Urofecal steroid profiles of captive Blue-fronted parrots (Amazona aestiva) with different reproductive outcomes.

Despite Psitaciformes (parrots) being the third largest nonpasserine order (398 species), it currently ranks second in number of threatened species (28%) according to the Internatinal Union for Conservation of Nature (IUCN) criteria. Since most of the literature concerning reproductive endocrinology in avian species derives from domestic and song birds, it is puzzling that advances in reproductive science for the Psitaciformes order lags far behind, in spite of the growing threats against them. In order to expand our knowledge of Neotropical parrots (Psittacidae), we examined annual changes in urofecal sex steroid metabolites of Blue-fronted amazon pairs (Amazona aestiva) exhibiting successful (nestlings) and unsuccessful breeding (infertile or no eggs). Urofecal samples were collected over a year from eight breeding pairs housed under the same environmental and management conditions. Fecal androgen and progestagen concentrations were determined in males and females, respectively, by enzyme immunoassays previously validated for this species. All eggs were registered between late winter and mid-spring, and egg-laying intervals varied between females (range: 1-8 days; average 3.60 ±â€¯0.51 days). Similar profiles of urofecal progestagens were observed in reproductively successful females and females producing infertile eggs, with progestagen peaks preceding egg laying events (1.77 ±â€¯0.50 days). In contrast, non-laying females had no rises in progestagens during the year. Successful and unsuccessful males did not displayed distinct annual patterns of androgen production, and apart from the peaks during the breeding season, more than half of the individuals intriguingly presented significant increases from late summer to early autumn, a period without reproductive activity. Finally, we noticed that samples with progestagen levels exceeding 40 ng/g had very high probability (>97.5%) to be from females in pre-laying or laying phases, suggesting a feasible application of this characteristic to noninvasively discriminate the reproductive status in amazon females with an accuracy and sensitivity of 94.55% and 58.13%, respectively. Our findings confirmed that urofecal progestagens and androgens are good indicators of the gonadal condition in Blue-fronted amazons, but there is still much to be done for their extensive use in artificial insemination or selection of the most suitable breeding birds for the season.

Characterization of the complete mitochondrial genome and a set of polymorphic microsatellite markers through next-generation sequencing for the brown brocket deer Mazama gouazoubira.

The complete mitochondrial genome of the brown brocket deer Mazama gouazoubira and a set of polymorphic microsatellite markers were identified by 454-pyrosequencing. De novo genome assembly recovered 98% of the mitochondrial genome with a mean coverage of 9-fold. The mitogenome consisted of 16,356 base pairs that included 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and the control region, as found in other deer. The genetic divergence between the mitogenome described here and a previously published report was ∼0.5%, with the control region and ND5 gene showing the highest intraspecific variation. Seven polymorphic loci were characterized using 15 unrelated individuals; there was moderate genetic variation across most loci (mean of 5.6 alleles/locus, mean expected heterozygosity = 0.70), with only one locus deviating significantly from Hardy-Weinberg equilibrium, probably because of null alleles. Marker independence was confirmed with tests for linkage disequilibrium. The genetic variation of the mitogenome and characterization of microsatellite markers will provide useful tools for assessing the phylogeography and population genetic patterns in M. gouazoubira, particularly in the context of habitat fragmentation in South America.

Comparing two different superovulation protocols on ovarian activity and fecal glucocorticoid levels in the brown brocket deer (Mazama gouazoubira).

BACKGROUND: Stress is a limiting factor in assisted reproduction in wild animals maintained in captivity. However, the knowledge of assisted reproduction techniques for wild animals is useful for future in situ and ex situ conservation programs. Thus, this study evaluated the ovulation rate, presence of functional corpora lutea and fecal glucocorticoid levels following treatments promoting superovulation in captive brown brocket deer. METHODS: The crossover design used six hinds, allocated to two groups (n=6): eCG Treatment, CIDR for 8 days, followed by 0.25 mg of EB on day 0, 700 IU of eCG on day 4 following device insertion and 265 mug of PGF2alfa on day 8; and FSH Treatment, CIDR for 7.5 days, followed by 0.25 mg of EB on day 0, 130 mg of FSH in 8 equal doses and 265 mug of PGF2alfa on day 7.5. Induced adrenal activity and treatment efficacy were evaluated by corpora lutea (CL) counts and fecal glucocorticoid and progestin concentration (ng/g feces) analyses for five different phases: Pre, two days before treatment; Early, first four days of treatment; Late, last four days of treatment; Total, entire treatment period; and Post, five days posttreatment. RESULTS: eCG Treatment resulted in the highest number of CL (P lower than 0.05). There was no significant difference for fecal glucocorticoid concentrations in five different time periods between the treatments; however Pre fecal glucocorticoid concentrations (90.06+/-19.64) were significantly different from Late (200.76+/-26.39) within FSH Treatment. The mean fecal progestin concentration and mean ovulation rate were higher in eCG Treatment (4293.69+/-769.47, 7.0+/-1.8) than in FSH Treatment (1571.26+/-240.28, 2.6+/-0.8) (P lower than or equal to 0.05). CONCLUSIONS: Although the eCG Treatment induced a good superovulatory response, with the formation of functional corpora lutea, we cannot yet affirm that we have established a suitable protocol for induction of SOV in the species M. gouazoubira because approximately 65% of the deer showed premature regression of the corpora lutea. Moreover, multiple FSH applications in FSH Treatment resulted in a low ovulation rate and induced an increase in fecal glucocorticoid levels.

