One wildlife objective is to enhance the quality and maintain the quantity of riparian bird nesting and foraging habitats. To test progress towards this objective, bird abundance and species diversity is measured at a selection of temporal and spatial scales across the 40-mile river reach. Monitoring trends can determine if populations and species diversity are being maintained along the river. As reported in 2009, trends in abundance over eight years for the five target species showed significant increases for four of the five species: Black-headed Grosbeak, Song Sparrow, Yellow-breasted Chat, and Yellow Warbler. Trends varied by species at the sampling reach scale. Analyses are focused on reach-scale trends and their relationships to habitat changes resulting from implementation.
Analyses to determine whether the current sampling enables the Program to detect changes in bird population measures have also been completed. The current sampling effort and distribution of sampling locations is considered sufficient for a 90 percent probability of detecting trends over five to ten years.
Suggested further reading:
Miller, S L; Ralph, C J; Wolfe, J D; and Ollivier, L M (2010) Trinity River Restoration Program riparian and riverine bird monitoring report 2002-2009 (except appendix D).
Miller, S L; Ralph, C J; Wolfe, J D; and Ollivier, L M (2010) Trinity River Restoration Program riparian and riverine bird monitoring report 2002-2009, appendix D.
Miller, S L and Ralph, C J (2010) Are riverine bird populations changing in the Trinity program area? Trends from 2002 to 2009. Oral presentation provided at the 2010 Trinity River Science Symposium
Miller, S L and Ralph, C J (2010) Desired habitat components for targeted Trinity River riparian birds. Oral presentation provided at the 2010 Trinity River Science Symposium
Miller, S L; Ralph, C J; and Herrera, P (2003) Trinity River Restoration Program avian monitoring 2002 report.