Complex sentence: Island birds appear to accumulate significant amounts of lead from scavenging on hunted animal carcasses and the long-term effect of this poison at a sublethal level is not known although it alters the mineralization of their bones.
Split into simpler sentences: Island birds appear to accumulate significant amounts of lead from scavenging on hunted animal carcasses. The long-term effect of this poison at a sublethal level is not known, although it alters the mineralization of their bones.