Species diversity and seasonality of free-living ticks (Acari: Ixodidae) in the natural habitat of wild Marsh deer (Blastocerus dichotomus) in Southeastern Brazil.

This study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the Paraná river, in Brazil. Eight field trips (once per season) for collection of ticks were performed during 2 years. Using CO2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: Amblyomma cajennense, Amblyomma dubitatum, Amblyomma triste, Amblyomma coelebs, and Amblyomma nodosum. The seasonal pattern of A. cajennense was characterized by the highest peaks for adult ticks in the summer/spring months, for nymphs in the winter and for larvae in the autumn and winter. A. dubitatum and A. triste presented similar seasonal patterns characterized by peaks of adult ticks in the autumn. Nymphs of A. dubitatum peaked in the winter of the first year and in the winter/spring of the second year. A. triste was the only species to be collected in significantly higher numbers in the marsh than in surrounding drier areas such as forest patches. Among domestic animals living close the marsh areas, horses were infested by Anocentor nitens, A. cajennense, and Boophilus microplus, bovines were infested solely by B. microplus, and dogs were infested by Rhipicephalus sanguineus. Adults of A. triste showed to be well adapted to the marsh environment. This result, at least partially, explains local previous observations on the association of A. triste with marsh deer, as this vertebrate host inhabits mainly the marsh area.

Detection of Ehrlichia chaffeensis in Brazilian marsh deer (Blastocerus dichotomus).

Ehrlichia chaffeensis was detected for the first time in blood samples from Brazilian marsh deers (Blastocerus dichotomus) captured in the marshes of Parana River in Southeast Brazil in 1998. Seven EDTA-blood samples from deers were analyzed by PCR and nested PCR for presence of Ehrlichia chaffeensis, Ehrlichia ewingii, Ehrlichia canis, Neoriickettsia risticii, Anaplasma phagocytophilum and Anaplasma marginale. Three samples showed positive reactions for E. chaffeensis and Anaplasma marginale. None contained detectable A. phagocytophilum, E. ewingii, E. canis or Neorickettsia risticii DNA. In Brazil, the wild marsh deer may be a natural reservoir of the agents that cause human monocytotropic ehrlichiosis and ruminant erythrocytic anaplasmosis.

Ticks (Acari: Ixodidae) on wild marsh-deer (Blastocerus dichotomus) from Southeast Brazil: infestations before and after habitat loss.

The lake from Porto-Primavera hydroelectric power station inundated an area of 2,200 km2 at the border of São Paulo and Mato-Grosso do Sul States, Brazil. Infestations by ticks were evaluated on 135 marsh deer, Blastocerus dichotomus (Illiger), captured before and after inundation. Ticks were collected for identification, and infestation level of animals was assessed by scoring. Deer were divided into four groups according to capture location and temporal relation to the inundation. Groups 1, 2, and 3 were captured before inundation. Group 4 was captured after inundation. Four tick species were found: Amblyomma cajennense (F.), Amblyomma triste Koch, Anocentor nitens (Neumann), and Boophilus microplus (Canestrini). Groups 1, 2, 3, and 4 had 30, 45, 100, and 96%, respectively, of animals carrying B. microplus ticks. A. triste was observed on 16, 22, 22, and 88% of animals from groups 1, 2, 3, and 4, respectively. A. nitens and A. cajennense were observed only on group 4, on 32 and 16% of the animals, respectively. Groups 1 and 2 had only 4.8 and 6.1% of animals with high infestation levels, respectively, and no ticks on 46.8% and 45.5% of the animals, respectively. Conversely, groups 3 and 4 lacked noninfested animals and had high infestation levels on 77.8 and 50% of deer, respectively. Marsh area shrinkage was blamed for higher infestation levels on deer from groups 3 and 4. The widespread presence of A. triste on marsh deer, a Neotropical tick species, raises the possibility of a natural host-parasite relationship.

