Geology topics

D.P. Rave

Publications and source records attributed to D.P. Rave.

3 recordsLinked to original sources

USGS2000

Relationships of habitat patch size to predator community and survival of duck nests

We studied duck nest success and predator community composition in relation to size of discrete patches of nesting cover in the Prairie Pothole Region (PPR) of the United States in 1993-95. We focused on nests in uplands that were seeded to perennial grasses and forbs and enrolled in the Conservation Reserve Program (CRP) in Minnesota, North Dakota, and South Dakota. We estimated daily survival rates (DSRs) of upland duck nests and indices of activity for red foxes (Vulpes vulpes), coyotes (Canis latrans), American badgers (Taxidea taxus), striped skunks (Mephitis mephitis), and Franklin's ground squirrels (Spermophilus franklinii), and related these variables to habitat patch size. The effect of patch size (small vs. large) on estimated annual mean DSR was dependent on date of nest initiation (early vs. late) and year. Examination of within-year comparisons for early and late nests suggested that DSR was generally greater in larger habitat patches. Activity indices for the 5 mammalian nest predators were influenced differently by year, location, and patch size. Activity indices of the red fox were greatest in small patches. Coyote indices were the most inconsistent, demonstrating a year X location X patch size interaction. Activity indices of the striped skunk and American badger varied only among years. Franklin's ground squirrel indices were affected by study area location, with higher indices in the southeast than the northwest. Red fox activity was weakly correlated with that of the striped skunk and coyote. Although a positive relationship between habitat patch size and nest success probably exists, we believe the experiment to fully test this hypothesis will continue to be elusive.

Journal of Wildlife Management↗

USGS1993

Time-activity budget of Northern Pintails using nonhunted rice fields in southwest Louisiana (Presupuesto de actividades cotidianas por parte de individuos de anas acuta en campos de arroz no utilizados para cazar en el suroeste de Louisiana)

Monthly behavioral observations of Northern Pintails ( Anas acuta ) were conducted on five leased tracts of nonhunted private land, each including 60 ha of flooded rice fields, in southwest Louisiana during November-February 1988-1989. Pintails spent 52% of diurnal time resting, 21% feeding, 16% in comfort activities, 6% in locomotion, 4% courting and 1% in other behaviors. Activities differed among months and periods of the day. Pintails used nonhunted rice fields only during the day, departing after sunset. Pintail time budgets in Louisiana approximated those reported in California. Pintails using rice fields during the day, however, fed more than did those roosting on open water pools at Lacassine National Wildlife Refuge (NWR), Louisiana. Small (60 ha), nonhunted rice fields provided wintering Northern Pintails security plus food during the day. Desde noviembre a febrero de 1988-1989 hicimos observaciones mensuales de la conducta de individuos de Anas acuta en cinco localidades privadas y libres de cacería, del suroeste de Lousiana. Cada área incluyó un campo de arroz inundado de 60 hectáreas. Los patos emplearon el 52% del tiempo diurno para descansar, 21% para alimentarse, 16% para actividades de confort, 6% para locomoción, 4% para cortejo y 1% para otras actividades. Hubo diferencias en las actividades a través de los meses de estudio y períodos del día. Los patos utilizaron las áreas libres de cacería durante el período diurno y partieron de las mismas con la puesta del sol. El presupuesto de tiempo de las aves de Louisiana se aproximó a los informados en California para la especie. Sin embargo, los patos que utilizaron los campos de arroz se alimentaron más que los que descansaron en pozas del Refugio Nacional de Vida Silvestre de Lacassine. Los pequeños campos de arroz, libres de cacería, proveyeron a los patos invernales de lugares seguros y de alimentación durante el período diurno.

Louisiana↗

USGS1990

Diurnal time-activity budgets of wintering canvasbacks in Louisiana

We determined diurnal time-activity budgets of Canvasbacks ( Aythya valisineria ) at Catahoula Lake and at the Mississippi River Delta, Louisiana, from December 1987 to March 1988. Canvasback feeding, resting, locomotory, and comfort activities varied by month and location with a month-location interaction. Moreover, the percentage of time spent feeding varied by sex with a month-sex interaction. Study site differences in the time- activity budgets of wintering Canvasbacks may be related to characteristics of their foods, foraging mode, disturbance level, and physical features of habitats at the two study sites. Canvasbacks wintering in Louisiana generally spent less time feeding and more time resting during the day than they did in Mississippi or coastal South Carolina. Levels of agonistic behavior were lower than those observed in South Carolina. We found no evidence of male dominance of female Canvasbacks in Louisiana.

Louisiana↗