mollwollfumble said:
Just finished reading book “Curlews on Vulture Street”
Can thoroughly recommended it.
It’s a biography as well as a series of scientific studies involving Darryl Jones from Griffith University urban ecology, in Brisbane and elsewhere.
He seems to have made a career in demolishing myths asociated with urban ecology.
There are about a dozen myths in he book that have been demolished with strict scientific rigor.
The overall outlook is positive, more native birds are entering urban areas and taking up residence there. And overall birds per hectare is higher in urban areas than in the surrounding countryside.
> What myth does this demolish?
> More applicants for the role of bin chickens.
I’ll get back to you on both of these.
In the debate about whether to feed or not feed wild birds, two of the key points of argument (by both sides) have been demolished by hard scientific observation.
1. Wild birds do not become dependent on human handouts.
2. Nutrition of wild birds does not suffer because of human handouts.
These have been scientifically confirmed for both magpies and bin chickens.
As for birds entering and staying in urban areas. The following species have moved into the city of Wagga Wagga, near Lake Albert, since the blackbird moved in about 50 to 60 years ago:
rainbow lorikeet, superb parrot, red-rumped parrot, the yellow version of the crimson rosella, white-winged chough, koel, blue-faced honeyeater, spotted dove, speckled warbler. And more. Only the apostlebird seems to have moved out.
Another myth busted. “Nothing in ecology plots as a straight line”. It turns out that ‘number of birds per hectare’ vs ‘age of street’ plots as a straight line increasing out 40 years old. Number of birds increases linearly with age of gardens. Confirmed scientifically for both Wagga Wagga and Townsville – vastly different environments.
The belief that brush turkeys were monogamous was an old myth that the author busted in his youth. The sex lives of brush turkeys are like those of bower-birds – wide ranging females and territorial males. In the Tambourine mountain area – one male accounted for 50% of the eggs, a second male 30% and half the males had no eggs at all.
Bin chickens proved an interesting study. The bin chickens of inner city Brisbane are a completely different population from the rest, never leaving the inner city. The outer suburban garbage dump feeders can travel as far as Rockhampton. Neither population is found among the ibises at the airport. That said, the diet of inner city bin chickens is identical to that of suburban ones, with a human-component origin of the diet being only 20% or less.
In interactions between bin chickens and humans, humans always approach the bin chickens, never the other way around, and the dominant human – bin chicken interaction is, wait for it, selfies.
The most troublesome birds in Brisbane so far as humans are concerned are the crows and rainbow lorikeets (noise) and magpies (attacks).
Female magpies never attack. Of male magpies, 90% never attack. Of those that do attack, there are two separate types – those that attack all cyclists, and those that attack a specific one or at most two pedestrians. With a very small population that attack everybody. Those male magpies that do attack everybody can be exceedingly vicious.
Magpies are capable of over-reaction to threat, and can recognise the same human face seen six years apart. To relocate magpies, use a trap baited with another male magpie, the offensive bird will enter the trap to threaten the intruder. Magpies relocated 20 km away can return but those relocated 30 km away cannot. When a male it relocated, another male will take of the territory. A myth was that the new male would lead to the death of nestlings, this was busted when it was found that stepfathers are more attentive to nestlings and feed them more than their biological father had.
Rainbow lorikeets. A couple of things about these birds came as a complete surprise to me. The first is that they adore night-lights. They roost overnight in tree canopies that are as brightly lit as possible. In one such roost in Brisbane, lit by bright stadium lights each night, 38,500 sleeping rainbow lorikeets were counted. They don’t mind noise or congestion while sleeping, just so long as the lights are bright. mollwollfumble thinks this may explain why their numbers have boomed in cities.
Another rainbow lorikeet myth busted was that they are just nectar feeders. Reports started coming in of rainbow lorikeets eating meat. First from SE Queensland, then over the whole of eastern NSW. They have been observed eating a dead cow for example, this is probably a pre-existing behaviour rather than a new food preference.
Torresian crows. In Brisbane they always choose the same eucalypt species to roost in. Very particular. But also very noisy for adjacent residents. The crows shift around, often sleeping in different trees each night. Due to the noise, a method was used to scare them off using a weather balloon tethered beside the tree at night.
Crows are smart. Much more aware of danger than magpies and butcher birds. If you catch one, you will never catch that same crow again, and you’re unlikely to catch any other crow at the same location.
So much more in the book, about brush turkeys moving into suburban Brisbane and surviving despite higher than normal losses and protests by gardeners.
About bush-stone curlews in Brisbane city centre and on a Moreton Bay Island. The chief enemy of the curlew is the fox, which is why curlews have largely vacated Southern Australia and increased in numbers in Northern Australia. But they also survive in cities. A pair of adult curlews can see off a fox.
About the white cockatoos, don’t feed them if you value the woodwork of your house. If you stop feeding them then they’ll leave the house alone.
About new behaviour of crows. Building nests on building ledges next to windows rather than well away from people in the tops of trees. New behaviour of bin chickens. Etc.
The author, Darryl Jones has also written the book “Feeding the Birds at Your Table: A guide for Australia”.
Darryl Jones is not in favour of feeding wild birds, but sees it as an inevitable consequence of human nature. People feed birds as a way to contribute to nature to counteract the bad things that people have done in the past.