Adult male emigration and a female-based social organization in swift foxes, Vulpes velox

Members of the family Canidae are distinguished from other carnivore families by pair bonding and male care of the young. Because of the importance of food provisioning and territorial defence by males, social structure among canids is shared or even dominated by males. However, small, insectivorous species of canids show little male parental care, although whether social structure differs from other canids is unknown. We combined data from three independent research projects on a small canid, the swift fox, to help elucidate the social organization of this species. Based on data on movements of 35 adult mated pairs and the fate of litters, we found that adult females maintained territories and family structure, whereas adult males tended to emigrate. This is the first evidence of a female-based social organization among any canid species. This type of social organization probably resulted from the decreased importance of territorial defence and food provisioning by males, as their diet is primarily insectivorous during summer when young are weaned. Our results, along with others, indicate that variations in social structure among canid species are strongly influenced by the importance of food provisioning and territorial defence by males.     

Vocalization toward conspecifics in silver foxes (Vulpes vulpes) selected for tame or aggressive behavior toward humans

We examined the production of different vocalizations in three strains of silver fox (unselected, aggressive, and tame) attending three kinds of behavior (aggressive, affiliative, and neutral) in response to their same-strain conspecifics. This is a follow-up to previous experiments which demonstrated that in the presence of humans, tame foxes produced cackles and pants but never coughed or snorted, whilst aggressive foxes produced coughs and snorts but never cackled or panted. Thus, cackle/pant and cough/snort were indicative of the tame and aggressive fox strains respectively toward humans. Wild-type unselected foxes produced cough and snort toward humans similarly to aggressive foxes. Here, we found that vocal responses to conspecifics were similar in tame, aggressive and unselected fox strains. Both cackle/pant and cough/snort occurred in foxes of all strains. The difference in the use of cackle/pant and cough/snort among these strains toward humans and toward conspecifics suggest that silver foxes do not perceive humans as their conspecifics. We speculate that these vocalizations are produced in response to a triggering internal state, affiliative or aggressive, that is suppressed by default in these fox strains toward humans as a result of their strict selection for tame or aggressive behavior, whilst still remaining flexible toward conspecifics.     

Variation in penis morphology and mating ability in the acorn barnacle, Semibalanus balanoides

I examined variation in penis morphology of the acorn barnacle, Semibalanus balanoides, at different aggregation densities and at different levels of wave exposure. Barnacles in sparse, un-crowded aggregations had significantly longer penises than those from densely crowded groups, suggesting a response to increase the chance of reaching distant mating partners. Barnacles exposed to oceanic waves had penises with significantly greater basal diameter, possibly to strengthen the penis and retain function in turbulent conditions. I compared the percentage of individual barnacles with fertilized broods over a range of distances to their nearest possible mate in sites exposed to or protected from waves. As neighbor distance increased, the proportion of individuals with fertilized egg masses decreased in both wave-exposed and protected sites. However, at greater mate distances in the wave exposed sites, the proportion of individuals with fertilized eggs was significantly lower than the proportion in protected sites, indicating that exposure to waves hinders mating with neighbors at increasing distances. These results suggest that the intensity of mate competition may differ for barnacles between environments with different levels of wave exposure. These differences in male ability are predicted to alter relative sex allocation to male and female function.     

Variation in the mating system of Vincetoxicum hirundinaria (Asclepiadaceae) in peripherial island populations

BACKGROUND AND AIMS: Self-fertility may be selected for in small and isolated plant populations of normally outcrossing species. In addition, adaptations for self-fertility are likely to arise in island populations and in populations that are located at the border of the species range. The mating system of Vincetoxicum hirundinaria (Asclepiadaceae) is examined in island populations that are located at the northern border of the species range. METHODS: Pollination experiments were conducted under glasshouse conditions with plants from four populations. KEY RESULTS: The frequencies of self-fertile individuals were relatively high and did not differ among populations. Cross-pollination resulted in higher fruit set than self-pollination. However, fruit-set from self-pollination and cross-pollination did not differ in the self-fertile individuals. Interestingly, the proportion of aborted fruits was on average higher following cross-pollination than following self-pollination. No differences were observed in seed number or seed mass between self- and cross-pollinated fruits. Pollen tube growth following self- and cross-pollinations was indistinguishable. CONCLUSIONS: The results of this study revealed that V. hirundinaria possess a mixed-mating system in the studied island populations. Evidence was also provided for a late-acting self-incompatibility system commonly observed in Asclepiadaceae. No clear signs of inbreeding depression were observed in the early stages of development.     

