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David G. Krementz

Publications and source records attributed to David G. Krementz.

At least 37 records · Page 2Linked to original sources

Nocturnal field use by fall migrating American woodcock in the Delta of Arkansas

The American woodcock ( Scolopax minor ) population has declined since the late 1960s across its range and is now considered a species of special concern. Research on woodcock habitat use during migration and migratory routes through the Central Flyway has been limited. We assessed woodcock phenology, estimated density, and nocturnal habitat use in fields on public lands in the lower Mississippi Alluvial Valley portion of Arkansas during November and December of 2010 and 2011. We used all-terrain vehicles to survey woodcock along transects in 67 fields of 8 field types. We analyzed data using hierarchical distance sampling. We detected woodcock from the first week in November through the third week in December but in low numbers. We did not detect woodcock in millet or rice fields, whereas woodcock had the highest estimated densities in unharvested soybeans. All other crop type-post-harvest management combinations had low woodcock densities. We did not detect woodcock in fields <8 ha or >40 ha. Woodcock in the lower Mississippi Alluvial Valley may benefit from management for unharvested soybean fields of moderate size (approx. 8-40ha).

Journal of Wildlife Management↗

Density and abundance of Wilson's snipe Gallinago delicata in winter in the Lower Mississippi Flyway, USA

Wilson's snipe Gallinago delicata is one of the least studied North American game birds, and information on snipe populations and abundance is mostly unknown. We conducted roadside surveys stratified at the township level in the lower Mississippi Alluvial Valley (LMAV) in Arkansas, Mississippi and Louisiana, as well as the Red River Region, and the Gulf Coastal Plain of Louisiana during winters of 2009 and 2010. We identified observer, vegetation cover, and water cover as important covariates in estimating snipe densities. We detected 2915 snipe along 814 line transects (1450 km) for 2009 and 2010 combined. We estimated snipe densities of 8.05 individuals km -2 (95% CI: 4.57-14.17) in 2009, and 2.13 individuals km -2 (95% CI: 1.47-3.08) in 2010. We used the resulting snipe density estimates within the study area to calculate abundance estimates of 1 026 431 (95% CI: 582 707-1 806 774) in 2009, and 271 590 (95% CI: 187 435-392 722) in 2010 for the LMAV. Our data indicate that a road transect survey method is effective for estimating wintering snipe density and abundance in the lower Mississippi Flyway.

Wildlife Biology↗

Population status and habitat associations of the King Rail in the midwestern United States

The migratory population of the King Rail ( Rallus elegans ) has declined dramatically during the past 50 years, emphasizing the need to document the distribution and status of this species to help guide conservation efforts. In an effort to guide King Rail breeding habitat protection and restoration, a landscape suitability index (LSI) model was developed for the Upper Mississippi River and Great Lakes Region Joint Venture (JV). To validate this model, 264 sites were surveyed across the JV region in 2008 and 2009 using the National Marshbird Monitoring protocol. Two other similarly collected data sets from Wisconsin (250 sites) and Ohio (259 sites) as well as data from the Cornell Laboratory of Ornithology's eBird database were added to our data set. Sampling effort was not uniform across the study area. King Rails were detected at 29 sites with the greatest concentration in southeastern Wisconsin and northeastern Illinois. Too few detections were made to validate the LSI model. King Rail detection sites tended to have microtopographic heterogeneity, more emergent herbaceous wetland vegetation and less woody vegetation. The migrant population of the King Rail is rare and warrants additional conservation efforts to achieve stated conservation population targets.

Illinois, Indiana, Iowa, Kansas, Michigan, Minneso↗

Autumn migration of of Mississippi Flyway mallards as determined by satellite telemetry

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 ( n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17&ndash;December 7). For those mallards that stopped for >1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The total distance migrated per mallard averaged 1,407 km (SE = 89.55 km; range = 142&ndash;2,947 km). The average time spent on migration per individual between September 15 and December 15 was 27 d (SE = 2.88 d; range = 2&ndash;84 d). The state where most mallards were located on December 15 was Missouri (11) followed by Arkansas (8), while 5 mallards were still in Canada, and only 8 of 43 females and 0 of 10 males were present in Arkansas. The eastern Dakotas are a heavily utilized migration stopover for midcontinent mallards that may require more attention for migration habitat management. The reasons for so few mallards, especially male mallards, returning to Arkansas the following year deserves further research. .

