RESUMO
The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.
A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.
Assuntos
Masculino , Feminino , Animais , Anti-Helmínticos/administração & dosagem , Dasyproctidae , Peso ao Nascer/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Tamanho da Ninhada/efeitos dos fármacosRESUMO
The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.(AU)
A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.(AU)
Assuntos
Animais , Masculino , Feminino , Dasyproctidae , Anti-Helmínticos/administração & dosagem , Reprodução/efeitos dos fármacos , Peso ao Nascer/efeitos dos fármacos , Tamanho da Ninhada/efeitos dos fármacosRESUMO
The objective of this research was to examine whether different types of litter (New, used, and mixed) and alum could interfere in litter quality, thereby also influencing the productive performance of laying hens. A total number of 450 Inshas chickens aged 24 weeks were randomly distributed into six groups (5 replicates, each with 15 hens) of floor litter. The groups included (G1) new wheat straw litter, (G2) used wheat straw litter, (G3) mixed wheat straw litter (50% new+50% used) and (4, 5 and 6) the same litter types in groups 1, 2 and 3 supplied with 500g of alum /m2 litter. The experiment lasted 16 weeks. Laying hens productive parameters, blood parameters, carcass parameters, respiratory rate, coliform count and pH, as well as ammonia emission, litter quality were assessed.The results showed that the litter type significantly affects the level of ammonia emission, litter characteristics, carcass characteristics, intestinal pH and coliform count, blood characteristics (T3, cholesterol, uric acid, total protein, albumin, globulin, hemoglobin, and PCV), as well as the body weight gain. In general, we found that reused litter followed by the mixed litter without added alum resulted in the lowest efficiency on the studied traits, as compared to the same types of litter treated with alum and the new litter. We therefore conclude that the addition of alum reduces ammonia emission and improves the characteristics of the litter, which is reflected in enhancement of productive performance and properties of blood and carcass.(AU)
Assuntos
Animais , Sulfato de Alumínio/análise , Galinhas/crescimento & desenvolvimento , Tamanho da NinhadaRESUMO
The temperatures at which eggs of crocodilians are incubated plays an important role in embryo survival, rate of embryonic development and sex definition. The aim of this study was to assess the nest temperatures of an American crocodile (Crocodylus acutus) population on the central coast of Oaxaca state in Mexico. The fieldwork was carried out from February to June 2018 at Palmasola Lagoon, Oaxaca. Ten natural nests of C. acutus were carefully excavated to determine clutch size. When putting the eggs back in the nests, we placed a data logger in the center of the egg mass to determine the temperature parameters in the nest chamber environment, as well as the variation in temperature during the incubation period. All nests were revisited to count the number of hatched eggs (NHE) and to determine the hatching success (HS), along with the duration of the incubation period (IP). Hatching success was 89.04%. The mean clutch size in the American crocodile nests was 30.7 ± 7.83 eggs (ranging from 17 to 46 eggs), and the mean incubation period was 77.6 ± 5.89 days. The mean nest incubation temperature throughout the reproductive season was significantly different among nests. Based on the average temperature during the middle third of the incubation period, the nests should have produced both sexes, but with a higher proportion of males. This study tried to elucidate the impact of nest temperatures during the incubation period on embryo survival, as well as hatchling sex ratio in a local climate on the central coast of Oaxaca.
