Spatial Models to Account for Variation in Observer Effort in Bird Atlases

To assess the importance of variation in observer effort between and within bird atlas projects and demonstrate the use of relatively simple conditional autoregressive (CAR) models for analyzing grid-based atlas data with varying effort. Pennsylvania and West Virginia, United States of America. We used varying proportions of randomly selected training data to assess whether variations in observer effort can be accounted for using CAR models and whether such models would still be useful for atlases with incomplete data. We then evaluated whether the application of these models influenced our assessment of distribution change between two atlas projects separated by twenty years (Pennsylvania), and tested our modeling methodology on a state bird atlas with incomplete coverage (West Virginia). Conditional Autoregressive models which included observer effort and landscape covariates were able to make robust predictions of species distributions in cases of sparse data coverage. Further, we found that CAR models without landscape covariates performed favorably. These models also account for variation in observer effort between atlas projects and can have a profound effect on the overall assessment of distribution change. Accounting for variation in observer effort in atlas projects is critically important. CAR models provide a useful modeling framework for accounting for variation in observer effort in bird atlas data because they are relatively simple to apply, and quick to run

Coverage and Results

This is part of a culmination of a 10 year collaborative effort involving many state agencies, academic institutions and NGOs. This 612 page atlas, based on the fieldwork of 2000 birdwatchers, provides details on the status and distribution of the Commonwealth’s 190 breeding bird species

Interpreting Species Accounts

This is part of a culmination of a 10 year collaborative effort involving many state agencies, academic institutions and NGOs. This 612 page atlas, based on the fieldwork of 2000 birdwatchers, provides details on the status and distribution of the Commonwealth’s 190 breeding bird species

Second Atlas of Breeding Birds in Pennsylvania

This book documents current distribution and changes in status for nearly two hundred bird species. More than two thousand dedicated birdwatchers completed surveys of birds across the state from 2004 to 2009. The data amassed reveal the distribution of each species and show changes in distribution since the publication of the first Atlas. Additionally, a highly trained survey crew carried out bird counts at more than 34,000 locations statewide. These counts tabulated not just species but individual birds as well, in a manner that—for the very first time—enabled precise estimates of the actual statewide populations for more than half of the 190 breeding species detected. In all, more than 1.5 million sightings were compiled for the second Atlas, providing an unprecedented snapshot of the bird life of Pennsylvania—and perhaps of any comparably sized region in the world. From the Publisherhttps://cupola.gettysburg.edu/books/1019/thumbnail.jp

Stewardship Responsibility of Pennsylvania Public and Private Lands for Songbird Conservation

Preservation of large blocks of suitable habitat is an important conservation strategy for many species, and such protected areas often are publicly owned. In some cases, however, the extent of private land far exceeds that of public land, or species may prefer habitats that are predominantly privately owned (e.g., agricultural). Thus, it is important to understand the stewardship roles of both public and private land for species conservation. We used hierarchical multispecies occupancy models to evaluate the occurrence probabilities of 59 passerine bird species, including Species of Greatest Conservation Need, on public and private land in Pennsylvania, USA. Species strongly associated with forests disproportionately occupied public land, whereas grassland-associated species were strongly associated with private lands. Species associated with early-successional or shrub/edge habitat had more mixed responses. Our results emphasize that, despite the obvious importance of public land for some species, addressing habitat conservation on private lands is crucial for effective conservation of most passerine species, even in a region with extensive public land and for species strongly associated with public land

Software Carpentry: Version Control with Git

A half-day introduction to version control with Git and GitHub for researchers, developed and maintained by the Software Carpentry team