I don't usually donate to charities because the vast majority of the donation never actually goes to the cause it was donated for in the first place. However, I try to give cash to the homeless as often as Ican. On my drive home I frequently see homeless people and I try to give money and also bottled water that I usually have in my car. I don't know what they'll use it for, but it's something I can do right there and then for them and I know they at least have the opportunity to buy some food / necessities, and I know they have water.

As other people have said it's somewhat all of the above, though the biggest and most visible on xray is the narrowing of the joint space from deterioration of the cartilage. This causes arthritis, and also calcification of the joint which is also all worsened with age and varying bone density which can change based on things like ancestry, gender, habits (drug use/smoking) or medical conditions.

Edit: I also forgot to mention that occupation can make a big difference here. Being overweight AND having a job that is strenuous on the knees (construction/manual labor/heavy lifting) is a bad combo which can lead to joint deterioration and premature joint replacement as well.

This is still really cool to think about, because I never really thought of an animal actively seeking out another as prey not only as food but also for other properties like chemicals that that animal may have ingested. In this situation is seems like an edge case if it ever did happen, or just as you said a happy surprise. Though that does make me wonder if there are any other instances of this in other animals and also how often it might be un-recognized by researchers. Lots of food for thought there.

Rad tech here: most people who have this phenomenon have arthritic knees from being fat. Internet disclaimer: I DIDN'T SAY ALL. But a huge number of people get to 30s or 40s and are overweight or have been for a significant part of their life and have worn out their knees at an early age. Then they come to get xrays with "idiopathic" knee pain.

Whelp now I too am wondering that.

That's where you're wrong: for nature's pocket can still be picked and it doesn't even need to be full to do so

White Faced Scops in dire need of some coffee

What a nice looking chap. I bet he's just happy to have visitors!

I love the pointy boys that make really good webs!

That's the real fucking mystery here

JUST KEEP DRINKING WATER AND CONCENTRATING THE SHEER FORCE OF YOUR ANGER INTO YOUR PEEHOLE AND THAT MF WILL FLY OUT OF THERE LIKE A BIRD WITH BACON IN IT'S BEAK

Gordon getting that goooooood stretch