Ernő Vincze

A comparison of problem-solving success between urban and rural house sparrows

Behavioural flexibility is an important component of adaptation because it can help animals to exploit new or diverse habitats. Due to abundance of novel objects and resources provided by humans, urban environments may select for behavioural flexibility, but empirical evidence for this hypothesis is controversial. In this study, we compared urban and rural house sparrows (Passer domesticus) in four foraging problem-solving tasks. In the most difficult task, urban birds with large body mass were faster than others. Urban and rural birds performed similarly in the three easier tasks and did not differ in their learning efficiency. Individuals successful in one task tended to be successful in other tasks, and the repeatability of performance did not differ between urban and rural birds. Individuals that attempted to access food more frequently solved the problem faster in all tasks, but urban and rural birds did not differ in the frequency of attempts. These results suggest that the effects of urbanization on problem-solving success are weak and context-dependent in house sparrows. We propose that while urban animals may be better at exploiting some aspects of novel environments than rural conspecifics, such differences may be modulated by other habitat effects such as reduced nestling development and adult body mass in urban sparrows, which might influence some long-term determinants of innovativeness such as cognitive capacity or physical skills.

Mate preference does not influence reproductive motivation and parental cooperation in female zebra finches

In socially monogamous species, low availability of sexually active unpaired individuals in the local population may constrain mate choice, resulting in mating with sub-optimal partners. Here we experimentally investigate whether female reproductive behaviour is different when paired with a preferred or a non-preferred male in the zebra finch (Taeniopygia guttata). First, we assessed female mating preferences using a four-way choice apparatus, then females were caged together with either their preferred or least-preferred male. Female reproductive motivation, assessed by the propensity of laying eggs within two weeks from pairing and clutch mass, did not differ between the two experimental groups. Females responded to mate removal by either increasing their care, so as to compensate for the lost care of their mate, or by significantly reducing incubation. This bimodal response was not explained by mate preference, nevertheless, we found that females with lower baseline (i.e., pre-manipulation) incubation effort were more likely to cease incubation during mate removal. Taken together, we found no evidence that female reproductive behaviour varies along with mate preference.

Chestnut-crowned babblers show affinity for calls of removed group members: a dual playback without expectancy violation

Cooperative breeding typically evolves within discrete, stable groups of individuals, in which group members derive direct and/or indirect fitness benefits from cooperative behaviour. In such systems, strong selection on group discrimination should emerge. Despite this prediction, relatively few studies have investigated the mechanism of group discrimination in cooperative vertebrates, and the results of many may be confounded by ‘expectancy violation’, since test individuals from which stimuli were derived remained in the group during experimentation. Here, we used a novel experimental protocol that eliminates this confounding effect in a test of group discrimination in cooperatively breeding chestnut-crowned babblers, Pomatostomus ruficeps , using long-distance contact calls. Long-distance contact calls were found to be individually specific, but to lack obvious group level signatures. Using dual playbacks of removed group and nongroup members, we found that these calls allow effective discrimination: groups unanimously approached the speaker broadcasting calls of group members and concomitantly increased their contact call rates. Together, our results suggest that group discrimination emerges from individual recognition. Additionally, the affiliative behaviour of group members towards playbacks of removed members contrasts with the aggressive responses towards nongroup members found in all other studies. One explanation for these differences stems from our elimination of expectancy violation, but further studies are required to verify this.

Innovative females are more promiscuous in great tits (Parus major)

Lay Summary We found that innovative great tit females are prone to cuckold their mates. Innovative problem solving can be important to animals for survival and reproduction in nature, yet we found no evidence that females mated to males with poor problem-solving performance compensate for poor male quality by obtaining superior genes for their offspring from other males via cuckoldry. Instead, females’ infidelity increased with their own innovativeness.

An infrared motion detector system for lossless real-time monitoring of animal preference tests

Automated behavioural observations are routinely used in many fields of biology, including ethology, behavioural ecology and physiology. When preferences for certain resources are investigated, the focus is often on simple response variables, such as duration and frequency of visits to choice chambers. Here we present an automated motion detector system that use passive infrared sensors to eliminate many drawbacks of currently existing methods. Signals from the sensors are processed by a custom-built interface, and after unnecessary data is filtered by a computer software, the total time and frequency of the subjects visits to each of the choice chambers are calculated. We validate the detector system by monitoring (using the system) and in the same time video recording mating preferences of zebra finches in a four-way choice apparatus. Manual scoring of the video recordings showed very high consistency with data from the detector system both for time and for frequency of visits. Furthermore, the validation revealed that if we used micro-switches or light barriers, the most commonly applied automatic detection techniques, this would have resulted in approximately 22% less information compared to our lossless system. The system provides a low-cost alternative for monitoring animal movements, and we discuss its further applicability.

Personality assortative female mating preferences in a songbird

Consistent individual behavioural differences (‘animal personalities’) are documented across a variety of animal taxa. Sexual selection, especially assortative mating has been suggested as a possible mechanism contributing to the maintenance of different personality types within populations but little is known about non-random pair-formation with respect to personality traits in unconstrained choice tests. We here tested whether female mating preferences were non-random with respect to male and female neophobia in zebra finches ( Taeniopygia guttata ), an important avian model of mate choice and animal personality research. Male and female neophobia was assessed by attaching novel objects to birds’ feeders. Females’ mating preferences were tested with randomly assigned, unfamiliar males in a four-way choice apparatus. Females associated most with males with neophobia scores similar to their own. These results provide evidence that mating preferences and personality traits can covary, supporting evolutionary scenarios of assortative mating contributing to the maintenance of personality traits.