In his 1912 Michigan Bird Life the ornithologist W.B. Barrows observed that the common loon nested “abundantly on most of the ponds and lakes of the state, even to the southernmost border.” Barrows was an informed naturalist, and in his declaration was identifying only that subset of Michigan’s legion waterbodies 6879 of them named that offered both the habitat (islands, hummocks, or bog shoreline) and the space (at least 10 acres) to accommodate nesting loons. Nonetheless, he was suggesting a figure in the many thousands. He was also, at the dawn of the 20th century, already speaking in the past tense:
“Formally it nested abundantly on most of the ponds and lakes of the state, even to the southernmost border, but of late years it is much less common in summer in the more thickly settled parts of the state, although it probably nests in every county. Toward the north it nests in undiminished numbers and during migrations is so abundant in some places as to be a serious annoyance to the fishermen in whose nets it is often entangled and drowned.”
Seventy years later, the first systematic surveying in Michigan’s history estimated the common loon population to be only 300 breeding pairs. In response, the species was listed as Threatened within the state one legislative step below formal Endangerment, and a very long way from the circumstances described by Barrows and his peers.
As of 2007, however, and with the species still Threatened, Common Coast estimated the state breeding population to be 700-800 pairs. In as much as the majority of the 20th century proved inimical to Michigan loons, its conclusion seemed to have reversed that pattern.
How exactly did the state of loons as articulated by the early ornithologists so drastically deteriorate across Michigan? And what mechanisms are responsible for the initiation of an apparent recovery? We attempt to answer these questions in three parts: the past as expressed by the historical record in Oakland County, the present as exemplified by the state’s Loon Lakes, and the future as embodied by the southern limit of the common loon’s range.