Assuntos
Jacarés e Crocodilos/fisiologia , Tamanho da Ninhada , Ecossistema , Temperatura , Animais , Feminino , Masculino , México , Razão de MasculinidadeRESUMO
Purpose The spleen is relevant in blood purification, hematopoiesis, metabolism, and immune response to antigens, in addition to the storage and control on the release of metals and amino acids. Its functions concerning reproduction characteristics are still unknown. The objective was to study the influence of splenectomies on reproduction. Methods This study analyzed 25 mice couples, distributed into five groups: group 1 control, no surgery: group 2 control, submitted to laparotomy and laparorrhaphy only; group 3 splenectomy in male mice; group 4 splenectomy in female mice; group 5 splenectomy in male and female mice. The animals were studied as regards the number of gestations and offspring generated in each gestation. Results A decrease in both the number of gestations and the number of offspring was verified in the male mice that had received a splenectomy when coupled with normal female mice. It is important to emphasize lower reproduction level when paired asplenic males with normal females, otherwise, the couples in which both mice had been splenectomized did not present change in the reproduction pattern. Conclusions A reduction in the number of pregnancies and litters occurs in mice couples when the male mice were previously splenectomized.(AU)
Assuntos
Animais , Camundongos , Esplenectomia/veterinária , Gravidez , Tamanho da Ninhada , Baço , ReproduçãoRESUMO
Rainfall in tropical semi-arid areas may act as a reliable cue for timing bird reproduction, since it precedes future food supply. With this in mind, we set-up a study to test the reproductive response of insectivorous bird to arthropod abundance and rainfall patterns. Sampling occurred in a seasonally dry Neotropical forest, in north-eastern Brazil, between October, 2015 and October 2016, at 14-day intervals. We used brood patch to assess reproductive periodicity of insectivorous birds (eight species, 475 captures, 121 patch records). We sampled arthropods to quantify abundance, using biomass and number of individuals (1755 individuals, 15 Orders). Rainfall temporal distribution was analyzed using daily precipitation data. We used a cross-correlation function to test for correlation and time-lags between the covariates under study. Both the number of reproductively-active birds and arthropod abundance were higher in time periods close to the rainy season. Increase in arthropod biomass in the aerial stratum preceded the period of greatest rainfall by one (14 days, r = 0.44) to three sampling periods (0.47). In contrast, the highest proportion of individuals with brood patches occurred after the main rainfall peak, with the strongest relationship occurring after two (0.52) to four (0.50) time lags. Finally, the proportion of individuals with brood patches was positively correlated with aerial stratum arthropod biomass when five time lags were considered (0.55). Our results support the hypothesis of a temporal process involving rainfall, arthropods and reproduction of insectivorous birds in the wet/dry tropics. However, rainfall did not appear to act as a cue for the timing of reproduction, since records indicated higher arthropod biomass before the main rainfall peak. At least occasionally in the study area, insectivorous bird reproduction peaks after food abundance.(AU)
Assuntos
Animais , Tamanho da Ninhada , Aves , Reprodução , Artrópodes , Zona Tropical , Estação Chuvosa , BrasilRESUMO
The Caatinga's black snake Boiruna sertaneja is a Pseudoboini species, endemic of the Caatinga biome. It is rare and fits in five traits that suggest it deserve more attention in reproduction research and conservation policies. Here we provide information on reproductive biology of B. sertaneja by adding new data about court and copula, fertility, nest, eggs and hatchling morphometry and pattern of color based on captivity specimens. The court and copula, as well as oviposition of B. sertaneja in the Caatinga are associated to period of high temperature and dry season. Our findings indicate that females of B. sertaneja, in nature, could select protected places or actively build their nests. We recorded three oviposture after a single event of copula by the female of B. sertaneja. The long time gap between copula and clutches strongly suggests that female B. sertaneja can store sperm in their oviducts for long periods or do facultative parthenogenesis. Clutch size and hatchling size of B. sertaneja was high. We observed variation on the pattern of coloration among hatchlings of same litter. This study comprises the first description of important aspects of reproduction and can give us some clues about how B. sertaneja reproduce in nature.