Arkansas↗

Habitat use of woodpeckers in the Big Woods of eastern Arkansas

The Big Woods of eastern Arkansas contain some of the highest densities of woodpeckers recorded within bottomland hardwood forests of the southeastern United States. A better understanding of habitat use patterns by these woodpeckers is a priority for conservationists seeking to maintain these high densities in the Big Woods and the Lower Mississippi Alluvial Valley as a whole. Hence, we used linear mixed-effects and linear models to estimate the importance of habitat characteristics to woodpecker density in the Big Woods during the breeding seasons of 2006 and 2007 and the winter of 2007. Northern flicker Colaptes auratus density was negatively related to tree density both for moderate (. 25 cm diameter at breast height) and larger trees (>61 cm diameter at breast height). Red-headed woodpeckers Melanerpes erythrocephalus also had a negative relationship with density of large (. 61 cm diameter at breast height) trees. Bark disfiguration (an index of tree health) was negatively related to red-bellied woodpecker Melanerpes carolinus and yellow-bellied sapsucker Sphyrapicus varius densities. No measured habitat variables explained pileated woodpecker Dryocopus pileatus density. Overall, the high densities of woodpeckers observed in our study suggest that the current forest management of the Big Woods of Arkansas is meeting the nesting, roosting, and foraging requirements for these birds.

Journal of Fish and Wildlife Management↗

Status and distribution of breeding secretive marshbirds in the Delta of Arkansas

We surveyed the Lower Mississippi Alluvial Valley of Arkansas ("the Delta") during the breeding seasons of 2005 and 2006 using the national marshbird monitoring protocol for secretive marshbirds. We detected and documented breeding by Podilymbus podiceps (Pied-billed Grebe), Ixobrychus exilis (Least Bittern), Rallus elegans (King Rail), and Gallinula chloropus (Common Moorhen). We detected but did not document breeding by Botaurus lentiginosus (American Bittern), Porphyrula martinica (Purple Gallinule), and Fulica americana (American Coot), all of which have been documented to breed in the Delta. Our estimated occupancy rates for breeding marshbirds in the study area ranged from a low of 6% for the King Rail in 2006 to a high of 27% for the Least Bittern in 2005. The range of these occupancy rates are low and reflect the rarity of secretive marshbirds in the Delta. Secretive marshbird occupancy rates were higher in the southern third of the Delta, probably because wetlands were more abundant or of higher quality there.

Southeastern Naturalist↗

Secretive marsh aird species co-eccurrences and habitat associations across the midwest, USA

Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus , co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina ) and open-water birds (pied-billed grebe Podilymbus podiceps , common moorhen Gallinula chloropus , and American coot Fulica americana ; coots were only surveyed in 2009), co-occurred more often than expected by chance. These groupings were consistent between years. We then estimated the relation of these species and groups to landscape and local site characteristics by using zero-inflated abundance models that accounted for incomplete detection. At the landscape level (5-km radius), the amount of emergent herbaceous wetland was positively associated with least bittern occupancy, whereas the amount of woody wetland was negatively associated with least bittern, rail, and open-water bird occupancy. At the local level, habitat variables that were associated with abundance were not consistent among groups or between years, with the exception that both least bitterns and open-water birds had a strong positive association between abundance and water-vegetation interspersion. Land managers interested in marsh bird management or conservation may want to consider focusing efforts on landscapes with high amounts of emergent herbaceous wetland and low amounts of woody wetland, and managing for high amounts of water-vegetation interspersion within the wetland.

