If you take out the experiment with 5 week old grouse chicks, there is no difference; well other than Pa have 500 blood samples for their data.
More to chew on, other than the mosquito cesspool of State College and a few other urban areas, WNV, and dead birds arent showing up until early August, at that time grouse chicks will be 9-10 weeks old. Again dead birds are showing up around the urban areas and now in the areas we typically find grouse. It isnt until September when horses start to show up with WNV, showing that the disease has now reached the more rural areas. By that time grouse chicks are almost full grown.
So all we really know so far is we can kill grouse chicks in a lab at 5 weeks old, wanna bet we can do the same thing to pheasant chicks? If the experiments were done at 9 & 13 weeks for both grouse and pheasants, what would the results be? But as of right now, everything is being based off 1 experiment at an age when WNV is still not present in the wild.
I think what the dead birds showing up tell us more than anything is that the mosquito are increasing in numbers as the season progresses. but we always knew that early on there were less sketters than there are in the fall. It also tells us the sketters have a jump start in the urban areas mainly because of water temps but also because of still water that is not moving or being disturbed.
However I do follow your logic that small chicks receiving the same dose as an older bird stands less of a chance of survival. I agree.
I also agree that when most chicks are hatched there are less sketters and thus less chances of WNV infection.
What we don't know is if older chicks have the same mortality rate.
So someone must have done a test on some type of foul that were older and has results to compare. I know chickens are used as indicator birds.
Another good point is in the Iowa study we have no idea at what age the roosters were infected.
My whole point in asking about the pheasants is to see if anyone even looked at the possibility.
Lost, what makes you say WNV is not present in the wild when the grouse chicks are born. I say it is there but the vector we all point to is in low numbers but still there.
Another point is that in urban areas more dead birds are found because the chances of being seen on a lawn is better than in the bush and more eyes in the area than in rural areas. The other factor is there are more critters feeding opportunistically on the dead birds in the bush than in the city and towns. Waugh!
Yes I had to use spell check to use that big word LOL.