Assuntos
Ovos , Serpentes , Animais , Brasil , Tamanho da Ninhada , Feminino , Fertilidade , ReproduçãoRESUMO
We studied avian development in 49 to 153 species of temperate and tropical New World passerine birds to determine how growth rates, and incubation and nestling periods, varied in relation to other life-history traits. We collected growth data and generated unbiased mass and tarsus growth rate estimates (mass n = 92 species, tarsus n = 49 species), and measured incubation period (n = 151) and nestling period (n = 153), which we analyzed with respect to region, egg mass, adult mass, clutch size, parental care type, nest type, daily nest predation rate (DMR), and nest height. We investigated covariation of life-history and natural-history attributes with the four development traits after controlling for phylogeny. Species in our lowland tropical sample grew 20% (incubation period), 25% (mass growth rate), and 26% (tarsus growth rate) more slowly than in our temperate sample. Nestling period did not vary with respect to latitude, which suggests that tropical songbirds fledge in a less well-developed state than temperate species. Suboscine species typically exhibited slower embryonic and post-embryonic growth than oscine passerines regardless of their breeding region. This pattern of slow development in tropical species could reflect phylogenetic effects based on unknown physiological attributes. Time-dependent nest mortality was unrelated to nestling mass growth rate, tarsus growth rate, and incubation period, but was significantly associated with nestling period. This suggests that nest predation, the predominant cause of nest loss in songbirds, does not exert strong selection on physiologically constrained traits, such as embryonic and post-embryonic growth, among our samples of temperate and lowland tropical songbird species. Nestling period, which is evolutionarily more labile than growth rate, was significantly shorter in birds exposed to higher rates of nest loss and nesting at lower heights, among other traits. Differences in life-history variation across latitudes provide insight into how unique ecological characteristics of each region influence physiological processes of passerines, and thus, how they can shape the evolution of life histories. While development traits clearly vary with respect to latitude, trait distributions overlap broadly. Life-history and natural history associations differ for each development trait, which suggests that unique selective pressures or constraints influence the evolution of each trait.
Assuntos
Aves Canoras/crescimento & desenvolvimento , Animais , Evolução Biológica , Clima , Tamanho da Ninhada , Análise Discriminante , Ecossistema , Feminino , Características de História de Vida , Modelos Lineares , Masculino , Michigan , Modelos Biológicos , Comportamento de Nidação/fisiologia , Oregon , Panamá , Filogenia , Comportamento Predatório/fisiologia , Reprodução/fisiologia , Seleção Genética , Aves Canoras/classificação , Aves Canoras/fisiologia , Especificidade da Espécie , Tarso Animal/crescimento & desenvolvimento , Clima TropicalRESUMO
The Chestnut-capped Blackbird, Chrysomus ruficapilus (Vieillot, 1819), is a common bird species in flooded areas of South America. Data on its reproductive parameters have been reported mainly for rice paddies from Uruguay and southern Brazil, where reproductive phenology might have been influenced by the chronology of agricultural activities. Here we provide reproductive data for a population in a natural marshland from São Paulo state, southeastern Brazil. A total of 45 active nests were monitored between December 2017 and April 2018. Clutch size was 2.8 ± 0.44. Incubation and nestling periods were respectively 11.8 ± 0.39, and 12.3 ± 0.75 days, and overall nesting success was 65%. The reproductive season lasted about five months, which is longer than that observed in rice paddies from southern Brazil. This suggests that the reproductive phenology has been underestimated before. Although clutch sizes were bigger in our study population than that from rice paddies from southern Brazil, nest survival was higher in the artificial habitat, suggesting that the Chestnut-capped Blackbird can obtain benefits from nesting in artificial habitats.(AU)
Assuntos
Animais , Passeriformes/fisiologia , Reprodução , Comportamento Sexual Animal , Tamanho da Ninhada , Áreas Alagadas , BrasilRESUMO
Mexico has made substantial contributions to marine turtle protection and conservation, especially since 1990. Several conservation projects entail monitoring efforts to recover nesting territories for marine turtles. The Sea Turtle Protection Program of Akumal, in the Mexican state of Quintana Roo, was created in 1993 and was developed by the Akumal Ecological Center. This paper provides the nesting ecology parameters for Caretta caretta over a protection period of 24 years (1995-2018). A well-defined nesting peak was observed in June, with a nesting success rate of 75.2 ± 23.0%. Nesting females showed a mean curved carapace length of 99.0 ± 5.6 cm. The mean clutch size was 108.6 ± 24.6 eggs, with variation among years. The mean incubation period was 57.2 ± 6.2 days. The hatching and emergence success rates were 87.2 ± 16.9% and 78.8 ± 24.4%, respectively. For the 926 tagged females that returned, the remigration interval peaked at 726 days, with a 12-day inter-nesting period. The results show not only the recovery of the nesting population over time but also a decrease in female size; we postulate that this decrease is due to the recruitment of young females, which has been increasingly pronounced since 2010. Hence, the Akumal rookery plays an important role in its corresponding regional management unit (Atlantic Northwest).
