Paternal care as a conditional strategy: distinct reproductive tactics associated with elaboration of plumage ornamentation in the house finch

When individuals in a population differ in physiological conditionand residual reproductive value, selection should favor phenotypicplasticity in reproductive investment such that individualsare able to adopt the reproductive tactic that results in thehighest fitness under given conditions. Here we examined reproductivetactics in relation to the elaboration of condition-dependentsexual ornamentation (carotenoid breast coloration) in a Montanapopulation of the house finches (Carpodacus mexicanus). Malesused distinct reproductive tactics depending on elaborationof their sexual ornamentation. Males with red pigmentation (maximum ornament elaboration) paired with females that nestedearlier, but these males did little provisioning of incubatingfemales and nestlings. In contrast, males with yellow colorationpaired with females that nested later, but these males fedfemale and nestlings more. Consequently, for red males offspringrecruitment was primarily affected by earlier nest initiation, whereas in yellow males it was affected most by male provisioning.In males with intermediate plumage coloration, all measuredcomponents, nest initiation, provisioning of incubating female,and nestling feeding, strongly contributed to offspring recruitment.The fitness consequences of alternative reproductive tacticsof males were influenced by breeding experience and fidelityof their mates. Among first-time breeders, red males achievedthe highest fecundity because of the advantage gained throughearly nesting and pairing with more experienced females andbecause of compensation by their mates for low male provisioningof nestlings. Among experienced breeders, males with intermediateplumage coloration achieved the highest fecundity because ofthe combined benefits of relatively early pairing and high parental care. High variation in sexual ornamentation in a Montana populationof house finches may favor distinct associations of sexualdisplays with a particular set of reproductive behaviors.     

The evolution of reproductive diversity in Afrobatrachia: A phylogenetic comparative analysis of an extensive radiation of African frogs

The reproductive modes of anurans (frogs and toads) are the most diverse of terrestrial vertebrates, and a major challenge is identifying selective factors that promote the evolution or retention of reproductive modes across clades. Terrestrialized anuran breeding strategies have evolved repeatedly from the plesiomorphic fully aquatic reproductive mode, a process thought to occur through intermediate reproductive stages. Several selective forces have been proposed for the evolution of terrestrialized reproductive traits, but factors such as water systems and co‐evolution with ecomorphologies have not been investigated. We examined these topics in a comparative phylogenetic framework using Afrobatrachian frogs, an ecologically and reproductively diverse clade representing more than half of the total frog diversity found in Africa (～400 species). We infer direct development has evolved twice independently from terrestrialized reproductive modes involving subterranean or terrestrial oviposition, supporting evolution through intermediate stages. We also detect associations between specific ecomorphologies and oviposition sites, and demonstrate arboreal species exhibit an overall shift toward using lentic water systems for breeding. These results indicate that changes in microhabitat use associated with ecomorphology, which allow access to novel sites for reproductive behavior, oviposition, or larval development, may also promote reproductive mode diversity in anurans.     

Reproductive phenology of a wet forest understorey in the Western Ghats, South India

The reproductive phenology of 60 understorey species was monitored at monthly intervals for 20 months in a medium elevation wet evergreen forest in the Southern Western Ghats. The life forms monitored were herbs (including terrestrial orchids), shrubs and small trees. Flowering and fruiting were non‐uniform with a dry season flowering peak and wet season fruiting peak. Flowering in the understorey correlated negatively with rainfall. No significant correlation was detected for fruiting. Life forms had flowering and fruiting peaks at different times of the year.     

Children's Help and the Pace of Reproduction: Cooperative Breeding in Humans

Because children's ability to support themselves falls below their consumption, human young are subsidized by others throughout much of their growth and development. Mothers, however, who often have multiple dependents of different ages, are faced with an allocation problem (Fig. 1). This has led to important debate about the evolution of a long period dependence and the development of nonmaternal strategies to provision young. This article focuses on the critical role that children themselves play. Because the human subsistence niche incorporates a broad diversity of resources that require variable procurement and processing costs, dependent children can also be important producers, furthering both a need and an opportunity for cooperative breeding.     

