Home ranges and aspects of the natural history of the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) (Aves,Thraupidae) in central Cerrado,Brazil

ABSTRACT

In the Cerrado, native grasslands have been dramatically lost, leading to an alarming decline in populations of bird species that require these vegetation physiognomies. Species such as the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) are vulnerable to extinction and remain poorly studied. The objective of this study was to examine home ranges of the Black-masked Finch at the Parque Nacional da Chapada dos Veadeiros, central Brazil. Ten males were studied in a patch of shrubby grassland (campo sujo) between February and December 2008. The mean sizes of home ranges were 4.47 ± 1.49 ha (Minimum Convex Polygon) and 3.48 ± 1.44 ha (Kernel 95%), and this varied significantly between seasons. Home ranges were significantly larger in the non-breeding dry season than during other periods, and significantly smaller in the breeding season than during other periods. Core areas (Kernel 50%) had a mean of 0.46 ± 0.26 ha. A large overlap of home ranges was observed. The home ranges of all banded males overlapped those of at least three co-specifics, and most had an area overlap of more than 50%. A nest containing an egg and a nestling was found in November. Small and largely overlapped home ranges can be considered as positive for the conservation of the Black-masked Finch. This is because both small grassland fragments and conservation units can substantially contribute to the conservation of its populations through the Cerrado extension.     

Orchid bees (Apidae: Euglossini) in Cerrado remnants in northeast Brazil

There is a general lack of information concerning the diversity of bees belonging to the Euglossini tribe in Cerrado areas closest to the Brazilian Amazon. The state of Maranhão is situated in the northeast Brazilian Cerrado and has become the agricultural frontier of the country due to the advancement of monoculture and cattle farming. These activities have suppressed animal and plant populations in large areas of the Cerrado remnants, for which we have not yet obtained adequate scientific knowledge of local species. The objective of this study was to conduct a survey of Euglossini fauna in the northeast Cerrado. We evaluated the variation in species richness, composition and abundance between two distinct vegetation types: Cerrado sensu stricto (s.s.) and gallery forest. Male bees were captured from 7:00 a.m. to 5:00 p.m. over two consecutive days. Captures were carried out once per month from July 2012 to December 2013, using a combination of passive and active collection techniques, including baited traps, as well as a collector with an entomological net to collect bees near traps. We collected a total of 766 Euglossini males belonging to 24 species and five genera. The most abundant species were Eulaema bombiformis, Eulaema nigrita and Eulaema cingulata for the gallery forest site, whereas Eulaema nigrita, Euglossa melanotricha and Euglossa cordata were more abundant in the Cerrado s.s. The gallery forest yielded a higher number of male Euglossini (n = 503, 21 species) compared with the Cerrado s.s. (n = 263, 16 species). The presence of seven exclusive species in the gallery forest and three in the Cerrado s.s. indicated that both environments are important for the maintenance of Euglossini species in this region and highlight the increasing need for conservation programmes for the protection of Cerrado environments.     

Natural history and ecology of foraging of the Camponotus crassus Mayr, 1862 (Hymenoptera: Formicidae)

ABSTRACT

Ants are abundant in terrestrial ecosystems, especially in the Brazilian Cerrado, where they can play several roles at different levels of the food chain, including protection of plants against herbivores. Although there are many studies that evaluate the ant–plant interaction in the Cerrado, little is known about the natural history of most species of ants. Camponotus crassus Mayr, 1862, for example, is considered one of the main agents of plant biotic defence in Cerrado. But there are no studies specifically focused on this species, which hinders the understanding of how arthropod–plant interactions are structured in Cerrado. Here, we describe the natural history and ecology of the foraging of the C. crassus. We conducted the study from January 2013 to December 2014 in 10 quadrants of 40 m² to measure: the abundance, density and distribution of nests, location of the nests, the internal structure of the nests, the daily foraging of workers out of the nest, the food items they collect and the existence of territoriality and dominance of the workers on the soil and vegetation. We found 18 nests, 13 in the soil and 5 in hollow trunks on the ground with variable internal structures. The distribution of nests is aggregate, with density of 0.045 nests/m² and average distance of 3.73 m between nests. The foraging activity occurs on the daytime during the rainy and dry season. Extrafloral nectar and honeydew were the resources most collected, comprising 83.33% of the resources in the rainy period and 30% in the dry period. Camponotus crassus is a dominant species, especially on vegetation, although it also forages on the soil. This is the first study to evaluate in detail the natural history and foraging ecology of C. crassus, a diurnal, aggressive and territorial ant that mainly forage climbing onto the plants.     