Journal of Fish and Wildlife Management↗

Spring migration of mallards from Arkansas as determined by satellite telemetry

We used satellite telemetry to document spring migration phenology, routes, stopover regions, and nesting sites of mallards Anas platyrhynchos marked in Arkansas during the winters of 2004-2007. Of the 143 marked mallards that migrated from Arkansas, they did so, on average, by mid-March. Mallards flew over the Missouri Ozarks and 42% made an initial stopover in Missouri, where they used areas that had larger rivers (Mississippi River, Missouri River) embedded in an agricultural landscape. From this stopover region they either migrated directly to the Prairie Pothole Region (PPR) or they migrated north to Minnesota where they either moved next to the PPR or to the north and east of the PPR. For those mallards (83%) that stopped for >1 d before entering the PPR, the average length at each stop was 12 d (SE = 0.90 d, range = 2-54 d). Mallards made more stopovers, made shorter migration movements, and took longer to move to the PPR in wetter than drier years. Mallards arrived in the PPR earlier in 2006 x - = 30 March, SE = 2.18 d) than in 2005 x - = 7 April, SE = 2.30 d). Females nested across nine Bird Conservation Regions. Nesting occurred most frequently in South Dakota (n = 9). The average date when females nested was 19 April (SE = 2.44 d, range = 12 March-26 May). Because many mallards headed for the large river corridors in Missouri for their first stopover, this region is an important spring migration stopover of continental importance to mallards and might be considered a focal area for conservation.

Journal of Fish and Wildlife Management↗

Distribution and habitat use of king rails in the Illinois and Upper Mississippi River valleys

The migratory population of the king rail ( Rallus elegans ) has declined dramatically during the past 40 years, emphasizing the need to identify habitat requirements of this species to help guide conservation efforts. To assess distribution and habitat use of king rails along the Illinois and Upper Mississippi valleys, USA, we conducted repeated call-broadcast surveys at 83 locations in 2006 and 114 locations in 2007 distributed among 21 study sites. We detected king rails at 12 survey locations in 2006 and 14 locations in 2007, illustrating the limited distribution of king rails in this region. We found king rails concentrated at Clarence Cannon National Wildlife Refuge, an adjacent private Wetlands Reserve program site, and B. K. Leach Conservation Area, which were located in the Mississippi River floodplain in northeast Missouri. Using Program PRESENCE, we estimated detection probabilities and built models to identify habitat covariates that were important in king rail site occupancy. Habitat covariates included percentage of cover by tall (> 1 m) and short (<= 1 m) emergent vegetation, percentage of cover of woody vegetation, and interspersion of water and vegetation ( 2007 only) within 50 m of the survey location. Detection probability was 0.43 (SE = 0.12) in 2006 and 0.35 (SE = 0.03) in 2007 and was influenced by observer identity and percentage of cover by tall herbaceous vegetation. Site occupancy was 0.11 (SE = 0.04) in 2006 and 0.14 (SE = 0.04) in 2007 and was negatively influenced most by percentage of cover by woody vegetation. In addition, we found that interspersion of vegetation and water was positively related to occupancy in 2007. Thus, nesting king rails used wetlands that were characterized by high water-vegetation interspersion and little or no cover by woody vegetation. Our results suggest that biologists can improve king rail habitat by implementing management techniques that reduce woody cover and increase vegetation-water interspersion in wetlands.

Journal of Wildlife Management↗

Woodpecker densities in the big woods of Arkansas

Sightings of the now-feared-extinct ivory-billed woodpecker Campephilus principalis in 2004 in the Big Woods of Arkansas initiated a series of studies on how to best manage habitat for this endangered species as well as all woodpeckers in the area. Previous work suggested that densities of other woodpeckers, particularly pileated Dryocopus pileatus and red-bellied Melanerpes carolinus woodpeckers, might be useful in characterizing habitat use by the ivory-billed woodpecker. We estimated densities of six woodpecker species in the Big Woods during the breeding seasons of 2006 and 2007 and also during the winter season of 2007. Our estimated densities were as high as or higher than previously published woodpecker density estimates for the Southeastern United States. Density estimates ranged from 9.1 to 161.3 individuals/km 2 across six woodpecker species. Our data suggest that the Big Woods of Arkansas is attractive to all woodpeckers using the region, including ivory-billed woodpeckers.

