1 April 2021

Yes, today is April Fool’s Day but it’s no joke that house sparrows are in trouble. Though still considered pests in North America their population has declined dramatically, even in their native range. Seven years ago their disappearance was a mystery. Has anything changed?

Native to Eurasia and northern Africa, humans introduced house sparrows (Passer domesticus) to continents and islands worldwide in the 1800s, making them the most widely distributed wild bird on Earth. (Green is native range, yellow is introduced in the map below.)

House sparrows were successful worldwide — too successful — but as recently as 30 years ago they began a steady decline. They are down 84% now in North America and 60% in Europe. In the UK they are red-listed as a species of high conservation concern.

There have been many studies but no one cause for decline. The reasons include:

• Agricultural intensification (2002): lack of spilled grain and gleanings, livestock not raised outdoors, changed sowing and harvest schedules.
• Poor diet plus air pollution in cities (2017)
• Global insect decline (2019). However supplemental feeding in the UK doesn’t increase the overall population.
• Hawks are a problem in the UK but not in the US (2021)

The one thing we do know since 2014 is that there is no lack of nest sites.

In North America house sparrows are not just in trouble, they are trouble because of their aggression toward native species while nesting.

We’ll be happy to see them go but their mysterious decline should make us think. If a bird as hardy and human-oriented as the house sparrow is declining, it bodes ill for us too.

For more information read :

• My vintage blog post in 2014: Mysterious Disappearance
• Matthew Miller’s Nature.org article, 2019: Where have all the house sparrows gone?
• Cornell Lab, Feb 2021: Study finds even the common house sparrow is declining.

(photo by Tim Vechter at Westmoreland Bird and Nature Club on Facebook)

7 March 2021

This winter’s influx of northern finches has brought new enjoyment to backyard birders and death to some of the feeder birds. Pine siskins (Spinus pinus) especially are succumbing to salmonellosis, a bacterial illness spread at bird feeders.

“The first indication of the disease for bird watchers to look for is often a seemingly tame bird on or near a feeder. The birds become very lethargic, fluff out their feathers, and are easy to approach. This kind of behavior is generally uncommon to birds,” Mansfield said. “Unfortunately, at this point there is very little people can do to treat them. The best course it to leave the birds alone.”

— WDFW: Help protect wild birds from deadly salmonellosis

Reports of dead and dying feeder-birds in Washington state have prompted the Washington Department of Fish and Wildlife to urge people not to feed the birds until at least April 1.

It’s happening here too though not enough for an advisory, but that’s beside the point. Protect your backyard birds. Clean your feeders! What you can’t see is hurting them.

The Spruce published these handy cleaning tips, summarized below:

• Clean your bird equipment every 2 weeks, more often when a lot of birds are visiting. Crowding spreads disease.
• Empty the feeder; throw away dirty seed! (I’ve learned this lesson, too. I once had mold in the nyger feeder.)
• Mix the cleaning solution: 1 part bleach to 9 parts hot water
• Take feeder apart and soak it to loosen dirt.
• Then clean thoroughly
• Dry thoroughly
• Reassemble and refill. Ta dah!

The Spruce suggests that when you’re in the market for new bird feeders, think about how you will clean them. Sometimes wood can be hard to clean.

Read more at All About Birds and The Spruce.

(photos from Wikimedia Commons; click on the captions to see the originals)