Chinnici (2024)
Author Information
Sal Chinnici: Humboldt and Mendocino Redwood Companies
Humboldt Redwood Company, LLC (HRC) continued the conservation activities for the Marbled Murrelet (Brachyramphus marmoratus) under the company’s Habitat Conservation Plan (HCP). Project leaders were Sal Chinnici and Mark Freitas of HRC. The HCP requires tracking of murrelet occupancy and numbers over time using both radar and audio-visual (AV) survey techniques. Surveys were continued in 2023 at the Headwaters Forest Reserve and Humboldt Redwoods State Park (the Reserves), and at the Marbled Murrelet Conservation Areas (MMCAs) on HRC forestlands, with the collaboration of Sean McAllister of North Coast Field Biologists, O’Brien Biological Consulting, and Adam Brown of Environmental Protection in the Caribbean.
Since the inception of HCP monitoring (1999), occupied behaviors have been observed in the MMCAs and Reserve stands using AV surveys. In 2023, surveyors conducted 143 surveys at 33 stations and observed occupied behaviors (below canopy flight or circling) in the Headwaters Forest Reserve, Humboldt Redwoods State Park, and all the HRC MMCAs (with the exception of the Shaw Gift MMCA).
Radar surveys track murrelets traveling to and from nesting areas within the MMCAs and Reserves. Radar counts are considered indices of the breeding population. In 2023, 56 radar surveys were conducted at 14 sites. Most murrelets tracked by radar were at Humboldt Redwoods State Park and the Shaw Gift MMCA. The 2023 data indicated that after 22 years of monitoring, trends in radar counts of murrelets in the MMCAs and Reserves have differed during the study period; there has been a significant decline in radar counts in both the Reserves and the MMCAs since the 2002 baseline, but the rate of decline in the MMCAs is slower.
A recent publication discusses the results of our monitoring: Brunk, et al., 2021. Assessing the effectiveness of a forest Habitat Conservation Plan for a threatened seabird, the Marbled Murrelet. Ornithological Applications, 123, 1–15.
