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At least 1,189 records · Page 66Linked to original sources
USGS2015

Nest-site characteristics of Glyptemys muhlenbergii (Bog Turtle) in New Jersey and Pennsylvania

Nest-site selection can affect both the survival and fitness of female turtles and their offspring. In many turtle species, the nest environment determines the thermal regime during incubation, length of incubation period, sex ratio of the hatchlings, and exposure to predators and other forms of mortality for both mothers and their offspring. Between 1974 and 2012, we collected detailed data on habitat variables at 66 Glyptemys muhlenbergii (Bog Turtle) nests in 9 different bogs, fens, and wetland complexes in New Jersey and Pennsylvania. The nests had a mean elevation above the substrate of 8.2 cm, and many were shallow and located in raised tussocks of grass or sedges. Females covered most nests, but we also observed partially or completely uncovered eggs. Some females deposited eggs in communal nests; we found 4 nests with 2 separate clutches, and 2 nests with 3 clutches. Principal component analysis confirmed the importance of cover and vegetation to nest-site selection in this species. Availability of open, shade-free, wet nesting areas is an important habitat requirement for Bog Turtles.

New Jersey, Pennsylvania↗
USGS2013

A simple device for measuring the minimum current velocity to maintain semi-buoyant fish eggs in suspension

Pelagic broadcast spawning cyprinids are common to Great Plains rivers and streams. This reproductive guild produces non-adhesive semi-buoyant eggs that require sufficient current velocity to remain in suspension during development. Although studies have shown that there may be a minimum velocity needed to keep the eggs in suspension, this velocity has not been estimated directly nor has the influence of physicochemical factors on egg buoyancy been determined. We developed a simple, inexpensive flow chamber that allowed for evaluation of minimum current velocity needed to keep semi-buoyant eggs in suspension at any time frame during egg development. The device described here has the capability of testing the minimum current velocity needed to keep semi-buoyant eggs in suspension at a wide range of physicochemical conditions. We used gellan beads soaked in freshwater for 0, 24, and 48 hrs as egg surrogates and evaluated minimum current velocities necessary to keep them in suspension at different combinations of temperature (20.0 ± 1.0° C, 25.0 ± 1.0° C, and 28.0 ± 1.0° C) and total dissolved solids (TDS; 1,000 mg L-1, 3,000 mg L-1, and 6,000 mg L-1). We found that our methodology generated consistent, repeatable results within treatment groups. Current velocities ranging from 0.001–0.026 needed to keep the gellan beads in suspension were negatively correlated to soak times and TDS and positively correlated with temperature. The flow chamber is a viable approach for evaluating minimum current velocities needed to keep the eggs of pelagic broadcast spawning cyprinids in suspension during development.

Prairie Naturalist↗
USGS1996

Dead and dying Brazilian free-tailed bats ( Tadarida brasiliensis ) from Texas: Rabies and pesticide exposure

Twenty-three dead and dying Brazilian free-tailed bats from roosts in downtown Mineral Wells, Palo Pinto County, Texas, were tested for rabies and for anticholinesterase (antiChE) effects of or- ganophosphorus (OP) and carbamate pesticides. Seventeen of the 23 bats tested positive for rabies. The cause of death or dying in five of the nonrabid bats is unknown; however, one of the six nonrabid bats had a ChE activity level equivalent to only 27% of the control mean and may have been exposed to a pes- ticide. Three bats (including the bat with depressed ChE) contained sufficient ingesta to analyze for an- tiChE compounds, but no antiChE compounds could be identified in the samples. Exposure may be dermal and pulmonary as well as dietary. It is feasible that other bat deaths not explained by rabies were attributable to a pesticide but missed due to postmortem reactivation of the ChE enzyme. The largest group of rabid bats was young males (13 of 17, 76.5%), and the largest group of nonrabid bats was older females (3 of 6, 50%). All older females were nonrabid, perhaps survivors of the disease in previous years. Rabid bats had a lower mean fat index and weighed less than nonrabid bats. Four bats (not includ- ing the low ChE bat) showed external bleeding, and none was rabid; thus the incidence of bleeding was greater among nonrabid bats than among rabid bats. The four affected bats came from roosts in three different buildings, making a roost-treatment with an anticoagulant chemical seem unlikely.

