Mate Choice in Non-Human Primates

Mate choice has been observed in many species of non-human primates.There are few definitive studies, however, due to the long lifespans, complex social behavior, and cognitive abilities of theseanimals. Here I review the current literature on mate choicein primates. Females typically prefer complex behavioral traitssuch as social status, familiarity, personality, and parentalcare abilities. This tendency to prefer behavioral traits isconsistent with the non-primate mammalian data. A female's abilityto express preferences, however, is often constrained by hersocial environment—in particular male mating tactics andfemalefemale competition. Males exhibit preferences for high-ranking females. In severalspecies, high-ranking females produce more offspring than low-rankingfemales. In addition, females may also influence male dominancerank and in doing so reduce male-male competition and increasemale mating success.     

Allochthonous coarse particulate organic material in forest and pasture reaches of two south-eastern Australian streams

1. Terrestrial plant litter entering two forest and two pasture sites on upland streams in south-eastern Australia was measured over a 2-year period using traps suspended above the streams. Laterally transported terrestrial plant litter was also determined in one stream, but found to be only 10% of the total. 2. Litter accession to traps suspended above the stream was significantly lower at both forested sites than was litter fall in the adjacent riparian vegetation. 3. Litter input was high (600–700g DW m^?2yr^?1) and seasonal, with 30–50% of the annual total entering the stream during December—February (summer). However, seasonality was not as great as that recorded in Northern Hemisphere deciduous forest streams. 4. Leaves comprised the largest litter component, but represented a relatively smaller proportion of the litter than is usually the case in Northern Hemisphere deciduous forest streams; in contrast bark was a relatively large proportion of the litter. 5. At the sites flowing through pasture, litter accession was about two orders of magnitude lower than at the forested sites.     

A REPORT ON VARIATION IN pH AND MICROSCOPICAL COUNT OF BACTERIA IN A PIT OF GRASS SILAGE

SUMMARY: Ignoring wasted material at the surface and sides, the variation in pH in six months old pit silage was smaller from side to side than from top to bottom. At the 2-foot level, where the best quality silage was found, variation was very slight. A correlation was found between pH and the logarithm of the microscopical count of bacteria, the total number of bacteria falling with decreasing pH.     

The Partitioning of Photosynthetically Fixed Carbon in the Leaf Blade and Leaf Sheath of Poa pratensis L.

The partitioning of photosynthetically fixed carbon betweencarbohydrate fractions and the processes of export and storagewere compared in mature leaf blades and sheaths of the grassPoa pratensis L. Most of the fixed carbon was destined for exportfrom the leaf blade with only 1% of the carbon fixed duringthe photoperiod being stored after 24 h. Although most of theassimilates imported to the sheath from the blade were subsequentlyexported, there was some unloading and storage of assimilates.Autoradiography was used to compare the translocation of ¹⁴C-labelledassimilates through non-fed areas of leaf blade and sheath andrevealed that the veins in the sheath showed a greater capacityfor storage of assimilates compared to the leaf blade. Biphasickinetics of sucrose and glucose uptake were observed in segmentsof leaf blade and sheath. Although similar carriers for eachof the sugars appear to exist in the blade and sheath, the rateof uptake via these carriers was significantly lower in thesheath compared to the blade. Assuming that unloading proceedsvia a symplastic pathway, it would appear that the conversionof sucrose to starch in the sheath could be an important meansof regulating unloading and in determining sink strength ofthe sheath. It is concluded that although the net amount ofsugars unloaded in the sheath is small, the storage of assimilatesin the vein network could be an important means of bufferingchanges in sucrose concentration in the translocate during periodsof fluctuating assimilation. Key words: Poa pratensis, autoradiography, sugar uptake, leaf blade, leaf sheath     

The Entry of Ammonia into Fungal Cells

When Scopulariopsis brevicaulis grown on an ammonia-free mediumis supplied with an ammonium salt ammonia enters the cells morerapidly than it is removed by assimilation, until an equilibriumlevel of ammonia is reached in the cells. The equilibrium concentrationin the cells is independent of metabolism and depends on theexternal concentration over a wide range. The internal concentra--tionof ammonia can be higher than the external under suitable conditionsof pH. The cells are shown to be permeable to ammonia also inthe outward direction, and the rate of entry or loss dependson the concentration difference between external and internalenvironment. The results support the view that ammonia enters the cells mainlyby the free diffusion of the undissociated molecule.     

