Biology subjects

Verbruggen, F.

Publications and source records attributed to Verbruggen, F..

8 recordsLinked to original sources

bioRxiv2026

Post-fledging space use and survival in hand-reared versuswild juvenile herring gulls

Parental care can shape post-fledging behaviour through provisioning, guidance and social information, yet its absence may alter how young birds establish space use and habitat preferences. We tested the consequences of absent parental care by comparing, hand-reared juvenile herring gulls released without parents with wild, parent-reared conspecifics, focusing on the first two months after fledging. Wild juveniles frequently revisited their natal nest during the first month, whereas hand-reared birds rarely returned to the release site; revisits declined in both groups by the second month but remained more common in wild birds. Wild juveniles used smaller ranges that subsequently expanded, while hand-reared birds began with larger ranges that later contracted, leading to convergence. Contrary to expectation, wild juveniles occurred in areas with higher human population density than hand-reared birds. Habitat use also differed between groups and changed over time. Early on, wild juveniles concentrated activity in anthropogenic and marine habitats, whereas hand-reared birds used rural green habitats more. Later, both groups shifted away from marine areas towards rural green habitats, reducing but not eliminating between-group differences. Short-term survival, did not differ between hand-reared and wild juveniles, indicating that parental care primarily reshaped early space use and habitat choice rather than immediate survival.

animal behavior and cognition↗

bioRxiv2025

Weak evaporative cooling capacity and body size shape thermal limits in tropical montane forest birds

Climate warming and forest fragmentation threaten tropical biodiversity by altering microclimates and narrowing the range of temperatures within which species can maintain optimal physiological performance. We investigated the thermoregulatory capacities of five forest-dependent bird species from the Taita Hills (Kenya), a montane biodiversity hotspot experiencing severe habitat loss. Using respirometry, we measured resting metabolic rate (RMR) across a range of temperatures to determine thermoneutral zone (TNZ) limits, quantified evaporative water loss (EWL), evaporative heat loss (EHL), and metabolic heat production (MHP) as proxies of cooling capacity, and estimated heat tolerance limits (HTLs). Contrary to expectations of a classical TNZ pattern, RMR-temperature relationships were predominantly V-shaped, suggesting the absence, or marked narrowness, of a TNZ. In contrast, HTL clearly increased with body mass, with larger species tolerating higher temperatures. Evaporative cooling efficiency remained weak across all species (EHL/MHP < 1), indicating limited capacity to dissipate metabolic heat. Compared with global data, the Taita Hills species exhibited low critical temperatures and narrow thermal ranges, consistent with specialisation to the stable microclimates of tropical montane forests. Our findings suggest that small-bodied, forest-dependent tropical birds function within narrow thermal margins, which may make them especially vulnerable to rising temperatures and the microclimatic changes associated with climate change and forest fragmentation.

ecology↗

bioRxiv2025

Early-life social instability affects aggression, but not response inhibition, in chickens

Living in complex social environments presents behavioural and cognitive challenges. A key challenge is the regulation of aggression, which may be facilitated by response inhibition, the ability to suppress inappropriate actions. In more complex social environments, greater variability in interactions may increase demands for aggression regulation, promoting the development of response inhibition. However, social instability, a form of complexity characterised by frequent changes in group composition, can elevate aggression and may instead impair inhibition. To test these competing predictions we raised 144 chickens (Gallus gallus domesticus) in either stable or unstable social groups for five weeks. We observed the aggression within their enclosures following the final manipulation, and assessed their response inhibition using a thwarting task and a cylinder task. Unstable groups initially showed more aggression than stable groups following regrouping, but this declined rapidly to the same lower level of aggression as the stable groups. Contrary to our predictions, there were no differences between birds raised in stable and unstable groups for any measure of response inhibition, and individual variation in aggression did not correlate with inhibitory performance. These findings suggest that social instability influences aggression but does not affect the development of response inhibition in chickens, highlighting the potential context- and species-specific nature of social effects on cognition.

animal behavior and cognition↗

bioRxiv2025

Evaluating wildlife rehabilitation: Successful return of rehabilitated gulls in the wild

The expansion of human activities has increased the need for animal rehabilitation, especially for urban-breeding species such as herring gulls (Larus argentatus) and lesser black-backed gulls (L. fuscus), which now commonly nest on buildings and industrial sites. This study evaluates rehabilitation effectiveness by comparing survival and post-release reintegration, measured through habitat use and the degree of association with human-dominated environments, between rehabilitated and wild juvenile gulls along the Belgian coast. From 2012 to 2023, 3443 juveniles were ringed and monitored. Estimated survival rates varied significantly with age, but there was no difference between rehabilitated and wild birds. Differences in habitat use and association with local human population density were largely confined to juveniles: rehabilitated juveniles were resighted more often in rural green areas with lower human population densities, with patterns converging in older age classes. Our results suggest rehabilitation can support urban gull populations by yielding wild-like survival and space use.

