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bird disappearance - is climate change only a minor part of the story? 2

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rotw

Mechanical
May 25, 2013
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There is so much media focus nowadays on the global warming issue and the CO2 emissions. But I am wondering if global warming is not the tree hiding the forest. I read some articles that suggest that about 30% of the bird population have disappeared from North America since the last 40 years. I understand things are inter connected. Is bird loss due to migration or just an absolute loss? Is there identical patterns throughout the rest of the world? is 30% figure realistic? I am afraid this may be much more. Are we facing massively accelerated extinction of birds (in which case there will be no birds anymore in 2 or 3 decades from now?).

I grew up as a kid with sounds of birds, among the many birds I am familiar with is the goldfinch, canary, serin, sparrow, redbreast and many others. Last year in both spring and summer seasons, I just noticed these birds sounds were literally muted.

Another thing I noticed, in the past if for some reason my car windshield was not wiped, say for 3 or 4 days in a row, the visibility decreases because insects and bugs would collapse on it, especially when I drive on the high way. Now its kind of not happening anymore, the windshield may stay clean for days.

Any testimonials?
 
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Some migration, but lots of extinction. Climate bands move relatively quickly, but plants and wildlife don't, so if certain birds are evolved to consume certain plants or bugs that are no longer in their habitat because of CC, then it's likely they'll be doomed, while other birds might be less picky or more adaptable.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
In Australia habitat loss is a big part of the changing wildlife. Marshes get drained and scrubby hedgerows replaced by barbed wire, and then all the local insect life gets wiped out (except flies, we're stuck with them). In the peninsula near where I live scrubby marsh is being turned into housing. Big drainage channels (which are going to be great for mosquitoes) and acres of concrete and asphalt replace what used to be fairly attractive horse paddocks and the like. Having said that, where I actually live we haven't seen much change in 10 years, but we are on the edge of state forest and in that time there have been no real backward steps (maybe two houses), and a local architect has taken some old farmland and is turning it back into natural bush, and an arboretum.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
Bird populations in NA were much larger a century ago, by some estimates more than 10x what they are today. the lows were in the 60-70's, with today's numbers generally a fair amount higher than the lows.
Habitat loss, food loss (insecticides), toxic chemicals (air and water), and a few more play a role. Considering that the 1 yr mortality rate for song birds is 50% it doesn't take much upset to hurt them badly.
But on a grander scale we really don't know much about overall climate fluctuation. Did we happen to begin pumping tons of CO2 into the atmosphere just as a natural warming cycle was starting?
I have never seen a paper on the long term cycles in climate from China, I would presume that they have the oldest records.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy
 
For me, the articles about bug population are some of the most frightening, and your observation about not cleaning the windscreen is supported by myself and longitudinal scientific studies in IIRC germany (75% decrease over the study term) and the Puerto Rican rainforest (a decrease of [frightened expletives] over the study term). I can dig up links when I'm not at work.
 
Will dig into this too and will do a thorough review of scientific publications on the matter. Will post back my findings here.
 
These are incredibly complex issues. To say that climate change is the cause seems pretty simplistic. We have to better understand the precise reasons for it. Some example of potentially precise knowledge that would elucidate the issue better:
1) The effect of DDT on bird eggs of apex birds.
2) The effect of various pesticides on the insect population. Noting that when I was a kid and driving in the rural areas, we got insane amounts of bugs on our windshields when they were spraying nearby fields. Now many of those fields are dry and barren (not specifically due to climate change, but rather to California water policy for the central valley). Therefore, I don't get bugs on my wind shield.
3) The effect of development on marshlands and the draining of swamps. What percentage of birds nested in those areas and where are they having their young now?
4) Does increased temperatures have a negative effect on marshlands in some way? Less water? More algae in the water which is bad for bird health?
5) Decreased fish populations? (may be over fishing, or global warming related) Which could result in fewer birds that rely on those fish populations for food.
6) Have certain birds (seagulls, ducks, geese) stopped migrating or greatly changed their migrating behavior due to reliance on human activities? Easier to get food at garbage dumps or man made ponds and such? Is the food they're getting at these locations less healthy?
7) The crow population has exploded in my area. Why? They're really smart birds and they are great scavengers. Digging through trash and such. But, is their population explosion having a negative effect on other birds in the area, with the crows attacking other birds, their eggs or their chicks?

Note: almost all of my examples are cases where we could still say the effect is caused by man. But, it's harder to directly link them to global warming.