Brain aromatase mRNA expression in two populations of the peacock blenny Salaria pavo with divergent mating systems

Aromatase, the key enzyme in the conversion of androgens to estrogens, regulates the availability of these hormones in tissues and controls many physiological and behavioral processes. In fish and other vertebrates, the regulation of aromatase expression in the brain has been implicated in the modulation of male sexual and aggressive behaviors. Here, the pattern of mRNA expression of the brain aromatase isoform (encoded by the CYP19A2 gene also referred as CYP19b) was quantified at the peak of spawning season in brain macroareas from males and females of the blenny Salaria pavo originated from two populations displaying male alternative reproductive tactics but differing in their mating systems. In Trieste (Adriatic) nesting males aggressively defend nests and take the initiative in courtship and perform sexual displays more often than females while in Ria Formosa (Southern Portugal) the pattern is reversed as a result of shortage of appropriate nesting sites. Nesting males from Ria Formosa had overall higher levels of brain aromatase mRNA expression than nesting males from Trieste, suggesting a higher brain estrogen synthesis in these males. Since in some fish species exogenous estradiol administration has been shown to decrease sexual and agonistic behaviors, the higher levels of brain aromatase in Ria Formosa nesting males may explain their reduced expression of sexual and aggressive displays when compared with nesting males from Trieste. Alternatively, the higher brain aromatase levels in nesting males from Ria Formosa could be a mechanism to decrease the putative androgen-induced activation of aggressive and sexual displays by reducing the local availability of androgens through their metabolization into estrogens. Although females and parasitic female-like males also differ in their displays between populations, the interpopulational pattern of brain aromatase mRNA expression was similar, suggesting that other neuroendocrine agents mediate the expression of female and female-like behaviors. In conclusion, brain aromatase availability seems like a probable mechanism to regulate the effects of steroids on the brain circuits underlying the expression of sexual and agonistic displays in S. pavo.     

Simultaneous mating disruption of two Grapholita species in apple orchards

Two Grapholita species (G. molesta and G. dimorpha) cause serious losses in apple production by means of direct fruit damage and destruction. These two congeners occurred at similar seasons in the same orchards. Furthermore, the two species occurred in similar population sizes in apple orchards, though G. molesta occurred much more in total occurrence density than did G. dimorpha in a pear orchard. The two species share two major sex pheromone components, (Z)-8-dodecenyl acetate (Z8-12:Ac) and (E)-8-dodecenyl acetate (E8-12:Ac), but differ with regard to the relative mixture ratio necessary to create conditions of maximal attraction. To develop a simultaneous mating disruption (SMD), a mass ratio of 95:5 of Z8-12:Ac and E8-12:Ac was selected due to its high cross-calling activity and subsequent high mating disruption against both species. When the mixture was applied to orchards, it resulted in significant mating disruption against both species. However, mating disruption efficacy was slightly higher in G. dimorpha than in G. molesta. Application dose and dispenser type affected efficacy duration of SMD. In addition, the high density occurrence of G. molesta significantly reduced the SMD efficacy. Using a wax-type of dispenser, an application of SMD in 100?g per hectare dispersed in early spring recorded >90% mating disruption efficacy through the entire growing season against both Grapholita species.     

Genetic structure of two Thalassia testudinum populations from the south Texas Gulf coast

The south Texas Gulf coast is a unique ecosystem that contains a number of different bay systems. We used random amplification of polymorphic DNA (RAPD) markers to assess genetic diversity, differentiation and genetic distance between populations from two different bays that differed significantly in terms of flowering rate and disturbance. We found that while each bay contained a number of unique RAPD profiles, the average genetic diversity in each population was low. Genetic distance between the two populations was also low (F_st = 0.084) and the majority (92%) of the genetic variation was attributed to differences between individuals within populations. The population from the Laguna Madre location, however, was polymorphic for a larger number of markers, had a higher average genetic diversity and a larger number of unique RAPD profiles. The higher level of flowering at this location most likely accounts for the higher diversity.     