Assuntos
Ecossistema , Comportamento de Nidação/fisiologia , Tartarugas/fisiologia , Migração Animal/fisiologia , Animais , Tamanho da Ninhada , Feminino , Geografia , México , Tartarugas/anatomia & histologiaRESUMO
The Chestnut-capped Blackbird, Chrysomus ruficapilus (Vieillot, 1819), is a common bird species in flooded areas of South America. Data on its reproductive parameters have been reported mainly for rice paddies from Uruguay and southern Brazil, where reproductive phenology might have been influenced by the chronology of agricultural activities. Here we provide reproductive data for a population in a natural marshland from São Paulo state, southeastern Brazil. A total of 45 active nests were monitored between December 2017 and April 2018. Clutch size was 2.8 ± 0.44. Incubation and nestling periods were respectively 11.8 ± 0.39, and 12.3 ± 0.75 days, and overall nesting success was 65%. The reproductive season lasted about five months, which is longer than that observed in rice paddies from southern Brazil. This suggests that the reproductive phenology has been underestimated before. Although clutch sizes were bigger in our study population than that from rice paddies from southern Brazil, nest survival was higher in the artificial habitat, suggesting that the Chestnut-capped Blackbird can obtain benefits from nesting in artificial habitats.
Assuntos
Animais , Comportamento Sexual Animal , Passeriformes/fisiologia , Reprodução , Tamanho da Ninhada , Brasil , Áreas AlagadasRESUMO
Rainfall in tropical semi-arid areas may act as a reliable cue for timing bird reproduction, since it precedes future food supply. With this in mind, we set-up a study to test the reproductive response of insectivorous bird to arthropod abundance and rainfall patterns. Sampling occurred in a seasonally dry Neotropical forest, in north-eastern Brazil, between October, 2015 and October 2016, at 14-day intervals. We used brood patch to assess reproductive periodicity of insectivorous birds (eight species, 475 captures, 121 patch records). We sampled arthropods to quantify abundance, using biomass and number of individuals (1755 individuals, 15 Orders). Rainfall temporal distribution was analyzed using daily precipitation data. We used a cross-correlation function to test for correlation and time-lags between the covariates under study. Both the number of reproductively-active birds and arthropod abundance were higher in time periods close to the rainy season. Increase in arthropod biomass in the aerial stratum preceded the period of greatest rainfall by one (14 days, r = 0.44) to three sampling periods (0.47). In contrast, the highest proportion of individuals with brood patches occurred after the main rainfall peak, with the strongest relationship occurring after two (0.52) to four (0.50) time lags. Finally, the proportion of individuals with brood patches was positively correlated with aerial stratum arthropod biomass when five time lags were considered (0.55). Our results support the hypothesis of a temporal process involving rainfall, arthropods and reproduction of insectivorous birds in the wet/dry tropics. However, rainfall did not appear to act as a cue for the timing of reproduction, since records indicated higher arthropod biomass before the main rainfall peak. At least occasionally in the study area, insectivorous bird reproduction peaks after food abundance.
Assuntos
Animais , Artrópodes , Aves , Reprodução , Tamanho da Ninhada , Brasil , Estação Chuvosa , Zona TropicalRESUMO
Even though nest architecture has been useful for phylogenetic inferences among the Thamnophilidae (Aves: Passeriformes), the nests of only three out of five species of Myrmoderus (Ridgway, 1909) are known to science. Here we describe the nests, eggs, and nestling of the Squamate Antbird Myrmoderus squamosus (Pelzeln, 1868). Two nests were bulky bottom-supported cups, measuring 7.3 and 12 cm in maximum outside diameter, with a noticeably smaller egg cup, and they were placed within the crown of short, broad-leafed plants. Eggs were short-oval, with chalky white background color, and purple blotches and streaks more concentrated in the large end. One nestling was dark reddish grey, with bluish white feet, pinkish gray tarsi, and a blackish bill with bright yellow rictal flanges. In face of the great diversity of nest types found among the Thamnophilidae, we concluded that the nest of M. squamosus was similar to those of other congeners, giving support to this currently phylogenetically-defined genus.(AU)
