Showing papers by "Lisa M. Angeloni published in 2023"
TL;DR: In this article , the authors harnessed decade-long behavioral data on parental male smallmouth bass, Micropterus dolomieu, to investigate contributions of energetic allometry to differences in reproductive timing.
Abstract: The seasonal onset of reproduction is constrained in many systems by a need to first accumulate energetic reserves. Consequently, the observation that larger individuals reproduce earlier may be due to a negative relationship between size and mass-specific basal metabolic rate that is shared across diverse taxa. However, an untested prediction of this hypothesis is that individuals should be metabolically efficient enough to escape energetic constraints above a certain size threshold. Seasonally reproducing species, such as temperate fishes, that must recover winter energy losses before reproduction and exhibit indeterminate growth are ideal models to test this prediction. We harness decade-long behavioral data on parental male smallmouth bass, Micropterus dolomieu, to investigate contributions of energetic allometry to differences in reproductive timing. At the population level, peak seasonal reproductive timing (i.e. the median date on which eggs were found in nests each year) was negatively related to degree days – a measure of thermal energy experienced – before reproduction. At the individual level, degree days accumulated by males before reproduction was related to male size and condition in every year, but the impact of temperature on reproductive timing by the largest males was relaxed in most years. Additionally, we used our data to replicate the analyses of two previous studies of M. dolomieu populations and found virtually identical negative associations between male body size and degree days accumulated before reproduction. Our results suggest that in smallmouth bass the onset of seasonal reproduction is constrained by basal metabolic rate – as indicated by total length – and that large individuals can escape size-associated energetic constraints. We reveal a more complicated relationship between size and reproductive timing than earlier studies, which may be relevant for many species. Knowledge of this relationship is critical to understanding how a changing climate will influence population dynamics of economically, ecologically and recreationally important species like M. dolomieu.
TL;DR: In this article , the authors investigate biological responses to prolific, anthropogenic noise sources associated with the physical presence of the source (vehicle noise and human voices) and disconnected from it (aircraft overflight).
Abstract: Anthropogenic noise sources impact ecological processes by altering wildlife behavior and interactions with cascading impacts on community structure. The distribution and magnitude of such noise has grown exponentially over the past century, and now inundates even remote areas. Here we investigate biological responses to prolific, anthropogenic noise sources associated with the physical presence of the source (vehicle noise and human voices) and disconnected from it (aircraft overflight). Bioacoustic responses to these noise sources were documented at 103 sites in 40 U. S. National Park units. The presence of bird sounds was noted in 10-s audio samples every 2 min, for 8 days at each site and related to the presence of human voices, vehicle noise, and aircraft noise in the same and preceding samples. Generalized additive models were used to fit smoothing splines to weight the influence of noise in past samples on the probability of detecting bird sounds in the present sample. We found that the probability of hearing birds increased immediately following noise events, and decreased about 2 h after the event. The negative effects were persistent more than 3 h after a noise event. The persistence of these responses – especially for noise from jets that were many kilometers distant – raises questions about the functional significance and ecological consequences of this altered activity, particularly in light of the widespread and diverse habitats in this study and ubiquity of the noise sources evaluated.
TL;DR: In this article , the authors evaluated the effectiveness of training hatchery-reared fish to recognize and respond to a novel esocid predator and also responded to predator cues (training), although the direction of the response to cues was opposite their prediction.
Abstract: Animal behavior has the potential to guide the management of populations at risk of extirpation. This includes insights into how animals respond to novel predators and whether those responses can be enhanced to improve survival. Training hatchery-reared fish to recognize predators has been proposed as a way to reduce postrelease mortalities in the wild. Identifying the presence of innate predator recognition and the capacity for learning to recognize predators in specific species or populations can inform conservation management practices. Here, antipredator behavior (time spent moving and distance from a predator) and the efficacy of predator training were assessed for three populations of a species of conservation concern, the Arkansas Darter Etheostoma cragini, which is vulnerable to predation by esocid predators like the introduced Northern Pike Esox lucius. Arkansas Darters demonstrated some innate ability to recognize and respond to a novel esocid predator and also responded to predator cues (training), although the direction of the response to cues was opposite our prediction. Populations differed in their response to the predator treatment, highlighting the value of managing populations separately. Although the fitness consequences of exposure to predator cues remain to be tested in Arkansas Darters, our results suggest that antipredator behavior is innate and that exposure to predator cues does affect behavior; however, whether or how those behavioral changes affect survival is unclear. This study demonstrates the importance of testing enrichment practices and incorporating behavioral observations into conservation programs to guide population-specific management decisions.