Benefits of modelling abundance for rare species conservation: a case study with multiple birds across one million hectares

Aim: Many management programs that are based on the needs of rare or threatened species are ineffective because they fail to collect enough data to reliably estimate abundance and map distributions for their target species. Information that does exist for rare species is often based on presence-only data, because it is difficult to collect sufficient data on abundance for such species. We targeted ten rare bird species that were excluded from a recent study due to insufficient data. For these species, we aimed to (a) collect sufficient abundance data, (b) identify important locations and (c) estimate population sizes.
Location: A large reserve system (~1M-ha) in south-eastern Australia.
Methods: We undertook intensive field surveys, using repeat area searches of 660 independent 25-ha sites, totalling 2,640 hrs of surveys (2-hr surveys; two surveys per site). We used N-mixture models to estimate abundance whilst accounting for imperfect detection.
Results: This survey effort returned eno..., This DOI comprises all the data required to run the N-Mixture models for each of the target species. It is also formatted for this purpose, with separate files for Bird observations, site covariates (e.g. fire-age, elevation) and observation covariates (e.g. wind, time of day). Details of data collection method are below: 
Site selection 
We randomly sampled 660 sites (25 ha each; 410 x 610 m), stratified according to fire-age (years since fire) and fire type (planned burn or wildfire). Through stratification we attempted to balance the dataset by maximising the number of sites in uncommon fire-age classes and in planned burns, which were scarce compared to wildfires. All sites were separated by > 1 km. Sites were arranged in ‘sets’ of three so that a single surveyor could complete one set per day. At least one site per set was within 1 km of the nearest track.
Survey method
From May to October 2022, we conducted 1,346 surveys (2,692 hrs covering 33,650 ha). To achieve this survey e..., , # Benefits of modelling abundance for rare species conservation: a case study with multiple birds across one million hectares

[https://doi.org/10.5061/dryad.c59zw3rgg](https://doi.org/10.5061/dryad.c59zw3rgg)

All the files required to run N-Mixture models for each target species in R ('unmarked' package; Fiske & Chandler 2011). Each species was analysed separately and each species required three different file types: Bird Observations (species counts per site per survey), Site Covariates (e.g. fire-age, elevation) and Observation covariates (e.g. wind, time of day). Details of each file type are provided below. 

## Description of the data and file structure

The data files are formatted for N-Mixture modelling i.e. separate files for Bird Observations, Site Covariates and Observation Covariates.

### BIRD\_OBSERVATIONS\_SPECIES\_NAME.csv files (separate file for each species):

Each of these files includes the bird survey results for a single species. Each 25-hectare study site s...