Life histories and mating system aspects of two Caucasian scorpionfly species: Panorpa similis Esben-Petersen and Panorpa connexa Mac Lachlan

Panorpa similis Esben-Petersen and Panorpa connexa MacLachlan are the most prominent Mecoptera in the Caucasian region. As our knowledge of mating systems and life histories of the different Panorpa species is unsatisfactory, it is the purpose of this contribution to add some interesting information on the life histories and mating behaviour of these two species. Further, we present results on successful breeding of these species, both in the field and the laboratory. Our data suggest that both species are monovoltine under the natural conditions in the Caucasian region, although our breeding experiments revealed a cryptic photoperiodic responsibility in a certain percentage of individuals of Panorpa connexa, which is completely absent in Panorpa similis. First, results on temporally and spatially differing foraging manners of the two species are presented. Male mating tactics of both species comprise copulations with one salivary mass as nuptial gift or copulations without any nuptial gift, but always without the use of force. This paper also gives information on egg deposition, egg hatching and larval development. Finally, we compare aspects of the mating systems for both species with those that have already been investigated for other Panorpa species.     

Habitat richness affects home range size in the red fox Vulpes vulpes

The spatial behaviour of the red fox Vulpes vulpes shows a great flexibility (Voigt and Macdonald, 1984). Home range size varies from 10 to over 5000 ha (Macdonald, 1987; Voigt, 1987). In carnivores, variations in home range size, weighed for body mass (Gittleman and Harvey, 1982), are largely related to differences in habitat productivity, but the intraspecific local variation in home range size can be only partially explained by differences in productivity. Macdonald (1981, 1983) suggested that home range size and configuration were determined in the red fox by the dispersion of food-rich patches. More recently, it has been found that

1.

(a) where humans are intolerant to the fox, resting sites are often located peripherally in home ranges (Meia and Weber, 1993);     

Variation of sesquiterpene lactones in Lactuca aculeata natural populations from Israel,Jordan and Turkey

A comparative phytochemical study of seven sesquiterpene lactones in natural populations of the wild lettuce Lactuca aculeata Boiss. (Asteraceae) was performed, based on 23 accessions derived from eight, two, and single localities from Israel, Jordan, and Turkey, respectively. The compounds were profiled and quantified in leaves and roots of the plants, grown from achenes (cypselas) in a greenhouse under controlled conditions, using reverse phase HPLC with on-line photodiode array detector. In the present study, L. aculeata was confirmed as a taxon strongly characterized by four dominant sesquiterpene lactones: 8-deoxylactucin, jacquinelin, crepidiaside B and lactuside A. An analysis of quantitative results of these four constituents led to the following conclusions: (i) the sesquiterpene lactone contents varied significantly, mainly within the populations; however, for two variables (crepidiaside B and lactuside A in root samples) the contents varied mostly between populations, (ii) these differences are likely to be genetically controlled since all accessions were grown under standardized glasshouse conditions. Accessions containing high levels of some sesquiterpene lactones were found in several populations. These traits should be conserved in situ and ex situ and utilized in further research and lettuce improvement.     

Assortative mating: Biodemographical structure of human populations

Concerning marriage, norms are existing in the collective conscience. These norms, to which everyone will try to agree, may vary in function of the societies, but in any way the choice of a partner will be always limited. The number of the potential partners is very limited. The assortative mating of the anthropological characters, studied in samples with limited geographical and socio-economic variability, is not always positive: the variability of the criteria at the level of the choice of a partner and the variability of the social norms relative to the marriage, can explain the variability observed in the coefficients of correlation. This variability relative to the assortative mating of physical characters is chiefly evident in the studies of non-European and non-industrial populations. In the European societies, even when the sample has a reduced variability, the assortative mating is on the contrary highly positive.     

