Influence of Development and Sea Level Rise on the Conservation of Redheads Along the Lower Texas Coast
During winter, nearly 80% of North America’s redhead population winters along the lower Texas coa... more During winter, nearly 80% of North America’s redhead population winters along the lower Texas coast. Increased development, particularly from wind energy, along the lower Texas coast has occurred, and the impact on redheads is unknown. The objective of this study was to prioritize coastal freshwater ponds and associated land areas for redheads. Additionally, I determined the effects that a wind energy development and sea level rise have on habitat availability along the lower Texas coast. I identified 156 coastal freshwater ponds used by redheads and concluded that the areas within and around the Kenedy Ranch, Laguna Atascosa NWR, and North Padre Island/Padre Island National Seashore are the most important for redhead conservation. Redhead pond use within the wind farm decreased by 77.48% from pre-construction to post-construction, and sea level rise of 1 m was projected to inundate 59.6% of freshwater ponds used by redheads with saltwater
The potential impacts of sea level rise to wildlife populations and their habitats are of concern... more The potential impacts of sea level rise to wildlife populations and their habitats are of concern. Localized relative sea levels have been rising at elevated rates compared to global sea levels, and this trend will impact coastal plant communities, particularly wetlands. The Laguna Madre, a hypersaline lagoon, is home to nearly 80% of North America's redheads (Aythya americana) during winter. The large, shallow lagoon provides optimal growing conditions for seagrasses, including shoalgrass (Halodule wrightii), the redhead's primary winter food. Adjacent to the Laguna Madre are coastal ponds, on which redheads rely for fresh water. The close proximity of these freshwater sources to the coast makes them vulnerable to saltwater intrusion due to sea level rise. Using Sea Level Affecting Marshes Model (SLAMM), we modeled the impacts of sea level rise on coastal ponds and foraging areas along the lower Texas coast through the year 2100. We also determined which coastal habitat types would be most affected by rising sea levels. The SLAMM model indicated that 9 land cover types had a !50% change in occurrence from the initial 1999 time period to 2100. The model also predicted that 93 of the known 156 coastal ponds would become inundated with salt water. The predicted loss of foraging habitat and its typical proximity to coastal ponds creates a need to identify where conservation and enhancement of wintering redhead habitat should be placed to mitigate the effects of sea level rise.
Grasslands provide important resources for pollinators in agricultural landscapes. Managing grass... more Grasslands provide important resources for pollinators in agricultural landscapes. Managing grasslands with fire and grazing has the potential to benefit plant and pollinator communities, though there is uncertainty about the ideal approach. We examined the relationships among burning and grazing regimes, plant communities, and Bombus species and Apis mellifera L. abundance and nutritional indicators at the Grand River Grasslands in southern Iowa and northern Missouri. Treatment regimes included burn-only, grazed-and-burned, and patch-burn graze (pastures subdivided into three temporally distinct fire patches with free access by cattle). The premise of the experimental design was that patch-burn grazing would increase habitat heterogeneity, thereby providing more diverse and abundant floral resources for pollinators. We predicted that both bee abundance and individual bee nutritional indicators (bee size and lipid content) would be positively correlated with floral resource abundanc...
Freshwater ponds adjacent to the Laguna Madre along the lower Texas coast provide an important an... more Freshwater ponds adjacent to the Laguna Madre along the lower Texas coast provide an important and heavily used source of fresh water for the redhead (Aythya americana) throughout winter. A 267-turbine wind farm was constructed within the core wintering area of the redhead on a private ranch along the western coast of the Laguna Madre, in 2010. Our objective was to investigate the effects of this wind farm on the habitat and potential displacement of redheads and their use of coastal ponds along the lower Texas coast. We conducted weekly aerial surveys to monitor coastal pond use by wintering redheads from mid-October through mid-March during pre-construction (2000-2003) and post-construction (2012-2014) of the wind farm. Pond availability and Palmer Drought Severity Index (PDSI) within the wind farm were significantly correlated during pre-construction (n ¼ 16, R 2 ¼ 0.53, P ¼ 0.035) and post-construction (n ¼ 11, R 2 ¼ 0.64, P ¼ 0.003). However, the number of ponds available at each PDSI level within the wind farm decreased during post-construction (paired t ¼ 3.2, n ¼ 5, P ¼ 0.033). The average number of redheads detected per survey on coastal ponds within the wind farm decreased by 77% from pre-construction to postconstruction. Redhead abundance on ponds across the entire Laguna Madre increased by an average of 3.26 times between pre-construction and post-construction, partly due to increases in the continental redhead population. It appears that the wind farm has altered the use of coastal ponds by redheads during winter. Future wind farm placement along the lower Texas coast should consider coastal pond distribution and the dynamics of redhead use between coastal ponds and foraging areas in the Laguna Madre.