Reproductive site selection in the leaf-frog Phyllomedusa azurea Cope, 1862 (Anura: Hylidae) in altered areas of the Brazilian Cerrado

The selection of reproductive sites by anurans may be associated with each species’ behavioural restrictions, reproductive modes, morphology and physiology. We investigated the use of reproductive sites by Phyllomedusa azurea in an area of Cerrado, Central-Western Brazil, which has been modified by agricultural and cattle ranching. Reproductive activity was studied during the peak of the rainy season in two consecutive years. No correlation was found between male body size and position of the calling site, and calling sites did not vary among ponds. Conversely, the height and distance from the water margin where clutches were found varied among ponds. Phyllomedusa azurea used mainly Brachiaria sp. and Brachiaria humidicola grasses as calling sites and the grass Brachiaria sp. and the shrub Melochia villosa (Malvaceae) as oviposition sites. Calling males used the vegetation according to its availability; however, individuals seemed to exhibit significant preferences regarding the type of vegetation used for oviposition.     

Activity and reproductive patterns of lizards in the Chaco of Argentina

We studied the activity and breeding pattern of dominant lizard species in the Arid Chaco, the southernmost subregion of the Chaco ecoregion (Chancaní Reserve, Córdoba province, Argentina). Lizards were captured with pitfall traps over a 4-year period. In total, 1449 individuals belonging to 11 of the 12 lizard species recorded in the area were trapped. Of these, we selected six species for a detailed analysis: Teius teyou and Stenocercus doellojuradoi accounted for 63% of the captures, Tropidurus etheridgei, Liolaemus chacoensis and Homonota fasciata accounted for 32%, and 5% comprised Leiosaurus paronae and the remaining five species. All the studied species were active during the warm–rainy season (September to March). Monthly lizard captures were highly correlated with monthly mean temperature and rainfall. No captures occurred during the remaining months of the year. All reproductive tactics known for the Chaco lizards were observed in Chancaní, including single clutch in a short breeding season in summer or autumn, as well as an extended breeding season with multiple clutches. Stenocercus doellojuradoi and L. paronae showed a singular reproductive timing, suggesting the occurrence of egg retention. Compared with sub-tropical Chaco sites, the Arid Chaco only differs in the lack of winter activity, resulting from the lower temperature and rainfall regime of our study site.     

Natural history of the marsupial Thylamys macrurus (Mammalia,Didelphidae) in fragments of savannah in southwestern Brazil

The objective of this study was to furnish information on the natural history of the Neotropical marsupial Thylamys macrurus in the southern Cerrado of Brazil. A range expansion of the species was observed to the northeast of the Mato Grosso do Sul state, Brazil. Specimens were surveyed in fragments of savannah (40–600 ha) during dry and wet seasons in 2003 and 2004 with live‐trap grids and pitfall lines. With an effort of 9767 trap nights and 2200 pitfall nights, we obtained 102 captures and 49 recaptures of T. macrurus. The data analyzed (57 males and 40 females) showed that males are more abundant in the dry season and females in the wet season. Young were recorded mostly during the wet season. Thylamys macrurus was scansorial, using the floor and the understorey. Sexual dimorphism was recorded, with males being larger than females. Information on ectoparasites is supplied.     

