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Ronald E. Kirby

Publications and source records attributed to Ronald E. Kirby.

6 recordsLinked to original sources
USGS2013

Sediment redistributed by coastal marsh mosquito ditching in Cape May County, New Jersey, U.S.A.

Effects of mosquito ditching on salt marsh sediment budgets have not been quantified for lack of sufficient records, but such information is necessary to provide historical context for current management objectives. We were able to do so in Cape May County New Jersey where Mosquito Extermination Commission records reported 1,493,900 m 3 of spoil redistributed through ditching from1902 to 1974. The amount of spoil redistributed rose to 2,240,850 m 3 –22,987,800 m 3 overall when ditch cleaning efforts were included. On a 54 km 2 study area, 161,560 m of ditches removed as much as 99,000 m 3 of material. If all such sediment stayed in the system and was deposited in open water, it would have added 0.082 mm/yr to those areas. If the sediments had accumulated only in the larger water bodies, it would have been sufficient to add 0.16 mm/yr to those areas. Alternatively, if the material had been deposited only on the marsh surface, the material displaced by mosquito ditching was capable of adding only 0.036 mm/yr. These rates are inconsequential in a system infilling at a rate of 4.4–7.4 mm/yr. Materials released by mosquito ditching thus have added to the sediment budgets of this coastal system, but shoaling of bays and sounds in recent centuries is a consequence of increases in all sediment sources including many of anthropogenic origin. Nonetheless, other consequences of ditching to the marsh (e.g., increased drainage, transport of water, and erosion of ditch banks) are not negligible in consideration of all anthropogenic effects. These data can help parameterize models of salt marsh accretion in the face of climate change.

New Jersey↗
USGS2000

Description and identification of American Black Duck, Mallard, and hybrid wing plumage

We developed a key to identify wings of hybrids between American Black Ducks (Anas rubripes) and Mallards (A. platyrhynchos). Material for analysis included review of historical descriptions dating from the late 1700's, older museum collections in Europe and North America, wings collected from hunters in North America and Great Britain, birds banded in Canada and the United States, and a flock of propagated hybrids. All first filial generation (F1) American Black Duck - Mallard hybrids were identified correctly with the key. A lower proportion of other hybrid cohorts (i.e., backcrosses of F1 to parental forms (P1), and second and third filial generations (F2, F3, etc.) were identified. We successfully identified a larger portion of male than female hybrids for all hybrid progeny cohorts examined except F1. The new key identified 2.37 times more hybrids in the 1977 U.S. Fish and Wildlife Service Parts Collection Survey (annual determination of the species, age, and sex composition of the waterfowl harvest using detached wings contributed by hunters) than were identified by standard techniques. The proportion of American Black Duck - Mallard hybrids to the American Black Duck parental population (the ratio: hybrids/[hybrids + American Black Ducks]) may therefore be closer to 0.132 than 0.056, the historically reported value. The hybrid key is suggested for use from North Carolina north in the Atlantic Flyway and Arkansas and Tennessee north in the Mississippi Flyway (areas where other members of the Mallard group will not confound assessment). We provide suggestions for further research that would assist identification of wings in parts collection surveys and permit estimation of the proportional representation of Mallard genes in the American Black Duck gene pool.

Report↗
USGS1986

Spring and summer survival of female mallards from northcentral Minnesota

Seasonal survival of 109 adult female mallards ( Anas platyrhynchos ) fitted with radio transmitters was evaluated in northcentral Minnesota during 1968-74. Survival rates for the 169-day breeding and postbreeding period were: 1.0 during nest initiation (36 days), 0.798 during incubation (28 days), 0.943 during brood rearing (51 days), 0.947 during molt (26 days), and 1.0 during premigration (28 days). Survival for the 169-day spring-summer period was 0.713 for adult females remaining on the study area. Fall-winter survival was estimated at 0.881 for those adult birds remaining on the study area throughout the summer. The data confirm speculation on relative risk to females of various phases of the mallard reproductive cycle and support previous conclusions that the northcentral Minnesota breeding mallard population is not self sustaining. The value of learning further details of processes affecting specific seasonal mortality factors for both adult and young waterfowl is emphasized.

Minnesota↗
USGS1978

Observations and reinterpretation of kingfisher-raptor interactions

Reported observations of Belted Kingfisher ( Megaceryle alcyon )-raptor interactions have ranged from brief encounters where the kingfisher escaped the raptor and the hawk subsequently flew away to repeated chases (Johnson 1925, McCabe and McCabe 1928, Skinner 1928, Smith 1963). In some repetitive chases, kingfishers appeared to initiate the interaction (McCabe and McCabe 1928, Skinner 1928).

The Auk↗