Seasonal variation in parental care, offspring development, and reproductive success in the burying beetle, Nicrophorus vespillo

1. Beetles of the genus Nicrophorus reproduce on small vertebrate carcasses that they bury in the soil to provide the larvae with food. Usually, both parents cooperate in brood care by feeding and guarding their progeny. 2. In pairs of the common European species N. vespillo, the duration of care depended on the time of year when the beetles reproduced. Both in 1990 and in 1991, male and female parents stayed longer with their broods when reproduction started in spring than when reproduction started in early or late summer. This was probably due to the longer development time of the larvae caused by lower temperatures in spring, because laboratory experiments suggested a strong influence of temperature on both the duration of brood care and offspring development. 3. The number of adult offspring produced by a beetle pair did not vary among different times of the year. 4. The median time required for offspring development, measured as time from burial of the carcass to emergence of young adults, was between 62 and 84 days. When the beetles reproduced in late summer, only about three-quarters of the offspring left the soil and hibernated as adults. The remaining offspring stayed underground and adults appeared on the soil surface the following spring. They still showed the flexible cuticle typical of newly-hatched beetles, suggesting that they may have overwintered in a pre-adult stage.     

The evolution of parental investment in caecilian amphibians: a comparative approach

Parental care is widespread among vertebrates and the observed patterns of parental care and investment are extremely diverse. Among amphibians, caecilians (Gymnophiona) exhibit considerable variation in reproductive modes, including both oviparity and viviparity, combined with highly unusual investment strategies (e.g. skin‐feeding and intrauterine feeding). In the present study, current knowledge on the reproductive modes is integrated into an analysis of the evolutionary scenario of parental investment of caecilians. Phylogenetically basal caecilians possessing a biphasic life cycle that includes an aquatic larval stage invest in macrolecithal eggs directly corresponding to size at hatching. Some phylogenetically derived caecilians (i.e. the Teresomata) have a smaller clutch size and show a reduction to either medium‐yolked (mesolecithal) or small‐yolked (microlecithal) eggs. Via alternative pathways of parental investment, such as intrauterine feeding in viviparous taxa and maternal dermatotrophy in oviparous taxa, teresomatan caecilians increase both offspring size and quality. However, more data regarding reproductive biology are needed to obtain a fully resolved understanding of the evolution of reproduction in caecilian amphibians.     

Burying beetles: intraspecific interactions and reproductive success in the field

Abstract. 1. The discovery and utilization of small carcasses by burying beetles (Silphidae, Nicrophorus ) was studied by placing dead mice at random points on large grids at two Iocations in Michigan, U.S.A.
2. The majority of mice are found within 24 h by more beetles than ultimately will utilize the carcass. If a carcass is likely to be usurped by a larger species of beetle or by a vertebrate, then intraspecific competition may be postponed until the carcass is concealed and buried.
3. Both males and females practice parental care. Maturing broods are tended by no adults, a single female, a single male, or a male—female pair. No differences in brood success were observed among these categories.
4. The female lays a larger clutch than ultimately will survive. Brood size is regulated after the egg stage, such that offspring number varies, but individual offspring size does not.
5. A large amount of unexplained variation exists in brood size, in both the laboratory and the field. This variation is probably caused by the environment, and not the reproductive physiology of the beetles. Competition with microbes is a likely candidate.
6. Differences exist not only between Nicrophorus species, but also between localities for a single species, suggesting adaptation to local environments.     