I tend to think that, while global warming is something to be seriously concerned about, it seems academically (and journalistically) lazy to tie something to global warming without good, specific reasons. The concerns about the polar bear population was, in my opinion, much more robust. a) Polar Bears rely on sea ice to get a lot of their food. b) Ice floats have been less in recent years. c) ergo the decrease in polar bear population can be tied to global warming.

Note: If the rational basis for the Polar Bear assumption is clearly laid out then we (as a responsible population) can re-examine this year after year. Do these facts continue to hold true? Is there a continuing trend? Or, was this an effect that may not be as valid as we previously thought and was previously reported?
 
I wonder how much is perceived rather than actual. My thinking is that we're a much more urban society these days, and so less encounters with birds and other animals. I don't doubt that we've negatively affected populations with our expansion into their domains and our impact on the environment.

another day in paradise, or is paradise one day closer ?
 
Sure glad that so many people have nothing more serious to worry about.... the world must be in really good condition
 
Just remember, if you can link your study to climate change you get an automatic 500% cash bonus, or something like that. Case in point: frogs. Now, I like frogs. Round here we have funny little ones without webbed feet who live under logs. They are cuter than buttons. In mating season they do amazing call and response choruses.

But, somebody noticed that in many places in Australia frogs were dying out. The usual suspects started wittering about climate change.

No, in fact the reason is some disgusting skin fungus that is native to the Korean peninsula, and when amphibians from Korea were brought here as pets, the fungus escaped into the wild. Yes, we (mankind) were responsible, but nothing in particular to do with climate change.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
greg, ever the cynic ! … on with the "climate change" gravy train.

watched a "Nature" show here, about salt. gone from "research shows salt bad" to "well actually in the original research (of some 50 groups around the world) there was only one group that showed a linkage between salt and -ve health outcomes (a group of some natives in the Amazon I believe), and normally these outliers are discarded" to "further research shows that the body doesn't work as we thought, it is more complex than we thought, and more research is required".

How soon till we hear that litary of woe repeated for cholesterol, 2nd hand smok, and … climate change ?

another day in paradise, or is paradise one day closer ?
 
Is the claim "climate change is the primary cause of bird loss" that common?

Where I live (Germany) one hot topic is loss of insects (especially bees) ant that is linked to pesticides (Glyphosate mostly) in headlines etc.

Now when I google "bird loss america" and skim some of the first articles that pop up, climate change is not mentioned as a primary cause (if at all).

Kinda ironic that this discussion starts with the question "if global warming is not the tree hiding the forest."
 
"if global warming is not the tree hiding the forest." was meant as : attracting our focus to the point of overlooking other issues probably more severe (or not) probably strongly connected to global warming (or not strongly at all).
 
The bees thing is plain weird, speaking as a currently disenfranchised beekeeper. The way I heard it is that bees are essential for Almond pollination. But Californian Almond growers also spray their trees to heck. So they pay professional beekeepers to send hives in (big bucks) to pollinate the trees, whilst also blasting them with insecticides.

But the quality of the stats is very poor, there's a lot of self reporting of problems, rather than industry wide surveys.




Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
"attracting our focus to the point of overlooking other issues" - do you see evidence for this? I'd say the push to ban Glyphosate is evidence against this. Then again, the discussion in the US may be totally different.

I think there's little doubt that land use (=habitat loss) and pesticides are strong, immedate drives of species loss.
I think its pretty much consensus among activists and scientists on the climate change from argue that we should drastically reduce meat (especially beef) in our diets. This would reduce agricultural land use for fodder etc which would *also* free up agricultural land as habitat.

One real discussion is wether it's better to have highly intensive, high yield agriculture with a smaller surface footprint, or organic or bioregenerative agriculture that takes more space but is better at carbon sequestration in soil and also serves as habitat.

There probably *is* a critical discussion to be had about land use for biofuels which is far smaller than agriculture but still.

 
"attracting our focus to the point of overlooking other issues" - do you see evidence for this?
In view of "is it the tree that hides the forest or not?", I could argue you that absence of evidence is not evidence of absence.
Now to your point, if some (whether its all, I do not know) of these issues (namely insects, birds extinction, etc.) are certainly brought to the public attention somehow, question that remains is, are these matters not overshadowed by the global warming problem and the attention that it gets, though I certainly do not want to diminish the amplitude of the global warming threat per se, definitely not.
 
Well, with a title like 'Climate-driven declines in arthropod abundance restructure a rainforest food web' I think the authors are leaning toward climate.


From the abstract said:
A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico’s Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo’s insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.

As for 'why care about bugs', read the last sentence carefully.
 
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