Southwestern Naturalist↗
USGS2004

A fish survey of the White River, Nevada

In spring and summer 1991 and 1992, we surveyed fishes of the White River system, Nye and White Pine Counties, Nevada, to determine the status of natives. There are 5 known native fishes to the White River: Lepidomeda albivallis (White River spinedace), Crenichthys baileyi albivallis (Preston White River springfish), Crenichthys baileyi thermophilus (Moorman White River springfish), Catostomus clarki intermedius (White River desert sucker), and Rhinichthys osculus ssp. (White River speckled dace). All 5 had declined in range. Lepidomeda albivallis had experienced the greatest decline, with less than 50 remaining, and these were restricted to a 70-m stream reach. Rhinichthys osculus spp. was most widespread, found in 18 spring systems. Cottus bairdi (mottled sculpin) was collected for the 1st time from the White River system, where it was probably native. Protective measures should be implemented to conserve all native White River fishes to include C. bairdi.

Nevada↗
USGS1999

Additional records of bats from the middle Rio Grande Valley, New Mexico

The resident and migratory bat fauna of the middle Rio Grande Valley in central New Mexico is inadequately known. Many of the specimen records from this valley are from Bosque del Apache National Wildlife Refuge, ca. 20 km S of Socorro, Socorro Co. Findley et al. (1975) reported Myotis lucifugus, M. yumanensis, Lasiurus cinereus, and Tadarida brasiliensis from the refuge to which Reith (1982) added Antrozous pallidus. During June and July 1994, we netted nine nights and conducted visual searches of known roosts to capture 67 bats of seven species as part of a baseline survey of bats on the refuge. We surveyed artificial wetlands in the transitional zone between riparian forest and adjacent desert-grassland, within ca. 2 km of the Rio Grande. Nearby agricultural fields and ponds managed primarily for use by waterfowl provided numerous sites suitable for foraging and drinking by bats. We report four new species records for the refuge, one of which is also a new county record. Voucher material is deposited in the Biological Survey Collection, Fort Collins (BS/FC), now housed in the Museum of Southwestern Biology (MSB), University of New Mexico.

Southwestern Naturalist↗
USGS1989

Diurnal and seasonal patterns of colony attendance in the Northern Fulmar, Fulmarus glacialis

The annual cycle of Northern Fulmars ( Fulmarus glacialis ) in the western Gulf of Alaska includes about six months from mid-April to mid-October when birds are associated with land at the Semidi Islands. The pre-laying stage in five years was marked by recurrent peaks in attendance that included up to 90% of the population, and alternate periods of 2 to 12 days when the breeding ground was deserted. Serial correlation of daily attendance indicated a cyclic pattern with a half-period of five to seven days. Maximum attendance at breeding sites usually occurred in the evening after a gradual increase in numbers during the day. Percentage of attendance by nonbreeding and failed birds varied widely with breeding success, but the seasonal occurrence of nonbreeders followed a consistent pattern: attendance by siteholding nonbreeders peaked before egg-laying, then steadily declined, whereas an influx of nonbreeding floaters occurred in July and August. Different wind directions and speeds influenced the number of birds at the colony for up to three days after they occurred, but it was not possible to explain the birds' behaviour during the pre-laying period in terms of simple linear relationships between attendance and weather. Rather, synchronized attendance appeared to be a social phenomenon mediated by environmental cues such as a change in wind direction.

Alaska↗
USGS1989

Nesting biology of pacific loons, Gavia pacifica, on the Yukon-Kuskokwim Delta, Alaska

The nesting biology of Pacific Loons, Gavia pacifica , was studied from 1973 to 1975 on the Yukon-Kuskokwim Delta, Alaska. Loons maintained territories on ponds throughout the pre-nesting period. Both adults incubated eggs and raised the young. Males incubated more than females during early incubation, and females more than males during late incubation. The female assumes much of the early brood rearing, with the male assisting more when food demands of young increase later in brood rearing.

Alaska↗
USGS2014

Survival of female white-cheeked pintails during brood rearing in Puerto Rico

Anas bahamensis (White-cheeked Pintail) is widely distributed across the Caribbean islands and South America. The species is classified as threatened in Puerto Rico and a species of least concern across most of its range. Little demographic data exist for the species, particularly during the breeding season. During 2000-2002, we radiomarked 31 incubating females at the Humacao Nature Reserve (Humacao) in southeastern Puerto Rico and estimated daily and interval survival rates of females during brood rearing. Only one of 31 birds died; the average ± 95% CI daily survival rate of pintails was 0.998 ± 0.989-0.999 for all years, and interval survival was 0.913 ± 0.527-0.987 for a 60-day brood-rearing period. High survival of females suggests their mortality during brood rearing does not influence White-cheeked Pintail populations at Humacao, but further studies of reproductive and annual ecology are needed.

