Source for this chart? 2.4 billion birds lost to cats in the US per year? Do these pussies lure mega-flocks to killing fields and carpet bomb them?
Think of it as:
1.0b killed by 84m domestic (owned) cats each killing 1 per month
1.4b killed by 30m feral (unowned) cats each killing 4 per month
These numbers are adapted by me from the root source, which is
Free-ranging domestic cats cause wildlife extinctions on islands, but their impact on wildlife in mainland areas is unclear. This study presents an estimate of mortality caused by cats in the United States, suggesting that 1.4–3.7 billion birds and 6.9–20.7 billion mammals are killed annually.
www.nature.com
Journal: Nature
Published: 29 January 2013
Article: The impact of free-ranging domestic cats on wildlife of the United States
Authors: Scott R. Loss, Tom Will & Peter P. Marra
WHEN YOU ASK "SOURCE FOR THIS CHART"
Graphically: published by TreeHugger from data in State of Birds 2014*
But their graphics seem actually drawn from:
http://archive.stateofthebirds.org/2014/ (a multi agency/NGO collaboration)
Data, US Totals by category, collected by US Fish & Wildlife Service across all threats to birds.
https://www.fws.gov/birds/bird-enthusiasts/threats-to-birds.php
Data, Specific threat by cats: an article published in Nature in 2013: The impact of free-ranging domestic cats on wildlife of the United States,
https://www.nature.com/articles/ncomms2380
Call me out for being US-centric and lazy, but I didn't hunt for sources on the Canadian numbers in the original chart. These links probably put you no more than 2 degrees away, though.
I'm all in favor of challenging sources, including that the challenger try it themselves. I tried it myself!
HERE'S HOW!
Googling "2,400,000,000 birds" leads us to the US Fish and Wildlife Service 2014 estimates
Threats to Birds MIGRATORY BIRD MORTALITY - QUESTIONS AND ANSWERS, complete with their table of high low and median (where median got made into charts that year)
Probably sufficient for an internet source cite, but (if you hadn't found the Nature article) you might ask "where'd these numbers come from?"
Googling "2.4 billion birds" actually works better, leading us to
Smithsonian:
https://insider.si.edu/2013/01/cats-kill-2-4-billion-birds-annually/
Which, in the blurb says:
Domestic cats in the United States kill some 2.4 billion birds and 12.3 billion mammals each year, most of them native mammals like shrews, chipmunks and voles according to the New York Times in a recent article about a new report in the journal Nature co-authored by Peter Marra, an ornithologist at the Smithsonian Conservation Biology Institute
Google "Peter Marra Journal Nature" and we find
Free-ranging domestic cats cause wildlife extinctions on islands, but their impact on wildlife in mainland areas is unclear. This study presents an estimate of mortality caused by cats in the United States, suggesting that 1.4–3.7 billion birds and 6.9–20.7 billion mammals are killed annually.
www.nature.com
as reported above.
Were I your local public reference librarian, I'd offer a xerox page (printed on half hemp-derived, half-recycled, unbleached paper, natch) along the lines of:
ELECTRONIC RESEARCH TECHNIQUES WE USE AT THE REFERENCE DESK
OPTION 1: GOOGLE IT!
For all those people who find it more convenient to bother you with their question rather than to Google it for themselves.
lmgtfy.com
OPTION 2: URL HACKING
1) Right click on image, open in new tab, inspect URL:
2)Which suggests the image was published by treehugger in September 2014, probably in an article about the state of birds.
3a)Advanced Search in Google for
Birds 2014 site:treehugger.com
3b) Regular Google search:
treehugger sept 2014 theats to birds
Media Source: TreeHugger.com
Wind turbines kill around 300,000 birds annually, house cats around 3,000,000,000
4) Following the obvious article leads to a sourced report at:
http://archive.stateofthebirds.org/2014/
Publication Source: stateofthebirds.org (a joint project of many reputable possible sources). They don't provide a clear link back to FWS that I've seen, but maybe you'd accept the collaborative as the source?
OPTION 3: GOOGLE IMAGE SEARCH
1) Open a new browser window at
https://images.google.com/
2) Click (and hold) on the image/chart you are trying to find a source for
3) (while still holding that click from (2)) drag it into the search box of the image search
4a) Check results forpages with the same text/numbers (e.g. the one above)
4b) Click on a link beneath "
Find other sizes of this image"
(which suggests Wapo as source:
https://www.washingtonpost.com/news...geons-demise-american-birds-fight-to-survive/
5) But reading the Media Source (the WaPo article) they source the chart reference as:
2014 State of the Birds Report
6) Googling that produces a link to:
archive.stateofthebirds.org
following that to:
http://archive.stateofthebirds.org/2014/abundance/anthropogenic (but source trail ends there)
