Threats to birds: learn about them

Birds face many threats to their health, well-being, and survival; some already exist in nature that humans do not cause or control (storms, disease, parasites, and predation are major sources of mortality and injury). But human activity in the modern world has increased the number, severity, and complexity of anthropogenic, or human-caused threats - not only to individual birds, but also to populations, regional or local sub-populations, or entire species or subspecies at differing geographic scales.

Here are some important sources of mortality, displacement, and injury to birds.

Habitat loss:
Read about habitat loss at these links from the American Bird Conservancy and the U.S. Fish & Wildlife Service:
https://abcbirds.org/threat/habitat/
https://www.fws.gov/birds/bird-enthusiasts/threats-to-birds/habitat-impacts.php

Habitat alteration or fragmentation also has negative effects on birds. Read a paper linked here:
https://tinyurl.com/y3ttlrh7

Effects of feral or free-ranging cats on birds
The enormous effect of cats on wild birds and other wildlife species cannot be overstated.Our WBCI Issues Paper on this topic may be found here:
http://www.wisconsinbirds.org/wp-content/uploads/2017/04/catsbirds-1.pdf
Another highly-read, valuable paper on this topic is linked at:
https://www.nature.com/articles/ncomms2380

Effects of pesticides or other chemicals
One of the "Issues Papers" from the Wisconsin Bird Conservation Initiative is linked here:
http://www.wisconsinbirds.org/wp-content/uploads/2017/04/effectspesticides-1.pdf
This paper has links to many additional sources of information.

Threats specific to migration
Birds face specific threats during migration.  It may be the time of highest mortality in the annual cycle for those species that move distances between breeding and winter ranges. Read more here:
https://tinyurl.com/y55x9edn

Lead poisoning
Lead affects birds in multiple ways. Birds can pick up lead fragments or lead shot, or lead fishing tackle, and then be poisoned by those fragments or other lead items. Here are several informative links:
http://www.wisconsinbirds.org/wp-content/uploads/2018/09/leadpoisoning-2.pdf
https://abcbirds.org/program/pesticides/lead/


Effects of climate change
The effects of climate change on birds are complex and far-reaching, extending into multiple aspects of birds' life cycles. Read more at these two links:
http://www.wisconsinbirds.org/wp-content/uploads/2017/04/climatechange-1.pdf
https://www.massaudubon.org/our-conservation-work/climate-change/effects-of-climate-change/on-birds


Window and glass collisions
Many millions of birds are killed by collisions with glass; much of this is avoidable. Learn more at these links:
http://www.wisconsinbirds.org/wp-content/uploads/2017/08/collisionsbirds_rev_7-2017.pdf
https://abcbirds.org/program/glass-collisions/why-birds-hit-glass/

Collisions with communication towers and/or wind turbines
Here's a paper on the effects of collisions with communications towers:
https://www.fws.gov/birds/bird-enthusiasts/threats-to-birds/collisions/communication-towers.php


Here is the WBCI Issues Paper on birds and wind power:
http://www.wisconsinbirds.org/wp-content/uploads/2017/04/windpower-1.pdf
Here is a very new paper on this and related topics:
https://pubs.er.usgs.gov/publication/sir20185157

the Barn Swallow - a worldwide aerial insectivore

Ph. by M. McMasters - Wikim. Commons

Barn Swallow is a bird nearly all rural people know: it is ubiquitous and widespread. It is in decline in some regions. See the animated eBird map (linked below) to watch its movement across North America through the seasons.

Declines are particularly marked in some areas of Canada. 

"Barn Swallow (Hirundo rustica) may be the most widespread and well-known passerine, with highly migratory populations that span the Americas as well as Europe, Asia, and Africa. Related species, and some Barn Swallow subspecies, are resident in Africa, the Middle East, and Australia. This remarkable variability makes Barn Swallow a great case study in migratory behavior. The varied migratory behaviors in this species globally are also seen on a smaller scale in the Americas, as this new eBird Abundance Model helps illustrate."

See the full hemisphere distribution at:


https://ebird.org/wi/science/barswa

Learn more about Partners in Flight:

Learn more about the consortium Partners in Flight: https://www.partnersinflight.org/about/

"Partners in Flight (PIF) is a dynamic and welcoming network of more than 150 partner organizations distributed throughout the Western Hemisphere. We are engaged in all aspects of landbird conservation from science, research, planning, and policy development, to land management, monitoring, education, and outreach. We are all dedicated to PIF’s simple, proactive mission: Keeping common birds common and helping species at risk through voluntary partnerships. To halt and reverse bird population declines before they are listed as threatened or endangered is a cost effective and common sense business model for the future."

