Being able to track them over their lifetimes.

Most surprising: Removing the baby crows from the nest to tag and weigh them and get blood sample.

I'm interested in the team snatching baby birds from the nest for blood draws and other tests. I assume the birds are then replaced in the nests. And the parents are okay with this?

For me the wing tags,

I was surprised by: the really big wing tags, the cradle-to-grave focus, and the life-span of the different kinds of markers.

I was also surprised that the baby crows have no feathers for so long, and that their nests are so hard to spot.

I didn't know that crows lived so long or that a blood test had to be done to determine sex.

Crow nestlings have blue eyes, just like kittens!

I was surprised that the crows were banded with the large patagial band at such a young age. Apparently it doesn't interfere with their growth or ability to learn to fly; otherwise, I'm sure you wouldn't do it.

I don't envy the researchers who have to scale the heights to reach the nests. That is dangerous (though, I imagine, thrilling) work. Do you record the height of each nest and statistically correlate it to the success of each nest?

I was surprised at the triple tagging for identification purposes.  Also interesting is the ability to follow a crow from egg to death with their lifespan being quite long.

I had no idea crows could live for so long, I expected them only to live a couple of years like most of the birds I hear about.

Using 3 types of ID and having them all wear off only halfway through the life cycle!  Very cool that wild crows can live close to 20 years.

It surprised me how much they track and remember the crows,  also I had no idea they lived that long!

It was interesting that they tagged the birds - especially for online tracking. I'd be curious if potential mates prefer certain colors or numbers. Basically, if the tag affects who they choose. It's awesome that they hang out with certain other crows.

Where the crow builds their nest and they pick it with a view. Also, that crows live for a long time and are followed from baby to being adult. The relationships that a crow has with siblings, etc.  Did not know one studied and followed crows.

-that you can go up as close to the nests and it doesn't seem to disturb the babies or parents
-that Crows can live for almost 2 decades
-that you can get to know and distinguish between Crow siblings, parents, relationships.

You probably know this but Vancouver, BC, has a huge (HUGE!) Crow population and every evening just before sundown they are seen flying over East Van back to their nesting grounds by the Trans Canada Highway #1, where they congregate in a large group of trees and talk and chatter to one another. Seeing that many Crows in a grove of trees is truly astonishing because there are so many Crows - literally thousands - the tree branches are black!

That they use trackers on crows to study where they travel and who they travel with. Also, I'm wildly impressed that Crows can live to be 19 years old!

I wasn't aware of the extent to which you study individual crows and how they interact in group settings. It sounds almost anthropological!

The fact that the crows have to be retagged given that they live as long as they do.  I had no idea crows could live up to 19 years or more.

I'm wondering if taking the nestlings to tag and draw blood causes the parents to be distrustful of the researchers.

The blue eyes on the babies was the most interesting for me. Also the greying feathers with age.

Longevity of the crow and the fact that you use multiple ID tools.

Question- When you find one nest how big of a radius do you search for another? Since they live in groups I am wondering how far apart they nest. Could it have something to do with how far they can hear ?

I was surprised to learn they use three different methods of identification and that the tag and bands actually wear off over time. It makes sense now; that possibility just never came to mind.

That picking them from the nest isn't contributing to the mother rejecting the babies.

I was surprised how much i.d. a bird could carry (bands, wing tag, radio transmitter) before it would be considered a burden to that bird. Do those crows get targeted as prey more easily by raptors? Because I notice them more readily because of the i.d. Some of them look like very peculiar crows with those extra “field marks.”