Thunderstorms and associated wind disturbance are becoming more common globally with a predicted 6% increase of tropical storms over the last three decades in Central America, compared to records from the 1970s (Brooks, 2013;ECLAC, 2018). In tropical landscapes, wind disturbance forms gaps in the forest canopy, altering forest structure (Marra et al., 2014;Peterson, 2007). For example, treefall vulnerability is a product of tree damage and mortality interacting across individual and community scales. Large diameter AbstractOn 19 May 2018, a microburst caused 600 isolated forest gaps in a Costa Rican tropical forest. We surveyed fallen and standing trees within gaps to determine whether certain variables are associated with treefalls. Our results highlight considerations for future research to understand the impacts of microbursts in tropical forests. Abstract in Spanish is available with online only

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Production and outmigration of young-of-year (YOY) northern pike from natal sites in Lower Green Bay, WI, USA, were documented over three consecutive years (2013)(2014)(2015). We tested the hypothesis that spawning success and outmigration characteristics of YOY northern pike would vary among natural and anthropogenically modified habitats. Sixteen focal study locations were surveyed, including a restored natural wetland, agricultural drainage ditches, a flooded forested wetland and several unimpounded tributaries. We collected 1469 YOY northern pike with most individuals (N = 1163) originating from a flooded forested wetland on the east shore. Most sites produced YOY in all years (range N = 2-1145 individuals among study years). Outmigration ranged between 1 and 40 days during 2013-2015.Greater production and extended outmigration times occurred at most sites in 2014 (range 17-40 days) when the region experienced a late spring with heavy precipitation. In contrast, the lowest production and shortest outmigration period occurred at most sites in 2015 (range 14-23 days) when environmental conditions reflected regional averages. Outmigration began nearly 3 weeks earlier in 2015 (5/8) than in other study years (8 June 2013 and 25 May 2014). Total length (TL) of outmigrating northern pike ranged between 17 and 138 mm. Total length of YOY was significantly different among sites in 2013 and 2014, with the smallest fish (17 mm TL) outmigrating from agricultural ditches in both years. There were no significant variations in size among sites in 2015 (range 21-95 mm TL). Our results indicate significant variation in YOY northern pike outmigration characteristics within Lower Green Bay that may reflect the interplay between adult spawning site selection and annual weather patterns. Our findings highlight the importance of quantifying overlooked habitats in regions of mixed development.

We investigated environmental variables associated with spawning migration behavior for a dual spawning population of endangered Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus in the Great Pee Dee River, South Carolina. From 2016 to 2021, 147 Atlantic Sturgeon were captured, implanted with acoustic transmitters, and monitored using a stationary array of 40 receivers located every 5‐20 km along a 302‐km section of the Great Pee Dee River from the river mouth at Winyah Bay to the first movement barrier at Blewett Falls Dam, North Carolina. We observed 47 Atlantic Sturgeon attempt 74 spring migrations and 39 Atlantic Sturgeon attempt 76 fall migrations across four years of telemetry observations (2018‐2021). Mixed effects models indicated that discharge interacted with water temperature to affect both migration initiation and upriver movement, and these interactions differed between spring and fall runs. Spring runs were cued by rising temperatures and high river discharge, whereas fall runs were cued by falling temperatures and low discharge. Within migrations, spring‐run fish migrated further upriver when discharge was falling, and fall‐run fish moved further upriver when discharge was rising. Overall, fall‐run sturgeon migrated significantly further upriver than spring‐run sturgeon. Differences in migratory behavior among runs suggest potentially unique adaptations to ambient river conditions during respective spawning seasons. Identifying the environmental factors that drive, and thereby limit, Atlantic Sturgeon migrations in the Great Pee Dee River informs regional recovery efforts and highlights the importance of studying and managing this species at the population level.