Estimating nest density when detectability is incomplete: Variation in nest attendance and response to disturbance by western meadowlarks

Matthew D. Giovanni, Max Post Van Der Burg, Lars C. Anderson, Larkin A. Powell, Walter H. Schacht, Andrew J. Tyre

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Researchers commonly model nest density as a function of ecological variables, but nests, like birds, can be undetected while present. In the Nebraska Sandhills in 2007, we used the rope-drag method on previously located Western Meadowlark (Sturnella neglecta) nests to model nest-detection error and nest density. Detecting nests by rope dragging (commonly used for nests of grassland birds) is conditional on two primary sources of nest availability, adults attending nests and adults flushing from nests in response to disturbance from the rope, the behavioral cue necessary for nest detection. On the basis of our trials with rope dragging, the probability of adults attending nests was 0.46. The probability of trials eliciting flight responses from adults was 0.19, indicating that observed estimates of nest density were subject to detection error and negatively biased. We compared our ability to detect differences in nest densities between two habitat types with a statistical power analysis, using (1) t-tests with estimates of apparent, uncorrected density and (2) a Bayesian hierarchical model incorporating nestdetection error. Our power analysis indicates that accounting for detection error in a hierarchical model increased statistical power for revealing differences in nest densities by habitat type. We discuss mechanisms underlying detection error for nests of grassland birds and make recommendations for sampling and modeling to maximize the reality of models for nest detectability and density.

Original languageEnglish (US)
Pages (from-to)223-232
Number of pages10
JournalCondor
Volume113
Issue number1
DOIs
StatePublished - Feb 1 2011

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nest
nests
disturbance
ropes
bird
habitat type
birds
grasslands
grassland
ecological function
habitats
statistical models
flushing
drag
flight
researchers
detection

Keywords

  • Bayesian hierarchical model
  • Detection error
  • False-negative errors
  • Nest attendance
  • Nest density
  • Sturnella neglecta
  • Western Meadowlark

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Animal Science and Zoology

Cite this

Estimating nest density when detectability is incomplete : Variation in nest attendance and response to disturbance by western meadowlarks. / Giovanni, Matthew D.; Van Der Burg, Max Post; Anderson, Lars C.; Powell, Larkin A.; Schacht, Walter H.; Tyre, Andrew J.

In: Condor, Vol. 113, No. 1, 01.02.2011, p. 223-232.

Research output: Contribution to journalArticle

Giovanni, Matthew D. ; Van Der Burg, Max Post ; Anderson, Lars C. ; Powell, Larkin A. ; Schacht, Walter H. ; Tyre, Andrew J. / Estimating nest density when detectability is incomplete : Variation in nest attendance and response to disturbance by western meadowlarks. In: Condor. 2011 ; Vol. 113, No. 1. pp. 223-232.
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