Tuesday, October 29, 2019


Mention and discussion of the UK and Europe declining bird populations has been a feature of this blog since it began some 10 years ago. 

Now, a recent study (September 2019) in the journal Science reveals that since 1970, bird populations in the United States and Canada have declined by 29 percent, or almost 3 billion birds, signalling a widespread ecological crisis. Let that number sink in for a moment. That's three billion - a number "3" followed by nine "0"s - 3,000,000,000.

The results of the study show huge losses across diverse groups of birds and habitats, from iconic songsters such as meadowlarks, to long-distance migrants such as swallows and backyard birds including sparrows. 

Eastern Meadowlark 

Tree Swallow 

American Tree Sparrow

"Multiple, independent lines of evidence show a massive reduction in the abundance of birds," said Ken Rosenberg, the study's lead author and a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy. "We expected to see continuing declines of threatened species. But for the first time, the results also showed pervasive losses among common birds across all habitats, including backyard birds." 

The study notes that birds are indicators of environmental health, indicating that natural systems across the U.S. and Canada are now being so severely impacted by human activities that they no longer support the same robust wildlife populations. 

The findings showed that of nearly 3 billion birds lost, 90 percent belong to 12 bird families, including sparrows, warblers, finches, and swallows - common, widespread species that play influential roles in food webs and ecosystem functioning, from seed dispersal to pest control. 

Among the steep declines noted: 
  • Grassland birds are especially hard hit, with a 53 percent reduction in population - more than 720 million birds since 1970. 
  • Shorebirds, most of which frequent sensitive coastal habitats, were already at dangerously low numbers and have lost more than one-third of their population. 
  • Waders - the volume of spring migration, measured by radar in the night skies, has dropped by 14 percent in just the past decade. 
"These data are consistent with what we're seeing elsewhere with other taxa showing massive declines, including insects and amphibians," said co-author Peter Marra, senior scientist emeritus and former head of the Smithsonian Migratory Bird Centre and now director of the Georgetown Environment Initiative at Georgetown University. 

"It's imperative to address immediate and ongoing threats, both because the domino effects can lead to the decay of ecosystems that humans depend on for our own health and livelihoods and because people all over the world cherish birds in their own right. Can you imagine a world without birdsong?" 

Evidence for the declines emerged from detection of migratory birds in the air from 143 NEXRAD weather radar stations across the continent in a period spanning over 10 years, as well as from nearly 50 years of data collected through multiple monitoring efforts on the ground. 

"Citizen-science participants contributed critical scientific data to show the international scale of losses of birds," said co-author John Sauer of the U.S. Geological Survey (USGS). 

"Our results also provide insights into actions we can take to reverse the declines." The analysis included citizen-science data from the North American Breeding Bird Survey coordinated by the USGS and the Canadian Wildlife Service -- the main sources of long-term, large-scale population data for North American birds - the Audubon Christmas Bird Count, and Manomet's International Shorebird Survey. 

Although the study did not analyse the causes of declines, it noted that the steep drop in North American birds parallels the losses of birds elsewhere in the world, suggesting multiple interacting causes that reduce breeding success and increase mortality. It noted that the largest factor driving these declines is likely the widespread loss and degradation of habitat, especially due to agricultural intensification and urbanisation. 

Other studies have documented mortality from predation by free-roaming domestic cats; collisions with glass, buildings, and other structures; and pervasive use of pesticides associated with widespread declines in insects, an essential food source for birds. More research is needed to pinpoint primary causes for declines in individual species. 

"The story is not over," said co-author Michael Parr, president of American Bird Conservancy. "There are so many ways to help save birds. Some require policy decisions such as strengthening the Migratory Bird Treaty Act. We can also work to ban harmful pesticides and properly fund effective bird conservation programs. Each of us can make a difference with everyday actions that together can save the lives of millions of birds - actions like making windows safer for birds, keeping cats indoors, and protecting habitat." 

The study also documents a few promising rebounds resulting from galvanised human efforts. Waterfowl (ducks, geese, and swans) have made a remarkable recovery over the past 50 years, made possible by investments in conservation by hunters and billions of dollars of government funding for wetland protection and restoration. 

Raptors such as the Bald Eagle have also made spectacular comebacks since the 1970s, after the harmful pesticide DDT was banned and recovery efforts through endangered species legislation in the U.S. and Canada provided critical protection. 

Bald Eagle 

"It's a wake-up call that we've lost more than a quarter of our birds in the U.S. and Canada," said Adam Smith from Environment and Climate Change Canada. "But the crisis reaches far beyond our individual borders. Many of the birds that breed in Canadian backyards migrate through or spend the winter in the U.S. and places farther south -- from Mexico and the Caribbean to Central and South America. What our birds need now is an historic, hemispheric effort that unites people and organisations with one common goal: bringing our birds back."