Aspects of the biology of a population of the cosmopolitan brittlestar Amphipholis squamata (Echinodermata) from the Firth of Forth,Scotland

In the Firth of Forth, Amphipholis squamata has continuous brooding, and pulsed breeding and recruitment, with highest numbers of brooded embryos and newly released juveniles occurring in the summer months. The estimated size of maturity was 1·5 mm disc diameter although the majority of reproductive output came from individuals of between 2·00–2·99 mm disc diameter. Brittlestar size and season had significant effects on embryo production. Embryos of different developmental stages were present in the bursae of the same individual, and newly spawned embryos and those of a potentially releasable size were present each month. The majority of juveniles apparently emerge at a disc diameter of between 0·8–1·2 mm.

Brittlestars were found with full stomachs throughout the year but a peak of feeding was recorded during summer when growth and seawater temperatures were highest. Stomach analyses indicated that almost all animals (99·4%) ingest fine particulate matter but a relatively wide range of plant and animal food items was also identified. Approximately 3% of this Scottish population of A. squamata was infested by the ectoparasitic copepod Cancerilla tubulata.     

Reproductive strategies used by moorhens (Gallinula chloropus) colonizing an artificial wetland habitat in south Wales

Over the last ten years, a high-density breeding population (c.180 individuals) of moorhens Gallinula chloropus (Linnaeus) has become established in an artificially created wetland habitat at the Wildfowl and Wetlands Trust (WWT) centre in Llanelli. The reproductive behaviour and success of this population was the subject of an intensive study between 1997–1999. Whilst monogamy was the dominant breeding system used at the site, some individuals bred annually in communal and co-operative groups. The majority of individuals within communal and co-operative groups in 1998 and 1999 were first order relatives. The number of communal groups recorded progressively declined whereas the number of co-operative groups increased over the period of study. Territory size of breeding groups was unrelated to either breeder type or group number. Most nests were constructed in Juncus although many birds also nested in trees and nest boxes intended for captive bred wildfowl. Vegetation height above nests strongly influenced breeding success, and nest site choice at the site was partially determined by vegetation management practices. Such practices may have been responsible for decreased nesting success in specific areas. Rats were the principal egg predators on site accounting for approximately 80% of eggs predated. The study reveals how the reproductive dynamics of this opportunistic bird influences its successful colonization of a new habitat.     

Biology of a tropical intertidal population of Cerithium atratum (Born, 1778) (Mollusca,Gastropoda)

The spatial distribution, population structure and secondary production of the gastropod Cerithium atratum were studied in the intertidal region of Engenho d'Água Beach in São Sebastião Channel on the northern coast of the state of São Paulo, Brazil, from May 1998 to April 1999. Twenty monthly samples were taken using a 0.25×0.25?m quadrat in each of two areas. Individuals showed a clustered dispersion pattern in both areas throughout the sampling period. Abundance and mean shell size were related to period of the year and to intertidal level, although no consistent pattern could be described when comparing the two sampling areas due to significant interaction between time and locality. Migratory events were evidenced by marked year-round variations in the frequency of individuals in the largest size classes. Thus, the size structure of this population could not be explained by recruitment and growth alone. Almost 90% of the intertidal population was represented by small individuals that recruited at the beginning of the sampling period (May to August 1998). The intertidal population was composed of annual cohorts formed by individuals recruited in different years. Each annual cohort could be divided into sub-cohorts with closely spaced recruitment periods in the same breeding season. The growth and annual P/B ¯ ratio (where P is the annual somatic production and B ¯ is the mean annual biomass) was estimated for the first year of life of recruits from 1998 occupying the intertidal region. Individuals may have an increment of up to 15?mm in shell length during the first year of life, but the growth was more pronounced in summer months. The high value of P/B ¯ (3.902) was a consequence of the dominance of small-sized individuals, which have a higher weight-specific increment than large-sized ones.     

