Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors th... more Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson's hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson's hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%-42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson's hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson's hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson's hawks arriving to the breeding grounds.
PRINTED ON RECYCLED PAPER The contents of this report are not to be used for advertising, publica... more PRINTED ON RECYCLED PAPER The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. The findings of this report are not to be construed as an official Department of the Army position, unless so designated by other authorized documents.
Vegetative characteristics and grassland passerine use of conservation plantings were studied in ... more Vegetative characteristics and grassland passerine use of conservation plantings were studied in eastern South Dakota Game Production Areas, June 2007-2008. Fourteen fields, from 1 to 8 years old at the onset of the study, were surveyed in each year to describe vegetative characteristics and to correlate grassland pas-serine use. Sites had been planted to a mixture of 5 native warm-season grasses, 3 cool-season grasses, and alfalfa. Grassland passerines were sampled along fixed width transects during June 2007-2008. Vegetation was sampled at 7 points along each of 3 parallel transects within the bird sampling transects. Younger plantings had lower height and percent canopy cover of dead vegetation, greater litter depth, higher coverage of alfalfa and unplanted forbs, and more bare ground than older plantings. Nonmetric multi-dimensional scaling based upon vegetative characteristics showed that sites tended to become more similar with age. A total of fifteen bird species were identif...
Prior to the 193Os, common cattail (Typha latifolia L.) was the only member of this genus to inha... more Prior to the 193Os, common cattail (Typha latifolia L.) was the only member of this genus to inhabit the northern prairies and was uncommon in most shallow wetlands (Metcalf 1931). During the late 193Os and early 194Os, narrowleaf cattail (T. angustifolia L.) extended its range westward into the Dakotas and Manitoba (Smith 1967). Concomitant with the invasion of narrowleaf cattail was the establishment of a hybrid between narrowleaf and common cattail, T. X glauca (Godron). Because both narrowleaf cattail and its hybrid are better adapted to fluctuating water regimes than common cattail (McDonald 1955), these species invaded shallow prairie wetlands. During the next 50 years, both spread rapidly throughout much of the Prairie Pothole Region (PPR) (Smith 1967), often forming dense monotypic stands in semipermanent wetlands (Stewart and Kantrud 1971). The value of cattail-dominated wetlands to waterfowl and other avian species is diminished following invasion (Beule 1979; Kantrud 1986...
The current status of the upland sandpiper (Bartramia longicauda) popula- tion in South Dakota is... more The current status of the upland sandpiper (Bartramia longicauda) popula- tion in South Dakota is of primary concern to natural resource managers be- cause the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 330 references to generate a comprehensive review of the occurrence and
The current status of the western willet (Catoptrophorus semipalmatus inor- natus) population in ... more The current status of the western willet (Catoptrophorus semipalmatus inor- natus) population in South Dakota is of primary concern of natural resource managers because the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 225 references to generate a comprehensive review on the occurrence and
The current status of the marbled godwit (Limosa fedoa) population in South Dakota is of primary ... more The current status of the marbled godwit (Limosa fedoa) population in South Dakota is of primary concern to natural resource managers because the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 250 references to generate a comprehensive review on the occurrence and ecology of
We describe a simulation model designed to study the effects of helicopter disturbance on molting... more We describe a simulation model designed to study the effects of helicopter disturbance on molting Pacific black brant near Teshekpuk Lake, Alaska. Locations of 18118 brant were digitized into the model based on 10 years of population survey data. Bell 206 and Bell 412 helicopters ...
... Steve Adair, Joe Moore, Frances Mann, Keith McKnight, Michael North, Jeff Odom, and Len Polas... more ... Steve Adair, Joe Moore, Frances Mann, Keith McKnight, Michael North, Jeff Odom, and Len Polasek spent one or more field sea-sons ... Rod King, Bill Butler, and others conducted annual aerial brant surveys, without which these lakes could not have been classified for waterfowl ...
Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors th... more Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson's hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson's hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%-42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson's hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson's hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson's hawks arriving to the breeding grounds.
PRINTED ON RECYCLED PAPER The contents of this report are not to be used for advertising, publica... more PRINTED ON RECYCLED PAPER The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. The findings of this report are not to be construed as an official Department of the Army position, unless so designated by other authorized documents.
Vegetative characteristics and grassland passerine use of conservation plantings were studied in ... more Vegetative characteristics and grassland passerine use of conservation plantings were studied in eastern South Dakota Game Production Areas, June 2007-2008. Fourteen fields, from 1 to 8 years old at the onset of the study, were surveyed in each year to describe vegetative characteristics and to correlate grassland pas-serine use. Sites had been planted to a mixture of 5 native warm-season grasses, 3 cool-season grasses, and alfalfa. Grassland passerines were sampled along fixed width transects during June 2007-2008. Vegetation was sampled at 7 points along each of 3 parallel transects within the bird sampling transects. Younger plantings had lower height and percent canopy cover of dead vegetation, greater litter depth, higher coverage of alfalfa and unplanted forbs, and more bare ground than older plantings. Nonmetric multi-dimensional scaling based upon vegetative characteristics showed that sites tended to become more similar with age. A total of fifteen bird species were identif...
Prior to the 193Os, common cattail (Typha latifolia L.) was the only member of this genus to inha... more Prior to the 193Os, common cattail (Typha latifolia L.) was the only member of this genus to inhabit the northern prairies and was uncommon in most shallow wetlands (Metcalf 1931). During the late 193Os and early 194Os, narrowleaf cattail (T. angustifolia L.) extended its range westward into the Dakotas and Manitoba (Smith 1967). Concomitant with the invasion of narrowleaf cattail was the establishment of a hybrid between narrowleaf and common cattail, T. X glauca (Godron). Because both narrowleaf cattail and its hybrid are better adapted to fluctuating water regimes than common cattail (McDonald 1955), these species invaded shallow prairie wetlands. During the next 50 years, both spread rapidly throughout much of the Prairie Pothole Region (PPR) (Smith 1967), often forming dense monotypic stands in semipermanent wetlands (Stewart and Kantrud 1971). The value of cattail-dominated wetlands to waterfowl and other avian species is diminished following invasion (Beule 1979; Kantrud 1986...
The current status of the upland sandpiper (Bartramia longicauda) popula- tion in South Dakota is... more The current status of the upland sandpiper (Bartramia longicauda) popula- tion in South Dakota is of primary concern to natural resource managers be- cause the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 330 references to generate a comprehensive review of the occurrence and
The current status of the western willet (Catoptrophorus semipalmatus inor- natus) population in ... more The current status of the western willet (Catoptrophorus semipalmatus inor- natus) population in South Dakota is of primary concern of natural resource managers because the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 225 references to generate a comprehensive review on the occurrence and
The current status of the marbled godwit (Limosa fedoa) population in South Dakota is of primary ... more The current status of the marbled godwit (Limosa fedoa) population in South Dakota is of primary concern to natural resource managers because the two main habitats this species needs, native rangelands and wetlands, are being converted to other land uses at a rapid rate. We synthesized over 250 references to generate a comprehensive review on the occurrence and ecology of
We describe a simulation model designed to study the effects of helicopter disturbance on molting... more We describe a simulation model designed to study the effects of helicopter disturbance on molting Pacific black brant near Teshekpuk Lake, Alaska. Locations of 18118 brant were digitized into the model based on 10 years of population survey data. Bell 206 and Bell 412 helicopters ...
... Steve Adair, Joe Moore, Frances Mann, Keith McKnight, Michael North, Jeff Odom, and Len Polas... more ... Steve Adair, Joe Moore, Frances Mann, Keith McKnight, Michael North, Jeff Odom, and Len Polasek spent one or more field sea-sons ... Rod King, Bill Butler, and others conducted annual aerial brant surveys, without which these lakes could not have been classified for waterfowl ...
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