Mesoscale Patterns in the Floristic Composition of Forests in the Central Western Ghats of Karnataka,India

We describe the mesoscale floristic patterns in the central Western Ghats of Karnataka, India, through combined analysis of woody species abundance and stand structure data from a network of ninety-six 1-ha sampling plots spread across 22,000 km². A total of 61,906 individuals (≥10 cm gbh) comprising 400 plant species from 254 genera and 75 families were recorded. Euphorbiaceae, Rubiaceae, Lauraceae and Moraceae families constituted 23.5 percent of the total number of species encountered. The relative dominance of species was skewed with Poecilonueron indicum, Xylia xylocarpa, Terminalia tomentosa and Anogeissus latifolia being dominant in some plots. Correspondence analysis (CA) and a nonmetric multidimensional scaling (NMDS) of plots by species abundances data showed similar arching patterns, with significant correlation between the first axis of CA and NMDS (r=0.77). Hierarchical clustering of plot scores along the three first CA axes resulted in splitting the plots into five different categories that broadly reflect the major bioclimatic features of the region. A multiscale bootstrapping test indicated that categorization of the wettest (wet evergreen group 1 and 2) and driest (dry deciduous) groups were robust (P<0.05 with 1000 bootstraps), while the remaining two transitional groups were uncertain (P=0.12 and 0.26 for moist deciduous and semi-evergreen group, respectively). Principal component analysis revealed that plots with similar floristic composition can encompass contrastingly different physiognomic structures (canopy cover, canopy height and mean tree diameter) probably in relation to their levels of disturbance. Observed patterns in the floristic composition have been discussed in the light of the complex interaction between the bioclimatic and disturbance regimes that characterize the region.     

Ecology of a pastoral caste: Gavli Dhangars of peninsular India

The Gavlis are a pastoral caste of the forested hill tracts of India 's Western Ghats region. This paper examines their shift under British colonial rule from buffalo-keepers to goatherds to cultivators of increasingly marginal hill tracts, the context of forest exploitation and malaria control as well as more recent dairy development programs of the Indian government. It concludes that if present trends continue Gavlis everywhere will follow the same progression, eventually becoming landless migrants.     

Life history evolution in cichlids 1: revisiting the evolution of life histories in relation to parental care

Empirical links between egg size and duration of parental care in fishes have generated a considerable amount of theory concerning life history evolution. However, to date, this link has not been investigated in relation to other important life-history traits such as clutch size and body size, or while controlling for shared ancestry between species. We provide the first phylogenetically based tests using a database with information on egg size, clutch size, body size and care duration in cichlid fishes (Cichlidae). Multiple regression analyses, based on independent contrasts on both the species and the genus level, showed that clutch size is the variable most closely related to duration of care. This pattern appeared to be driven by post-hatch care relationships. Our results show that, contrary to expectation, there is no positive link between egg size and care duration in Cichlidae. Instead, greater reproductive output through increased clutch size investment appears to have coevolved with greater care of offspring. We suggest that re-evaluation of the generality of current models of the evolution of egg size under parental care in fishes is needed.     

Phenotypic selection and function of reproductive behavior in the subsocial bug Elasmucha putoni (Heteroptera: Acanthosomatidae)

To investigate the function of maternal care and determinantsof reproductive success in the subsocial bug Elasmucha putoni (Heteroptera: Acanthosomatidae), I used two different approaches,the measurement of phenotypic selection and female-removalexperiments under conditions differing in biotic-environmentalpressure. For two field populations, unattended eggs and youngernymphs consistently suffered severe predation pressure andattendance by parent females greatly enhanced their survival.In contrast, under enemy-excluded conditions, offspring performance was not reduced in broods without parent females, indicatingthat maternal care functions as a physical defense againstpredators. However, the determinant of female reproductivesuccess in E. putoni in the field was not the care behavioralone. Selection gradient analysis showed that early seasonoviposition and larger clutch size, as well as a longer durationof care by a female, was favored during the breeding episode.This study is the first to evaluate phenotypic selection onparental care and other reproductive traits in arthropods.     

