Konventionelle Geschlechterrollen, die insbesondere bei Vögeln und Säugetieren weitverbreitet sind, besagen, dass sich vor allem Weibchen um die die Brutpflege kümmern, während Männchen versuchen, ihren individuellen Fortpflanzungserfolg durch Paarungen mit möglichst vielen Partner zu erhöhen. Bei einigen Arten haben es allerdings Weibchen geschafft, sich von diesem klassischen Rollenmodell zu emanzipieren. In meinem Vortrag werde ich am Beispiel des Schneeregenpfeifers Charadrius nivosus mit Hilfe von Langzeitdaten zeigen, wie sich die Emanzipation darstellt und weshalb es gerade in dieser Art zur Rollenumkehr kommt. [more]

During this presentation, I will outline the research program I have put in place over the past five years at the University of Ottawa, on the coadaptations between metabolic, performance, and personality traits. I will present the first results obtained from studies on wild mice, laboratory insects, as well as humans. A common theme in all of our research is the use of quantitative genetic techniques to partition the (co)variance between several traits at different levels of variation. Doing so commonly reveals trait associations that are otherwise undetectable at the aggregated level. [more]

The white-throated sparrow (Zonotrichia albicollis) is an ordinary looking songbird with extraordinary genetics. Both sexes exist in either a white-striped or tan-striped morph, as determined by a >100-Mb inversion-based supergene on the second chromosome. White morph birds are almost all heterozygous for the supergene, suggesting that homozygousity is deleterious. Tan morph birds are homozygous without the supergene. The supergene is associated with a suite of coadapted traits that are expressed by both white males and females, including higher levels of aggressiveness, song and copulation, and lower levels of parental care. Due to behavioral and genetic incompatibilities within white male x white female pairs, white-throated sparrows pair dissassortively by morph. Tan males and white females share parental care relatively equally, whereas white males provide little paternal support to tan partners. We leveraged this unique system and an 18-year long-term dataset regarding reproduction and survivorship to test different evolutionary theories of aging, and elucidate how differences in actuarial and reproductive senescence might affect the balance in fitness between morphs. On one hand, some theories of aging suggest that competitive traits, such as those associated with the supergene, have high physiological costs and promote a live-fast-die-young strategy and faster senescence. On the other hand, intense investment in parental care, as in the tan morph, can also have costs. Furthermore, a more cooperative reproductive strategy, as observed in tan males x white femalepairs, might lessen reproductive costs and dampen senescence rates. Our data do not support high costs of the competitive traits associated with the morph-determining supergene, but rather suggest high costs of unsupported parental care, and that cooperative reproductive strategies might dampen rates of senescence. To better understand how genetics contribute to morph differences in life-history and senescence, more work is needed regarding how specific genes within the supergene affect physiological and self-maintenance differences between the morphs. Such work will ultimately advance understanding of how supergenes promote the persistence of multiple morphs with distinct life-history strategies within a species. [more]

Human activities are globally pervasive. Although applied ecology and conservation biology has typically focused on how changes in vegetation or land cover influence wild populations and communities, growing evidence suggests that changes in other ecological dimensions, such as the acoustic and lit environment, can have comparable or larger ecological consequences than land cover changes. In this talk, I will discuss my lab’s use of natural and manipulative field experiments, plus large-scale databases, to understand how changes to the acoustic environment and light regimes can influence behavior, reproduction, distributions and ecological interactions. I will focus primarily on birds, but highlight key examples of how changes in sensory environments are highly relevant to human health and wellbeing. [more]

In evolutionary ecology, the process of mate sampling is often considered as a secondary problem compared to the more important question of co-evolution between the traits expressed in one sex and the preferences in the other sex. Since there are direct benefits from choosing a partner, the processes of pair formation have been overlooked as a somewhat trivial question. Yet, the question of the choice between several partners of varying quality is not as simple and immediate as it may seem at first look. Difficulties arise at several levels. The study of mating strategies often begins with field observations at the group or population level, but it is not straightforward to identify the actual choice criterion. If non-random pairing is observed, many authors are tempted to conclude to the existence of an underlying sexual preference. Yet, one cannot directly link the pattern of assortative mating at the population level to a given process of individual choice. Indeed, simple models show that one can easily generate such a pattern without assuming any sexual preference for the individuals. On the contrary, a pattern apparently resulting from random choices can be generated from assumptions in which the individuals actually rely on explicit sexual preferences. More generally, the scramble competition (always arising when there is a limited number of sexual partners) is a sufficiently strong constraint to severely impair the evolution of any choosy decision rules. In most cases, the evolutionary stable strategy is to use very low acceptance threshold. We also provide experimental mechanisms in favour of the adaptive value of this apparent absence of choice. These results emphasize the urgent need for carefully considering the pairing process in sexual selection. [more]

