Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16759
Avian communities in riparian forests of different widths in Maryland and Delaware Avian communities in riparian forests of different widths in Maryland and Delaware
In agricultural landscapes, much of the remaining forest is in linear tracts along streams. These riparian forests provide habitat for forest birds, but their use by forest interior birds may depend on forest width. We conducted point-count surveys of birds in riparian forests on the Eastern shore of Maryland and Delaware to assess whether the presence of any species was dependent on...
Authors
C.M.E. Keller, C.S. Robbins, Jeff S. Hatfield
First results of a deep tow CHIRP sonar seafloor imaging system First results of a deep tow CHIRP sonar seafloor imaging system
The latest and most innovative technology has been applied towards the development of a full-ocean depth multi-sensor sonar system using linear swept-FM (Chirp) technology. The seafloor imaging system (SIS- 7000) described herein uses Chirp sidescan sonar to provide high resolution imagery at long range, and Chirp subbottom sonar to provide high resolution profiles in both the near...
Authors
M. Parent, Changle Fang, Thomas F. O’Brien, William W. Danforth
Volitional migration of Atlantic salmon from seasonal holding ponds Volitional migration of Atlantic salmon from seasonal holding ponds
For 5 years we used seawater tolerance tests (seawater challenges) to identify smolts, and tunnel fish counters to record the time of migration, of Atlantic salmon Salmo salar that volitionally left holding ponds on the Merrimack River near Litchfield, New Hampshire. We compared timing of Atlantic salmon movements with environmental conditions and blood composition of migrating and...
Authors
S. Rottenborn, Lori A. Redell
Preservation of genetic variation in the Green Lake strain lake trout derived from remnant domestic and feral populations Preservation of genetic variation in the Green Lake strain lake trout derived from remnant domestic and feral populations
The Green Lake, Wisconsin, strain of lake trout Salvelinus namaycush was discontinued as a hatchery brood stock in 1976 after Lake Michigan was stocked with the 1975 year‐class. In 1982, a decision was made to restore the Green Lake strain as a production brood stock. Five groups were produced by spawning marked fish that were survivors from the 1976 stocking of southern Lake Michigan. A...
Authors
H. L. Kincaid, C.C. Krueger, B. May
Genetic comparison of naturally spawned and artificially propagated Lake Ontario lake trout fry: Evaluation of a stocking strategy for species rehabilitation Genetic comparison of naturally spawned and artificially propagated Lake Ontario lake trout fry: Evaluation of a stocking strategy for species rehabilitation
Two strategies have been used in the effort to restore lake trout Salvelinus namaycush to Lake Ontario. First, lake trout strains from multiple wild and hatchery sources have been stocked to maximize genetic variability in the lake, Second, a unique hatchery “strain” of fish to be stocked was created each year with gametes collected from adult, hatchery‐origin fish that had survived to...
Authors
J.E. Marsden, C.C. Krueger, P.M. Grewe, H. L. Kincaid, B. May
Edge-driven microplate kinematics Edge-driven microplate kinematics
It is known from plate tectonic reconstructions that oceanic microplates undergo rapid rotation about a vertical axis and that the instantaneous rotation axes describing the microplate's motion relative to the bounding major plates are frequently located close to its margins with those plates, close to the tips of propagating rifts. We propose a class of edge-driven block models to...
Authors
Hans Schouten, Kim D. Klitgord, David G. Gallo
Wolf nipple measurements as indices of age and breeding status Wolf nipple measurements as indices of age and breeding status
We measured nipple sizes of 29 captive wolves (Canis lupus), of known breeding histories, throughout the year and tested distinctions among various known breeding statuses of 20 wild wolves examined in northeastern Minnesota from May through September. For ca. 8 mo of the year only breeders and nonbreeders can be classified. Distinctions between current and former breeders were not...
Authors
L. David Mech, Thomas J. Meier, Ulysses S. Seal
Relative effects of nutrient enrichment and grazing on epiphyte-macrophyte (Zostera marina L.) dynamics Relative effects of nutrient enrichment and grazing on epiphyte-macrophyte (Zostera marina L.) dynamics
The independent and interactive effects of nutrient concentration and epiphyte grazers on epiphyte biomass and macrophyte growth and production were examined in Zostera marina L. (eelgrass) microcosms. Experiments were conducted during early summer, late summer, fall, and spring in a greenhouse on the York River estuary of Chesapeake Bay. Nutrient treatments consisted of ambient or...
Authors
Hilary A. Neckles, R. L. Wetzel, R.J. Orth
Simulation testing of unbiasedness of variance estimators Simulation testing of unbiasedness of variance estimators
In this article I address the evaluation of estimators of variance for parameter estimates. Given an unbiased estimator X of a parameter θ, and an estimator V of the variance of X, how does one test (via simulation) whether V is an unbiased estimator of the variance of X? The derivation of the test statistic illustrates the need for care in substituting consistent estimators for unknown...
Authors
William A. Link
The common wolf snake, Lycodon aulicus capucinus, a recent colonist of Christmas Island in the Indian Ocean The common wolf snake, Lycodon aulicus capucinus, a recent colonist of Christmas Island in the Indian Ocean
The discovery of the common wolf snake, Lycodon aulicus capucinus, on Christmas I . in the Indian Ocean suggests that individuals of the species have colonised the island recently. On the basis of biological information for this widespread colubrid snake and for the brown tree snake, Boiga irregularis, a well-documented pest species on Guam, the establishment of the common wolf snake...
Authors
T. H. Fritts
40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia 40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia
40Ar/39Ar age spectra of hornblende, muscovite, and microcline, and total fusion ages of biotite from metamorphic rocks of the Inner Piedmont, Pine Mountain, and Uchee belts are reported. Mineral cooling ages from the eastern part of the Inner Piedmont are as follows: hornblende, 320 Ma; muscovite, 296 Ma; biotite, 293 Ma; and microcline (diffusional release patterns) Tmax = 267 Ma, Tmin...
Authors
Mark G. Steltenpohl, Michael J. Kunk
Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland
A Variscan,deep-crustal-level (eclogite-facies),continental basement massif in western Poland, the Snieznik complex, was tectonically exhumed. Crustal-penetrating mylonite zones record three main kinematic events: early top-to-the-north-directed thrusting, right-slip transpression-tension, and late top-to-the-south and -east normal faulting. Thrusting resulted in extreme crustal...
Authors
Mark G. Steltenpohl, Zbignew Cymerman, E.J. Krogh, Michael J. Kunk