Lead Exposure Creates Mean(er) Mockingbirds

As we all know, there is considerable evidence that exposure to lead as an infant interferes with brain development, producing teenagers and adults who are more impulsive, more aggressive, and less intelligent. But suppose you want to really prove this. Ideally, what you’d want is a randomized controlled trial in which a group of infants is split randomly in two, with one half exposed to lead while the other half isn’t. Then you wait 20 years and see what happens.

Needless to say, this presents some wee ethical problems, so we can’t do it. And who wants to wait 20 years anyway? Instead, how about if we try this on some other animal? What we’d want is a species that tends to be sort of obnoxious already. For example, the northern mockingbird, which I just happen to have an excellent picture of:

So when are northern mockingbirds even more obnoxious than usual? When they’re building their nests. And how do you bait them into aggressive acts? Like this:

Researchers placed a taxidermized mockingbird on a tripod, 25 feet away from nests that pairs of mockingbirds were constructing, a situation in which the birds act most territorial. The researchers also played recorded songs of singing males to alert the mockingbirds and make the intrusions more realistic.

So you make the mockingbirds think they’re under attack and then observe their behavior. Here’s what happened:

In the neighborhoods with low lead levels, the mockingbirds responded to the threat somewhat conservatively, with scolding call vocalizations, raised-wing displays or fly-bys. In high-lead neighborhoods, though, the mockingbirds responded far more aggressively, attacking the perceived intruder and even ripping out its feathers. Researchers learned quickly they had to place the fake bird in a cage to continue the study and protect it from damage.

This study was done at Tulane University in New Orleans, where Howard Mielke has done considerable research into lead and already has detailed maps showing the lead content in various neighborhoods:

In the Lakeshore neighborhood, at the top of the map, the mockingbirds had an average aggressiveness score of about -1.0. In the Marigny and Uptown neighborhoods the birds scored 0 and 1.2.

So there you have it. Lead is bad for human infants, and apparently it’s bad for mockingbirds as well. In both cases, the problem is lead in soil: human babies crawl around outside and then stick their hands in their mouths, while mockingbirds eat worms that have ingested lead particles. Either way, it’s bad news.

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WHO DOESN’T LOVE A POSITIVE STORY—OR TWO?

“Great journalism really does make a difference in this world: it can even save kids.”

That’s what a civil rights lawyer wrote to Julia Lurie, the day after her major investigation into a psychiatric hospital chain that uses foster children as “cash cows” published, letting her know he was using her findings that same day in a hearing to keep a child out of one of the facilities we investigated.

That’s awesome. As is the fact that Julia, who spent a full year reporting this challenging story, promptly heard from a Senate committee that will use her work in their own investigation of Universal Health Services. There’s no doubt her revelations will continue to have a big impact in the months and years to come.

Like another story about Mother Jones’ real-world impact.

This one, a multiyear investigation, published in 2021, exposed conditions in sugar work camps in the Dominican Republic owned by Central Romana—the conglomerate behind brands like C&H and Domino, whose product ends up in our Hershey bars and other sweets. A year ago, the Biden administration banned sugar imports from Central Romana. And just recently, we learned of a previously undisclosed investigation from the Department of Homeland Security, looking into working conditions at Central Romana. How big of a deal is this?

“This could be the first time a corporation would be held criminally liable for forced labor in their own supply chains,” according to a retired special agent we talked to.

Wow.

And it is only because Mother Jones is funded primarily by donations from readers that we can mount ambitious, yearlong—or more—investigations like these two stories that are making waves.

About that: It’s unfathomably hard in the news business right now, and we came up about $28,000 short during our recent fall fundraising campaign. We simply have to make that up soon to avoid falling further behind than can be made up for, or needing to somehow trim $1 million from our budget, like happened last year.

If you can, please support the reporting you get from Mother Jones—that exists to make a difference, not a profit—with a donation of any amount today. We need more donations than normal to come in from this specific blurb to help close our funding gap before it gets any bigger.

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