An article has appeared in the Blue Mountains Gazette local newspaper dated Wed 29th July 2015 (Page-20) featuring an article by B.C. Lewis wondering why our once abundant population of Gang Gang Cockatoo's is now on a seemingly rapid decline?
The Blue Mountains Bird Observer (BMBO) group has reported that the population of these birds has decreased by up to 70% in the past two decades and cites the huge increase of Sulphur Crested Cockatoo's as possibly the main culprit?
I have noticed fewer Gang Gang Cockatoo's in my area in the Upper Blue Mountains and a huge increase in Sulphur Crested Cockatoo's. It's nothing to see a flock of 20 or more Sulphur Crested Cockatoo's hanging around just after dawn, during the day and around sunset.
The ridiculous thing is many local residents have taken up the pastime of putting seed out for the raucous vandalisitic birds and thus encouraging more of them as word gets around where the free feeds are.
In the past 12 months I have noticed only two or three Gang Gang's at the most, instead of the usual eight to 12 or more that usually hang around here seasonally. However, there is no shortage of the flying sulphur Crested pests.
The house on the corner sold to a Sydney family earlier this year and already they have taken up feeding the Sulphur Crested Cockies with great gusto, it's nothing to see between 10 and 15 birds at their place each evening. The said birds get a very short shift if they arrive here.
A friend further down the mountains at Woodford has also mentioned to me the great number of Sulphur Crested Cockatoo's at his place in the past couple of years or so.
Fortunatley one can still see sizeable flocks of Gang Gang's out at Glen Davis. So, the Sulphur Crested Cockatoo is becoming a menace not only in suburban Sydney but now out west in the Mountains region, why is their population rapidly increasing? And what can we do to make sure they don't force out other native parrots?
As is so often the case it appears human behaviour has a lot to do with changes in bird species numbers. In the case of Gang Gang Cockatoos & Sulphur Crested Cockatoos it seems an education programme is needed to get people to change their behaviour from artificial feeding to habitat improvement. Raven, have you thought of writing to your local paper, letter boxing your neighbourhood or some similar approach?
This issue is particularly important because the Gang Gang Cockatoo distribution is far more restricted than that of the Sulphur Crested Cockatoo. It's also important because artificial feeding will probably lead to many Cockatoos suffering the dreaded beak & feather disease.
I wonder if weed control attempts to eradicate hawthorns, cotoneaster hedges etc., are inadvertently reducing the Gang gang's food resources in lieu of appropriate reveg projects with suitable native foodplants, compounded with habitat destruction of remnant native species.
The local paper, The Blue Mountains Gazette, is very proactive with nature issues and time and time again I have seen letters to the editor regarding the feeding of native birds, especially Sulphur Crested Cockatoo's being a no-no.
The Blue Mountains City Council has been very active in the removal of noxious weeds, especially Privet, Lantana, Willows and Blackberries, amongst others, in the mountains. The council will also issue Landholders a "Notice Of Removal" letter regarding noxious weeds on individual properties seen by council Rangers. (My neighbour got one last February!)
Personally, I think the Sulphur Crested Cockatoo is an over rated Aussie favourite and hence people will keep putting food out for them not realising the detrimental effect it's having on other Australian native parrots, regardless of "professional" well intended advice.
A bit like a previous Forum posting about cats and native birds, good sound logical advice goes in one ear and out of the other, flogging a dead horse I think would be the best description?
Yes but these introduced plant species are for better not worse now integral to the Gang-gang's diet.
I have an uncomfortable suspicion that might actually prefer them to native species but you didn't hear it from me.
I'm surprised at the popularity of the sulphur-crested feeding there. here it is illegal due the property-wrecking propensity of the species.
I lived in the Blue Mts and still visit regularly. I have never seen many gang gangs there, I don't think they like the presence of so many people. I think it is more likely to be humans rather than sulfur cresteds that are driving them away. Though I don't understand why anyone would want to encourage sulfur cresteds.
I have noticed there are more lyre birds these days, I recently saw one on the short cut track at wentworth falls. Also I always hear eastern yellow robins around now and i saw a bassian thrush near the ruined castle.
Zosterops & Raven, is the council encouraging replacement of the feral plants with indigenous vegetation? If not, then they're only going half way in my view.
I have a small flock of Gang-Gangs who return to breed each year. There are currently 13 in the gang, including three new fledglings. I live on the edge of the National Park at Wentworth Falls. In winter most of the flock heads to lower altitudes, however, one small family group stayed through last winter. One of the younger females, from last year's brood is happy to feed from my hand.
