Males Mating With Males?

I found the article Pollution Making Males Birds Mate With Each Other on TreeHugger, which later led me to a more indepth explination on a UK website Daily Mail. The name of the article caught my eye, and it infact, turned out to be very interesting.
Pollution has been known to have small effects on many animals reproductive systems, but never to this extreme.  Researchers have found that when even low levels of the poisonous metal compound methylmercury is ingested in a male white Ibises' diet, the male birds attempt to mate with other male birds and completely ignor the female birds.  Methylmercury is a form of mercury. The metal  is liquid at room temperature and has been seeping into groundwater from ­industries for years.
One researcher, Peter Frederick ­captured 160 young white Ibises and gave them food laced with methylmercury. They put the birds into four groups. One group ate food with 0.3  parts per ­million methylmercury (most U.S. states would call this too high for human consumption). A second group was fed 0.1 ppm, and the third 0.05 ppm (a dose that wild birds would be exposed to frequently). The fourth group received food with no poison. All three dosed groups had significantly more homosexual males than the control group. Male-male pairs courted, built nests together and paired off for several weeks.
Scientisit are not exactly sure why this is happening.  They knew mercury could depress their testosterone levels, but not to this effect.
This relates to class because if the male birds keep ignoring the female birds, the reproduction rate will go down, making the overall population of that species go down.  This can later start affecting other species as well.