2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
unsuitable for accurate and effective data collection, including an absence of territorial behavior by the
sparrows. No such problems were encountered during these two surveys. All survey data were
initially recorded in the field on hard copy maps of each zone and then transferred in the office to GIS
database files.
The location of each Belding’s Savannah sparrow territory observed was plotted on a map based on the
behavior observed which included: singing by a perched male, extended perching together of mates,
territorial defensive behavior demonstrated by circular chasing of birds from a territory, scolding,
carrying nesting material or food, feeding young, extended high and fully exposed perching of
individuals, and scolding. All behaviors were marked on the field map of the zone being assessed. At
the completion of the survey of each zone, the biologist reviewed the notes, assessed the significance
of each behavior noted, and wrote down a tally of the total number of territories assessed in that zone.
Biologists were careful to keep track of birds within a zone to avoid over counting territories and did
not spend too much time in a particular zone to avoid confusion. The ranking of behavior used to
determine a territory, listed from most-certain to least-certain, was: extended perching of a pair,
singing male, territory by chase, and extended exposed perching by a male. If the biologist mapped a
male as perched for an extended period of time, but it later began singing, the singing would supersede
the perching in making the determination and the final map would show a single singing male.
From these breeding and territorial behaviors, the number and approximate locations of territories
within each zone were estimated. This method has been used by the U.S. Fish and Wildlife Service
and California Department of Fish and Game when the scope of the surveys does not include precise
determination of the number of territories present. This technique has been used for statewide surveys
(Zembal et al., 2006). However, a clearly defined, written protocol for surveys of this type does not
exist and there will therefore be some unavoidable variation in technique and judgment between survey
programs.
Results
The location of the Belding’s Savannah sparrow territories estimated by the observed breeding and
territorial behaviors is shown in Figure 1-19. A total of 177 territories were identified within the study
site in April 2008 and 208 territories in May 2008. The majority of territories were determined by
observation of a singing male (65%), followed by extended perching of pairs (14%), and extended
perching by a male (12%), with the other behaviors making up roughly 9% of the territories
determinations. Territories appeared to be relatively evenly dispersed throughout areas where
pickleweed-dominated salt marsh occurred. Nearly all areas of non-flooded pickleweed that appeared
to be of high quality but had no territorial birds in it were observed to be occupied by Belding’s
Savannah sparrows, though they were engaged in non-territorial behaviors such as foraging or moving
about in groups.
The Future Full Tidal Basin supported the most territories, followed by the Muted Tidal Basins, then
the Seasonal Ponds (Table 1-21). The number of territories did not correlate with the amount of salt
marsh available. The number of territories recorded was about 50% of what was counted in 2007 and
was similar to the count in 2006 (Zembal et al., 2006). The Seasonal Ponds supported 52%-59% of the
territories in 2008 as it did in 2007. The salt panne in this area was flooded throughout the breeding
season and in some cases this flooding also entered into areas of pickleweed. The FFTB also had
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