Can bird atlas data be used to estimate population size? A case study using Namibian endemics

Identification and gap analysis of key biodiversity areas: targets for comprehensive protected area systems

“…compared to field records across quarter-degree grid (area of occupancy; Harrison et al 1997). Reporting rates correspond to the percentage of visits to each cell in which the species was seen, a proxy for relative abundance (Robertson et al 1995). This reveals that the species is absent from a large part of its extent of occurrence, and that its abundance varies significantly among the quarter-degree cells where it does occur.…”

A new habitat availability index to integrate connectivity in landscape conservation planning: Comparison with existing indices and application to a case study

“…Evidence of breeding in the period 1999-2002 was obtained in that atlas by analyzing field data (species occupancy) collected in each UTM 10 km × 10 km square lying completely within the territory of Catalonia. Then, presence-absence data gathered within a large sample of UTM 1 km × 1 km squares that fell within the known 10 km × 10 km distribution of the species was the basis for estimating its probability of occurrence (from 0 to 1), which is assumed to be a surrogate for species abundance, as supported by additional analysis and validation with independent bird abundance data (Robertson et al, 1995;Estrada et al, 2004). The presence of the species in unsampled areas (nonsurveyed UTM 1 km × 1 km squares) was predicted through niche-based models, which are based on modeling the species' response to a set of environmental variables (forest types, land use, climate, relief, human influence, etc.)…”

Structure of the species–energy relationship

“…We consider presence or absence and reporting rate data for 651 native species excluding marine, vagrant, marginal and introduced or escaped species. Reporting rates are the proportion of checklists submitted for each grid cell with presence records for a given species, and reflect broad differences in local abundances (Robertson et al 1995).…”