Convergent evolution across the Australian continent: ecotype diversification drives morphological convergence in two distantly related clades of Australian frogs

Animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution, but this has been rarely tested at the transcontinental level and across entire classes of animal. Australia's biome diversity, isolation and aridification history provide excellent opportunities for comparative analyses on broad‐scale macroevolutionary patterns. We collected morphological and environmental data on eighty‐four (98%) Australian hylid frog species and categorized them into ecotypes. Using a phylogenetic framework, we tested the hypothesis that frogs from the same ecotype display similar body shape patterns: (i) across all the Australian hylids, and (ii) through comparison with a similar previous study on 127 (97%) Australian myobatrachid species. Body size and shape variation did not follow a strong phylogenetic pattern and was not tightly correlated with environment, but there was a stronger association between morphotype and ecotype. Both arboreal and aquatic frogs had long limbs, whereas limbs of fossorial species were shorter. Other terrestrial species were convergent on the more typical frog body shape. We quantified the strength of morphological convergence at two levels: (i) between fossorial myobatrachid and hylid frogs, and (ii) in each ecomorph within the hylids. We found strong convergence within ecotypes, especially in fossorial species. Ecotypes were also reflected in physiological adaptations: both arboreal and cocooned fossorial frogs tend to have higher rates of evaporative water loss. Our results illustrate how adaptation to different ecological niches plays a crucial role in morphological evolution, boosting phenotypic diversity within a clade. Despite phylogenetic conservatism, morphological adaptation to repeatedly emerging new environments can erase the signature of ancestral morphotypes, resulting in phenotypic diversification and convergence both within and between diverse clades.     

Patterns of species discovery in the Western Ghats,a megadiversity hot spot in India

Even since Linnaeus, naturalists and taxonomists have been systematically describing species new to science. Besides indicating gaps in taxonomic effort, understanding the temporal patterns of species discovery could help in identifying drivers that determine discovery. In this study we report the patterns of discovery of eight taxa — birds, butterflies, frogs, tiger beetles, grasses, asters, ferns and orchids — in the Western Ghats, a megadiversity centre in India. Our results indicate that the discovery curves for birds and butterflies have been saturated while those for frogs and grasses continue to increase. Within each taxon, the major drivers of discovery were commonness of the species and their size. The average years taken for discovery across taxa were directly related to the per cent endemicity and species richness of the taxa. We discuss the trajectories of discovery with respect to rarity or endemicity of the species and life history features, and the implications these might have for strategizing the discovery process in India.     

Studies on the aquatic hyphomycetes of a sulfur spring in the Western Ghats, India

Studies on the occurrence of aquatic hyphomycetes were carried out in Panekal sulfur spring in the Western Ghats, India by incubation of leaf litter and analysis of natural foam and of induced foam. Sampling was done once every three months over a period of two years from September 1989 to June 1991. The temperature, pH, dissolved oxygen, and sulfide content of water were also measured. No fungi were observed within the spring, whereas 16 species belonging to 13 genera were isolated from two outflow sites of the stream. The percent frequency of Triscelophorus monosporus was high (24.0%). The temperature of water in the spring ranged between 30.0 and 38.5°C and the sulfide content between 3.2 and 4.3 mg 1^–1. Studies showed that sulfide water (4.0 mg 1^–1). from the spring inhibited the growth of the colonies of Dactylella aquatica, Phalangispora constricta, Tetracladium setigerum, Vermispora cauveriana, and Wiesneriomyces laurinus. When the leaves colonized by aquatic hyphomycetes were incubated at different temperatures in sulfur-spring water and stream water separately, sporulation was not observed in any of the fungi at and above 35°C except Phalangispora constricta, which could sporulate at 35°C. At lower temperatures (15–30°C) relatively fewer species were found to sporulate in sulfur-spring water than in stream water. Correspondence to: K.M. Kaveriappa     

Relationship between oocyte morphology and reproductive strategy in loricariid catfishes of the Paraná River, Brazil

