acta ethologica最新文献

The interactions between plants and their pollinators are the result of convergent evolution of floral attributes reflecting pressure exerted by pollinators. Nonetheless, the strategies employed by floral visitors to collect floral resources are extremely complex, and commonly involve theft or robbery in addition to pollination. We describe here the behavioral repertory of Apis mellifera during the collection of the floral resources, and evaluated the robbing rates of A. mellifera on the buds and flowers of Pyrostegia venusta during periods of intense and sparse flowering. We recorded the behaviors exhibited by foraging bees while collecting floral resources, quantified the numbers of floral buds and flowers with perforations in their corolla tissues, and determined whether that damage reduced nectar production. The evaluations were conducted during two distinct periods: during the period of intense flowering of P. venusta, and during the period of sparse flowering. Nectar robbing was observed during 93.4% of the visits of foraging A. mellifera bees, while nectar theft was observed during only 0.7% of the visits, and pollen theft during 5.9%. The robbing of floral buds and flowers was most intense during the period of heavy flowering. Flowers that had been intensely robbed secreted significantly less nectar than those non-robbed. The unusual nectar robbing activities of A. mellifera, especially during the period of intense flowering indicates an optimization of access to larger volumes of food resources. Our results therefore point to a major limitation of nectar per floral unit during the intense flowering period of P. venusta due to the high activity of nectar robbing by A. mellifera bees.

Lateralization is one of the specific characteristics of animals, occurring in both invertebrates and vertebrates. Lateralization exists at two levels, individual level and population level. This research is focused on the individual- and population-level lateralization of the European green lizard (Lacerta viridis) under laboratory conditions. Lateralization was observed experimentally in a modified T-maze without the possibility of visual control by lizards. Lizards were stimulated by a piston from the caudal side to simulate a predator attack from behind. The numbers of left and right choices were evaluated. Statistical analysis confirmed no statistically significant difference in lateralization at both the individual and population levels. The absence or presence of autotomy suggests that non-biased lizards have a better chance of escape from a predator than left- or right-biased individuals. In the population of L. viridis studied by us, it seems that to be non-biased could be the best strategy to survive predator attacks.

We provide a systematic review of the current scope of published behavioral research on flamingos (Phoenicopteridae), to answer the following questions: (1) what is the profile of ethology and behavioral research on flamingos, (2) which are the behaviors displayed by flamingos already observed and described in nature and captivity, and (3) what are the prospects in the ethological research of the group? Eighty-eight studies, from 1978 to 2020, met our inclusion criteria and were analyzed. Most involved maintenance and social behaviors in the context of ecology and welfare. Furthermore, most studies were performed on animals in captivity and controlled conditions, but there was a recent trend of studies in the field, mainly in South America and the Caribbean. The most studied species were greater and American flamingos, but there is a recent rise in studies on Chilean and Andean flamingos in Latin America. Most ethological studies on this group included quantitative analyses, ignoring a more qualitative perspective of the individuals’ displays. Behavior description can also help in comparative studies between flamingo species and other water birds. Expanding research to Andean, James’s, and lesser flamingos is a priority, since their populations are more vulnerable. Ethological research can help identify the threats and measure the impacts on these species, which can be useful for setting up management plans and conservation actions to mitigate the damage and avoid extinction.

Anthropogenic noise is a pervasive environmental feature across both urban and non-urban habitats and presents a novel challenge especially for acoustically communicating species. While it is known that some species adjust acoustic signals to communicate more effectively in noisy habitats, we know very little about how the receivers of these signals might be impacted by anthropogenic noise. Here, we investigated female and male Litoria fallax frogs’ ability to distinguish between high- and low-quality acoustic signals during the presence of background traffic noise and without. We performed a controlled behavioural experiment whereby frogs were presented with simultaneously broadcasted attractive and unattractive calls from opposing directions, once with background traffic noise and once without. We found that females in particular chose the unattractive call significantly more often (and males significantly less often) when noise was being broadcast. This indicates that anthropogenic noise potentially affects receiver responses to acoustic signals, even when calls are not acoustically masked, with potential consequences for maladaptive mating behaviours and population outcomes.

