The reproductive flight phenology of a neotropical ant assemblage

1. Alate flights reflect an ant colony's investment in sexual reproduction and dispersal yet little is known about community‐wide patterns of alate phenology. Two Malaise traps (for 2 years) and two light traps (for 1 year) were used to explore the flight phenologies of 22 common neotropical species from Barro Colorado Island, Panama. 2. The traps caught 23 182 individuals and 286 species/morphospecies. The two trap methods shared only 18 species. Samples also differed in sexual composition: light trap samples were 80% female, Malaise trap samples were 2.6% female. 3. Of 22 common species, all but one flew over half the year, with about half flying every month of the year. These data, combined with a literature review, suggest a latitudinal gradient in alate flight season: one north temperate assemblage (42°N) averaged 1.6 lunar months per species. The ever‐warm tropical year provides a larger flight window that allows a diversity of phenologies, from continuous to strongly pulsed. 4. Rainfall was correlated with alate flights in one‐third of the species. Quantile regression suggested that high weekly rainfall was necessary but not sufficient to produce alate flights in about a quarter of the species. 5. By decreasing the number of nests releasing alates on a given day, long flight seasons may lower the probability of finding a mate. At the same time, long flight seasons may increase the opportunity of finding vacant nest sites. High population densities and high incidence of nest disturbance in this community may ameliorate the first cost while enhancing the second benefit.     

Reproductive cycle of Pitcairnia flammea Lindl. (Bromeliaceae/Pitcairnioideae) in an insular Atlantic rainforest area in southeastern Brazil

We studied for 6 years the reproductive cycle of the bromeliad Pitcairnia flammea in the Atlantic Rainforest of Ilha Grande, an island located in the south of Rio de Janeiro state, southeastern Brazil. We marked 150 adult individuals of the species, for which we monthly observed the occurrence of reproductive characteristics. The phenological attributes were related to environmental factors such as photoperiod, rainfall and temperature. Additionally, we estimated a mortality rate that was related to the rainfall in the area. P. flammea possesses a seasonal reproduction pattern, with a relatively fixed and well-defined time span during the winter dry period; flowering precedes fruiting by approx. 1 month. Due to the occurrence of P. flammea preferably on boulders of river channels and banks mortality of the plants is highest when floods from strong rainfall remove the plants mechanically from their growing places.     

QUANTITATIVE GENETICS OF SIZE AND PHENOLOGY OF LIFE-HISTORY TRAITS IN CHAMAECRISTA FASCICULATA

Despite numerous adaptive scenarios concerning the evolution of plant life-history phenologies few studies have examined the heritable basis for and genetic correlations among these phenologies. Documentation of genetic variation for and covariation among reproductive phenologies is important because it is this variation/covariation that will determine the potential for response to evolutionary forces. To address this problem, I conducted a breeding experiment to determine narrow-sense heritabilities for and genetic correlations among the phenologies of life-history events and plant size in Chamaecristafasciculata, a temperate summer annual plant species. Paternal families showed no evidence of heritable variation for two estimates of plant size, six measures of reproductive phenology or two fitness components. Similarly, paternal estimates of genetic correlations among these traits were low or zero. In contrast, maternal estimates of heritability suggested the influence of maternal parent on one estimate of plant size and four phenological traits. Likewise, maternal effects influenced maternal estimates of genetic correlations. These maternal effects can arise from three sources: endosperm nuclear, cytoplasmic genetic and/or maternal phenotypic. The degree to which the phenology of one life-history trait acts as a constraint on the evolution of other phenological traits depends on the source of the maternal influence in this species.     

Expression of taste signal transduction molecules in the caecum of common marmosets

The extraoral presence of taste signal transduction proteins has recently been reported in rodents and humans. Here, we report for the first time the presence of these signal transduction proteins in the caecum of a non-human primate, the common marmoset. Quantitative RT-PCR data on the gene expression of taste signal transduction molecules (gustducin and TRPM5) in common marmosets suggested high expression in the caecum, which was not observed in other non-human primates. Immunohistochemical analysis confirmed the specific presence of gustducin and taste receptors in marmoset caecal cells. These results may relate to the specific feeding behaviour of marmosets, which consume plant exudates, primarily gums.     