Assuntos
Animais , Tamanho da Ninhada , Filogenia , Passeriformes/classificação , Ovos/classificaçãoRESUMO
This study describes aspects of the life history of the Tropical Mockingbird Mimus gilvus (Vieillot, 1808), including the breeding period, clutch size, nestlings and a list of plants used for nesting. Nests were monitored in an area of Restinga (sand-coastal plain) habitat in a protected area in southeastern Brazil. The data from 181 nests during five breeding seasons (2010-2014) showed that the Tropical Mockingbird has a long breeding season (26.1 ± 2.6 weeks) with up to two peaks of active nests from August to March. The breeding pairs made up to four nesting attempts in the same breeding season. The mean (± SD) clutch size was 2.4 ± 0.6 eggs (n = 169). The mean (± SD) incubation period was 14 ± 0.6 days, and the nestling remained in the nest for 14.5 ± 2.2 days. The nests were built on thirty plant species, and Protium icicariba (DC.) Marchand. was the plant species most commonly used for nesting. The breeding parameters of the Tropical Mockingbird are similar to those of other Mimidae species. The knowledge gained from this study makes the Tropical Mockingbird a good choice for future studies, particularly for testing ecological and evolutionary hypotheses regarding life history attributes, habitat selection and parental investment.(AU)
Assuntos
Animais , Fenômenos Reprodutivos Fisiológicos , Aves/fisiologia , Tamanho da Ninhada , Comportamento Sexual Animal , Brasil , Animais SelvagensRESUMO
We analyzed some aspects of reproduction and sexual dimorphism of the semi-aquatic dipsadid snake Erythrolamprus miliaris in the state of Rio de Janeiro, southeastern Brazil. We detected sexual dimorphism in body size (snout-vent length), with females averaging larger than males, but no sexual dimorphism in the relative length of the tail. Oviductal eggs and secondary follicles were found in all seasons, suggesting that female reproductive cycles are continuous, in spite of the tropical seasonal climate in the region. Reproductive males were present throughout the year, suggesting a continuous cycle for males as well. Clutch size averaged 10.3 ± 4.8 (range 4-21) and there was a positive and significant relationship between clutch size and female size. Compared to conspecific populations previously studied in other Atlantic Rainforest areas, populations of E. miliaris from the state of Rio de Janeiro appear more similar overall in their reproductive traits to a more northern population from the state of Bahia than to populations from further south in the states of São Paulo and Paraná.
Assuntos
Colubridae/fisiologia , Animais , Tamanho Corporal , Brasil , Tamanho da Ninhada/fisiologia , Colubridae/anatomia & histologia , Feminino , Modelos Lineares , Masculino , Floresta Úmida , Reprodução/fisiologia , Estações do Ano , Caracteres Sexuais , Fatores Sexuais , Estatísticas não ParamétricasRESUMO
Herein we investigated diet, sexual dimorphism and reproductive biology of two sympatric congeneric species at the coastal Brazilian Pampa, Philodryas aestiva and P. patagoniensis. Analysis of the stomach content of the scansorial Philodryas aestiva revealed that it feeds mainly on Anura and small mammals, while it occasionally consumes Insecta, Squamata and Aves. The more terrestrial Philodryas patagoniensis presented a broader diet, composed mainly of Anura, Squamata and small mammals. Insecta and Actinopterygii were found in lower frequencies. In females of both species, snout-vent length was significantly larger than in males, while tail length/snout-vent length ratio was significantly higher in males. Males reach sexual maturity at smaller sizes than females in both species. Fecundity was higher in P. patagoniensis (3 to 24 eggs; 15 ± 8.15) than in P. aestiva (10 to 20 eggs; X = 14.50 ± 3.53). Females of P. aestiva showed secondary follicles in all seasons while eggs occurred from middle-winter to early-summer. Secondary follicles occurred throughout the year in P. patagoniensis, but concentrated in spring. Eggs occurred in late-summer, middle-autumn and spring. Both species presented positive correlations between SVL and clutch size. Differences in analyzed traits seem to reflect divergences in species morphology and use of habitat/microhabitat.
