Journal of Ethology 

About: Journal of Ethology is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Animal ecology & Population. It has an ISSN identifier of 0289-0771. Over the lifetime, 1277 publications have been published receiving 18431 citations. The journal is also known as: Journal of ethology (Print).

Parental care and mating systems of cichlid fishes in Lake Tanganyika: a preliminary field survey

Abstract: Reproductive ecology and ethology of 52 cichlid fishes were studied along the shore of Myako, east-middle coast of Lake Tanganyika. Seventeen species were substrate-brooders (guarders), 31 were mouthbrooders, and the remaining 4 were intermediate, performing prolonged biparental guarding of fry after mouthbrooding. Among the substrate-brooders maternal care (and polygyny) was seen about as frequently as biparental care. In most of the mouthbrooders only females took care of the brood, but in 3 species eggs and small larvae were mouthbrooded by females and larger fry by males. In most of the maternal mouthbrooders males defended mating territories which females visited to spawn. The mating system differed from lekking in that there was no concentration of territories and males fed within them. In the remaining maternal mouthbrooders males and overlapping home ranges and only temporarily defended courtship sites in each bout of spawning. Brood size, egg size, breeding site, and sexual differences in body size and color are described. The relationship between parentalcare patterns and mating systems within the family Cichlidae are discussed.

Mate securing tactics and the cost of fighting in the Japanese horned beetle,Allomyrina dichotoma L. (Scarabaeidae)

Abstract: Males of the horned beetleAllomyrina dichotoma L. show a bimodal frequency distribution with respect to horn size. The 2 morphs distinguished by this criteria showed different mate-securing tactics. Major males fought for possession of areas on oak trees that exuded sap. Fights escalated through a series of stereotyped encounters before entering the potentially damaging phase of close-quarter combat when the largest males in particular risked serious damage. Minor males, on the other hand, were never observed to fight with conspecific males, but retreated after making contact with them. Minor males arrived at sap sites earlier in the diurnal cycle than major males and so avoided them temporally as well as behaviourly. Minors appeared to be relatively as successful at gaining copulations as majors, but did so earlier in the diurnal cycle. Since females showed a slight tendency to remate on the same night, minors may lose fertilization opportunities if last male sperm precedence is high. Actual sperm precedence values are not know so the reproductive payoffs for the 2 morphs could not be assessed.

Wing pigmentation, immune ability, fat reserves and territorial status in males of the rubyspot damselfly, Hetaerina americana

Abstract: An explanation for courting traits is that they convey information about the bearer’s condition to conspecifics, more specifically immune ability. Here we test a series of immune-based assumptions in the territorial damselfly Hetaerina americana, whose males bear wing pigmentation patterns, which are maintained via male–male competition. H. americana males emerge and take some time to mature sexually, after which, depending on their fat reserves, may start defending territories where females arrive at for copulation. Territorial males are eventually defeated and lose their territories. This loss is a consequence of a reduction in muscular fat reserves. We tested whether: (a) territorial males had more pigmented wings, more intense melanine-based immune response (encapsulation response to a nylon filament implant) and higher fat reserves than non-territorial males; (b) pigmentation is related to immunity and fat reserves; (c) the immune response held constant in two different episodes (3 days between each) in the same male during territorial tenure; and (d) immune response and fat reserves decreased after experimentally simulated fighting event. Our results agree with current views of immune ability and courting traits: (1) territorial males had more wing pigmentation, higher immune responses and fat reserves than non-territorial males; (2) pigmentation was also correlated with immunity and fat reserves; and (3) immune response was similarly intense in the two episodes during territorial tenure. However, this response and fat reserves were considerably lower after fighting compared to that of territorial males and non-territorial males. Our work points out a link between fat reserves and immune ability which agree with previous studies in insects. Given, however, that in this species the use of wing pigmentation via male–male competition is more likely to provide information about current fat reserves than immunity, it is suggested that immune ability is only indirectly selected and may not be the information that pigmentation would convey to conspecifics.

Opportunistic and restrictive matings among wild chimpanzees in the Mahale Mountains, Tanzania

Abstract: The mating patterns of free-ranging chimpanzees (Pan troglodytes) of the Mahale Mountains, Tanzania, were studied. Opportunistic mating (non-competitive and temporary mating) was frequently observed in a large-sized unit-group, among young, low-ranking males, and among young, newcomer, non-ovulating females. Restrictive mating (a continuous sexual relationship between a particular pair which includes possessiveness and consortship) was frequently observed in a small-sized unit-group, among middle- and old-aged, high-ranking males, and among old, resident, ovulating females. Relations between those characteristics, such as group size and composition, ages of the individuals of both sexes, female estrous stages, and life history, and the 2 mating patterns are discussed.

Effects of farming practices on spatial behaviour of common voles

Abstract: This study aimed to reveal changes in spatial behaviour of common voles (Microtus arvalis) after alteration of their habitat by farming practices. Radio-collared common voles were tracked before and after mulching, mowing, harvesting wheat, and ploughing in the flood plain of the river Unstrut in central Germany. Voles undisturbed by agricultural practices were tracked on a mulchland, an abandoned pasture, and a cattle pasture. There was a large decrease in home-range size after harvesting wheat (96%, P<0.001). Changes after mowing (–74%, P=0.06) were almost significant whereas changes after mulching were not (+14%, P=0.60). On the cattle pasture we found a decrease in home-range size (42%, P=0.03) possibly due to increased spatial activity of cattle in autumn. There was a positive correlation of home-range size and vegetation height for plots with and without farming activity but no correlation with vegetation cover, population density, and breeding. Radio-collared common voles did not show evasive movements and farming practices did not cause a shift of centres of activity. Common voles clearly reacted to sudden changes in vegetation height, which may indicate an immediate response to predation risk.