Sunday, July 30, 2017

Eastern Forest Birds Face Wintering Grounds Habitat Loss

Rose-breasted GrosbeakWithin the next few decades, human-caused habitat loss looms as the greatest threat to some North American breeding birds and the problem will be most severe on their wintering grounds, according to a new study published  in the journal Global Change Biology. By the end of this century, the study’s authors say predicted changes in rainfall and temperature will compound the problem for birds that breed in eastern North America and winter in Central America. Migrant wintering grounds are important because the birds spend a greater proportion of the year in these places.

The scientists ran dozens of scenarios to predict what the future might look like for 21 species, most of them flycatchers, vireos, and warblers. They used observations that volunteers entered into the eBird database from 2004 through 2014 to establish where and in what density the species are found throughout the year. Then, they layered in modeled climate change projections (temperature and rainfall) and habitat data (land-use changes and the location of protected areas).

The study finds loss of wintering habitat in the near future will likely be magnified by the long-term effects of climate change. By the end of this century the study species are expected to encounter several significant changes:

  • Greater warming on the northern breeding grounds and during autumn migrations — a surface temperature increase of about 9°F (5°C) with uncertain consequences for breeding and migration success; a smaller increase of about 5.4°F (3°C) is projected for their wintering grounds.
  • Less rain on the nonbreeding grounds: a projected decline of 20 percent or more during the summer would reduce available habitat and food for birds arriving after fall migration.
  • More rain on the breeding grounds, nearing 25 percent more during the winter on their breeding grounds. This could enhance vegetation growth and increase insect densities for returning spring migrants — a positive trend if the birds arrive at the right time.

“By examining the birds’ full life cycle, we learn that birds face a host of challenges all year long — and the intensity of those challenges shifts, depending on whether the birds are breeding, wintering, or migrating. Short-term conservation action will be most effective if it’s targeted to the times and places birds face their biggest threats. Knowing what may lie ahead in the long term underscores the need for action right now to offset the impact of climate change,” lead author Frank La Sorte said in an announcement of the publication sent to the press.

Photo: Rose-breasted Grosbeak, courtesy David Brezinski, USFWS.

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12 Responses

  1. Boreas says:

    While some species of migratory birds may have the ability to adapt to climate changes alone, habitat loss due to human deforestation is something that is relatively new to birds and their evolutionary traits. It also happens much more dramatically and quickly. This double whammy is having a pronounced impact on birds worldwide. Generalists seem to be weathering the stresses better than more sensitive specialists. I am afraid these factors will deal a significant blow to the diversity of bird species over the next century.

  2. Ethan says:

    We need a new, progressive administration that recognizes, not denies, the reality of global warming.

    • Paul says:

      Well we better start working and talking with people we don’t agree with or that will never happen.

  3. Paul says:

    “most of them flycatchers, vireos, and warblers” I think the photo is a type of gross beak.

    The red eyed vireo I think is the most common song bird in the Adirondacks. They stay high in the canopy where you can’t see them. But you hear them all the time.

    • Boreas says:


      You are correct. At the very bottom:

      “Photo: Rose-breasted Grosbeak, courtesy David Brezinski, USFWS.”

      I don’t know if they are the most common, but Red-eyed and Blue-headed Vireos certainly seem to be the most frequently heard! They sound very similar.

      Thrushes, at least in my area, seem to be on the decline. !5 years ago I typically had several breeding Hermit Thrushes and Veerys and the occasional Wood Thrush in the woods around my house. They are gone. Black-throated Blue and Chestnut-sided Warblers are also absent the last few years. Some of these populations are cyclical depending on caterpillar populations, but the presence of Vireos would indicate there are at least SOME insects present.

      Leaders ignoring “climate change” are only part of the problem. Nations around the world are systematically destroying forests where many species of wildlife breed or overwinter. People can believe in climate change or not, but destruction of forests, wetlands, and other type of habitat is definitely happening. There needs to be global discussion of this as well!

  4. Charlie S says:

    “destruction of forests, wetlands, and other type of habitat is definitely happening.”

    It’s going to get worse with these right wing nut jobs in office now Boreas….as is always the case when they are in control!

    • Boreas says:


      I am afraid that may be the case. But it is a worldwide problem, with global ramifications. Forests scrub CO2. We need to stop deforestation for many reasons – including greenhouse gas sequestration.

    • Paul says:

      George Pataki – the “right wing nut job” set aside more Adirondack land from development than the non-right winger we have in office now. Just the facts.

    • Paul says:

      Before Obama the president with the most number of acres set aside as national monuments was the right winger George Bush. 218 million acres. the left winger Bill Clinton set aside 5.7.

      Charlie do you even know the stats?

    • Boreas says:

      “There needs to be global discussion of this as well!”

      This is crucial for a global problem. Without political leadership that can effectively communicate and interact with other world leaders, this agenda will likely languish. We need to keep their feet held to the fire and not allow the background noise of Washington politics to get in the way.

  5. Charlie S says:

    I’m with you Boreas. It’s worse than anybody seems to realize. Did you read the NY Times report recently about the rate of extinction of species going on as we speak? And here you have these freaks who will deregulate and loosen restrictions on the very things set up to protect species. These people are outright monsters! And look at all of the support they have!

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