birding-aus

Vanishing House Sparrow wrap-up

To: "birding aus" <>
Subject: Vanishing House Sparrow wrap-up
From: "Cas and LISA Liber (& family)" <>
Date: Thu, 2 Mar 2006 08:13:20 +1100
It is certainly odd - I guess one expects in climate and environmetal change certain (generally adaptable widespread species) adapt well while others in more specialised niches don't. The only other really common bird that collapsed I guess was the Passenger Pigeon but that had a very obvious cause of death (shooting) although I am not sure - was there a point that popualtion continued to collapse after the shooting stopped?
Is it something about the gregariousness of a species which suffers?
Cas
 
-----Original Message-----
From: [On Behalf Of Ricki Coughlan
Sent: Thursday, 2 March 2006 7:33 AM
To: birding aus
Subject: [BIRDING-AUS] Vanishing House Sparrow wrap-up

G'day nature lovers.
 
After the chatter here on Birding-Aus re House Sparrows, I contacted a number of lists across the world. Here's my take on it which I circulated to a list in the USA. . .
 
Thanks to everyone who responded to my House Sparrow querie.
 
Every part of the developed world that I write to reports the same thing - a big decline in House Sparrows. They are temporarily increasing in Scotland and Wales in the United Kingdom, but crashing on the east coast of that country. Generall, the pattern is the same: First they vanish in the cities, then the suburbs and then around country towns and finally down on the farm.
 
A recent exhaustive study in Britain indicated that House Sparrows tend to raise two clutches in a season; one as a back-up. The parents primarily provision their young with insects whilst in the nest. It appears that insects are vanishing at that critical time when the second clutch is being raised and the young are rarely surviving. The author of the study felt that this is behind the gradual decline. I'm not sure if this can explain such a universal decline or the pattern of declines, but it may be an area which requires further examination.
 
Perhaps the House Sparrow will bounce back. Perhaps those with behavioural/physical character traits which overcome their current difficulties will emerge and we'll have a new breed of Super House Sparrows (Passer domesticus giganteus) to contend with. Time will tell.
 
Meanwhile, it has to be a concern that a small generalist granivorous/insectivorous bird with an incredibly successful past is declining comparatively rapidly, fairly uniformly and in the same pattern all over the world. Many would like to celebrate the disappearance of what is a feral species in Australia and the US (I'm told that they're actually feral in Great Britain too - supposedly brought in by the Romans). However, this celebration has to be tempered by the fact that a bird like this can be disappearing when we don't know the cause . . . a bird which appears to share much the same sort of characteristics as many of our own native species here in Australia and the US too.
 
We are no doubt all aware that our environment is under threat from a number of quarters, but an almost universal decline of a species like House Sparrows confirms what I and probably most nature lovers and conservationists are beginning to suspect: that there may be something subtle, fundamental and very far reaching going very wrong in our world and the tip of the iceberg is a small brown, vanishing bird.
 
Happy Birding (anyway)
Ricki Coughlan
Sydney, Australia
 
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