How Healthy is the Forest? Ask This Owl.

In the days of coal mining, 工人们会把金丝雀带到隧道里检测一氧化碳. 金丝雀会警告矿工周围即将发生的危险.

一些环保人士说，太平洋西北部森林里的北方斑点猫头鹰就像煤矿里的金丝雀一样. As an indicator of forest health在美国，斑点猫头鹰的数量也可以作为其环境状况的警告信号.

But there’s bad news.

“[The spotted owl] is on a trajectory to be functionally extinct, probably within this century,” says Dan Donato, a scientist with the Washington Department of Natural Resources.

So what does that mean for the forests the spotted owl frequents?

A GOLDILOCKS HABITAT DILEMMA

According to Donato, 如果你把森林健康定义为一个景观维持所有本地物种种群的能力, 然后斑点猫头鹰的减少表明它居住的森林可能遇到了麻烦.

多纳托专门研究和监测北方斑点猫头鹰的栖息地, which are dependent on old-growth forests to survive. The U.S. Department of Agriculture has varying definitions for what constitutes old-growth forests, but they all typically include old, mature trees with large trunk diameters and dense canopy layers.

经过几十年的采伐，这种特殊类型的森林正变得越来越稀少, disease, and insect infestation. The Arbor Day Foundation 与华盛顿自然资源部合作，在数千英亩的土地上种植茂密的澳门威尼斯人游戏冠，以帮助斑点猫头鹰生存. The plantings of Douglas fir, 西部铁杉和西部红杉模仿了原始森林的类似结构，可以帮助猫头鹰筑巢, roost, and forage.

2022年，对原始森林的破坏引起了白宫的注意. The Biden Administration issued an executive order that requires the U.S. 农业部和内政部制定政策，解决对原始森林的威胁.

北方斑点猫头鹰的大部分活动范围是在喀斯喀特山脉沿海的原始森林中. Unfortunately, within this wetter region, 古老的澳门威尼斯人游戏木被砍伐，森林变成了新生的澳门威尼斯人游戏木. 多纳托说，这种土地的转换和栖息地的破碎化对该物种产生了巨大的影响，是猫头鹰生存的最严重威胁.

Though the owl can mostly be found on the moist side of the mountains, 在喀斯喀特山脉峰顶以东，也有一些干燥的森林. But the lack of moisture, coupled with the typical characteristics of old-growth, makes conserving the forest difficult.

“Many structural features of spotted owl habitat, like dense multi-layered canopies, 这些都是你所说的燃料堆积吗,” Donato warns, referring to the plant material wildfires use to tear through forests.

To help prevent wildfires — a dire issue in the American West — dense trees need to be thinned as part of fuel management.

“But if you thin it too much and make it open so it’s fire-resistant, you’ve made it not-spotted owl habitat anymore,” Donato cautions. “It’s just this constant tension, 这实际上是研究和管理的一个重要活跃领域:“我们如何同时提供这两种服务??’”

不过，多纳托指出，栖息地的缩小并不是北方斑点猫头鹰面临的唯一问题. There’s also a different adversary at play:

THE BARRED OWL

On top of losing its preferred habitat, the spotted owl faces another challenge: a larger, aggressive cousin. 横斑猫头鹰原产于北美东部，但现在已经在斑点猫头鹰的西海岸领地安营扎寨. And scientists aren’t sure why.

“It wasn’t brought here as far as anyone can tell. It just immigrated across the continent,” Donato says.

No matter why barred owls came to the region, 美国西部不断变化的景观使他们更容易留在这里. While spotted owls need old-growth forests to survive, barred owls can thrive in both young and old forests. That means the current landscape now favors the barred owl.

Left: Northern Spotted Owl. Right: Barred Owl. Photos courtesy of U.S. National Park Service.

乍一看，这两只鸟很容易被误认为是彼此. The barred and spotted owls are the same size, have about the same wingspan, and have brown and white feathers. The photo above is a comparison from the National Park Service. But Donato says that’s where their similarities end. 而多纳托将北方斑点猫头鹰描述为一种“成熟”的生物, the barred owl is infamous for its hostility.

“Barred owls are just super aggressive. They don’t have the same personality at all.”

This evil twin is causing problems for its easygoing look-a-like. 横斑猫头鹰与斑点猫头鹰竞争，将它们赶出自然栖息地. Sometimes, the barred owl even preys on the spotted owl. With the spotted owl population now in a downward spiral, scientists are stepping in.

“鱼类和野生动物管理局正在进行实验，以消除横斑猫头鹰,” Donato explains. “If you create a vacuum with no barred owls in it, the spotted owls, if they are still out there somewhere, will they come back and use the habitat?”

多纳托怀疑潜伏在原始森林阴影中的斑点猫头鹰比一些专家认为的要多.

“They’ve actually just learned to be quiet. 它们不再回应我们的呼唤，因为它们已经学会了，当它们回应我们的呼唤时, they get beat up by barred owls,” Donato says.

Despite a litany of challenges facing the Northern spotted owl, Donato says he’s hopeful their fate won’t feel quite as bleak one day. 他说，这种希望在一定程度上源于他职业生涯早期的一个晚上，当时他和一个猫头鹰叫声播音员一起被派去试图引起斑点猫头鹰的反应.

“他们让我去做这个荒谬的练习，感觉就像一切都被完全剪掉了一样. 所有的森林都是年轻的，除了这些小块的老森林分散在周围，”他回忆道.

After many calls went unanswered, he was ready to pack up and go home.

“Then from the distance, I heard a spotted owl respond. 这对我来说很痛苦，因为我有点放弃了，”多纳托说. “It was like the owl was telling me, ‘Don’t give up on me yet. I’m still finding a way somehow.’”

WHY IT MATTERS

As the plight of the Northern spotted owl shows, 再造林比种澳门威尼斯人游戏和抱最好的希望要复杂得多. 这只鸟的挣扎是一个重要的提醒，提醒我们需要保持微妙的平衡 world’s most critical ecosystems. Because everything is interconnected.

改变一个因素，你就改变了大自然赖以生存和繁荣的复杂系统. 有时，这些决定可以引导生态系统朝着积极的方向发展. Done thoughtlessly, it can backfire altogether. It’s a fragile dynamic that can’t be ignored.

这就是植澳门威尼斯人游戏节基金会与全球重点地区的专家保持联系的原因, like the American West. 通过与经验丰富的人合作，他们了解景观的复杂需求, we’re able to put the right tree, in the right place, for the right reason.