The Effectiveness of Tape Playback in Estimating Black Rail Density

Yellow-Billed Cuckoo Distribution, Abundance, and Habitat Use Along the Lower Colorado and Tributaries, 2006 Annual Report

“…Song playback is commonly used to survey for bird species that are not readily detected visually and to increase response rate compared to passive surveys. With secretive species, song playback is often the only way to survey efficiently, especially if natural rates of vocalization are low (Legare et al 1999). The method is thus appropriate for yellow-billed cuckoos, which are secretive and not readily detected visually, and vocalize infrequently, especially in areas with low cuckoo densities (as evidenced during this study).…”

Distribution and Habitat Associations of California Black Rail (Laterallus jamaicensis coturniculus) in the Sacramento–San Joaquin Delta

“…Additionally, the secretive nature of all rail species leads to low and imperfect detection rates which require the use of call playback survey techniques and high levels of survey replication in order to estimate the metrics needed to model distributions and habitat associations (Spear et al 1999;Legare et al 1999;Conway et al 2004). Data which are collected using less intensive methods are still useful but should be considered to represent presence-only rather than abundance or presenceabsence (Conaway et al 2004).…”

“…Though this could indicate lower densities within the Delta, we suspect that detection rates were influenced by the timing of surveys, the logistical challenges associated with surveying Delta habitats (i.e., callplayback surveys from medium-sized watercraft), low detection probability, and a lack of survey replication within season (Spear et al 1999;Legare et al 1999;Conway et al 2004). Our results do not represent a comprehensive survey of the Delta and should not be interpreted as an indication of population size or density in the region; focused surveys which incorporate occupancy sampling would better inform density and population size estimation.…”

Effect of Tide Level and Time of Day on Detection Rate and Abundance of Clapper Rails (Rallus longirostris) in a Mid-Atlantic Tidal Marsh System

“…Estimates of abundance or density rely upon estimates of detection probability and either 1) a consistent positive correlation between number of individuals detected during a survey and number of individuals actually present in the area sampled (i.e., low spatial and temporal variation in detection probability), or 2) incorporating environmental covariates into the estimation process that effectively control for most of the variation in detection probability. Few reliable estimates of detection probability during marsh bird surveys are currently available (but see Conway et al 1993, Legare et al 1999, Conway and Gibbs 2001, Bogner and Baldassarre 2002. However, these survey protocols incorporate methods for estimating components of detection probability.…”

“…Estimate distance to each bird when the bird is first detected (birds will approach the callbroadcast [Legare et al 1999, Erwin et al 2002 so surveyors need to record the distance to the bird when the bird was first detected). Recording distance to each individual will allow us to use distance sampling to estimate density for each species in each habitat type.…”