You're right about the Sulphur Crested cockatoos, I stand guard while the Gang-Gangs are feeding otherwise they wouldn't stand a chance, though the lorikeets can be just as assertive.
Hi vland. Great birds, aren't they? And interesting observations you've made of their movements.
You might want to type <artificial feeding> into the search box near the top of this page to get the low down on the pros & cons of artificially feeding birds.
what are the pros?
close encounters and photograph opportunities?
I was thinking in terms of pros for the birds. Some people argue that in drought conditions artificial feeding substitutes for scarce food & keeps birds alive. Under natural conditions I don't support this argument. However, where humans have severely depleted habitat there may be an argument for artificial feeding to maintain a sufficiently large population of birds to restock an area once it has recovered or been restored from human depredation.
Other than that I would see that artificial feeding is not for the birds but rather to meet the needs & wants of humans.
in many northern hemisphere countries many people feed birds to help them survive the winter, in fact some species no longer migrate to better pastures as there's no need. also some species have expanded their ranges into regions where they formerly could not survive due to lack of suitable food resources. however mass urbanisation and intensive agricultural expansion have meant that in many cases the birds would not be doing very well if it weren't for artificial feeding.
e.g. in the uk alone an estimated 60,000 tonnes of birdseed is provided to wild birds annually
http://www.bto.org/news-events/press-releases/garden-feeders-support-more-birds-ever
I wonder how long this feeding relationship between birds & people has existed, zosterops. Has the relationship naturally evolved over hundreds of thousands of years or is it a recent development?
Also, I wonder what the effect is on local ecologies of birds no longer migrating because of artificial feeding. In this respect I'm reminded of the story told by an ecologist at an SA Ornithological Society (now Birds SA) meeting. Melbournians planted lots of introduced Eucalypts which flowered at different times of the year from the indigenous Eucalypts so Red Wattlebirds no longer needed to migrate to other parts once the indigenous Eucalypts finished flowering; they could rely on the introduced Eucalypts for their main food. However, this took them away from insects which they consumed in the locations to which they normally migrated. The result was that many Red Wattlebirds died from thiamin deficiency because they were no longer eating the insects which provided them with their thiamin.
interesting.
the red wattlebird used to a migratory species in melbourne, it is now a permanent resident feeding on introduced plants.
the population does not seem to be affected (the red wattlebird is the commonest native bird in melbourne alongside noisy miners and rainbow lorikeets). perhaps the sedentary urban populations have since adapted to local insects?
incidentally i've long reckoned the rainbow lorikeet is introduced in melbourne, or at least the vast majority of the population is descended from escapees. it's listed as an extremely rare vagrant by early settlers with no sightings in the region for decades. now ultra-abundant they feed mainly on exotic trees and are rarely recorded in surrounding areas. interestingly the little lorikeet, the original species of the area is now seldom encountered.
That's interesting, too, zosterops. Which exotic trees do they feed on & are they taking fruit or nectar or both?
I've observed large populations of Rainbow & Musk Lorikeets feeding on bird seed & sweetened water at a popular tourist destination in the Adelaide Hills. It's made me wonder if they were unintentionally being removed from their natural function of pollination & whether this might affect regeneration of the Sclerophyll forests over a wide area of the Hills.
I've seen the melb rainbow lorikeets feeding on everything from apples, plums to introduced eucalypt nectar. liquidambars, silver birches seed cones.
one of their favourite nesting sites are the canary island date palms which abound in much of melbourne suburbia.
I wouldn't be at all surprised if the rainbows are introduced in south australia as well, the range formerly was only from queensland to eastern victoria* (they are rare in most of western victoria for example and only found near settlements). the original resident lorikeet in your region was probably the purple-crowned lorikeet.
*and even then they used to be seasonal migrants, they are now resident in vic due to the provision of artificial feed and introduced trees for nectar and nesting sites.
The Australian bush is a dynamic rather than a static system. The variation between seasons can be very large, which always affects the distribution and populations of plants and insects. It is hard to generalise about population dynamics of birds when we know so little about the original pre-settlement conditions before clearing for agriculture. It's easy to make assumptions based on current observations, much harder to really understand the changes that are happening.
a good point to make, often range expansions and apparent introductions may be recolonisation events.
melbourne's scaly-breasted lorikeets for example may be descended from escapees, or they may be vagrants (or both) 'caught' in migrating flocks of rainbow lorikeets from the north. early records indicate the species was once found in northern vic where it is now apparently extinct, not an inconceivable distance for nectar nomads which traverse long distances (and they were able to colonise melbourne due in part to the widespread planting of east coast vegetation and other eucalypts).