Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16782
Polychlorinated biphenyls in a wild mink population
No abstract available.
Authors
T. J. O'Shea, T. E. Kaiser, G.R. Askins, J.A. Chapman
Remarks on the use of mark-recapture methodology in estimating avian population size
No abstract available.
Authors
J. D. Nichols, B.R. Noon, S.L. Stokes, J. E. Hines
Analysis of bird survey data using a modification of Emlen's method
No abstract available.
Authors
F.L. Ramsey, J. M. Scott
Effect of time of day on bird activity
Breeding season activity, based on detections recorded on more than a million 3. minute Breeding Bird Survey stops, reaches a peak for most species during the hour centered at sunrise or in the following hour. Activity of most species then declines gradually as the morning progresses. When large samples are considered, activity patterns for a given species are quite constant from year to year; bu
Authors
C.S. Robbins
Bird activity levels related to weather
The Breeding Bird Survey data bank serves as a primary source for studying effects of sky cover, wind speed, and temperature on bird census results. Other standardized methods, such as spot-mapping (Breeding Bird Census), point counts, banding, and the Winter Bird Survey, provide additional, but limited, means of assessing effects of weather. Numbers of songbirds detected are generally inversely
Authors
C.S. Robbins
Reappraisal of the Winter Bird-Population Study technique
Standardized morning and afternoon counts were conducted in two deciduous forest plots during seven winters. Morning counts yielded more species than afternoon counts, as well as higher counts of most species. A minimum of eight visits is recommended. Six visits yielded 2% to 5% fewer species, depending on the size and bird population of the study plot. Cumulative means for individual species vari
Authors
C.S. Robbins
Length of count period as a possible source of bias in estimating bird densities
No abstract available.
Authors
J. M. Scott, F.L. Ramsey
Problems in separating species with similar habits and vocalizations
The possibilities for species misidentification based on vocalization or habitat association are high. However, the magnitude of the errors actually perpetrated is generally within an acceptable range in most types of bird survey work. Examples of problems discussed are: congeners that are similar in appearance or in song (such as Chimney and Vaux's Swifts, Chaetura pelagica, C. vauxi; Hammond's,
Authors
C.S. Robbins, R.W. Stallcup
Distance estimation as a variable in estimating bird numbers from vocalizations
No abstract available.
Authors
J. M. Scott, F.L. Ramsey, C.B. Kepler
Nutritionally-related diseases of captive-reared cranes and ratites
No abstract available.
Authors
J.A. Serafin