Conserving and Restoring Critical Habitats II

Bats provide invaluable ecological services but some species are facing population declines throughout the southeast region. As threats such as white-nose syndrome and loss of roost habitat increase, the importance of identifying and protecting habitats utilized by bats is increasing. This project focuses primarily on identifying presence and habitat-use of the endangered northern long-eared bat (Myotis septentrionalis) and proposed endangered tricolored bat (Perimyotis subflavus) by monitoring activity on the Mississippi coast. Both these species have been extremely impacted by white-nose syndrome because of their hibernation behaviors during winter months. They are also susceptible to loss and disturbance of maternity roosting habitat within forests by urban development, but data on warm-month habitat-use by these two species in coastal Mississippi is lacking. To address data gaps, this project is acoustically monitoring and mist netting across Mississippi coastal forest areas to identify the presence and habitat-use of the tricolored and northern long-eared bat. Findings from this project will improve understanding of the distribution, activity, and habitat preference of the tricolored and northern long-eared bat in coastal Mississippi and along the northern US Gulf of Mexico coast.

North American grassland bird populations have declined, due in part to the loss of suitable winter habitats, including the longleaf pine (Pinus palustris) savanna ecosystem, across the Southeastern United States. Longleaf pine savanna coverage has vastly declined across the Southeast region of the United States from approximately 23 million hectares prior to European colonization to less than 1.2 million hectares in most recent years due to habitat conversion, but perhaps most importantly, lack of fire. Several bird species of conservation concern are found during the winter in these longleaf pine savanna ecosystems along the Gulf of Mexico coast including Henslow's Sparrows (Ammodramus henslowii). Our objectives in this study are to (1) document changes in bird communities associated with habitat management activities (i.e., mechanical clearing, prescribed fire, etc.) and (2) determine the presence/absence and density of winter grassland birds, with a primary focus on Henslow's Sparrows, in relation to pine savanna restoration efforts. Avian surveys conducted December-March 2021-24, established baseline bird communities across sites to measure bird response to intensive land management actions, indicate most of the restoration areas are dominated by species characteristic of shrub and forest. Preliminary data also showed a representative presence of grassland birds including Sedge Wren (Cistothoris stellaris) and Swamp Sparrow (Melospiza georgiana) and Henslow's Sparrow. One site in particular, a regularly managed area using prescribed fire, had a significant number of winter grassland birds including 37 Henslow's Sparrow, a Species of Greatest Conservation Need. Though our vegetation communities showed a significant change in the communities based on restoration techniques, our bird communities did not show that same significant relationship between restoration type and bird communities. This is due to many factors that could not be controlled, yet the data still showed that Henslow's Sparrows were representative of the most recently restored sites.

The Chinese tallow (Triadica sebifera) is identified as one of Alabama's most harmful invasive species. It is a danger to the biodiversity of the Mobile-Tensaw Delta and the coastal plain which spans from Florida to Texas. Nectar from tallow trees produces a significant source of honey contributing to the $350 million worth generated in the US in 2023. To mitigate the spread of tallow, biological controls are now under consideration and being tested. Beekeepers, however, are against these strategies due to concerns about the impact to their livelihoods and the potential risks associated with introducing additional non-native species. Session participants will learn the relationship between beekeepers and Chinese tallow and what biological controls are being considered to slow the spread of Alabama's most noxious plant species.

The Mississippi Sound is an estuary that provides a wide range of nursery habitats for many important coastal species and is recognized for its prominent commercial fisheries. Previous freshening events linked to the Bonnet Carré Spillway, a Mississippi river flood mitigation structure in Louisiana, proved catastrophic for oyster populations in the Mississippi Sound; but the effects on mobile fish and shellfish species are not well-defined. The planned Mid-Breton Sediment Diversion (MBSD), an initiative to combat wetland loss in Louisiana, is also forecasted to lower salinities in the region. Therefore, investigating how important species respond to increased occurrences of freshening conditions is valuable. The objective of this study is to characterize the relationship nekton species in the Mississippi Sound have with salinity and temperature under average conditions and during freshening events. State field survey data were analyzed using PCA, NMDS, and a negative binomial GLM to investigate how salinity and temperature influence the abundance of Blue Crab, Atlantic Croaker, Bay Anchovy, and Brown and White shrimp. Results varied by species, with some likely benefiting from prolonged freshenings while others had more complex relationships with salinity and temperature, indicating a need to better understand these interactions. Secondly, laboratory-based exposure experiments were used to quantify survival, biomass change, and caloric content of Grass Shrimp (Palaemon spp.), an important estuarine prey species, under different combinations of salinity and temperature. Salinities between 7-20 and a temperature of 26°C were found to be optimal for Grass Shrimp, and the survival results were used to construct response curves that dictate how they respond to various conditions in an ecosystem model. Ultimately, this study provides a characterization for how salinity and temperature effects abundances of important five species in the Sound and helps elucidate the interactive effects of salinity and temperature on Grass Shrimp.