After the Vision Fire : Monitoring Landbirds in the Riparian Zone

We monitored the riparian bird community for two years following the 1995 Vision Fire in the Point Reyes National Seashore (PRNS), Marin County, Cal i for nia. We compare bird and vegetation data on burned and unburned sites within PRNS and the Golden Gate National Recreation Area. Bird abundance, as indexed by fi xed-radius point counts, was higher for sev er al shrub-nesting species at burned sites than at un burned sites. For some tree nest ing spe cies, however, abundance was lower at burned sites. A comparison of vegetation data collected at the bird survey points showed that burned riparian had sig nifi cant ly less tree cover and had greater shrub and herb cover than unburned sites. Re pro duc tive success and sur viv al may serve as better in di ca tors of habitat quality and pop u la tion health than abun dance of individuals. There fore, we lo cat ed and monitored nests of the Song Sparrow (Melospiza melodia) – a spe cies whose abun dance was greater in the re cent ly burned riparian hab i tat – to es ti mate nest survival at one burned site (Muddy Hol low) and two unburned sites (Lagunitas and Olema Creeks). We then built population growth rate models ( ) to de ter mine the rela tive “source-sink” status of this species by site, to index local pop u la tion health. Nest sur viv al was sig nifi cant ly higher on the burned site than the un burned sites, and the values suggested that the burned site was a population source while the unburned sites were sinks. The fact that abun dance and re pro duc tive success were higher at the burned site is intriguing because it suggests that high Song Spar row abundance can be used to infer habitat quality in coastal riparian areas, but more rigorous studies are need ed. Our results provide evidence that fi res in riparian zones may benefi t breeding populations of songbirds (given the right conditions and timing) and high light the utility of mon i tor ing programs to land man ag ers.