Journal Reference: Kenneth V. Rosenberg, Adriaan M. Dokter, Peter J. Blancher, John R. Sauer, Adam C. Smith, Paul A. Smith, Jessica C. Stanton, Arvind Panjabi, Laura Helft, Michael Parr, Peter P. Marra. Decline of the North American avifauna. Science, 2019; eaaw1313 DOI: 10.1126/science.aaw1313

Linking today to Eileen's Saturday Blog and Anni's Birding.


eileeninmd said...


This was awful news for our country and the world. Our current administration does not care about the environment or the bird's habitat. Enjoy your day, have a great week ahead.

Angie said...

Phil - I am familiar with this report, and it is discouraging, to say the least.

David M. Gascoigne, said...

Hello Phil: The results of this report are shocking, but not surprising to anyone who has followed bird populations over the past fifty years, and there have been countless indicators that declines on a massive scale have been taking place. I doubt whether there is sufficient resolve on the part of those who can make a difference to reverse the trend,

David M. Gascoigne, said...

I should also have mentioned that Ken Rosenberg and Pete Blanched stayed at the same lodge in Panama in April as we did, and we chatted with them every evening after dinner, and shared any information we had on northbound migrants. In an odd twist of fate, Pete formerly held the job with Environment Canada now occupied by Greg Mitchell, the scientist who comes down from Ottawa to attach the radio trackers to our swallows. And we had to go to Panama to meet him!

italiafinlandia said...

It really makes me sad to read something so tragic... I must admit the Italian government does not have any clear plans about environment either.
Thanks for sharing.

Wally Jones said...

Those of us who observe birds with any sort of regularity relate to the bad news contained in the referenced report. It is easy to succumb to despair. That does not help, however.

What can be done?

In my very humble opinion, the best we can do is instill a love of Nature in our children, our relatives and our acquaintances. Practice what we preach and lead by example. Be involved in local birding activities, provide data on our observations, correspond with elected government officials, support organizations dedicated to documenting and improving avian and other wildlife conditions.

Follow the valuable work of citizen scientists, such as Phil performs faithfully by hosting this blog.

Individually, we may think we don't have much impact. As a mass movement of planetary ambassadors, our voice can be stronger than you may imagine!

Lowcarb team member said...

It is quite saddening to read this, but somehow not altogether surprising.
I worry about what world we are leaving for our grandchildren …

All the best Jan

Mary Howell Cromer said...

Phil, it's been a very long time since I have had the opportunity to check in with you. I am pretty sure that I did when I posted in September, but never heard from you. I hope that you and Sue are doing well.

The loss of so many birds has also been a huge issue talked about over here. It's such a frightening thing to think that so many billions are gone, and what does the future for those that remain going to look like?! I have wondered about insecticides sprayed on crops over here as well as the same that is used for lawn services. A lot of the birds that have gone missing are huge insect eaters. That probably has something to do with the losses.

This year we had so many Ruby-throated Hummingbirds and as they began to leave and begin their journey South, I felt sick. A great portion of their Amazon jungle has been burned up and I am sure that a lot of the floral vegetation that draws them will be gone upon their arrival of so many thousand miles.

I felt the same kind of angst when the Swallows and Martins left. They seemed to leave a couple of weeks ahead of schedule this season.

Even the Monarch butterflies were totally confused as well. We had a nine week drought that only broke with a good soaking finally 2 weeks ago. The heat stayed around well into October and the Monarchs were caught here, rather than flying South. I just saw two of them yesterday and we are expecting a hard freeze this evening...All of it very sad.

We cannot turn things back, but we can sure make some changes, however the leader of this land is simply not interested in doing anything to help. Ugh I cannot even get started.

I have messed so many blogging friends and I hope that soon, I can be back up and running at least every couple of weeks. Until then, do take care~

Best to you.

Anni said...

This post if yours is so shocking (but over a decade I've noticed a decline in migrants & year 'round birds) this all sends chills up my spine to read such drastic numbers. We humans need to wise up and hope for comebacks of all species of wildlife & plant life.

Great eye opener & a big huge thanks for sharing.

Linda aka Crafty Gardener said...

A very informative post,

sandyland said...

i miss the meadowlarks so much in Fla

The Ornery Old Lady said...

Such a terrible thing. It breaks my heart.

Carol @Comfort Spring Station said...

I just watched a movie (romantic comedy with emphasis on elephant conservation) where the character said the most dangerous animal in Africa is not the rhino or big cats but MAN. I'd say that's the truth everywhere.

Fun60 said...

What shocking numbers. What kind of world are we passing on to our grandchildren?

Lady Fi said...

Such sad reading.

judee said...

Yes, it is very sad what we do to the environment. Thanks for all the valuable information .

eileeninmd said...


I wanted to stop back and say thank you so much for linking up and sharing your critters. I hope you have a happy day and weekend ahead.

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