Gender ration on declining species

[Pajarita]

This is a study done on a species which numbers have been declining in the wild and, when they studied the different flocks, they found that males were outnumbering females in lots of them and propose that as an explanation for the decrease in populations. But what I found very interesting as well as puzzling was the fact that, apparently, the researchers are not taking into consideration that mother birds would produce more males than females on purpose when the conditions are not good so, in my personal opinion, the elevated number of males is not the cause of the decline but a consequence of the problem. Did I read this correctly or do any of you see anything there that I might have missed?

https://www.sciencedaily.com/releases/2 ... 215022.htm