Heterospecific eavesdropping of jays (Garrulus glandarius) on blackbird (Turdus merula) mobbing calls

Abstract

Heterospecifics eavesdrop on mobbing calls and respond with appropriate behavior, but the functional aspects are less studied. Here, I studied whether jays (Garrulus glandarius) eavesdrop on blackbird (Turdus merula) mobbing calls in comparison to blackbird song. Furthermore, it was studied whether jays provided with extra information about predators differ in their response. Three different experimental designs were carried out: (1) control playback of blackbird song to control for the species’ presence, (2) experimental playback of different mobbing events of blackbirds towards different predators, (3) experimental playback similar to (2) but combined with different predator models. In the combined experiments, mobbing calls were tied to the respective visual stimuli. Comparing the experiments with and without predator presentation, a similar number of jays occurred during the playback-only experiment (n = 7) and the playback combined with model presentation (n = 6). However, during the playback-only experiment, jays approached the speaker closer and stayed for longer time in the nearer surrounding. These results show that jays need extra information to make an informed decision.

The underground system of Clyomys laticeps changes in structure and composition according to climatic and vegetation variations

Abstract

Ecological factors may affect resource availability and distribution, impacting foraging and burrow construction behaviours. Clyomys laticeps is a caviomorph rodent with subterranean habits occurring on the Brazilian Cerrado domain (savanna-like) until the Paraguayan Chaco. We investigated their underground system’s architecture taking into account the vegetation and climate. We hypothesised that the sparse food distribution in the winter would promote longer tunnels and more complex architectures to connect more distant foraging areas, supposing that the species moved underground to avoid predators; moreover, the winter would promote food storage. We excavated eleven Clyomys underground systems and measured their size and internal parameters (tunnel and chamber width, length and depth) and complexity (linearity and convolution). We noticed that half of the systems were in the open landscape (OL) and half on vegetation covered (VL). If the anti-predation theory was right, we would find shorter tunnels on the VL systems. We found systems from 2 to 24 m2 and up to 22 m long. The deeper and biomass scarcer tunnels were on VL during the dry season, supposedly when animals would need underground water but not stocked food (the palm season). Also, they were more complex (higher circularity and convolution indexes) in OL, favouring our anti-predation hypothesis. Furthermore, Clyomys burrows offer refuge for other species such as arthropods, snakes, amphibians, and birds. We conclude that systems’ architecture is related to vegetation presence and seasonal foraging challenges. This rodent may construct its systems for shelter, food storage and as a safe trail among foraging areas.

Hide and flirt: observed behavior of female jaguars (Panthera onca) to protect their young cubs from adult males

Abstract

Common across various taxa, infanticide is a highly variable phenomenon present from insects to birds to mammals. In felids, antagonistic sexual coevolution led to the development of female counterstrategies to infanticide spanning particular sexual behavior, physiology, and social strategies. Numerous protective behaviors are well documented for large felids such as lions, cheetahs, and pumas that rely on cooperative defenses and polyandrous mating to protect their cubs from infanticide. Nevertheless, little is known about other wildcat species adopting such behaviors. Solitary and enigmatic, jaguars (Panthera onca) are the largest cat existing in the Americas. Little is known about this big cats’ reproductive and rearing behavior, mainly due to its secretive nature. Here, field observations in two major wetland ecosystems of South America show new and unique findings on female jaguar counterstrategies towards male infanticide. Our findings suggest that, like their big cat relatives in Africa, jaguars have evolved behavioral counterstrategies to protect their young in response to antagonistic sexual coevolution.

Invasive Italian wall lizards outcompete native congeneric species in finding food in a Y-maze

Abstract

Though biological invasions constitute one of the biggest threats for global biodiversity, our understanding of the mechanisms that enable invasive species to outperform native species is still limited, especially, in terms of behavior. Most available studies have examined behavioral traits which favor invasive species on the later stages of invasion, however, our knowledge on earlier stages, namely, when alien species face novel environments and must exploit new resources, remains obscure. Here, we focus on one crucial behavioral trait, finding food. The Italian wall lizard (Podarcis siculus) has been widely introduced and established viable populations in S. Europe and N. America. We examined whether P. siculus has enhanced exploratory behavior and abilities to find food compared to two native congeneric species with which it may come in contact in the near future, an insular endemic (P. milensis) and a widely distributed lizard (P. erhardii). We performed a Y-maze experiment, in which we varied arm markings in a standard way to prevent learning. Podarcis siculus was more efficient than its congenerics in finding and consuming food. This exploitative superiority was persistent, more frequent and repetitive. Interesting behavioral differences were also detected within the native species. Some P. milensis individuals showed no interest in exploring the maze, while few P. erhardii individuals remained rather indifferent to food even after detecting it. Our results suggest that the invasive P. siculus displays behavioral traits that could provide better opportunities for survival in the new environment and thus facilitate establishment even in the presence of congenerics. This provides further support to the idea that behavior plays a crucial role in animal invasions.

Time-activity budget of urban-adapted free-ranging dogs

Abstract

The domestic dog (Canis lupus familiaris) is known to have evolved from gray wolves, about 15,000 years ago. They frequently exist as free-ranging populations across the world. They are typically scavengers and well adapted to living among humans. Most canids living in and around urban habitats tend to avoid humans and show crepuscular activity peaks. In this study, we carried out a detailed population-level survey on free-ranging dogs in West Bengal, India, to understand the activity patterns of free-ranging dogs in relation to human activity. Using 5669 sightings of dogs, over a period of 1 year, covering the 24 h of the day, we carried out an analysis of the time activity budget of free-ranging dogs to conclude that they are generalists in their habit. They remain active when humans are active. Their activity levels are affected significantly by age class and time of the day. In addition, we provide a detailed ethogram of free-ranging dogs. This, to our knowledge, is the first study of this kind, which might be used to further study the eco-ethology of these dogs.

Interspecific nest destruction in the Tropical Kingbird Tyrannus melancholicus: kleptoparasitism or competition?

Abstract

Bird nest destruction and nest material kleptoparasitism (i.e., the theft of nest material from other bird’s nests) are poorly documented behaviors, and little is known about the parasite species and their hosts. Here, I present the first account of nest material kleptoparasitism in the Tropical Kingbird (Tyrannus melancholicus) followed by nest destruction, which occurred on a Variegated Flycatcher nest (Empidonomus varius). I explore the implications of these behaviors for both the kleptoparasite and the victim species and, due to the lack of basic information on the general behavior of both species, I point out some directions to guide future researches on the subject.

Primary nectar robbing by Apis mellifera (Apidae) on Pyrostegia venusta (Bignoniaceae): behavior, pillaging rate, and its consequences

Abstract

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.

What do we know about flamingo behaviors? A systematic review of the ethological research on the Phoenicopteridae (1978–2020)

Abstract

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.

Lateralization at the individual and population levels of European green lizard in Slovak Karst

Abstract

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.