My interest in this subject is fairly new as I thought I was doing the right thing with my birds - they were breeding and I’d overcome the air-sac mite problem that that plagued the female.  The juveniles, who shared the aviary with the adults, had almost completed colouring up but it was the parents that worried me.  In mid-April the adults abandoned their latest nest and over the next week or so started to look dreadful - the male could barely flutter from the ground, which in my aviary can mean death because of the ants that scavenge in there.  What I subsequently found out about Gouldians I thought I’d share.

Figure 1.  Juvenile Gouldians entering their first adult moult. Photo from Birdcare.

Gouldians are not hard to breed but are none-the-less expensive birds to buy no matter where you live and the question has to be asked why?  Obviously their beautiful colour is only gained at maturity and interestingly this moult is said to be simultaneous for all cohorts so that juveniles (Figure 1) assume adult plumage at this time too regardless of when they fledged whereas in other Australian finches this occurs at around 6-10 weeks of age.  I have however seen juveniles in the Philippines go through the adult moult from May to September so the issue is more complex than some believe.

Unfortunately for both captive and wild Gouldians it appears that moulting is a very stressful event and keeping a bird for up almost a year only to lose it before sale helps keep the price up and adds to their mystique.  Something has gone wrong with Gouldian reproduction in the wild since the late 1970s with a dramatic decline numbers that is almost certainly due to human intervention.  It is likely that changes in the frequency of fires and foraging by introduced animals which has somehow affected the availability and quality of feed available to these birds (1,3) and this is the focus of the Save The Gouldian Fund’s research (4).

 Unlike other native finches of the northern Australian grasslands, Gouldian finches appear not to undergo a seasonal conditioning prior to moulting which coincides with the start of the wet season - before any of the perennial grasses, which they depend on, for food have produced seed (1).  According to Sarah Pryke (pers. comm.. 2008), a prominent researcher of wild Gouldians, the seasonal lack of seed is overcome by other finches by switching to an insect rich diet.  As occurs in the Philippines just before the start of the wet season, alate termites (the winged breeding caste) swam in the face of stormy weather.  Dr Pryke has noted that in mixed Gouldian and shaft-tail finch flocks the later species feasts on the fat and protein rich insects while the Gouldians remain disinterested.  As a consequence the populations of shaft-tails are presently increasing and the Gouldians declining in the wild. 

Figure 2.  Seasonal calendar for northern Australia.  Illustration and further reading from the Department of Environment (8).

The climate of the northern Australian topical savannah, illustrated in Figure 2 is counter-seasonal to the Philippines.  In the Philippines Gouldian moulting occurs in April-May whereas in their home territory it occurs in October-November.  In the wild, nesting occurs from February to October while they are in the hilly country and after the start of wet-season, they fly down to the low-land drainage areas to eat the seeds of perennial grasses.  The Eucalypt woodlands in the hills are also where they nest.  Historically these savannah woodlands have provided a plentiful supply of spear grass (a native sorghum) and the birds are able to drink at small rocky waterholes in the dry watercourses until the rains come.  The transition period from dry to wet seasons has, at least in the last ten years, proved is a lean time with little food and that coincides with theri annual moult so the birds become extremely stressed.  From about mid-December, once the wet season started, the Gouldians move from the hills into lowland drainages where they feed on the seeds of perennial grasses . 

Unfortunately no base-line data was collected before the Gouldian decline to prove that this the present seasonal decline in food and body condition was always the case.  Moulting is obviously is an extremely stressful time for the birds and as might be expected populations have ceased to breed but this occurs at a time when there is little seed and so, at least in modern times, many birds perish.  While this probably reduces completion prior to the plentiful months from February through to October when breeding occurs (3) it does seem unusual given the large flocks that used to occur right up until the 1970s.  Another unusual observation mentioned by Dr Pryke is that in the wild Gouldian’s seldom live beyond 2 years of age.  Just what combination of factors has tipped the Gouldian towards extinction in the wild is unknown but there are other co-occurring factors that further weaken the birds. Mites appear to prefer Gouldians over other wild birds (1, 6) but that may be because they are already weakened.

 Getting back to moulting, some authors recommend strong intervention with expensive propriety blends of vitamins and minerals (2) while others don’t even bother to mention that there is a problem (7).  Certainly my birds have just about recovered but in the wild I’m sure that they would not have survived.  In retrospect I can see that I probably shouldn’t allowed nesting from March to mid-May but I believe that the answer is more complex than that.  There was certainly no lean period in my aviary and maybe I could worm them more often but no other species suffered like the adult gouldians - not even their own young.  If anyone has some thoughts on this matter I’d really like to hear.  In the mantime I eagerly await the outcomes of research sponsored by the Save the Gouldian Fund and others.  Avicultural populations are the last stronghold of the Gouldian which has an estimated remaining wild population of only about 2500 (3, 4) birds and is still in decline.  The research facility funded by the Save the Gouldian Fund in NSW alone holds around 1500 captive bred individuals, so if anyone ever tells you that keeping and breeding birds is wrong you might try to educate them and dispel their ignorant anthropomorphic views.

 References

1 http://www.nt.gov.au/nreta/wildlife/programs/gouldian/theory.html

2 www.ladygouldianfinch.com

3 http://mygouldianaviary.tripod.com/sitebuildercontent/sitebuilderfiles/gouldianrecovery.pdf

4 http://users.skynet.be/fa398872/ensave02.htm 

5 http://www.savethegouldian.org/plea.htm

6 http://www.publish.csiro.au/paper/WR9960675.htm

7 http://www.efinch.com/species/gould.htm

8 http://www.environment.gov.au/parks/kakadu/nature-science/seasons.html