Hematology and serum biochemistry of captive swift foxes (Vulpes velox)

Blood samples were taken from 23 swift foxes (Vulpes velox) which were to be used in a reintroduction program. The foxes originated from two different captive breeding programs: one at the Calgary Zoo (CZ) and one at the Wildlife Reserve of Western Canada (WRWC). Several differences between swift fox and domestic canine hematology were seen, including an increased number of smaller red blood cells and lower absolute leukocyte counts in swift foxes. Serum glutamic pyruvic transaminase was higher than in the domestic canine normal range while serum creatinine values were lower. Hemoglobin, serum potassium, total protein, globulin in the two groups (CZ and WRWC) were statistically different as were male versus female mean corpuscular volume values.     

Inhibition of female mating receptivity by male-derived extracts in two Callosobruchus species: Consequences for interspecific mating

We investigated the effects of injecting male-derived extracts on congeneric female receptivity in two species of Callosobruchus beetle, C. chinensis and C. maculatus. We also examined the influence of interspecific mating on female remating behaviour in these two species. Male-derived extracts reduced congeneric female receptivity in both species. As quick-acting components, extracts of C. chinensis male seminal vesicles reduced the receptivity of C. maculatus females, whereas extracts of C. maculatus male testes reduced the receptivity of C. chinensis females. As slow-acting components, extracts of male accessory glands of other species reduced the receptivity of both C. maculatus and chinensis females. After interspecific mating, the sperm of C. maculatus males were transferred to the reproductive organs of C. chinensis females, thereby reducing their receptivity. In contrast, no C. chinensis sperm were transferred to the reproductive organs of C. maculatus females; accordingly, the latter's receptivity was not reduced. Furthermore, the survival rate of C. chinensis females decreased markedly after interspecific mating. These results raise the possibility that under circumstances where populations of these two species share the same habitat, reproductive interference would occur only in the interactions between C. maculatus males and C. chinensis females.     

A comparative investigation of the mating system of Drosophila hydei

Drosophila hydei mating system characteristics were studied and compared to what has been observed for two other Drosophila species. Hydei females will copulate when they are 3 days old, while males do not exhibit courtship behaviour until they are 9 days old. Unlike any other Drosophila, D. hydei females will re-mate as often as four times in one morning. However, re-mating in the same morning does not increase the number of progeny a female produces. Male D. hydei appear to deal with the continual receptivity of females and the pressures of sperm competition by passing less material to any given female but maintaining a constant level of fertility across numerous successive copulations. D. hydei is a cosmopolitan species which utilizes a wide variety of resources. As in D. melanogaster, another cosmopolitan species which is not closely related to it, male success appears to be dependent upon genetic quality only. This pattern differs from that observed in its relative D. mojavensis, a cactiphilic species endomic to the Sonoran desert, in which males contribute material benefits to females in their ejaculate.     

Genetic structure of Phlebotomus (Larroussius) ariasi populations, the vector of Leishmania infantum in the western Mediterranean: Epidemiological implications

In recent years there has been growing interest in analyzing the geographical variations between populations of different Phlebotomus spp. by comparing the sequences of various genes. However, little is known about the genetic structure of Phlebotomus ariasi. In this study, we were able to sequence a fragment of the mitochondrial Cyt b gene in 133 sandflies morphologically identified as P. ariasi and proceeding from a wide geographical range covering 35 locations in 11 different regions from five countries. The intra-specific diversity of P. ariasi is high, with 45 haplotypes differing from each other by one to 26 bases and they are distributed in two mitochondrial lineages, one limited geographically to Algeria and the other widely dispersed across Mediterranean countries. The Algerian lineage is characterized by having 13 fixed polymorphisms and is made up of one sole haplotype. The European/Moroccan P. ariasi lineage is characterized by being made up of a great diversity of haplotypes (44) which display some geographical structuring. This could be one of the multiple factors involved in the epidemiological heterogeneity of the foci of leishmaniasis. Phlebotomus chadlii is the sister group of European/Moroccan P. ariasi. The separation of the Algerian haplotype, H45, from the rest of the specimens, European/Moroccan P. ariasi and P. chadlii, is well supported by the bootstrap analysis.