähetetty 20. joulukuuta 2021 19:55 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

18. joulukuuta 2021

Gang-gang Hollow Search study already yielding results.

Thanks to Katie, Chris, Matt, Amber and Susan for their identification and monitoring of nests in Campbelltown and Moruya where Gang-gang chicks have already fledged. This is about 4-6 weeks ahead of the nesting occurring in the twenty observed nests in the Canberra area and one in Cooma (thanks Ange). In terms of the Gang-Gangs total range, Campbelltown and Moruya are at the higher latitude and or lower altitude parts of this range. Thus they achieve higher temperatures than most areas in which Gang-gangs occur.

Peter and Judy Smith in their 2018 Gang-gang survey of Hornsby Shire, (https://www.researchgate.net/publication/340599663), failed to record any Gang-gangs in areas where from 1970-2010 they were commonly sighted. They concluded that Gang-gangs in the Hornsby and Ku-ring-gai Local Government Areas are certainly very close to extinction if not already extinct. They noted that a similar decline had occurred within a 20km radius of their study area and at the lower elevations of the Blue Mountains. They proposed that this pattern of decline suggests a climate change effect. They noted that the Gang-gang is adapted to cooler conditions and has always been more common at higher elevations and more southern latitudes. They hypothesized that as the climate warms up, Gang-gang Cockatoos can be expected to decline at lower elevations in the northern parts of their distribution.

A result of our citizen science study suggests that Gangs-gangs in at least part of the northern lower elevation range may be able to avoid the higher summer temperatures by breeding earlier than more elevated or southern birds. This is a hopeful finding, that will need further investigation.

Some of you are also watching nests in Tumbarumba, on the outskirts of Melbourne and in western Victoria – none of which appear yet to have produced fledglings. Fingers crossed you will be able to observe fledglings and you will add to our knowledge of breeding times across the Gang-gangs range. Now that there is a large band of us looking for nests, we can expect that next season we will have the range well covered.

In addition to climate, the Smith’s mentioned other factors that may be contributing to the decline including competition with other species for nest hollows (particularly the over-abundant Sulphur-crested Cockatoos and Rainbow Lorikeets). Our study is also throwing light on this issue – but reporting of these initial results is for the next Journal report.

Lähetetty 18. joulukuuta 2021 20:20 käyttäjältä michaelmulvaney michaelmulvaney | 2 kommenttia | Jätä kommentti

29. marraskuuta 2021

Our first Gang-gang chick emerges

Thank you to all 51 of you that have contributed Gang-gang hollow activity images to this project. We have our first sighting of a chick by Katie O'Connor in Campbelltown.
https://www.inaturalist.org/observations/102051305

Well done Katie. The white bill is a good indicator of a young bird. We are not sure how long the greying process takes but it is at least weeks and probably months. Sometimes there is confusion when youngish looking birds are reported as new chicks. The presence of a white bill or not is a good way to cross-check such claims.

Given Katie's great observation it would be good for all to check the hollows they are watching over the next few days. However we have 12 identified active nests in the Canberra area and some of those have only just laid eggs and chicks won't appear till towards the end of January and our earliest is expected around Christmas. Will be interesting to see whether all Campbelltown pairs are early breeders (which may aid their survival as they will miss the higher temperatures of mid -late summer. We suspect that in 2019-2020 we lost two chicks in Canberra to heat exhaustion while they were still in the hollow). We are still checking potential nests that people have alerted us to and expect to find between 15-20 nests. So far we have checked about 100 hollows for our 12 nests and many nests of known Gang-gang interest are empty (even of potential competitors such as sulphur crested cockatoos or rainbow lorikeets). Will keep you informed of results and please let us know if you have activity at the hollows you are watching.

Thanks again and particularly to Katie and the Campbelltown crew

Lähetetty 29. marraskuuta 2021 20:48 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

19. lokakuuta 2021

Eurobodalla nest-tube project

Some of you are involved in the Eurobodalla nest tube project. Nest-tubes are being placed near known or likely hollows as Gang-gangs appear to like nesting near each other. In addition the entrance and depth measurements from any new hollows that you help find will help refine future nest tube design.

You can read more about the nest tube project at
https://www.naroomanewsonline.com.au/story/7475273/gang-up-to-save-special-cockatoo/?cs=12

We have our first birds on eggs in Canberra and Campbelltown and it is likely that most pairs will commence nesting within the next two weeks. Gang-gang activity will slow down during this period with birds being less noticeable for the next 5-7 weeks or so.

