I had more trouble understanding how nest deprivation could be equivalent to “**** me, make it stop. Like someone slicing into my leg with a hot, sharp live wire.” So I looked up the underpinnings of this metric, in Ch. 6 of the book they build their analysis on (pg. 6-9 is the key material).
They base this on the fact that chickens pace, preen, show aggressive competition for nests when availability is limited, and will work as hard to push open heavy doors to access nests as they will to access food after 4-28 hours of food deprivation. Based on this, the authors categorize nest deprivation as a disabling experience that each hen endures for an average of about 45 minutes per day.
This is a technically accurate definition, but I still had trouble intuiting this as equivalent to a daily experience of disabling physical pain equivalent to having your leg sliced open with a hot, sharp live wire.
Researchers are limited to showing that chickens exhibit distress during nest deprivation, or, in more sophisticated research, that they work as hard to access nest boxes as they do to access food after 4-28 hours of food deprivation.
I am suspicious of the claim that these methods are adequate to allow us to make comparisons of physical and emotional pain across species. This is especially true with the willingness-to-work metric they use to compare the severity of nest deprivation and starvation on chickens.
Willingness-to-work is probably mediated by energy. After starvation, chickens will be low-energy, and willingness-to-work probably underestimates their suffering. A starving person would like to do 100 pushups to access an all-you-can-eat buffet, but physically is unable to do so. If he’s also willing to do 100 pushups to join the football team, does that mean that keeping him off the team is as bad as starving him?
People show distressed behaviors in the absence of suffering. I bite my fingernails pretty severely. Sometimes, they even bleed. It’s not motivated by severe anxiety in those moments. It’s just force of habit. Chickens may be hardwired by evolution to work hard to access nests, without necessary suffering while they do so.
Our perceptions of how distressed a behavior is is culturally-specific, not to mention species-specific. I pace and walk around the neighborhood when I’m thinking hard. People get piercings and tattoos. People fight recreationally. We don’t assume that people are experiencing high emotional distress in the moments they choose to do these things. Why do we assume that about chickens?
I’ve spent too long writing this comment, so I’m going to just stop here.
Thank you for contributing more information.
I understand and appreciate the thinking behind step in Ren’s argument. However, the ultimate result is this:
My main takeaway is that the breadth and variety of experience that arguably falls under the umbrella of “disabling pain” is enormous, and we can only have low-moderate confidence in animal welfare pain metrics. As a result, I am updating toward increased skepticism in high-level summaries of animal welfare research.
The impact of nest deprivation on laying hen welfare may still be among the most pressing animal welfare issues. But, if tractability was held constant, I might prefer to focus on alleviating physical pain among a smaller number of birds.
Also, to disagreevoters, I’m genuinely curious about why you disagree! Were you already appropriately skeptical before? Do you think I am being too skeptical? Why or why not?