Lyons, Eddie Keith (2008-05). Lesser prairie-chicken demographics in Texas: survival, reproduction, and population viability. Doctoral Dissertation. Thesis uri icon

abstract

  • Lesser prairie-chickens (Tympanuchus pallidicinctus) have declined throughout their range because of overgrazing and loss or fragmentation of habitat from conversion of native prairie to agricultural cropland. Lesser prairie-chickens were radio-marked (n = 225) as part of 2 separate field studies in the Texas Panhandle (2001-2003, 2003- 2007). These data were used to evaluate whether differences in demographic parameters existed between populations occurring in 2 areas dominated by different vegetation types (sand sagebrush [Artemisia filifolia] versus shinnery oak [Quercus havardii]) in the Texas Panhandle from 2001-2007. A model-selection approach was used to test hypotheses explaining differences in survival and reproductive success of lesser prairiechickens. Additionally, a population viability analysis was constructed using the above demographic parameters to evaluate effects of harvest and no harvest scenarios on viability and population persistence of lesser prairie-chickens in Texas. Overall, survival, reproduction, and population viability were lower in the shinnery oak compared to the sand sagebrush vegetation type. Lesser prairie-chicken survival differed between breeding and non-breeding periods. I estimated annual survival of lesser prairiechickens at 31% in the shinnery oak and 52% in the sand sagebrush vegetation type. Nest success was (41%, 95% CI = 25-56%) in the shinnery oak population compared to the sand sagebrush population (75%, 95% CI = 54-94%). Population viability analysis predicted continued declines in lesser prairie-chicken populations in Texas. Estimates of local occupancy indicated lesser prairie-chicken populations would go extinct in the southwestern shinnery oak vegetation type more quickly compared to the northeastern sand sagebrush vegetation type (approximately 10 years compared to 30 years, respectively) without changes in population vital rates. Harvest at all levels increased risk of extinction. Results suggest that differences in survival and reproduction of lesser prairie-chickens within sand sagebrush and shinnery oak vegetation types throughout the Texas Panhandle should be evaluated, especially during the breeding season. Improvements to vegetation conducive for successful nesting are important to the viability of lesser prairie-chickens. Conservation and recovery strategies for lesser prairie-chicken populations should address variables that increase survival and nest success and consideration of no harvest.
  • Lesser prairie-chickens (Tympanuchus pallidicinctus) have declined throughout
    their range because of overgrazing and loss or fragmentation of habitat from conversion
    of native prairie to agricultural cropland. Lesser prairie-chickens were radio-marked (n
    = 225) as part of 2 separate field studies in the Texas Panhandle (2001-2003, 2003-
    2007). These data were used to evaluate whether differences in demographic parameters
    existed between populations occurring in 2 areas dominated by different vegetation types
    (sand sagebrush [Artemisia filifolia] versus shinnery oak [Quercus havardii]) in the
    Texas Panhandle from 2001-2007. A model-selection approach was used to test
    hypotheses explaining differences in survival and reproductive success of lesser prairiechickens.
    Additionally, a population viability analysis was constructed using the above
    demographic parameters to evaluate effects of harvest and no harvest scenarios on
    viability and population persistence of lesser prairie-chickens in Texas. Overall,
    survival, reproduction, and population viability were lower in the shinnery oak compared to the sand sagebrush vegetation type. Lesser prairie-chicken survival differed between
    breeding and non-breeding periods. I estimated annual survival of lesser prairiechickens
    at 31% in the shinnery oak and 52% in the sand sagebrush vegetation type.
    Nest success was (41%, 95% CI = 25-56%) in the shinnery oak population compared to
    the sand sagebrush population (75%, 95% CI = 54-94%). Population viability analysis
    predicted continued declines in lesser prairie-chicken populations in Texas. Estimates of
    local occupancy indicated lesser prairie-chicken populations would go extinct in the
    southwestern shinnery oak vegetation type more quickly compared to the northeastern
    sand sagebrush vegetation type (approximately 10 years compared to 30 years,
    respectively) without changes in population vital rates. Harvest at all levels increased
    risk of extinction. Results suggest that differences in survival and reproduction of lesser
    prairie-chickens within sand sagebrush and shinnery oak vegetation types throughout the
    Texas Panhandle should be evaluated, especially during the breeding season.
    Improvements to vegetation conducive for successful nesting are important to the
    viability of lesser prairie-chickens. Conservation and recovery strategies for lesser
    prairie-chicken populations should address variables that increase survival and nest
    success and consideration of no harvest.

publication date

  • May 2008