Arkansas↗

Habitat use by Least Bitterns in the Arkansas Delta

Least Bittern ( Ixobrychus exilis ) occupancy surveys were conducted in the Arkansas Delta, USA, during April-July 2005-2006 to determine the proportion of area occupied and relate occupancy to habitat characteristics. Previous large-scale surveys indicated few Least Bitterns were present in the Delta. During surveys at 190 sites, Least Bitterns were detected at 15 sites in 2005 and at 16 sites in 2006. Several candidate models were tested to explain occupancy based on habitat variables. Emergent vegetation cover was positively related to occupancy while the proportion of forest within 400 m of a survey site was negatively related to occupancy. The study suggests that managing the breeding habitat of Least Bitterns for emergent vegetation cover and controlling forest cover near occupied sites may contribute to this species' recovery throughout its range.

Waterbirds↗

Occupancy and habitat use of the Least Bittern and Pied-Billed Grebe in the Illinois and Upper Mississippi River Valleys

The Least Bittern ( Ixobrychus exilis ) and the Pied-billed Grebe ( Podilymbus podiceps ) are secretive marsh bird species that breed in the Illinois and Upper Mississippi River Valleys. Marsh bird surveys were conducted on public and private wetlands in this region during the breeding seasons of 2006 and 2007. Detection probability (ῥ) and site occupancy probability (&psi;) were estimated for each species separately for each year. Candidate models including sampling and habitat covariates were compared using AIC( c ) to determine what variables had the greatest influence on ῥ and &psi;. Average ῥ for Least Bitterns was 0.29 in 2006 and 0.18 in 2007, and varied throughout the 2007 survey season. Average &psi; for Pied-billed Grebes was 0.44 in 2006 and 0.22 in 2007, and an observer effect was found in 2007. Overall &psi; for Least Bitterns was 0.17 in 2006 and 0.14 in 2007. Least Bittern occupancy was positively related to tall emergent vegetation cover in both years and to water-vegetation interspersion in 2007, and was negatively related to woody vegetation cover in 2007. Overall &psi; for Pied-billed Grebes was 0.21 in 2006 and 0.31 in 2007. Pied-billed Grebe occupancy was negatively related to woody vegetation cover in both years, and was positively related to areas of open water in 2006. Land managers targeting these species should provide wetlands free from woody vegetation with extensive areas of open water for Pied-billed Grebes, and tall emergent vegetation interspersed with small pools of water for Least Bitterns.

Waterbirds↗

Use of radio-telemetry to reduce bias in nest searching

We used traditional searching, as well as radio-telemetry, to find 125 Wood Thrush ( Hylocichla mustelina ) nests during 1994–1996 at the Piedmont National Wildlife Refuge in Georgia, USA. We compared daily nest survival rates for 66 nests of radio-marked birds with 59 nests of birds found through systematic searching. By using radio-telemetry, we found Wood Thrush nests in higher elevation pine habitats, in addition to the more usual hardwood forests with moist soils. We found nests of radio-marked birds farther from streams than nests found by systematic searching. Thirty-two percent of radio-marked birds' nests were found at the tops of slopes, compared to 15% of the nests found by traditional searching. In addition, radio-marked birds generally moved up-slope for re-nesting attempts. Although the distribution of nests found with telemetry and searching varied, daily nest survival did not vary between the two groups. Radio-telemetry provided new information about Wood Thrush nesting habitats. We believe radio-telemetry can be a valuable addition to traditional searching techniques; it has the potential to provide a sample of nests free from a priori habitat biases.

Georgia↗

Survival and recovery rates of American woodcock banded in Michigan

American woodcock (Scolopax minor) population indices have declined since U.S. Fish and Wildlife Service (USFWS) monitoring began in 1968. Management to stop and/or reverse this population trend has been hampered by the lack of recent information on woodcock population parameters. Without recent information on survival rate trends, managers have had to assume that the recent declines in recruitment indices are the only parameter driving woodcock declines. Using program MARK, we estimated annual survival and recovery rates of adult and juvenile American woodcock, and estimated summer survival of local (young incapable of sustained flight) woodcock banded in Michigan between 1978 and 1998. We constructed a set of candidate models from a global model with age (local, juvenile, adult) and time (year)-dependent survival and recovery rates to no age or time-dependent survival and recovery rates. Five models were supported by the data, with all models suggesting that survival rates differed among age classes, and 4 models had survival rates that were constant over time. The fifth model suggested that juvenile and adult survival rates were linear on a logit scale over time. Survival rates averaged over likelihood-weighted model results were 0.8784 +/- 0.1048 (SE) for locals, 0.2646 +/- 0.0423 (SE) for juveniles, and 0.4898 +/- 0.0329 (SE) for adults. Weighted average recovery rates were 0.0326 +/- 0.0053 (SE) for juveniles and 0.0313 +/- 0.0047 (SE) for adults. Estimated differences between our survival estimates and those from prior years were small, and our confidence around those differences was variable and uncertain. juvenile survival rates were low.

