In monogyne (single queen) ant colonies, worker aggression against intruders, including newly-mated sister queens (gynes) seeking readoption, prevents the development of multi-queen colonies. Some ant species, however, produce multiple queen colonies (polygyny) via the adoption of new gynes in response to ecological, genetic and social parameters. Cuticular chemistry mediates nestmate recognition as well as plays a role in intra-colonial regulation of reproduction. Although aggression against intruders is diminished in some polygyne species, apparently due to depauperate allelic diversity at loci that code for recognition cues or a loss of receptor sites, the mechanism underlying the development of polygyny is largely unknown. Here, we examine the cuticular chemical profiles of new gynes at several stages post-emergence, males and workers from monogyne and polygyne colonies in the facultatively polygyne ant Formica truncorum. Individuals from the two colony types were chemically distinguishable, as were gynes according to developmental stage post-emergence (callow versus mature) and with respect to wing presence and mating status. Overall profile complexity did not differ between populations. These results suggest an association of cuticular hydrocarbon profiles with dispersal tendencies and that the disparate tendency of workers from monogyne and polygyne colonies to adopt new gynes is due to a complex interaction between gyne cuticular chemistry and differential worker sensitivity to those cues.

Improvement of invasive American mink (Neovison vison) trapping methods in the Cape Horn Archipelago is a priority for wildlife managers. We assessed the use of cubby sets (16 × 16 × 30 cm plywood boxes) containing body gripping lethal traps to control mink along the Beagle Channel. We compared effectiveness, selectivity and weather condition resistance between two cubby set designs: (i) open front, and (ii) restricted entrance (lidded with a 6 cm aperture). The effectiveness of bait was evaluated between fresh versus canned fish. Thirteen minks and no non-target species were captured with the restricted entrance systems, as compared with three minks and 25 non-target individuals (six species) in open front cubby sets. Fresh fish resulted in more captures than canned fish, and lids made traps less susceptible to false activation. Traps inside restricted entrance cubby sets, baited with fresh fish were found to be most suitable for mink control and/or eradication efforts.

We studied the impacts of a large skiing and hiking resort on the distribution of semidomesticated reindeer in Saariselkä, eastern Finnish Lapland, in 1986 and 2000. The effect of intensity of outdoor activities on reindeer density in terms of pellet-group density was dependent variably on habitat, the year of inventory and season. Despite the overall doubling of visitor numbers between the inventory years, pellet-group density in winter increased in the study area by 20%. The sex ratio of reindeer in summer 1986 was male-biased up to a distance of 8–12 km, indicating that females with calves avoided the vicinity of the resort, but in 2000 the bias existed only at a distance of 0–4 km. However, pellet-group density in summer at the distance of 0–4 km was 53% and 28% lower than that at 4–8 km and 8–12 km, respectively. In winter, a similar pattern was observed in lichen-rich coniferous habitats. Cladonia stellaris, which has low tolerance to heavy grazing, reached its maximum abundance at the distance of 0–4 km. Observations on the increased tolerance of reindeer were very probably associated with improved channeling of tourists into fewer and better marked hiking and skiing routes, changes in the reindeer herd-management and frequent contacts with humans, but the adverse effects of outdoor activities could not be avoided.

Seasonal changes in body size and stable isotope ratios of bluegill Lepomis macrochirus were monitored at three sites in Lake Biwa in an attempt to investigate the latitudinal variation in the fish growth pattern. δ¹³C values of bluegill tended to decrease as latitude increased, implying the presence of a thermal gradient across the lake. In contrast, δ¹⁵N values of bluegill increased with increasing latitude. Better digestive performance of the fish at higher latitudes was assumed to explain this result, whereas the discharge from a sewage treatment plant seemed to have a more direct impact on the extremely high δ¹⁵N values of bluegill at the highest latitude site. Length—weight relationships were used to assess the changes in the body weight of fish with a normalized body size. Bluegill at higher latitudes exhibited greater body weights with a prolonged duration of body weight gain. Bluegill at lower latitudes may have adapted to grow rapidly from late spring to early summer when feeding activity increases in response to increasing water temperature, while the catabolic activity remains at a low level. In contrast, bluegill at higher latitudes can continue to grow until the midsummer months owing to the lower water temperature. The seasonal growth pattern of bluegill was analyzed using a logistic-type equation. The assumption that the selection of growth rate or final body size depends on temperature may reasonably explain the latitudinal variation in the growth pattern of bluegill in Lake Biwa.

A number of studies have reported how neighbouring plants may influence herbivory on palatable or unpalatable plants. Such neighbourhood effects can have important evolutionary consequences as they may either promote the evolutionary stability of plant defences or, alternatively, select against the fixation of plant defences and instead promote a stable polymorphism of palatable and unpalatable plants. These consequences depend on whether the difference in herbivore damage between unpalatable and palatable plants is smaller or, alternatively, greater when the neighbours are unpalatable instead of palatable. Such relations can arise when the neighbourhood effects are non-parallel among palatable and unpalatable plants. We outline two basic situations of non-parallel neighbourhood effects and illustrate how they can come about. A detailed dissection of these interactions reveals that there are several qualitatively distinct mechanisms that promote either evolutionary stability of plant defences or alternatively polymorphism. Our classification of mechanisms can be used to clarify and explain observations obtained in the field of plant—herbivore interactions and predator—prey interactions, both at the population and the community level.

