Hagan Bird Research Results Distorted by Industry

by LeRoy Bandy

Neotropical migrant bird species (NTMS) are birds which breed in temperate and arctic North America and winter in the Caribbean Region or Central and South America. During the period preceding the Ban Clearcutting Referendum in the summer and fall of 1996, timber industry personnel and representatives of so-called "moderate" environmental organizations, made statements to the effect that clearcuts were beneficial to forest- inhabiting NTMS. For example, a forester employed by one of the major timberland management corporations stated at a public meeting that "neotropical migrant songbirds love clearcuts," implying that all NTMS benefit from clearcutting. However, this is untrue.

The habitat types required by the various NTMS range from the early stages of forest succession to mature woodlands. Some species such as the Gray Catbird, Chestnut-sided Warbler and Common Yellowthroat do reach their greatest abundance in the young tree growth such as that found on regenerating clearcut sites. Other species, however, are adversely affected by clearcutting. For many species such as the Black-throated Blue Warbler, Ovenbird and Bay-breasted Warbler, mature woodlands are essential for reproductive success. Clearcutting, heavy partial cuts, and short-term rotations are eliminating these mature woodlands.

Opponents of the Ban Clearcutting Referendum cited the research work of Dr. John M. Hagan of the Manomet Observatory, as evidence of the beneficial effects of clearcuts. Dr. Hagan has been conducting research on bird populations on timber company lands since 1992. In a private meeting with FEN biologists in Augusta this past July, Dr. Hagan admitted that his findings were taken out of context and distorted by opponents of the Ban Clearcutting Referendum.

In direct contradiction to the claims made by timber corporation employees and misguided environmental organization representatives, Dr. Hagan's recent paper (1996) published in the journal Conservation Biology provides evidence that clearcutting on Maine's woodlands may actually be threatening certain NTMS over extensive areas. The sudden loss of habitat on clearcut sites forces some species to crowd into adjoining forest fragments.

For Ovenbirds, the only species Hagan studied in detail, crowding resulted in decreased mating success. There is a possibility that a similar decrease in breeding success is occurring among other clearcut-displaced songbird species. Dr. Hagan's published data taken in context do not justify clearcutting as a forest practice. Environmental organizations which opposed the Ban Clearcutting Referendum were too quick to accept a misleading interpretation of his data.