Journal of Wildlife Management↗

Clearcut stand size and scrub-successional bird assemblages

We investigated the effects of clearcut stand size on species richness, reproductive effort, and relative abundance of scrub-successional birds and the entire bird assemblage at the Savannah River Site in South Carolina. We used standardized mist-net grids to mark and recapture birds in clearcuts replanted with longleaf pine ( Pinus palustris ) in stands of 2 to 57 ha that were two to six years old. Species richness for the entire bird assemblage was not explained by stand size ( P = 0.67), stand age ( P = 0.95), or the interaction of these two variables ( P = 0.90). Similarly, species richness of scrub-successional birds was not explained by stand size ( P = 0.63), stand age ( P = 0.55), or the interaction of stand size and stand age ( P = 0.35). Regressing species richness on clearcut stand size, we found a significant negative relationship between these variables for the entire bird assemblage ( P = 0.01) and for scrub-successional birds ( P = 0.02). The ratio of juveniles to adults in mist-net samples varied by year ( P = 0.04), but neither clearcut size ( P = 0.23) nor the interaction of clearcut size and year ( P = 0.25) was related to the ratio of juveniles to adults in the sample. We found no relationship between the frequency of capture of any category of birds and stand size (scrub-successional, P = 0.52; woodland, P = 0.77; combined sample, P = 0.55). Neither bird-species richness, reproductive effort, nor relative abundance differed across clearcut stand sizes. Clearcut stand size does not appear to be an important management variable if variation in species richness, reproductive effort, or relative abundance are objectives. We suggest that even-aged forestry is a useful tool for managing birds in the southeastern United States.

The Auk↗

Breeding season demography and movements of Eastern Towhees at the Savannah River Site, South Carolina

The Eastern Towhee ( Pipilo erythrophthalmus ) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the breeding season of radio-marked towhees did not vary by sex or stand type. Daily nest success rates were very low [0.629 ± 0.088 (SE)] as a result of high predation levels. Abundance estimates adjusted for sampling effort differed between years. In 1995, the abundance estimate was significantly lower in mature stands (7.1 ± 0.47) than in young stands (9.6 ± 0.60) while in 1996, there was no different between mature stands (26.2 ± 5.67) and young stands (16.5 ± 3.39). Average daily movements by radio-marked towhees did not vary by sex or stand type. Movements among adjacent stands were common, and sometimes great distances.

South Carolina↗

Survival rates of American woodcock wintering in the Georgia Piedmont

We estimated survival rates of wintering American woodcock ( Scolopax minor ). We found no age- or sex-specific differences in period survival rates. The survival rate for the period 25 December 1994-7 February 1995 for all age and sex classes combined (0.72) was not different from a similarly derived estimate for woodcock wintering along the Atlantic Coast. Survival rates of wintering woodcock are relatively low compared to other seasons.

Georgia↗

Population dynamics of white-winged scoters

A significant ( P < 0.01) decline between 1961 and 1993 in ratio of harvested young per adult in the Atlantic Flyway (age ration) of white-winged scoters ( Melanitta fusca ) led us to examine annual survival rates and harvest of this species. Compared to waterfowl with similar life histories, black scoters ( M. nigra ) and surf scoters ( M. perspicillata ), the decline in age ratios of white-winged scoter age ratios was not significantly different ( P = 0.11). Adult females banded at Redberry Lake, Saskatchewan that winter along both coasts, had high annual survival rates (0.773 ± 0.0176 [SE]). High harvest in the Atlantic Flyway was not followed by an increase in production (age ratios) the following year or 2, i.e., there was no short-term rebound in recruitment by the population. Harvest of white-winged scoters in the Atlantic Flyway was explained by the age ratio in the fall flight and by hunter effort.

Connecticut, Delaware, Maryland, Massachusetts, Ne↗