From what I remember, during one of the times that I previously volunteered. I too had a similar question regarding Ali’s tusk. According to what a staff member said, they told me that during his musth period, Ali was apparently messing around with some tire enrichment in which, while doing so, his tusk somehow managed to crack off due to his roughhousing. With the zoo’s vets surgically removing what was left of the tusk not too long afterward.
As for the lapwings, they must have been added into the aviary sometime last year. Since I did manage to see (and photograph them), during my second-to-last visit back in December.