The stinging pattern of a predatory wasp is a behavioural trait, affecting the possible evolutionary changes of its niche, e.g. widening or shifting the prey spectrum. We tested the hypothesis that the ability of a predator to adjust its handling effort to the size of prey is a species-specific trait, the parameters of which depend on the size and size range of the exploited prey. We found that wasps better adjust their stinging effort to prey size if they hunt relatively larger or relatively more variable prey. This adaptability differs amongst neighbouring phylogenetic lineages. We presume that evolution of prey-handling behaviour may result in two types of tactics: the first, an application of precise techniques for optimal prey immobilization, little dependent on prey size and typical of specialists. The second tactic typical of generalists is a less precise handling, causing more general damage to the prey with an intensity dependent on its size.

Most of the boreal forest in Norway is used for forestry, and only 2% of the productive forest is protected. However, low spatial coverage of reserves may be compensated for by higher species' densities and higher number of species so that larger fractions of total population sizes occur inside reserves than their area alone suggests. We compared densities of boreal birds and proportion of known sites for species found within boreal forest reserves and unprotected boreal forest in SE Norway. Point counts showed that neither mean density nor species numbers differed between areas, and only a few species were more common inside reserves. To increase data quantity for rarer species, we used species lists from 429 sites. Several species occurred more frequently inside reserves than outside, and reserves most often had 5%–35% of known sites of individual species. Many of the reserves were protected in 1993, when a number of other areas, still unprotected, were proposed as reserves. Logging has occurred in 74% of proposed reserves and 28% of their total area has been logged after 1993. Although boreal forest reserves had higher proportions of known sites for many species than the size of the reserves would suggest, the majority of the populations of most species occurred outside reserves. Thus, the future of boreal bird species in Norway will to a large degree depend on how unprotected forest is managed.

Ecological research using biometric data is only sound if biometrics themselves are accurate and not confounded by measurement error. Given concerns about the accuracy of biometrics taken directly (physical measurement of animals), digital measurement of photographs is often advocated, particularly for small or live specimens. However, there is currently limited understanding of intra- and inter-observer variability of such measurements (i.e. variability of multiple measurements of the same specimen by the same observer, and variability of multiple measurements of the same specimen by different observers, respectively). We took biometrics (two linear, two curvilinear, two angular) from moth photographs using standard image software and calculated two fluctuating asymmetry measures. Inter-observer variability was always higher than intra-observer variability. Measurement error was low for linear/curvilinear measurements (< ∼4%), but high for angular variables (52%) and asymmetry measures (45%). Measurement precision correlated positively with trait size. Variability caused significant differences in mean measurements inter-specifically for half the biometrics; there were no significant intra-specific differences. We discuss the implications of our findings for research using photographically-derived biometrics and offer recommendations for reducing measurement error.

Researchers have suggested that female strategies for sexual selection in humans include the promotion of sperm competition. Sperm competition entails the simultaneous presence of fertile sperm from at least two males in the female's reproductive organ competing for the opportunity to fertilise the ovum. Certain behaviour patterns near ovulation may enable such competition. In this paper, we describe relative preferences for female sexual fantasy types and explore the idea that these preferences may help us understand the settings and mechanisms that promote sperm competition, and discourage interfemale competition. To expand this exploration, we also examine whether preferences vary with respect to the menstrual cycle. Our preliminary findings indicate notable preferences among females for multiple male-partner fantasies over multiple female-partner fantasies or fantasies that include multiple male and female partners. This suggests that females find multipartner settings as arousing as males do, but the psychological mechanism relating to settings that include the presence of same sex competitors may differ from that of males. We also discovered some indications that the female preference for promoting sperm competition and avoiding interfemale competition is the highest and strongest near ovulation.

The introduction of immigrants into resident populations may disturb the social organisation of the latter. It is often stated that males compete with males for access to mates, while females compete with females and/or males for limited resources (e.g., nest sites, food). Therefore, the impacts of introductions on residents should depend on the immigrant's sex. To test this hypothesis, we experimentally introduced either male or female immigrants into field vole (Microtus agrestis) populations, and observed the consequences in terms of space use and survival of both residents and immigrants. Our results showed intra-sexual competition: (i) resident females responded to the introduction of females by reducing their home range size and their interactions with neighbours; (ii) immigrant males suffered high mortality, probably due to contests with resident males for access to females. We conclude that the role of social interactions should not be underestimated when releasing unfamiliar individuals into small populations.

With some raptors showing widespread declines, management of grassland to enhance access to their small mammal prey may be an important conservation tool. Many small mammal species prefer long grass as a habitat that offers protection from predation, and past studies on the consequences of grass cutting to small mammals have yielded mixed results. Using live trapping, we show that although mowing grass causes a rapid decline in small mammal captures, a small proportion of captures (20%–27%) still occurred in patches of mown grass immediately after cutting. This proportion more than halved again when the cut grass that was initially left in situ was removed. We conclude that some small mammals may remain in mown areas provided some form of cover — i.e. the cut grass — is present. These findings are discussed in light of agri-environment scheme options (e.g. grass margins) that could be improved to benefit birds of prey.

Nine-spined stickleback (Pungitius pungitius) is a good model species for studying personality traits such as boldness and aggression as large variation in these behaviours has been observed in populations from different habitats. Here we used genomic information from three-spined sticklebacks to identify and characterise 13 new nine-spined stickleback microsatellite loci which are located close to candidate genes for behaviour. All loci were polymorphic with 3–31 alleles per locus and expected heterozygosity varied from 0 to 0.97 and observed heterozygosity from 0 to 1. These markers should provide a useful resource for better understanding the genetic basis of behaviour in stickleback fishes.