Cheers Michael Mulvaney

Lähetetty 19. lokakuuta 2021 20:34 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti

22. syyskuuta 2021

Gang-gang nesting tell tale behaviours

Covid lockdowns are making it difficult to visit hollows with pole cameras. Should be ok for sites on the NSW South Coast, Campbeltown City Council and the ACT where local arrangements are being put in place, but for others a site visit may have to wait till next season. Nevertheless you can confirm sites purely by observation and below is a list of behaviour and signs to look out for, according to particular nesting stages. If you capture any of these behaviours at your hollow site in an image I would appreciate you posting it on INaturalist.

thanks Michael Mulvaney

ONE - Checking out and selecting a nesting site (September-Early October)
Gang-gangs peer into hollows all year round and will enter hollows to access pooled water. It appears that a Gang-gang pair will have multiple hollows of interest and that in the Canberra area they are most active around hollows they are examining as potential nest sites in mid to late September. Hollow selection appears to take some time and may relate to weather conditions and presence of predators, such as possums. In the four years of study, three years have been hot and dry and all selected hollows found were in the main trunk or a primary branch of a live tree. Last year was wet and cool in comparison and for the first time we found nesting hollows in dead/near dead trees and in smaller spouts.

During this stage Gang-gangs are easy to see anytime during the day, are sometimes quite noisy and need to fight off other bird species and compete with possums for the hollows; these encounters can be very noisy. Some other birds, which seem to challenge for the hollows are sulphur crested cockatoos, rainbow lorikeets and galahs.

Behaviours/signs to look out for
• Both partners of a pair entering a hollow (usually not at the same time)
• Multiple visits by a pair to the same hollow over multiple days (visits may be less than a minute)
• Chewing of bark around or near a hollow. (Gangs-gangs lay their eggs on about 2-3 cm of chewed bark. Gang-gangs do not line their nest with leaves).
• Multiple pairs in the same vicinity (within a few hundred meters) – Gang-gangs tend to nest close to each other.
• Wood duck feathers around hollow entrance. Wood ducks are early season nesters. Gang-gangs and wood ducks can use the same hollow in the same year.
• Gang-gang pair driving other birds away from a hollow.
• If Gang-gangs are calling loudly or “growling” down a hollow, with raised wings, it means that the hollow is probably occupied by a threatening animal such as a brushtail possum or boobook owl.

TWO - Incubation (October –Early November)
The female spends the night on eggs, while during the day the male and female share incubation responsibilities. Thus there is always one bird in the nest. Incubation takes about 4 weeks. There is very little activity at all around the hollow and this may involve as little as two nest sitting change-overs in a day. Change-overs can be quick and easily missed. The non-nesting bird spends very little time around the nest site. In Canberra most incubation begins mid-October but it can occur well into November. At least one pair has also switched hollows early in the season and begun again at a new site. This may have been in response to possum visitation.

Behaviours/signs to look out for
• Male or female seen sitting inside and on the edge of the hollow, looking out.
• Change-over. The incoming Gang-gang gives a very small call on the way in which gives the one on the egg(s) time to be prepared. It then comes in and changeover occurs. During this period the Gang gangs are very quite, changeover happens in a matter of minutes. Best time to observe an incubation changeover is within the hour after dawn when the female leaves or in the evening when the females takes on night duties. Change-overs can occur at any time of the day.
• There is little Gang-gang activity around hollow

THREE - Hatched chicks
The female continues to spend the night on the nest. Both partners feed chicks during the day, but initially only a few feeding visits are made each day. Young leave the nest about eight weeks after hatching.

Behaviours/signs to look out for
• Female leaving or entering hollow at times other than early morning or late evening.
• The Gang gangs appear to be happy to be away from eggs/young chicks for longer periods at changeover and the frequency of changeover increases, to at least a few times a day.
• Chicks chirping from inside hollow can sometimes be heard and you may also hear them being fed.
• Both partners visiting hollow during the day and may leave hollow together. Other Gang-gang couples may accompany a returning adult and be present during change-over. These birds may help “guard” the hollow when both adults are away. A Gang-gang pair or individual looking into a hollow may not be the parent but they will not be seen entering the hollow.
• Adult birds driving other birds away from hollow. Note adult birds from other nearby nests will drive other species like lorikeets and Sulphur Crested Cockatoos away from a neighbours nest.
• Birds calling to and joining other nearby nesting Gang-gangs on foraging flights
• As the chicks grow both parents are required for feeding with frequent feeding happening every hour or two.

