Search results for "Cog"
showing 10 items of 17676 documents
How Do Infanticidal Male Bank Voles (Myodes glareolus) Find the Nest with Pups?
2016
Infanticide, the killing of conspecific young, occurs in most mammal species, like in our study species, the bank vole (Myodes glareolus). Infanticide by adult males is regarded as a strong factor affecting recruitment of young into population. It is considered as an adaptive behaviour, which may increase male fitness via resource gain or an increased access to mates. When an intruder is approaching the nest, the mother should not be present, as her nest guarding is very aggressive and successful. Pups use ultrasonic vocalisation to call their mother when mother leaves nest for foraging but it is not know which cues do infanticidal males use to find the nest with vulnerable pups to commit i…
Foraging Bumblebees Selectively Attend to Other Types of Bees Based on Their Reward-Predictive Value.
2020
Using social information can be an efficient strategy for learning in a new environment while reducing the risks associated with trial-and-error learning. Whereas social information from conspecifics has long been assumed to be preferentially attended by animals, heterospecifics can also provide relevant information. Because different species may vary in their informative value, using heterospecific social information indiscriminately can be ineffective and even detrimental. Here, we evaluated how selective use of social information might arise at a proximate level in bumblebees (Bombus terrestris) as a result of experience with demonstrators differing in their visual appearance and in thei…
Divergence is not speciation, or why we need females : a comment on Tinghitella et al
2018
Postprint Peer reviewed
Seasonal survival in a non-hibernating Mediterranean garden dormouse population
2020
The seasonal survival pattern of a garden dormouse Eliomys quercinus population was studied in a Mediterranean agricultural field area from East Spain, a geographical location in which this species does exhibit no hibernation. Individuals were captured from nest—boxes checked monthly during a 4-year period. Data were analysed using an open population Cormack–Jolly–Seber model including sex, age class and season as factors. Best models included the effect of age and differences in survival between adult males and females. Survival rate was more variable between seasons in males than in females or juveniles. Maximum adult male survival was reached in autumn, decreased in winter and dropped to…
Energetic costs of size and sexual signalling in a wolf spider
1998
A prerequisite for honest handicaps is that there are significant condition–dependent costs in the expression of sexual traits. In the wolf spider Hygrolycosa rubrofasciata (Ohlert), sexual signalling (drumming) is costly in terms of increased mortality. Here we investigated whether this mortality may be caused by increased energy expenditure. During sexual signalling, metabolic rate was 22 times higher than at rest and four times higher than when males were actively moving. Metabolic rate per unit mass was positively related to absolute body mass during sexual signalling but not during other activities. This positive relationship is novel to any studies of metabolic rates. Indeed, it seems…
Insect personality: what can we learn from metamorphosis?
2018
6 pages; International audience; Ontogeny of animal personality is still an open question. Testing whether personality traits correlated with state variables (e.g. metabolic rate, hormones) and/or life history traits, and which ones are involved, requires more empirical studies. Insects with metamorphosis represent a good opportunity to tackle this question. Because of the various degrees of internal (physiological, nervous) and environmental changes linked to metamorphosis they allow testing whether these modifications drive consistency in personality traits between immature and adult stages. In this review, we establish general predictions for the effects of metamorphosis on personality i…
Integrated management strategies of Meloidogyne incognita and Pseudopyrenochaeta lycopersici on tomato using a Bacillus firmus-based product and two …
2019
Abstract Because of the restrictions on chemical pesticide use and their negative effects on the environment, as well as on human and animal health, alternative strategies for plant pest and pathogen managements are highly desirable. The objective of this work was to evaluate the suitability of a commercial formulation of Bacillus firmus strain 1-1582, applied either alone or in combination with oxamyl or fosthiazate, to control the southern root-knot nematode Meloidogyne incognita and the fungal plant pathogen Pseudopyrenochaeta lycopersici under greenhouse conditions during two tomato crop cycles. Application of B. firmus suppressed nematode population levels during the second crop cycle …
Risk of inbreeding : problem of mate choice and fitness effects?
2016
Mating with close kin may cause inbreeding depression with negative consequences to offspring and local populations. There exist mechanisms like kin-recognition or sex-specific dispersal to avoid mating with kin. In fluctuating population densities, like in many small mammals, both very low and very high densities provide conditions for inbreeding, if kin males are prone to stay in their natal area. Females are choosy and male dominance is thought to be the key feature when selecting mating partners. The aim of this study was to test the possible discrepancy in mate choice and negative fitness effects of inbreeding in two experiments, one in the laboratory and one in field enclosures. We as…
Maternal investment in relation to sex ratio and offspring number in a small mammal - a case for Trivers and Willard theory?
2009
Summary 1. Optimal parental sex allocation depends on the balance between the costs of investing into sons vs. daughters and the benefits calculated as fitness returns. The outcome of this equation varies with the life history of the species, as well as the state of the individual and the quality of the environment. 2. We studied maternal allocation and subsequent fecundity costs of bank voles, Myodes glareolus, by manipulating both the postnatal sex ratio (all-male ⁄ all-female litters) and the quality of rearing environment (through manipulation of litter size by )2 ⁄ +2 pups) of their offspring in a laboratory setting. 3. We found that mothers clearly biased their allocation to female ra…
Sexual display complexity varies non-linearly with age and predicts breeding status in greater flamingos.
2016
AbstractThe long-lived greater flamingo (Phoenicopterus roseus) is famous for performing conspicuous group displays during which adults try to acquire a new mate each year with varying success. We examined variation in the sexual display complexity (SDC) of wild flamingos aged between 4 and 37 yrs. SDC was defined as the product of richness (the number of different display movements) and versatility (the number of transitions between movements) within a 5 min behavioral sequence. In both sexes, date in the pairing season had a linear and positive effect on SDC, whereas age had a quadratic effect, with SDC increasing until about age 20yrs, and declining afterwards. SDC better explained pairi…