Establishment of eastern Purple Martin colonies within privately owned working forests

Establishment of eastern Purple Martin colonies within privately owned working forests
Dr. Daniel Greene, Weyerhaeuser
Many long-distance avian migrants breeding within North America, including the Purple Martin (Progne subis), are entrenched in steep population declines. Loss of breeding habitat, including nesting areas are among the many reasons implicated in these declines. Today, 87% of the forested land throughout the southern U.S. is privately owned. Much of this area consists of working forests used for timber production that is managed under a sustainable forestry standard. These working forests cover nearly 12.15 million hectares within this region and contribute substantially to the conservation of native flora and fauna, including numerous imperiled species. With a shift of private lands management in promoting early successional conditions and open canopy conditions, we are evaluating the ability of managed provisioned housing erected within private working pine (Pinus spp.) forests to establish and maintain new colonies of eastern Purple Martins (P. s. subis). In January 2020, we deployed 9, 12-unit Purple Martin gourd racks throughout approximately 25,000 hectares of mostly contiguous, working forests in the Interior Flatwoods and Upper Coastal Plain geographic provinces of east-central Mississippi. These forests are predominately loblolly pine (Pinus taeda) with mature pine-hardwood or hardwood stands occur intermittently throughout the study area. We systematically selected 0 to 2-year-old clearcuts in areas of high landscape heterogeneity, streamside management zones, and with adjacent stands to be clearcut within three years that will serve as relocation sites when early successional conditions around gourd racks decline. In 2020, we first detected Purple Martins in July, had occupancy at 3 racks, and breeding at one rack. In 2021, we observed martins at 6 racks and had breeding at 5 racks. Martins are still arriving in 2022, but to date, we documented our earliest arrival on Feb 28, with occupancy at 7 racks, and breeding 6 racks. Increasing use of nest colonies within our study sites reflects positive adoption of colonies within this managed forest system. To our knowledge, these are the first martins fledged in a working forest within the range of P. s. subis, supporting evidence that working forests provide conservation opportunities for this species and other colonial-nesting, insectivorous birds.