FOUR - Fledging
The average depth of a Gang-gang hollow in Canberra is about 50cm. When birds are getting near fledgling, parents encourage the chicks to climb to the hollow entrance by feeding them there. Chicks will stay perched at the hollow entrance and are visible over a 3-11 day period, just prior to fledging. The average is 7 days per chick. Longer visibility times usually involve multiple chicks. Thus the window in which a nest hollow can be confirmed purely by observation is short. In Canberra most chicks are first observed between Christmas and 15 January but has occurred from 8 December to 26 February. Time from laying to fledging varies from 61 to 79 days.
Behaviours/signs to look out for
• Chicks chirping from inside hollow can sometimes be heard
• Parents perched on hollow with head in hollow, body or at least head rocking rapidly
• Heads of chicks appearing above hollow entrance. Gang-gangs usually have between 1-3 chicks per nest with two being the most common. Chicks can develop at different rates so not all may be visible at one time. Thus determining the number and gender of chicks at a nest hollow should include multiple visits – preferably two a day once chicks are visible.
• In Canberra during the days of record temperatures and smoky air of the 2019/2020 season, we had chicks leaving the nest prematurely and falling helplessly to the ground. Where these chicks (two occasions) were replaced back into a hollow (by a volunteer climber) they were cared for by parents and successfully fledged. On the one occasion where a chick couldn’t be replaced it was predated.
• If a chick falls to the ground the adults will continue to feed it so do not disturb unless there is the possibility of predation. If a climber is available then placing it back in the hollow is best.

• Both Gang gangs are present at fledging, seemingly encouraging the young to leave the hollow through calling, being close by, making repeated short flights from the hollow and if the young followed rewarding them with food. This process can take a number of days.
• The fledged chick will fly to a nearby tree, where both parents will then preen and feed the chick.
• Chicks do not return to a hollow once fledged.
• The newly fledged chicks in the area tend to form creches for a while and a large number of chicks can be seen together at times.

Lähetetty 22. syyskuuta 2021 23:58 käyttäjältä michaelmulvaney michaelmulvaney | 3 kommenttia | Jätä kommentti

15. syyskuuta 2021

Some project background and aims

Thank you all for joining the Gang-gang nests (tree hollows) project and contributing records that help us better understand this species. September is the month when Gang-gangs are most actively checking out the real estate before deciding on a hollow in which to nest. So please keep your eyes and ears open and report any hollow activity. Gangs-gangs are quite fussy in the hollows they will use. Hollow measurements from our Canberra study are

• Average height above ground = 7.5m
• Height range 5m – 9.4m
• Average hollow depth = 50.5cm
• Hollow depth range 22cm – 90cm
• Average entrance width = 13.1cm
• Range in entrance width 9cm – 20cm
• Average entrance height = 21.3cm
• Range in entrance width 12cm – 24cm
These measurements have been utilised in a design of a nest tube, about to be trialled but modelled on a successful Glossy Black Cockatoo nesting tube program on Kangaroo Island. One of the aims of this project is to check how hollow selection may vary across the Gang-gangs range and use any variation to refine the nest tube design.

We also hope that the data that you provide to this project can also test conclusions from the Canberra study that Gang-gangs tend to nest close to each other and that only around 30% of hollows will be reused in a subsequent year.

Because Gang-gangs like to nest within hundreds of metres of each other, local populations are probably reliant on having stands of suitable hollow bearing trees. This and the low re-usage rates exacerbates what is thought to a severe shortage of hollows.

Observations of the hollows of Gang-gang interest, identified in this project, will provide an indication of who else is interested in the same hollows and what this competition may mean for the Gang-gang. Once in a hollow Gang-gangs seem able to hold their own and avoid eviction by competitor species. However, of the 24 hollows utilised by nesting Gang-gangs that we have observed for more than two breeding seasons, some of these hollows have been utilised in subsequent years by Rainbow Lorikeets, Eastern Rosella, Starling, Galah, Australian Wood Duck, Brushtail Possum and Ringtail Possum.

Will be great to get more data from across the Gang-gangs range to see how consistent these findings are and to help develop measures to better conserve this heart-warming species.

Thanks you again for your contribution.

Michael Mulvaney

Lähetetty 15. syyskuuta 2021 05:46 käyttäjältä michaelmulvaney michaelmulvaney | 0 kommenttia | Jätä kommentti