Habitat use and diet of the endemic lizard Ameivula nigrigula (Squamata: Teiidae) in Caatinga domain,Northeastern Brazil

ABSTRACT

The lizard Ameivula nigrigula is endemic to Caatinga vegetation and the transition zone between the Caatinga and Cerrado domains in Brazil. It was recently described, but little is known about its biology. We analysed microhabitat use and the diet of this species in Caatinga vegetation in Santo Inácio, Bahia State. Its diet consisted mainly of arthropods and plant material, and in particular aggregate (e.g. termites) and large preys (e.g. Coleoptera, insect larvae and spiders), reflecting their nutritional and energy values and high water contents. With regard to habitat use, we found A. nigrigula using microhabitats with tall vegetation over accumulated leaf litter, which could potentially contribute to temperature regulation. Together, those characteristics contribute to the survival of lizards in environments with low water availability and high temperatures, such as the Caatinga domain.     

Life cycle and population structure of the terrestrial isopod Hemilepistus klugii (Brandt, 1833) (Isopoda: Oniscidea) in Iran

The life cycle and population structure of Hemilepistus klugii were studied in a population in Varamin, Iran. The population was sampled monthly (or fortnightly during the breeding season) from February 2008 to June 2009 and a total of 7015 individuals, comprising 1069 males, 1079 females and 4867 juveniles, were collected. As in other Hemilepistus species, five distinct phenophases, namely pair formation, gestation, hatching, growth and stationary, were recorded during the life cycle of H. klugii. The overall sex ratio was 1 : 1 but varied over time. Ovigerous females were observed only in April, indicating a seasonal and very short breeding period. With a short lifespan after breeding, females demonstrated true semelparity. The mean cephalothorax width for ovigerous/post-ovigerous females was higher in 2008 than in 2009. These females attained the largest size in the population throughout the year. The number of eggs per female ranged from 28 to 147 (mean ± SE, 78 ± 1.8). There was a positive correlation between female size and fecundity. Recruitment occurred in late April and resulted in the highest population density in this month, whereas the lowest densities were observed during November to January. Despite a high percentage of ovigerous females carrying undeveloped eggs (72.3%), intramarsupial mortality was low (3.5%).     

Breeding biology of Ameerega braccata (Steindachner, 1864) (Anura: Dendrobatidae) in the Cerrado of Brazil

Reproductive aspects of Ameerega braccata, a Cerrado endemic species of Dendrobatidae, were studied in the surroundings of the type locality of the species, Chapada dos Guimarães, mid-southern Mato Grosso State, Brazil. We found that males call mainly early in the morning and in the late afternoon. During courtship, the female approaches a calling male and tactile and visual communication occurs. Males call continuously while guiding females to the oviposition site, which may be situated as far as 24 m (in a straight line) from the initial encounter site. Spawn are deposited over fallen leaves on the soil surface or in burrows. Female snout–vent length and body mass did not explain the variation in ovary mass, or the variation in the number and size of post-vitellogenic oocytes. The results reported here for A. braccata might help to understand trends in the evolution of dendrobatids in open Cerrado environments.     

Reproductive biology of Scinax fuscomarginatus (Anura,Hylidae) in south‐eastern Brazil

The present study describes the reproductive biology of Scinax fuscomarginatus in a remnant of Cerrado in south‐eastern Brazil. Observations were made between September 2002 and March 2004 at Estação Ecológica de Itirapina, State of São Paulo, south‐eastern Brazil. Breeding activities occurred in lentic and temporary bodies of water during the rainy season. Scinax fuscomarginatus exhibited a prolonged breeding pattern and a lek mating system. Males were smaller than females and defended individual calling areas through acoustic and physical interactions. Resident males consistently won encounters, but did not differ in size or mass from intruder males. Satellite behaviour was observed, but no female or amplected pair interception was registered. Scinax fuscomarginatus exhibited low operational sex ratios and the general reproductive mode in which eggs are laid in the water and tadpoles are aquatic. Amplexus was axillary and the eggs were deposited at the bottom of temporary ponds. Details on oocytes, egg masses, and eggs are included.     