Puerto Rico↗
USGS2016

A GIS model of habitat suitability for Solanum conocarpum (Solanaceae) in St. John, US Virgin Islands

Solanum conocarpum (Solanaceae) (Marron Bacora) is a rare, dry-forest shrub endemic to the island of St. John, US Virgin Islands, considered for listing under the Endangered Species Act. Given its status as a species of conservation concern, we incorporated environmental characteristics of 3 observed populations and 5 additional known locations into a geographic information system (GIS) analysis to create a habitat-suitability model for the species on the island of St. John. Our model identified 1929.87 ha of highly suitable and moderately suitable habitat. Of these, 1161.20 ha (60.2%) occurred within the boundaries of Virgin Islands National Park. Our model provides spatial information on potential locations for future surveys and restoration sites for this endemic species of the US Virgin Islands.

Caribbean Naturalist↗
USGS2006

Reproductive development in the sicklefin chub in the Missouri and Lower Yellowstone Rivers

We describe aspects of sicklefin chub (Macrhybopsis meeki) reproductive development from three study areas encompassing greater than 2,700 km of the Missouri and Lower Yellowstone rivers. The sicklefin chub was collected between late July and early October in 1996 and 1997. A total of 193 sicklefin chub was collected and examined for reproductive characteristics. Twenty-nine sicklefin chub were found to be reproductively mature females. Some sicklefin chub matured at age 2, but most matured at age 3 and all matured by age 4. Females first became mature at 70 to 79 mm total length (TL) in the Upper Missouri River reach in central Montana, 80 to 89 mm TL in the Missouri and Lower Yellowstone rivers in eastern Montana-western North Dakota, and 90 to 99 mm TL in the lower Missouri River in Nebraska, Iowa, Kansas, and Missouri. Gonad mass of gravid females averaged 6.9% of total body mass and ranged from 1.7 to 13.5%. Total number of oocytes per female, ranged from 7 to 1,561. Reproductive development of the sicklefin chub appeared to be group synchronous or synchronous indicating multiple spawnings during a spawning season. This variability in spawning mode required cautious interpretation of gonadosomatic index values and oocyte counts as estimates of total fecundity, because some females might have released a cohort of oocytes prior to their capture.

The Prairie Naturalist↗
USGS2017

Long-term changes in Canade Goose nest success and nest densities at an Iowa wetland complex

Giant Canada geese ( Branta canadensis maxima ) were extirpated from Iowa by the early 1900s due to unregulated hunting, egg gathering, and wetland drainage in the nineteenth century (Bishop 1978). Ef- forts to reintroduce Canada geese in Iowa began in 1964 (Bishop and Howing 1972) and involved releasing flightless adults and goslings at nearly 30 sites across the state (Zenner and LaGrange 1998a). In 1972, 13 flightless pairs were released at Rice Lake Wildlife Management Area (WMA; Bishop 1978). By 1989, the breeding population of Canada geese at Rice Lake WMA had increased to 420 nesting adults (G. G. Zenner, Iowa Department of Natural Resources, unpublished data). Canada goose nest success and nest densities were documented from 1989–1991 on extant islands at Rice Lake WMA (Zenner and LaGrange 1998b).

Iowa↗
USGS2016

Mink predation on brown trout in a Black Hills stream

In the early 2000’s, declines in the brown trout (Salmo trutta) fishery in Rapid Creek, South Dakota, caused concern for anglers and fisheries managers. We conducted a radio telemetry study in 2010 and 2011 to identify predation mortality associated with mink, using hatchery-reared (2010) or wild (2011) brown trout. Estimated predation rates by mink (Mustela vison) on radio-tagged brown trout were 30% for hatchery fish and 32% for wild fish. Size frequency analysis revealed that the size distribution of brown trout lost to predation was similar to that of other, radio-tagged brown trout. In both years, a higher proportion of predation mortality (83–92%) occurred during spring, consistent with seasonal fish consumption by mink. Predation by mink appeared to be a significant source of brown trout mortality in our study.

South Dakota↗
USGS2015

Mate replacement and alloparental care in Ferruginous Hawk (Buteo regalis)

Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Tella et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for future seasons, a benefit that might outweigh the investment of time and effort associated with adoption and rearing (after Rohwer 1986). Anticipated mating opportunity at the cost of adoption (Gori et al. 1996, Rohwer et al. 1999) may explain step-parental benevolence and therefore, in such a scenario would enhance individual fitness through subsequent recruitment of related young.

The Prairie Naturalist↗