Assuntos
Colubridae/fisiologia , Dieta , Caracteres Sexuais , Simpatria/fisiologia , Animais , Brasil , Tamanho da Ninhada/fisiologia , Colubridae/anatomia & histologia , Ecossistema , Feminino , Masculino , Reprodução/fisiologia , Estações do Ano , Fatores Sexuais , Especificidade da EspécieRESUMO
This study describes aspects of the life history of the Tropical Mockingbird Mimus gilvus (Vieillot, 1808), including the breeding period, clutch size, nestlings and a list of plants used for nesting. Nests were monitored in an area of Restinga (sand-coastal plain) habitat in a protected area in southeastern Brazil. The data from 181 nests during five breeding seasons (2010-2014) showed that the Tropical Mockingbird has a long breeding season (26.1 ± 2.6 weeks) with up to two peaks of active nests from August to March. The breeding pairs made up to four nesting attempts in the same breeding season. The mean (± SD) clutch size was 2.4 ± 0.6 eggs (n = 169). The mean (± SD) incubation period was 14 ± 0.6 days, and the nestling remained in the nest for 14.5 ± 2.2 days. The nests were built on thirty plant species, and Protium icicariba (DC.) Marchand. was the plant species most commonly used for nesting. The breeding parameters of the Tropical Mockingbird are similar to those of other Mimidae species. The knowledge gained from this study makes the Tropical Mockingbird a good choice for future studies, particularly for testing ecological and evolutionary hypotheses regarding life history attributes, habitat selection and parental investment.
Assuntos
Animais , Aves/fisiologia , Comportamento Sexual Animal , Fenômenos Reprodutivos Fisiológicos , Tamanho da Ninhada , Animais Selvagens , BrasilRESUMO
Even though nest architecture has been useful for phylogenetic inferences among the Thamnophilidae (Aves: Passeriformes), the nests of only three out of five species of Myrmoderus (Ridgway, 1909) are known to science. Here we describe the nests, eggs, and nestling of the Squamate Antbird Myrmoderus squamosus (Pelzeln, 1868). Two nests were bulky bottom-supported cups, measuring 7.3 and 12 cm in maximum outside diameter, with a noticeably smaller egg cup, and they were placed within the crown of short, broad-leafed plants. Eggs were short-oval, with chalky white background color, and purple blotches and streaks more concentrated in the large end. One nestling was dark reddish grey, with bluish white feet, pinkish gray tarsi, and a blackish bill with bright yellow rictal flanges. In face of the great diversity of nest types found among the Thamnophilidae, we concluded that the nest of M. squamosus was similar to those of other congeners, giving support to this currently phylogenetically-defined genus.
Assuntos
Animais , Filogenia , Ovos/classificação , Passeriformes/classificação , Tamanho da NinhadaRESUMO
Phenotypic plasticity is thought to evolve in response to environmental unpredictability and can shield genotypes from selection. However, selection can also act on plastic traits. Egg-laying behaviour, including clutch size regulation, is a plastic behavioural trait among tephritid fruit flies. We compared plasticity in clutch size regulation among females of Anastrepha ludens populations stemming from environments that differed in the degree of predictability in egg-laying opportunities. Clutch size regulation in response to hosts of different sizes was compared among flies from (a) a wild, highly isolated population, (b) a wild population that switches seasonally from a small wild host fruit that varies greatly in abundance to an abundant large-sized commercial host, and (c) a laboratory population. Flies from all three populations adjusted clutch number and size according to host size. However, flies from the heterogeneous wild environment were more plastic in adjusting clutch size than flies from agricultural settings that also laid fewer eggs; yet both populations were more plastic in adjusting clutch size in line with host size when compared with laboratory females. When wild and orchard females encountered the largest host, clutch size was extremely variable and egg regulation did not follow the same trend. Heterogeneity in host availability in space and time appears to be as important as seasonal variation in host size in maintaining plastic clutch size regulation behaviour. In stable environments, there was a clear reduction in the plasticity of these traits.
Assuntos
Adaptação Fisiológica , Tamanho da Ninhada , Oviposição , Seleção Genética , Tephritidae/genética , Animais , Citrus paradisi , Feminino , Frutas , Espécies Introduzidas , MasculinoRESUMO
In the past 30 years, sows have been successfully selected for increased litter size. This review discusses the consequences of this selection for the reproductive physiology of sows, including the consequences for litter characteristics at birth. It also discusses breeding and management opportunities to deal with these modern genetics.