Comparative anatomy of brain monoaminergic neurons in New World and Old World monkeys

A comparison of the distribution of brain monoamine neurons in several New World and Old World monkeys was undertaken using the Falck-Hillarp formaldehyde histofluorescence technique. The overall organization of the monoamine neurons was very similar in all species, although subtle variations were found. Catecholamine (noradrenaline and dopamine) and indoleamine (serotonin) cell bodies corresponding to groups A1–A7, A8–A10, and B1–B9, respectively were found throughout the brainstem. A few catecholamine (dopamine) cells equivalent to groups All and A12 in the diencephalon were also observed. Noradrenaline neurons, rather than those of the dopamine and serotonin systems, tended to be less numerous in the New World monkeys. Ascending catecholamine and indoleamine fiber bundles were observed in most monkeys. It is interesting that fibers corresponding to the “ventral noradrenaline bundle” appeared to be much finer in the common marmoset and tamarin than in other species. In addition, a substantial catecholamine (noradrenaline) innervation of the diencephalon was noted in all the Old World monkeys, while a much lower overall terminal density was apparent in the New World forms.     

Prehistoric New World population size: Historical review and current appraisal of North American estimates

Prehistoric North American tribal population estimates recently submitted for publication in the Handbook of North American Indians are markedly higher than those estimates published by Mooney in 1928 and subsequently used by Kroeber (1939) and others. Although these estimates reflect the current trend among prehistorians to accept larger prehistoric population estimates than suggested by Mooney, they fall considerably short of those recently predicted by Borah (1964) and Dobyns (1966).     

Dermatoglyphic patterns and pattern intensities of the genus Cacajao (Cebidae,platyrrhini) with observations on interspecific and subspecific differentiation

Palmar and plantar dermatoglyphic pattern types, area and total pattern intensities (API and TPI), and pattern intensity (PI) profiles are presented for the South American genus Cacajao of the subfamily Pitheciinae. The data are based on prints from 41 bald-head uacaries (C. calvus), 9 white bald-head uacaries (C. c. calvus), and 15 black-head uacaries (C. melanocephalus). In each extremity, loops of differing orientation were the most frequent pattern type; whorls were dominant at palmar interdigital (I) area 3 in C. calvus and at both I3 and I4 in C. melanocephalus. Open fields characterized the palmar thenar and plantar proximal hypothenar, thenar, calcar, and I3 and I4. There was little evidence of significant sexual dimorphism as assessed from PI values. The genus displayed significant asymmetry at palmar I3 (P?0.001) and plantar distal hypothenar (P?0.004). There were significant group differences between C. calvus and C. c. calvus in the palmar thenar API and plantar TPIs. The combined bald-head sample of C. calvus and C. c. calvus differed from C. melanocephalus in API of palmar I4 and plantar distal thenar, I2, and distal hypothenar (marginally), and in plantar TPIs. In PI profiles, C. melanocephalus departed from the pattern shared by C. calvus and C. c. calvus in both palmar and plantar interdigital areas. As a genus, the uacaries have markedly low plantar TPI values relative to palmar values (palm-sole index > 195). Of eight comparison cebid genera, only Chiropotes, another pitheciine genus, approximated these values.     

Reproductive ecology of Dendrocoelum lacteum (Turbellaria) in a rapid stream in southern Sweden and comparisons with a lake population

Rapid streams in southern Sweden are often inhabited by the triclad Dendrocoelum lacteum. Outside Fennoscandia, this species is mainly restricted to lentic habitats. The normal food refuge for D. lacteum, the isopod Asellus aquaticus, is seldom found in the stream habitats, and probably the prey here is the amphipod Gammarus pulex. With respect to spatial and trophic niche components, it seems that D. lacteum has taken the place of Crenobia alpina in southern Sweden.Two parameters of reproduction, namely production of cocoons and of hatchlings, both peaked approximately one month later in a stream than in an adjacent lake. This difference was attributed to a low temperature regime in the stream. Number of hatchlings per cocoon and cocoon sterility were higher in the stream than in the lake. Similar cocoon and hatchling output per adult was found in the two habitats, indicating a similar reproductive effort for the two triclad populations. I suggest that D. lacteum, by virtue of its choice of microhabitat, viz., under stones, is not so vulnerable to the more severe stream environment.