J. Yantachka. Forest Bird Communities in the Adirondack Mountains: Effects of Calcium Availability and Evaluation of an Automated Survey System. 128 pages, 7 tables, 18 figures, 2013.
The Adirondack Mountains have experienced widespread soil calcium depletion due to chronic acidic deposition. Calcium depletion alters snail communities and negatively affects passerine clutch formation and nestling development. To investigate ecosystem effects of acidic deposition and calcium availability in the Adirondacks, I surveyed upland hardwood bird communities along a soil calcium gradient. Passerine diversity and species richness were not related to soil calcium availability, acidic deposition inputs, or snail abundance. Passerine and ground gleaner abundance were positively related to snail abundance, indicating snails may be the mechanistic link between soil calcium and some passerine populations. Future studies should investigate how snail availability may affect songbird reproduction in the Adirondacks. Microphone-based automated digital recording systems may help by increasing the number, consistency, and efficiency of time- and labor-constrained avian survey efforts. If some bird species are limited by calcium availability, then conservation efforts could prioritize calcium-rich sites as refugia from acidification.
Key Words: acidic deposition, soil calcium, snails, songbird surveys, automated digital recording systems.