The flexible control of sequential behavior is a fundamental aspect of speech, enabling endless reordering of a limited set of learned vocal elements (i.e. syllables or words). Songbirds are phylogenetically distant from humans, but share the capacity for vocal learning as well as neural circuitry for vocal control that includes direct cortical-brainstem projections. Based on these similarities, we hypothesized that songbirds might likewise be able to learn flexible, moment-by-moment control over vocal production. Here, we demonstrate that Bengalese finches, which sing variable syllable sequences, can learn to rapidly modify the probability of specific sequences (e.g. ‘ab-c’ versus ‘ab-d’) in response to arbitrary visual cues. Moreover, once learned, this modulation of sequencing occurs immediately following changes in contextual cues and persists in the absence of external reinforcement. Our findings reveal a capacity in songbirds for learned contextual control over syllable sequencing that parallels aspects of human cognitive control over speech. [more]

Crickets use sound to find each other space over which potential mates can sense each other is determined by the loudness of song and the sensitivity of the auditory system. According to the textbooks, this space is enhanced purely ‘passively’ through morphology and mechanical resonance. Song producting wings and females ears resonate at the same frequency enhancing the size of their acoustic space. But some crickets didn’t read the textbook. In this talk, I will present my research on Oecanthus henryi which is one such species. O. henryi is a tree cricket, and males of this species use an active behavioural strategy to make themselves louder. They manufacture an acoustic baffle, a tool that makes them louder. In fact, using a series of models and experiments, we showed that not only do they manufacture a tool, but they manufacture an optimal tool. Not to be outdone, we found that O. henryi females, have an active physiological amplification system in their ears. Using careful neurobiology we show that the amplifier doesn’t actually make them more sensitive than other crickets, as previously speculated. Rather, it allows them to change the frequency that they are sensitive to. What is even more remarkable is that this amplification is acheived through the activity of only a handful of motors protein. Both findings underline the poverty of our descriptions of invertebrate behaviour and biophysics, and point to a wealth of innovations yet to be discovered even among these ‘simple’ organisms. [more]

What generates and maintains biological diversity? This major question in evolutionary biology has fascinated scientists for centuries and continues to drive new and exciting research. Explore recent findings that examine avian hybridization in chickadees and wagtails, species boundaries in redpoll finches, and the genetic basis of spatial cognition, to gain a better understanding of divergence and speciation in birds. From the genetic basis of feather color to metabolic pathways that differ between closely related species, this work is helping us better understand what makes species different, and how those differences contribute to the maintenance of avian biodiversity [more]

The Norwegian Institute for Nature Research (NINA) is a private research institute with responsibility for monitoring of plants and animals of management interest in Norway: invasive species, harvested species, and red-listed species of conservation concern. Long-term ecological monitoring of these taxa requires efficient sampling methods that provide information on population trends and habitat requirements, while controlling for the problem of imperfect detection rates under field conditions. Occupancy models are a mark-recapture model based on repeated sampling that has the advantage that sampling can be based on detections of unmarked animals. Detections can be recorded with a variety of different kinds of sampling gear, including eDNA for freshwater species, Malaise traps for insects, den checks for mammals, or sound recordings for birds. I will introduce occupancy models and available software tools. To demonstrate the utility of occupancy models for ecological monitoring, I will discuss a variety of recent case studies where models based on single season sampling, multilevel sampling designs, and multiple detection states have provided insights into early detection of invasive species, and population trends and key ecological drivers for harvested populations and species of conservation concern in Norway. [more]

Using sounds for social interactions is common across many taxa. Humans engaged in conversation, for example, take rapid turns to go back and forth. This ability to act upon sensory information to generate a desired motor output is a fundamental feature of animal behavior. How the brain enables such flexible sensorimotor transformations, for example during vocal interactions, is a central question in neuroscience. Seeking a rodent model to fill this niche, we are investigating neural mechanisms of vocal interaction in Alston’s singing mouse (Scotinomys teguina) – a neotropical rodent native to the cloud forests of Central America. We discovered sub-second temporal coordination of advertisement songs (counter-singing) between males of this species – a behavior that requires the rapid modification of motor outputs in response to auditory cues. We leveraged this natural behavior to probe the neural mechanisms that generate and allow fast and flexible vocal communication. Using causal manipulations, we recently showed that an orofacial motor cortical area (OMC) in this rodent is required for vocal interactions (Okobi*, Banerjee* et. al, 2019). Subsequently, in electrophysiological recordings, I find neurons in OMC that track initiation, termination and relative timing of songs. Interestingly, persistent neural dynamics during song progression stretches or compresses on every trial to match the total song duration (Banerjee et al, in preparation). These results demonstrate robust cortical control of vocal timing in a rodent and forces us to reconsider the evolutionary origins of motor cortical control of vocal output. [more]

Longitudinal studies of animal social behavior and demography allow us to understand how environments at one stage of life affect fitness outcomes at another stage of life. This question is important both in the biological sciences and in the human social sciences. Here, I briefly review evidence from the human social sciences that document, and raise important questions about, the profound links between early life, adult life, and longevity. Next, I draw parallels between those studies and biological studies of wild animal systems, where researchers have long studied these links. I argue that wild animal systems, by answering questions that are difficult or impossible to answer in human studies, shed light on the deep evolutionary roots of the human sensitivity to the social environment. They also provide insight into the mechanisms by which environments at one stage of life affect survival outcomes at a later stage of life. Most of the examples I discuss come from my long-term research project, the Amboseli Baboon Research Project. [more]