Accessing camera trap survey feasibility for estimating Blastocerus dichotomus (Cetartiodactyla, Cervidae) demographic parameters / Avaliação da viabilidade do uso de armadilhas fotográficas para estimar parâmetros demográficos de Blastocerus dichotomus (Cetartiodactyla, Cervidae)

Demographic information is the basis for evaluating and planning conservation strategies for an endangered species. However, in numerous situations there are methodological or financial limitations to obtain such information for some species. The marsh deer, an endangered Neotropical cervid, is a challenging species to obtain biological information. To help achieve such aims, the study evaluated the applicability of camera traps to obtain demographic information on the marsh deer compared to the traditional aerial census method. Fourteen camera traps were installed for three months on the Capão da Cruz floodplain, in state of São Paulo, and ten helicopter flyovers were made along a 13-kilometer trajectory to detect resident marsh deer. In addition to counting deer, the study aimed to identify the sex, age group and individual identification of the antlered males recorded. Population estimates were performed using the capture-mark-recapture method with the camera trap data and by the distance sampling method for aerial observation data. The costs and field efforts expended for both methodologies were calculated and compared. Twenty independent photographic records and 42 sightings were obtained and generated estimates of 0.98 and 1.06 ind/km², respectively. In contrast to the aerial census, camera traps allowed us to individually identify branch-antlered males, determine the sex ratio and detect fawns in the population. The cost of camera traps was 78% lower but required 20 times more field effort. Our analysis indicates that camera traps present a superior cost-benefit ratio compared to aerial surveys, since they are more informative, cheaper and offer simpler logistics. Their application extends the possibilities of studying a greater number of populations in a long-term monitoring.(AU)

Informações demográficas constituem a base para a avaliação e planejamento de estratégias de conservação de uma espécie ameaçada. No entanto, em muitas situações existem limitações metodológicas ou financeiras para a obtenção de tais informações para algumas espécies. O cervo-do-pantanal, um cervídeo neotropical ameaçado de extinção, é uma espécie desafiadora para obtenção de informações biológicas. Para suprir essa demanda, o presente trabalho avaliou a aplicabilidade das armadilhas fotográficas para obtenção de informações demográficas de cervo-do-pantanal em comparação com o tradicional método de censo aéreo. Na várzea Capão da Cruz, Estado de São Paulo, foram instaladas 14 armadilhas fotográficas durante três meses e realizados dez sobrevoos de helicóptero num trajeto de 13 km para detecção dos cervos-do-pantanal ali residentes. Além da contagem dos animais, objetivou-se identificar o sexo, a faixa etária e a identificação individual dos machos galhados registrados. As estimativas populacionais foram realizadas pelo método de captura-marcação-recaptura com os dados de armadilhas fotográficas e pelo método de amostragem por distâncias para os dados de observação aérea. Foram contabilizados e ponderados os custos e esforços de campo despendidos para ambas metodologias. Obteve-se 20 registros fotográficos independentes e 42 visualizações que geraram estimativas de 0,98 e 1,06 ind./km² respectivamente. Ao contrário do censo aéreo, as armadilhas fotográficas permitiram a identificação individual dos machos galhados, a proporção sexual e a detecção de filhotes na população. O custo das armadilhas fotográficas foi 78% menor, porém demandou um esforço de campo 20 vezes maior. Avaliamos que as armadilhas fotográficas apresentaram uma relação custo-benefício superiores em relação aos levantamentos aéreos, por ser mais informativa e barata e com uma logística mais simples. Sua aplicação abre a [...](AU)

Accessing camera trap survey feasibility for estimating Blastocerus dichotomus (Cetartiodactyla, Cervidae) demographic parameters / Avaliação da viabilidade do uso de armadilhas fotográficas para estimar parâmetros demográficos de Blastocerus dichotomus (Cetartiodactyla, Cervidae)

Demographic information is the basis for evaluating and planning conservation strategies for an endangered species. However, in numerous situations there are methodological or financial limitations to obtain such information for some species. The marsh deer, an endangered Neotropical cervid, is a challenging species to obtain biological information. To help achieve such aims, the study evaluated the applicability of camera traps to obtain demographic information on the marsh deer compared to the traditional aerial census method. Fourteen camera traps were installed for three months on the Capão da Cruz floodplain, in state of São Paulo, and ten helicopter flyovers were made along a 13-kilometer trajectory to detect resident marsh deer. In addition to counting deer, the study aimed to identify the sex, age group and individual identification of the antlered males recorded. Population estimates were performed using the capture-mark-recapture method with the camera trap data and by the distance sampling method for aerial observation data. The costs and field efforts expended for both methodologies were calculated and compared. Twenty independent photographic records and 42 sightings were obtained and generated estimates of 0.98 and 1.06 ind/km², respectively. In contrast to the aerial census, camera traps allowed us to individually identify branch-antlered males, determine the sex ratio and detect fawns in the population. The cost of camera traps was 78% lower but required 20 times more field effort. Our analysis indicates that camera traps present a superior cost-benefit ratio compared to aerial surveys, since they are more informative, cheaper and offer simpler logistics. Their application extends the possibilities of studying a greater number of populations in a long-term monitoring.