Relationships between ovarian structure, oocyte structure/development, and parental care/life history strategies of six loricariid catfishes common in the upper Paraná River, Brazil were examined with analysis of catch data, relative gonad weight, histology, and microscopy. Three life history strategies were observed. Loricariichthys platymetopon , Loricariichthys sp. And Loricaria sp. produce several small clutches of large eggs over a protracted spawning period. Males of these species guard their eggs and larvae, which are transported as a mass on the ventral surface of the male's body. Hypostomus ternetzi and Megalancistrus aculeatus produce the largest mature eggs and the smallest clutches relative to adult mass. The spawning periods of these species are short, and males guard their broods in excavations. Rhinelepis aspera has high fecundity, high relative mass of mature gonads (both sexes), small mature eggs, and broadcast spawning with no parental care. This species migrates to spawn over firm substrates in channel areas during a contracted period. Mature oocytes of external bearers had the thickest zona radiata, followed by the egg scatterer, and cavity nesters. The thickness of the zona radiata probably is an adaptation to protect the developing egg from injury from abrasion. The zona granulosa appeared to be associated with production of secretions responsible for egg adhesion, and this layer was thickest in mature oocytes of the cavity nesting species, followed by the external bearers. All six species have wide distributions in the Paraná River, tributaries, floodplain lagoons, and the Itaipu Reservoir, but brood guarders tended to be most common in lentic habitats.     

Equilibrium reproductive strategy of the peacock bass Cichla kelberi facilitates invasion into a Neotropical reservoir

The reproductive strategy of the non-native predator cichlid Cichla kelberi was determined to explain its success after more than 60 years of being introduced into an isolated reservoir in southeastern Brazil. This was one of the first-known translocations of the genus Cichla out of its natural range. Macro- and microscopy characteristics of the gonadal development stages and the maturation phases, along with the reproductive features (size at first maturation size, gonado-somatic index and sex ratio), were described. It was hypothesized that the stable conditions of the reservoir, with low connectivity, weakly defined spatial gradient and slight seasonal changes in environmental variables, favour the equilibrium strategy that enables predators to have high offspring survivorship because of great parental investment in individual progeny. Sex ratio was well balanced, with males and females reaching first maturity between 30.0 and 28.6 cm total length (L_T), respectively. The stages of oocyte (primary and secondary growth, vitellogenic and atresia) and spermatocyte (spermatogonia, spermatocytes, spermatids and spermatozoa) development were identified. Five phases of gonadal development (immature, developing, spawning capable, regressing and regenerating) were described for both sexes. A long reproductive season was found, with spawning peaks in August/September and, to a lesser extent, in April/May. Parental care and spawns in parcels (batch spawns) corroborated the raised equilibrium strategy that was effective in this isolated reservoir. This species developed reproductive mechanisms that fit to different environmental conditions, with multiple spawning being associated with lentic environments and asynchronous development of oocytes, which are released over long periods. The reproductive plasticity in reservoirs may be one of the main factors inherent to the successful of colonization and establishment of the peacock bass in the environments in which they were introduced.     

The frequency and fitness consequences of communal breeding in a natural population of burying beetles: a test of reproductive skew

Abstract.  1. Reproductive cooperation occurs in diverse taxa and a defining characteristic of these social systems is how reproduction is shared. Both male and female burying beetles ( Nicrophorus spp.) facultatively form associations to bury a carcass and rear a single brood, making burying beetles a model system for testing skew theory.
2. In this study, 50% of 40–45 g carcasses and 75% of 55–60 g ones were buried by more than one male and/or female Nicrophorus tomentosus .
3. Females were significantly more likely to cooperate on 55–60 g carcasses than on 40–45 g ones.
4. Analysis of parentage of 13 broods using microsatellite loci as genetic markers showed that maternity analysis of only 2% of the young excluded all females captured leaving the brood chamber after burial. Males previously mated with resident females or displaced by resident males fathered 7% of the young.
5. The male and female remaining the longest were usually the parents of the most offspring, and reproductively dominant individuals also tended to be the largest.
6. Although all but two or three individuals that helped to bury the carcass produced some offspring, reproduction was often not shared equitably. Reproduction of females was significantly skewed on six of nine 40–45 g carcasses but shared fairly equitably on all three 55–60 g ones. Reproduction was skewed among males on 7 of 10 broods.
7. Both males and females relinquished a greater proportion of the brood as the days of assistance from all consexuals increased.     