ecology↗

bioRxiv2024

To Peck or Not To Peck: The influence of early-life social environment on response inhibition and impulsive aggression in Japanese quails

Deficits in response inhibition (i.e., the ability to suppress inappropriate responses) may contribute to increased impulsive aggression (i.e., unplanned behaviors that harm others). Since early-life environment might influence the development of response inhibition, it could also indirectly affect impulsive aggression. However, this relationship has rarely been directly examined. Here, we investigated whether response inhibition is associated with impulsive aggression and whether this relationship explains the effects of early-life social environments on impulsive aggression in juvenile Japanese quails (Coturnix japonica). Quails (n = 120) were raised in two social conditions: Small groups of five birds or Large groups of 15 birds. Response inhibition was assessed using the Barrier and Cylinder tasks, while impulsive aggression was measured in two contexts - within a group of five familiar individuals and in a dyad with an unfamiliar individual. We found that some aspects of response inhibition were related to impulsive aggression. Furthermore, quails reared in small groups showed significantly poorer response inhibition than those reared in large groups. Yet, impulsive aggression did not significantly differ between the two conditions. These findings suggest that, while impulsive aggression is partly related to response inhibition, other factors mitigate the effects of early social environments on its expression.

animal behavior and cognition↗

bioRxiv2024

Early-Life Group Size Does Not Influence Japanese Quails' Learning in a Response Inhibition Task

In complex social environments, animals benefit from suppressing inappropriate responses (known as Response Inhibition - RI) to avoid conflicts and maintain group cohesion. Recent research suggests that an individuals early-life social environment can shape their RI. However, these findings have mostly been correlational, and results vary across species. Furthermore, the role of learning is often overlooked when measuring RI, despite its potential importance to understanding group differences. We investigated the effect of early-life group size, a key determinant of social complexity, on RI in Japanese quails (Coturnix japonica), whilst taking the role of learning into account. Quails (n = 120) were raised in either small groups of five or large groups of 15 individuals. RI was assessed using the cylinder task. Up to 10 trials were administered to assess whether the birds responses changed with increasing experience of the task. Among the quails that completed 10 trials, we found that those raised in large groups consistently spent less time pecking the cylinder than those raised in small groups. The quails responses were also influenced by their body condition, food motivation, and sex. Importantly, the quails learned to inhibit their responses - successful trials increased, and time spent pecking the cylinder decreased, across 10 trials. However, learning rates did not differ between the treatment groups. These findings suggest that early-life social group size promotes the development of RI in quails, but not their learning during the cylinder task.

animal behavior and cognition↗

bioRxiv2024

Beyond a unitary construct: Dissecting stopping behaviour in two bird species

The ability to stop behaviour is essential for adapting to changes in the environment, a principle that holds true across various species. While traditionally considered a unitary psychological construct, recent studies indicate that this ability is multifaceted. Our research evaluates this multifaceted nature using three tasks that measure stopping in different contexts in two related gull species: herring gulls (Larus argentatus) and lesser black-backed gulls (L. fuscus). These species were selected for their distinct migration and foraging strategies, offering a unique lens through which to examine behavioural adaptations. Across tasks and species, we conceptualised stopping as a race between a go and a stop runner, and predicted correlations based on the type of stop stimulus, the relative timing of the go and the stop stimuli, and the type of action that needed to be stopped. We found correlations between measures of going across tasks, but there was less consistency in measures of stopping. Furthermore, we observed significant differences in going and stopping behaviours that were specific to each species, which may be linked to their migration and foraging strategies. These findings highlight the importance of considering the multifaceted nature of stopping in evolutionary and behavioural studies.

animal behavior and cognition↗

bioRxiv2021

Post-error slowing reflects the joint impact of adaptive and maladaptive processes during decision making

Errors and their consequences are typically studied by investigating changes in decision speed and accuracy in trials that follow an error, commonly referred to as "post-error adjustments". Many studies have reported that subjects slow down following an error, a phenomenon called "post-error slowing" (PES). However, the functional significance of PES is still a matter of debate as it is not always adaptive. That is, it is not always associated with a gain in performance and can even occur with a decline in accuracy. Here, we hypothesized that the nature of PES is influenced by ones speed-accuracy tradeoff policy, which determines the overall level of choice accuracy in the task at hand. To test this hypothesis, we investigated post-error adjustments in subjects performing the same task while they were required to either emphasize speed (low accuracy) or cautiousness (high accuracy) in two distinct contexts (hasty and cautious contexts, respectively) experienced on separate days. Accordingly, our data indicate that post-error adjustments varied according to the context in which subjects performed the task, with PES being solely significant in the hasty context. In addition, we only observed a gain in performance after errors in a specific trial type, suggesting that post-error adjustments depend on a complex combination of processes that affect the speed of ensuing actions as well as the degree to which such PES comes with a gain in performance.

neuroscience↗