Influence of Development and Sea Level Rise on the Conservation of Redheads Along the Lower Texas Coast
During winter, nearly 80% of North America’s redhead population winters along the lower Texas coa... more During winter, nearly 80% of North America’s redhead population winters along the lower Texas coast. Increased development, particularly from wind energy, along the lower Texas coast has occurred, and the impact on redheads is unknown. The objective of this study was to prioritize coastal freshwater ponds and associated land areas for redheads. Additionally, I determined the effects that a wind energy development and sea level rise have on habitat availability along the lower Texas coast. I identified 156 coastal freshwater ponds used by redheads and concluded that the areas within and around the Kenedy Ranch, Laguna Atascosa NWR, and North Padre Island/Padre Island National Seashore are the most important for redhead conservation. Redhead pond use within the wind farm decreased by 77.48% from pre-construction to post-construction, and sea level rise of 1 m was projected to inundate 59.6% of freshwater ponds used by redheads with saltwater
The potential impacts of sea level rise to wildlife populations and their habitats are of concern... more The potential impacts of sea level rise to wildlife populations and their habitats are of concern. Localized relative sea levels have been rising at elevated rates compared to global sea levels, and this trend will impact coastal plant communities, particularly wetlands. The Laguna Madre, a hypersaline lagoon, is home to nearly 80% of North America's redheads (Aythya americana) during winter. The large, shallow lagoon provides optimal growing conditions for seagrasses, including shoalgrass (Halodule wrightii), the redhead's primary winter food. Adjacent to the Laguna Madre are coastal ponds, on which redheads rely for fresh water. The close proximity of these freshwater sources to the coast makes them vulnerable to saltwater intrusion due to sea level rise. Using Sea Level Affecting Marshes Model (SLAMM), we modeled the impacts of sea level rise on coastal ponds and foraging areas along the lower Texas coast through the year 2100. We also determined which coastal habitat types would be most affected by rising sea levels. The SLAMM model indicated that 9 land cover types had a !50% change in occurrence from the initial 1999 time period to 2100. The model also predicted that 93 of the known 156 coastal ponds would become inundated with salt water. The predicted loss of foraging habitat and its typical proximity to coastal ponds creates a need to identify where conservation and enhancement of wintering redhead habitat should be placed to mitigate the effects of sea level rise.
Grasslands provide important resources for pollinators in agricultural landscapes. Managing grass... more Grasslands provide important resources for pollinators in agricultural landscapes. Managing grasslands with fire and grazing has the potential to benefit plant and pollinator communities, though there is uncertainty about the ideal approach. We examined the relationships among burning and grazing regimes, plant communities, and Bombus species and Apis mellifera L. abundance and nutritional indicators at the Grand River Grasslands in southern Iowa and northern Missouri. Treatment regimes included burn-only, grazed-and-burned, and patch-burn graze (pastures subdivided into three temporally distinct fire patches with free access by cattle). The premise of the experimental design was that patch-burn grazing would increase habitat heterogeneity, thereby providing more diverse and abundant floral resources for pollinators. We predicted that both bee abundance and individual bee nutritional indicators (bee size and lipid content) would be positively correlated with floral resource abundanc...
Freshwater ponds adjacent to the Laguna Madre along the lower Texas coast provide an important an... more Freshwater ponds adjacent to the Laguna Madre along the lower Texas coast provide an important and heavily used source of fresh water for the redhead (Aythya americana) throughout winter. A 267-turbine wind farm was constructed within the core wintering area of the redhead on a private ranch along the western coast of the Laguna Madre, in 2010. Our objective was to investigate the effects of this wind farm on the habitat and potential displacement of redheads and their use of coastal ponds along the lower Texas coast. We conducted weekly aerial surveys to monitor coastal pond use by wintering redheads from mid-October through mid-March during pre-construction (2000-2003) and post-construction (2012-2014) of the wind farm. Pond availability and Palmer Drought Severity Index (PDSI) within the wind farm were significantly correlated during pre-construction (n ¼ 16, R 2 ¼ 0.53, P ¼ 0.035) and post-construction (n ¼ 11, R 2 ¼ 0.64, P ¼ 0.003). However, the number of ponds available at each PDSI level within the wind farm decreased during post-construction (paired t ¼ 3.2, n ¼ 5, P ¼ 0.033). The average number of redheads detected per survey on coastal ponds within the wind farm decreased by 77% from pre-construction to postconstruction. Redhead abundance on ponds across the entire Laguna Madre increased by an average of 3.26 times between pre-construction and post-construction, partly due to increases in the continental redhead population. It appears that the wind farm has altered the use of coastal ponds by redheads during winter. Future wind farm placement along the lower Texas coast should consider coastal pond distribution and the dynamics of redhead use between coastal ponds and foraging areas in the Laguna Madre.
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