Digital Commons Network^™

Early Evidence Of Natal-Habitat Preference: Juvenile Loons Feed On Natal-Like Lakes After Fledging, Brian A. Hoover, Kristin M. Brunk, Gabriella L. Jukkala, Nathan Banfield, Andrew L. Rypel, Walter H. Piper

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many species show natal habitat preference induction (NHPI), a behavior in which young adults select habitats similar to those in which they were raised. However, we know little about how NHPI develops in natural systems. Here, we tested for NHPI in juvenile common loons (Gavia immer) that foraged on lakes in the vicinity of their natal lake after fledging. Juveniles visited lakes similar in pH to their natal lakes, and this significant effect persisted after controlling for spatial autocorrelation. On the other hand, juveniles showed no preference for foraging lakes of similar size to their natal one. When …

Modeling Action Potential Reversals In Tunicate Hearts, John W. Cain, Luran He, Lindsay D. Waldrop

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Tunicates are small invertebrates which possess a unique ability to reverse flow in their hearts. Scientists have debated various theories regarding how and why flow reversals occur. Here we explore the electrophysiological basis for reversals by simulating action potential propagation in an idealized model of the tubelike tunicate heart. Using asymptotic formulas for action potential duration and conduction velocity, we propose tunicate-specific parameters for a two-current ionic model of the action potential. Then, using a kinematic model, we derive analytical criteria for reversals to occur. These criteria inform subsequent numerical simulations of action potential propagation in a fiber paced at …

Functional Morphology Of Gliding Flight Ii. Morphology Follows Predictions Of Gliding Performance, Jonathan Rader, Tyson L. Hedrick, Yanyan He, Lindsay D. Waldrop

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The evolution of wing morphology among birds, and its functional consequences, remains an open question, despite much attention. This is in part because the connection between form and function is difficult to test directly. To address this deficit, in prior work we used computational modeling and sensitivity analysis to interrogate the impact of altering wing aspect ratio, camber, and Reynolds number on aerodynamic performance, revealing the performance landscapes that avian evolution has explored. In the present work, we used a dataset of three-dimensionally scanned bird wings coupled with the performance landscapes to test two hypotheses regarding the evolutionary diversification of …

Plunging Floater Survival Causes Cryptic Population Decline In The Common Loon, Walter H. Piper, Jason Grear, Brian Hoover, Elaina Lomery, Linda M. Grenzer

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Populations of many vertebrates are declining and geographic ranges contracting, largely as a consequence of anthropogenic threats. Many reports of such decline, however, lack the breadth and detail to narrow down its causes. Here we describe population decline in the Common Loon (Gavia immer), a charismatic aquatic bird, based on systematic resighting and measurement of a marked population. During our 27-year investigation, age-adjusted chick mass has fallen by 11%, mortality among young and old chicks has increased by 31% and 82%, respectively, and fledging success has declined by 26%. Meanwhile, the return rate of marked nonbreeders (“floaters”) has …

Functional Morphology Of Gliding Flight I. Modeling Reveals Distinct Performance Landscapes Based On Soaring Strategies, Lindsay D. Waldrop, Yanyan He, Tyson L. Hedrick, Jonathan Rader

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The physics of flight influences the morphology of bird wings through natural selection on flight performance. The connection between wing morphology and performance is unclear due to the complex relationships between various parameters of flight. In order to better understand this connection, we present a holistic analysis of gliding flight that preserves complex relationships between parameters. We use a computational model of gliding flight, along with analysis by uncertainty quantification, to 1) create performance landscapes of gliding based on output metrics (maximum lift-to-drag ratio, minimum gliding angle, minimum sinking speed, lift coefficient at minimum sinking speed); and 2) predict what …

Wild Mice With Different Social Network Sizes Vary In Brain Gene Expression, Patricia C. Lopes, Barbara König

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background

Appropriate social interactions influence animal fitness by impacting several processes, such as mating, territory defense, and offspring care. Many studies shedding light on the neurobiological underpinnings of social behavior have focused on nonapeptides (vasopressin, oxytocin, and homologues) and on sexual or parent-offspring interactions. Furthermore, animals have been studied under artificial laboratory conditions, where the consequences of behavioral responses may not be as critical as when expressed under natural environments, therefore obscuring certain physiological responses. We used automated recording of social interactions of wild house mice outside of the breeding season to detect individuals at both tails of a distribution …

The Role Of Dislodgement In The Territorial Ecology Of The Owl Limpet, Lottia Gigantea, Ryan T. Kabala, Natalie Swinford, Maria J. Mason, William G. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ascertaining the risks and benefits of different behaviors is a central goal of research on territoriality. Although most territorial behavior is ritualized, with concomitant reduced risks for both residents and intruders, this ritualization is generally found to be underpinned by rare, highly consequential, interactions. The agonistic behavior of the intertidal owl limpet, Lottia gigantea, involves defense of a feeding territory, and includes a relatively explosive thrusting response by territory holders against intruding conspecifics. We here ask whether this thrusting behavior is capable of entirely dislodging intruders from their rocky wave-swept substratum, thereby ridding the resident of future challenges by …

Immune-Endocrine Links To Gregariousness In Wild House Mice, Patricia C. Lopes, Esther H. D. Carlitz, Morgan Kindel, Barbara König

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Social interactions are critically important for survival and impact overall-health, but also impose costs on animals, such as exposure to contagious agents. The immune system can play a critical role in modulating social behavior when animals are sick, as has been demonstrated within the context of “sickness behaviors.” Can immune molecules affect or be affected by social interactions even when animals are not sick, therefore serving a role in mediating pathogen exposure? We tested whether markers of immune function in both the blood and the brain are associated with gregariousness, quantified as number of animals interacted with per day. To …