Trends and uncertainties in Siberian indicators of 20th century warming

Estimates of past climate and future forest biomass dynamics are constrained by uncertainties in the relationships between growth and climatic variability and uncertainties in the instrumental data themselves. Of particular interest in this regard is the boreal-forest zone, where radial growth has historically been closely connected with temperature variability, but various lines of evidence have indicated a decoupling since about the 1960s. We here address this growth-vs.-temperature divergence by analyzing tree-ring width and density data from across Siberia, and comparing 20th century proxy trends with those derived from instrumental stations. We test the influence of approaches considered in the recent literature on the divergence phenomenon (DP), including effects of tree-ring standardization and calibration period, and explore instrumental uncertainties by employing both adjusted and nonadjusted temperature data to assess growth-climate agreement. Results indicate that common methodological and data usage decisions alter 20th century growth and temperature trends in a way that can easily explain the post-1960 DP. We show that (i) Siberian station temperature adjustments were up to 1.3 °C for decadal means before 1940, (ii) tree-ring detrending effects in the order of 0.6–0.8 °C, and (iii) calibration uncertainties up to about 0.4 °C over the past 110 years. Despite these large uncertainties, instrumental and tree growth estimates for the entire 20th century warming interval match each other, to a degree previously not recognized, when care is taken to preserve long-term trends in the tree-ring data. We further show that careful examination of early temperature data and calibration of proxy timeseries over the full period of overlap with instrumental data are both necessary to properly estimate 20th century long-term changes and to avoid erroneous detection of post-1960 divergence.     

Phylogenetic relationships among marsupial frog genera (Anura: Hylidae: Hemiphractinae) based on evidence from morphology and natural history

We reassess the phylogenetic relationships of genera of hemiphractine hylid frogs (Marsupial Treefrogs) and discuss the evolution of several distinctive characters within this group using parsimony analysis. Fifty-one morphological and life-history characters were sampled from two species of Cryptobatrachus , three species of Flectonotus , 17 species of Gastrotheca , all five species of Hemiphractus , and one species of Stefania as the ingroup and three hyline, one phyllomedusine, and one pelodryadine species as outgroups. Our results support the mon-ophyly of Flectonotus, Cryptobatrachus , and Hemiphractus. Gastrotheca is paraphyletic with respect to Hemiphractus , dorsal pouches were lost in the ancestor of Hemiphractus. Direct development is a synapomorphy for Hemiphractinae and tadpoles were regained independently several times. These results stand in stark contrast to the prevailing paradigm regarding marsupial frog relationships.     

Testosterone treatment of female Superb Fairy-wrens Malurus cyaneus induces a male-like prenuptial moult, but no coloured plumage

When selection strongly favours a testosterone-dependent trait in males, and this trait is not beneficial to females, a correlated response to selection in females, which also circulate some testosterone, could slow the rate of evolution in males. Here I investigate whether experimental testosterone treatment in female Superb Fairy-wrens Malurus cyaneus can induce the testosterone-dependent sexually selected moult into nuptial plumage, as it does in males. Silastic testosterone implants in females rapidly induced a moult akin to the male prenuptial moult, involving all body areas that are colourful in nuptial males (head, upper back, ear tufts, breast). Moreover, the newly moulted feathers had a similar glistening appearance and morphology as male nuptial feathers. However, the treatment failed to induce production of the blue and black structural colours, and the breast and ear tufts were lighter than the normal grey-brown feathers of females and males in eclipse plumage. Microscopic and ultrastructural analyses of these unusual feathers could further our understanding of structural colour production.     

Illumination of cryptic species boundaries in long-tailed shrew tenrecs (Mammalia: Tenrecidae; Microgale), with new insights into geographic variation and distributional constraints

The increasing use of mitochondrial DNA (mtDNA) to explore and test species limits among morphologically similar species is potentially compromised by phenomena poorly reflective of organismal history and speciation, including (but not limited to) stochastic lineage sorting and gene flow. In situations where molecular data are only available from a single gene or linkage partition (e.g. mtDNA), corroboration of suspected species boundaries should be sought from independent lines of evidence, such as morphology. Recent attempts to delimit species using mtDNA and morphology have either implicitly or explicitly ignored the possibility that distinct species can occur in direct sympatry throughout much of their range, presumably because such situations are believed to be rare. We examined phylogenetic relationships within the long‐tailed shrew tenrecs (Mammalia: Tenrecidae; Microgale spp.) from Madagascar. Current taxonomy recognizes two broadly sympatric species, though as many as six have been described. Given that alpha taxonomy within shrew tenrecs has been controversial, and that patterns of morphological variation can be especially difficult to assess for this group, some authors have suggested that additional cryptic species may exist. To examine this possibility, we conducted a phylogenetic study using the mitochondrial NADH dehydrogenase subunit 2 gene and a morphometric analysis of 29 craniodental, postcranial, and external measurements from a broad geographical sample of long‐tailed shrew tenrecs. The two data sets were nearly perfectly congruent in identifying four groups that can be classified as species, thereby doubling the currently recognized number of species. We present previously unrecognized distributional evidence consistent with our conclusions and provide an empirical example of how a revised understanding of species limits alters inferences of geographic variation and species coexistence, particularly with respect to fine‐scale habitat partitioning. The results of this study suggest that certain species pairs, previously assumed to be single species occupying broad elevational ranges, are actually reproductively isolated units that are partitioning their environment along elevational lines. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83 , 1–22.