Reproduction,phenology and mortality sources of a species of Physalaemus (Anura: Leptodactylidae)

Physalaemus cf. fuscomaculatus is a foam-nesting frog of seasonally dry environments of south-eastern Brazil. We report on the reproduction and other natural history features of this species. Population parameters were based on trapped specimens. The advertisement call is described. The calling and spawning season is coincident with the rainy period. Calling and spawning were performed in ponds. Most of the adults were trapped in October and the juveniles during wetter months and the beginning of the dry season. At the end of the reproductive season, the median size of adults lowered. Egg clutches averaged 2350 eggs, each egg being about 1.4?mm in diameter. Males were more abundant than females in traps. Communal foam nests were frequent, involving up to 40 individual nests. Tadpoles entered the water within about 40?h. Maggots (Diptera) infested egg clutches; water bugs and mammals preyed upon adults. In this region, the dry/cold season may be so difficult for survival that early maturation at small size would be advantageous. The male-biased sample may be related to the greater motility of males. The rapid abandonment of the foam by the tadpoles and communal nesting may help to reduce predation by maggots. Skin toxins were not effective in deterring predation upon adults. The call of P. cf. fuscomaculatus differs from that of other species in the biligonigerus group and can help to define the specific status of the studied population.     

Abundance variations and life history traits of two sympatric species of Neotropical annual fish (Cyprinodontiformes: Rivulidae) in temporary ponds of southern Brazil

We investigated abundance variations and life history traits (body size, sex ratio, length–weight relationships and condition factor) of two species of annual fish (Austrolebias minuano Costa and Cheffe and Cynopoecilus fulgens Costa) in temporary ponds of southern Brazil. Six samples were taken from small temporary ponds during three annual seasons over 2 years (2008–2009). A total of 104 individuals of A. minuano and 433 individuals of C. fulgens were collected. The abundance of both species tended to decrease from autumn to spring in the 2 years. The overall sex ratio of A. minuano and C. fulgens were 1.0 male to 1.8 females and 1 male to 1.04 females, respectively. Juveniles of both species occurred only in autumn over the two years and no adult was observed during this season. While the length–weight relationship of A. minuano indicated hyperallometric growth, the relationship of C. fulgens indicated values close to isometric growth.     

Reproductive aspects of Leptodactytus hylaedactylus (Anura: Leptodactylidae), a member of the Leptodactylus marmoratus species group,with a description of tadpoles and calls

In this paper we describe some aspects of the reproductive biology of Leptodactylus hylaedactylus from open areas of Central Amazonia, Brazil. We describe the calling site, reproductive season, daily pattern of calling activity, chamber structure, vocalizations and tadpole morphology. Males of Leptodactylus hylaedactylus called amidst grasses and bushes in open and urban areas, throughout the year, and a greater number of males were heard in the period from 16:00 to 20:00 h. The eggs are deposited in underground chambers, which are spherical or elliptical. Larval development occurs inside the chambers. Two types of vocalizations were detected, the advertisement and the territorial call. The advertisement call of the species studied herein differs from other calls described for L. hylaedactylus from other localities of Brazil, but is very similar to that described from Peru. Tadpole morphology is similar to that described from individuals in French Guiana.     

Comparison of zooplankton community structure between impacted and non-impacted areas of Paranaguá Bay Estuarine Complex,south Brazil

We analysed the seasonal distribution of the zooplankton community in an anthropogenically impacted area (Paranaguá Bay) and a non-impacted area (Laranjeiras Bay) of the Paranaguá Bay Estuarine Complex. Large phytoplankton (> 50 μm) and zooplankton were collected every two months, between August 2003 and June 2004. The phytoplankton community was numerically dominated by diatoms (78%) and dinoflagellates (19%). Zooplankton abundance varied between 670 and 100,716 individuals m^–3, with a dominance of copepods, mainly the calanoids Acartia lilljeborgii, Acartia tonsa and Pseudodiaptomus acutus. A clear seasonal pattern was observed: copepods were significantly more abundant during the rainy than in the dry season. Significant differences in abundance between the two bays were detected only for cirripede larvae, which were more abundant in Paranaguá Bay. This lack of difference between the two areas was probably a consequence of the water circulation along the estuary, which may have diluted and dispersed the pollutants from Paranaguá Bay to other areas of the estuary.     

