@misc{indiciae3d25ddb8aeb1,
  title = {Censusing wading bird colonies: An update on the 'flight-line' count method},
  author = {R.M. Erwin},
  year = {1981},
  doi = {10.2307/1521120},
  url = {https://pubs.usgs.gov/publication/5221705},
  note = {Source identifier: 5221705}
}