Biology subjects

Tebbich, S.

Publications and source records attributed to Tebbich, S..

4 recordsLinked to original sources

bioRxiv2025

Neophilia in wolves and dogs

The study of domestication provides a unique opportunity to analyze the effects of natural selection in the attraction towards novelty --known as neophilia. This is chiefly due to the fact that selective pressures acting on domesticated animals are often greatly diminished or at least very different from their wild counterparts. In this study, we investigated the neophilic levels of three canine populations differing in their level of contact with human environments both from an evolutionary and ontogenetic perspective: wolves, pack-living dogs, and pet dogs. In order to study their neophilic response, we presented the animals with two objects. The first of these objects was displayed in the animals enclosure for several days. After the animals were habituated to this first object, the second one was introduced together with the first one in a shorter test session meant to explore their preferences for either of the objects. We predicted that dogs --and pet dogs in particular to display higher levels of neophilia, since human-created environments tend to change at a faster pace, and thus, a higher drive to explore these changes would be more beneficial than in a comparably more stable environment. Our results show no apparent differences between the populations in terms of latency to approach the new object, nor in the identity of the object they approached first. Nonetheless, all populations interacted more with the new object during the test phase. Wolves did also interact longer with the object presented in the first phase of the experiment.

animal behavior and cognition↗

bioRxiv2025

Nutritional state and predator exposure jointly mediate stress resilience and behavioural flexibility

Behavioral flexibility plays an important role in adaptation to changing environments within an individuals lifetime. Stress resilience influences flexibility, as short-term stress can enhance attention and memory, while prolonged stress may impair cognitive function. Nutritional state also plays a role, with overweight individuals often suffering greater consequences of chronic stress. The allostatic load model predicts that individuals under prolonged stress remain in a chronically activated state, potentially reducing flexibility. Using a cichlid, we manipulated body condition and exposed individuals to occasional or frequent predator presentations. We then assessed stress responses and behavioral flexibility via a reversal learning test. Contrary to predictions, fish in a high nutritional state - but not overweight - that were frequently exposed to predators recovered rapidly from stress and exhibited enhanced flexibility. Our results provide direct evidence that nutritional state interacts with behavioral flexibility, revealing the costs of coping with repeated stressors. We highlight a link between brief stress responses, characterized by rapid cortisol recovery, and behavioral flexibility. This association only emerged in well-nourished individuals facing frequent stressors, suggesting energy reserves buffer the costs of repeated stress. Thus, resilience benefits behavioral flexibility, while it is energetically costly, as a reduced diet hindered adaptation to environmental change.

animal behavior and cognition↗

bioRxiv2023

The role of the stress axis in mediating behavioural flexibility in a social cichlid, Neolamprologus pulcher

Behavioural flexibility plays a major role in the way animals cope with novel situations, and physiological stress responses are adaptive and highly efficient mechanisms to cope with unpredictable events. Previous studies investigating the role of stress responses in mediating behavioural flexibility were mostly done in laboratory rodents using stressors and cognitive challenges unrelated to the ecology of the species. To better understand how stress mediates behavioural flexibility in a natural context, direct manipulations of the stress response and cognitive tests in ecologically relevant contexts are needed. To this aim, we pharmacologically blocked glucocorticoid receptors (GR) in adult Neolamprologus pulcher using a minimally invasive application of a GR antagonist. GR blockade prevents the recovery after a stressful event, which we predicted to impair behavioural flexibility. After the application of the GR antagonist, we repeatedly exposed fish to a predator and tested their behavioural flexibility using a detour task, i.e. fish had to find a new, longer route to the shelter when the shortest route was blocked. While the latencies to find the shelter were not different between treatments, GR blocked fish showed more failed attempts during the detour tasks than control fish. Furthermore, weak performance during the detour tasks was accompanied by an increase of fear related behaviours. This suggests that blocking GR changed the perception of fear and resulted in an impaired behavioural flexibility. Therefore, our results support a causal link between the capacity to recover from stressors and behavioural flexibility in N. pulcher with potential consequences for an effective and adaptive coping with changing environments.

animal behavior and cognition↗

bioRxiv2020

Evidence of hidden hunger in Darwin's finches as a result of non-native species invasion of the Galapagos cloud forest

Invasive species pose a major threat to forest biodiversity, particularly on islands, such as the Galapagos. Here, invasive plants are threatening the remnants of the unique cloud forest and its iconic Darwins finches. We posit that food web disturbances caused by invasive Rubus niveus (blackberry), but also the management measures used to control it, could contribute to the rapid decline of the insectivourous warbler finch (Certhidae olivacea). We compared changes in long-term management, short-term management and unmanaged areas. We measured C:N ratios, {delta}15N-nitrogen and {delta}13C-carbon signatures in bird blood and arthropods, as indicators of resource use change, in addition to mass abundance and diversity of arthropods. We reconstructed the birds diets using isotope mixing models. The results revealed that finches in (Rubus-invaded) unmanaged areas foraged on abundant yet low quality arthropods and had shorter tarsi. Is this the first evidence of hidden hunger in degraded terrestrial ecosystems in Galapagos?

ecology↗