Incorporating landscape transformation into local conservation prioritization: a case study in the Western Ghats, India

In fast-changing tropical landscapes, effective strategies for conservation must incorporate information on ecosystems and species distribution with that on landscape change. A possible methodology for conservation prioritization is developed and illustrated using a 27.5 km² tropical landscape in the Western Ghats hill chain of southern India. Vegetation types or ecosystems within the landscape are ranked based on the ecosystem services they might provide: number of endemic species harbored, species richness, contribution to carbon uptake, economic value of produce per ha and contribution to soil renewal. For a vegetation type, the weighted average of these ranks indicates its net conservation value. Weights thus provide a means of ascribing differential importance to an ecosystem service. Information on landscape change is also summarized by a matrix depicting the likelihood of transformations between vegetation types present in the landscape, projected 5 years into the future. For each transformation between two vegetation types, information on ecosystem service and dynamics is then integrated. Implications from the perspective of conservation are assessed as the product of transformation probability and the resultant gain/loss in conservation value. Strongly positive transformations are likely to result in positive impacts on conservation value, and occur without any additional conservation effort. Strongly negative transformations are likely to occur and have a strong negative impact on conservation value. Maximum conservation effort may be directed at halting or reversing these. This study thus describes a method for conservation prioritization, which integrates information on ecosystem function and services with ecosystem dynamics.     

Alpha diversity of lianas in a tropical evergreen forest in the Anamalais, Western Ghats, India

Abstract. Species richness, abundance, size-class distribution, climbing mode and spatial patterns of lianas were investigated in a 30-ha permanent plot of tropical evergreen forest at Varagalaiar in the Anamalais, Western Ghats, India. Each hectare was subdivided into 10 m × 10 m quadrats, in which all lianas ≥ 1 cm d.b.h. were measured, tagged and identified. The total liana density was 11, 200 individuals (373 ha–1) and species richness was 75 species, representing 66 genera and 37 families. The richness estimators employed for species and family accumulation curves after 100 times randomization of sample order, have stabilized the curves at 16th and 15th hectares, respectively. A greater proportion of lianas was twiners (55% of species and 44.4% of density) and root climbers (5% of species and 14% of density), and a few were tendril climbers, reflecting the late successional stage of the forest. In the size-class distribution, 82% of abundance and 97% of species richness fell within 1–3 cm diameter threshold. The dominance of succulent diaspore type signifies the faunal dependence of lianas on vertebrate frugivores for dispersal. The diversity, population density and family composition of lianas of our site is compared with those of other tropical forests. The need for biomonitoring of this synusia in the permanent plot for forest functioning is emphasized.     

The influence of temperature on nest site choice and reproductive strategy in a temperate zone Polistes wasp

Abstract. 1. Field experiments with Polistes fuscutus showed that more nests were initiated, co-foundress groups were larger, broods developed faster, and workers eclosed earlier in sun-warmed sites than in cool ones.
2. These results suggest that colonies nesting in sun-warmed shelters gained a fitness advantage over those in cooler shelters. More rapid brood development means that such colonies reach the ergonomic stage more quickly, which in turn means a higher expectancy of survival and greater productivity at the end of the season.
3. We argue that thermal properties constitute an important component of Polistes nest site quality in temperate regions and that these properties influence joining and usurping strategies as well as nest site choice in spring Polistes females. Other factors being equal, a joining or usurping female should opt for a colony in a warm site over one in a cool site, leading to the larger foundress groups we found in warm shelters.
4. We hypothesize that the selective advantage of philopatry in temperate zone Polistes populations is that it brings spring females to nest sites of proven quality.