Biological repellents have been used as a control method to mitigate human-wildlife conflict worldwide. We aimed to evaluate the effect of jaguar (Panthera onca) feces as a repellent for a free-living urban population of capybaras (Hydrochoerus hydrochaeris), which are considered a vertebrate pest in some regions of their range. Observational data were collected during two consecutive 5-day periods: control and treatment. Scan samples within a 2-h observational session were carried out, recording capybara incursions into a 15 m × 15 m marked perimeter and alertness behavioral state. During the treatment period, 30 g of jaguar feces were added daily every 5.0 m around the perimeter in four selected areas (around Lake Paranoa, Brasilia, Brazil) frequented by capybara. The presence of predator feces induced changes in capybaras’ behavior as there was a decrease in actual presence at the sites as a whole with the presence of jaguar feces. Of those capybaras that did continue to visit a site, incursions into the marked perimeter were initially greatly reduced, but did rebound relatively rapidly over the trial period. Although our results showed that capybaras recognize jaguar’s feces as a predator threat, odor habituation may limit the repellent’s efficacy at a local level, but appeared to have a longer term effect on the overall numbers of capybara visiting a site in general. Improvements in this technique will be required for it to become practicable, to reinforce capybaras’ aversion to predators, to decrease their habituation to predator’s feces, and to provide more humanitarian control.

Biological invasions may involve species colonising different climatic regions than those in their native ranges, and it is not straightforward to predict how breeding phenology changes in the invasive ranges. The common waxbill Estrilda astrild is one of the most widespread invasive birds worldwide. It is an opportunistic breeder, adapted to transient breeding opportunities in its native sub-Saharan African range, which is often climatically unpredictable. The least equatorial range of invasive waxbills is now in Europe, in the Iberian Peninsula, where they experience predictably seasonal climate. Previous reports of waxbill breeding phenology in two different regions in Iberia show a very long breeding season, but differ in whether or not peak breeding coincides with the Spring breeding of native passerines. Using field data from over 20 sites across climatically different regions in their Iberian range, we show that waxbills have a long breeding season extending until Autumn, but with a clear Spring peak around May, both in regions with hotter and milder summers. Nest monitoring in a large mesocosm with over 50 waxbills, across 3 years, confirmed these field observations and showed what appears to be year-to-year plasticity in phenology, which may include smaller nesting peaks outside Spring. This behavioural flexibility, together with the long breeding season of waxbills in the Iberian temperate climate, likely facilitates their invasion success.

Social-space–time-behaviour has developed very differently (e.g. a, loner, a herd, a pack) in the animal kingdom and depends on many different factors, like food availability, competition, predator avoidance or disturbances. It is known, that red deer are differently distributed in human disturbed areas compared to areas with less anthropogenic influences. But knowledge about the potential influence of human presence on social associations and interactions is rare, albeit differences may result in changing impacts on the environment, such as habitat utilization and feeding damage. Therefore, we investigated differences in the space use and social association of red deer. We studied two radio-collared herds of non-migratory populations in two study areas, which were comparable in landscape structure and vegetation structure, but differed in accessibility for visitors and the extent of their presence. Between the two study sites we compared the home range size, the differences in the extent of home range overlap within each study site and the space–time association (Jacobs Index) of individuals. Additionally, we present data on seasonal variations of home range sizes and social association all year round. In order to compare human activity in the study sites, we used the data from our long-term camera trap monitoring. The herd in the area with more human activity had significantly smaller home ranges and had greater year-round social associations in almost all seasons, except summer. We assume that smaller home ranges and higher association between animals may result in a higher feeding pressure on plants and a patchier utilization in areas with higher disturbances.

Due to the importance of camouflage to avoid detection by predators, predation pressure can cause coupled evolution of skin colour and preference for substrate colour. Individuals can choose regions where the background makes their skin colour less noticeable (crypsis) or where it accentuates warning coloration (aposematism). In such scenario, individuals should optimally choose substrate according to their skin colour and mechanism of predation avoidance: toxic species are expected to choose highly lit places and non-toxic species should avoid such places. We studied substrate choice on five species of tadpoles that differ in body colour and toxicity. The results of the present study did not confirm our prediction that non-toxic and cryptically coloured species would prefer a lower contrast substrate that maximizes camouflage. We show that individuals preferred highly lit areas that accentuated their contrast with the substrate. The general preference for lighter substrate might be related to the tadpole’s limited vision on a dark substrate, which hampers their ability in detecting predators. This study demonstrates that tadpoles can distinguish the substrate colour and that their choice of habitat might be linked to both their defence mechanism in the case of aposematic species and recognition of habitat elements in the case of cryptically-coloured species.

Aggressive behaviour in fishes, particularly in territorial species, is a common trait used to defend resources such as food or mates. Territorial males of the Mediterranean parrotfish Sparisoma cretense have been described to chase away conspecifics yet other aggressive behaviour repertoire has not been reported for this species. We describe, for the first time, an extreme aggressive behaviour between two male Mediterranean parrotfish which includes biting and prolonged mouth locking.