Breeding phenology and performance for four swallows over 57 years: relationships with temperature and precipitation

 by

Tara L. Imlay

Joanna Mills Flemming

Sarah Saldanha

Nathaniel T. Wheelwright

Marty L. Leonard

 "Aerial insectivores, birds that feed on insects caught in flight, are experiencing steep population declines possibly because of shifts in the timing and/or abundance of aerial insects."
Learn more by reading this paper at:

 https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.2166

Whitman's bird

Praised by many, reviled by some, both in his day and since, Walt Whitman was a quintessentially American poet. He believed fiercely in America and in democracy.

Although you can read widely on Whitman and his work, about his personality and beliefs, I'm writing here to focus on his interest in a bird - the Hermit Thrush.

In his famous elegy for Abraham Lincoln, written shortly after Lincoln's death, he incorporated lyric imagery about the Hermit Thrush in the 206 lines of "When Lilacs Last in the Door-yard Bloom'd".

More on the poem, the repeated emphases on the thrush and its song, and perhaps why Whitman chose this image:  https://hokku.wordpress.com/2015/04/26/whitmans-trinity-of-remembrance-when-lilacs-last-in-the-door-yard-bloomd/

Some say the Hermit Thrush is North America's finest avian singer. As subjective as that evaluation may be, most of us who have heard it will at the very least agree it is a wonderful song.

Hear one at:  https://www.allaboutbirds.org/guide/Hermit_Thrush/sounds

Read more at:  https://northernwoodlands.org/outside_story/article/twilight-singer-hermit-thrush

And about Hermit Thrushes' song variation:  https://academic.oup.com/auk/article/134/3/612/5149313


But finally, let Whitman have his say; let it drift over you, like the thrush's song itself:

4

5 In the swamp, in secluded recesses,

A shy and hidden bird is warbling a song.

6 Solitary, the thrush,

The hermit, withdrawn to himself, avoiding the settlements,

Sings by himself a song.

7 Song of the bleeding throat!

Death's outlet song of life—(for well, dear brother, I know,

If thou wast not gifted to sing, thou would'st surely die.)

and again a bit later...

13

20 Sing on! sing on, you gray-brown bird!

Sing from the swamps, the recesses—pour your chant from
the bushes;

Limitless out of the dusk, out of the cedars and pines.

21 Sing on, dearest brother—warble your reedy song;

Loud human song, with voice of uttermost woe.

22 O liquid, and free, and tender!

O wild and loose to my soul! O wondrous singer!

You only I hear……yet the star holds me, (but will soon
depart;)

Yet the lilac, with mastering odor, holds me.

insects and birds - population relationships

If you have been reading recent news about insect declines, you may notice that they often reflect, or approach in some ways the similar kinds of declines in certain bird species or species groups. The links between insect and bird declines are not proven, but evidence is growing that worldwide changes affect many groups of organisms, including birds.

Here are some sources that help to explain what is happening, and implications of these occurrences:

Human society under urgent threat from loss of Earth's natural life

https://www.theguardian.com/environment/2019/may/06/human-society-under-urgent-threat-loss-earth-natural-life-un-report

As Insect Populations Decline, Scientists Are Trying to Understand Why

https://www.scientificamerican.com/article/as-insect-populations-decline-scientists-are-trying-to-understand-why/?redirect=1

Insect and bird populations declining dramatically in Germany

https://www.dw.com/en/insect-and-bird-populations-declining-dramatically-in-germany/a-41030897
  
Why insect populations are plummeting—and why it matters

https://www.nationalgeographic.com/animals/2019/02/why-insect-populations-are-plummeting-and-why-it-matters/

Could Loss Of Flying Insects Be Leading To Loss Of Birds?

https://www.wxpr.org/post/could-loss-flying-insects-leading-loss-birds#stream/0

learn about the Midwest Migration Network

 See the website of the Midwest Migration Network, to learn more:
https://midwestmigrationnetwork.org/

Background:

https://midwestmigrationnetwork.org/about/background

Steering Committee:

 https://midwestmigrationnetwork.org/about/steering-committee

Our projects:

 https://midwestmigrationnetwork.org/our-projects