Breeding biology and population structure of the intertidal crab Petrolisthes laevigatus (Anomura: Porcellanidae) in central-southern Chile

The present study describes the seasonal reproductive cycle and population structure of the porcellanid crab Petrolisthes laevigatus, a typical inhabitant of the rocky intertidal. A total of 960 individuals (including 372 females) was collected in monthly samples from October 1993 to December 1994 in central-southern Chile. Ovigerous females were present between August and December, and were absent between January and July. The breeding season started during late winter (August), and females with embryos close to hatching occurred between October and end of spring (December). Considering the gonadosomatic index and the duration of the incubation period, it is concluded that P. laevigatus has a markedly seasonal breeding period with probably two successive spawnings per female per season. Our results compared with previous studies in temperate intertidal porcellanids suggest a lower structural variability of the population during the sampling period, but a pronounced seasonal variation in both sex ratio and abundance. The influence of environmental habitat conditions (i.e. temperature) is suggested to be responsible for the lower variation in the crab population size structure in ovigerous females, and the almost constant size distribution observed in males.     

Larval food sources of Centris (Heterocentris) analis (Fabricius, 1804) (Hymenoptera: Apidae), an oil-collecting bee

Pollen analysis of larval food allows identification of plants used as nest provision sources. Considering the importance of Centris analis in pollination, we aimed to identify its plant sources, food niche width in Cerrado, and analyze the use of sources between cool/dry and warm/wet seasons. We sampled 22 nests collected in two areas from February 2008 to October 2009. Heteropterys spp. (Malpighiaceae) were the main pollen sources, but Byrsomia spp. (Malpighiaceae), Banisteriopsis malifolia (Malpighiaceae), Solanum lycocarpum (Solanaceae) and Machaerium spp. (Leguminosae) were also important food sources. There was no difference in the use of the sources between the seasons (F_1,100?=?0.001; p?=?0.979). Despite the high number of pollen types (n?=?14) the food niche widths were low, H?=?0.777 and H?=?0.949, which can be explained by the dominance of some food items. Hence, C. analis use, profusely, a few plants as food sources that could be considered conservation targets.     

Ecology and field biology of two dominant Camponotus ants (Hymenoptera: Formicidae) in the Brazilian savannah

Camponotus renggeri and C. rufipes are very abundant in Brazilian cerrado savannah, where they feed extensively on liquid rewards and commonly associate with plants bearing extrafloral nectaries and honeydew-producing insects. Here, we provide a qualitative and quantitative field account on the natural history and ecology of these two ant species. The study was carried out in a cerrado reserve in south-eastern Brazil across a rainy/hot season (summer) and a dry/cold season (winter). The ants were found in two vegetation physiognomies: all nests of C. rufipes were located in the cerrado sensu stricto (scrub of shrubs and trees, 3–8 m tall), whereas C. renggeri occurred mostly in the cerradão (forest with more or less merging canopy, 10–12 m tall). Both species nested in fallen or erect dead trunks, as well as underground. In addition, C. rufipes built nests using dead plant material arranged or not around shrub bases. Colonies of C. rufipes were generally more populous than those of C. renggeri, and both species had colonies with more than one dealated queen. Both species were active mainly at night and foraged for resources near their nests, mainly extrafloral nectar and hemipteran honeydew (aphids and mealybugs). The average size of the home ranges of C. renggeri in cerrado sensu stricto and cerradão varied from ≈ 2.8 to 4.0 m² and apparently were not affected by season. In C. rufipes, however, foraging grounds in cerrado sensu stricto showed a twofold increase from dry/cold (≈ 4.5 m²) to rainy/hot season (≈ 9.8 m²). Our study highlights the importance of natural history data to understand the foraging ecology and role of these ants in cerrado savannah.