Informações demográficas constituem a base para a avaliação e planejamento de estratégias de conservação de uma espécie ameaçada. No entanto, em muitas situações existem limitações metodológicas ou financeiras para a obtenção de tais informações para algumas espécies. O cervo-do-pantanal, um cervídeo neotropical ameaçado de extinção, é uma espécie desafiadora para obtenção de informações biológicas. Para suprir essa demanda, o presente trabalho avaliou a aplicabilidade das armadilhas fotográficas para obtenção de informações demográficas de cervo-do-pantanal em comparação com o tradicional método de censo aéreo. Na várzea Capão da Cruz, Estado de São Paulo, foram instaladas 14 armadilhas fotográficas durante três meses e realizados dez sobrevoos de helicóptero num trajeto de 13 km para detecção dos cervos-do-pantanal ali residentes. Além da contagem dos animais, objetivou-se identificar o sexo, a faixa etária e a identificação individual dos machos galhados registrados. As estimativas populacionais foram realizadas pelo método de captura-marcação-recaptura com os dados de armadilhas fotográficas e pelo método de amostragem por distâncias para os dados de observação aérea. Foram contabilizados e ponderados os custos e esforços de campo despendidos para ambas metodologias. Obteve-se 20 registros fotográficos independentes e 42 visualizações que geraram estimativas de 0,98 e 1,06 ind./km² respectivamente. Ao contrário do censo aéreo, as armadilhas fotográficas permitiram a identificação individual dos machos galhados, a proporção sexual e a detecção de filhotes na população. O custo das armadilhas fotográficas foi 78% menor, porém demandou um esforço de campo 20 vezes maior. Avaliamos que as armadilhas fotográficas apresentaram uma relação custo-benefício superiores em relação aos levantamentos aéreos, por ser mais informativa e barata e com uma logística mais simples. Sua aplicação abre a [...]

Accessing camera trap survey feasibility for estimating Blastocerus dichotomus (Cetartiodactyla, Cervidae) demographic parameters

ABSTRACT Demographic information is the basis for evaluating and planning conservation strategies for an endangered species. However, in numerous situations there are methodological or financial limitations to obtain such information for some species. The marsh deer, an endangered Neotropical cervid, is a challenging species to obtain biological information. To help achieve such aims, the study evaluated the applicability of camera traps to obtain demographic information on the marsh deer compared to the traditional aerial census method. Fourteen camera traps were installed for three months on the Capão da Cruz floodplain, in state of São Paulo, and ten helicopter flyovers were made along a 13-kilometer trajectory to detect resident marsh deer. In addition to counting deer, the study aimed to identify the sex, age group and individual identification of the antlered males recorded. Population estimates were performed using the capture-mark-recapture method with the camera trap data and by the distance sampling method for aerial observation data. The costs and field efforts expended for both methodologies were calculated and compared. Twenty independent photographic records and 42 sightings were obtained and generated estimates of 0.98 and 1.06 ind/km², respectively. In contrast to the aerial census, camera traps allowed us to individually identify branch-antlered males, determine the sex ratio and detect fawns in the population. The cost of camera traps was 78% lower but required 20 times more field effort. Our analysis indicates that camera traps present a superior cost-benefit ratio compared to aerial surveys, since they are more informative, cheaper and offer simpler logistics. Their application extends the possibilities of studying a greater number of populations in a long-term monitoring.

RESUMO Informações demográficas constituem a base para a avaliação e planejamento de estratégias de conservação de uma espécie ameaçada. No entanto, em muitas situações existem limitações metodológicas ou financeiras para a obtenção de tais informações para algumas espécies. O cervo-do-pantanal, um cervídeo neotropical ameaçado de extinção, é uma espécie desafiadora para obtenção de informações biológicas. Para suprir essa demanda, o presente trabalho avaliou a aplicabilidade das armadilhas fotográficas para obtenção de informações demográficas de cervo-do-pantanal em comparação com o tradicional método de censo aéreo. Na várzea Capão da Cruz, Estado de São Paulo, foram instaladas 14 armadilhas fotográficas durante três meses e realizados dez sobrevoos de helicóptero num trajeto de 13 km para detecção dos cervos-do-pantanal ali residentes. Além da contagem dos animais, objetivou-se identificar o sexo, a faixa etária e a identificação individual dos machos galhados registrados. As estimativas populacionais foram realizadas pelo método de captura-marcação-recaptura com os dados de armadilhas fotográficas e pelo método de amostragem por distâncias para os dados de observação aérea. Foram contabilizados e ponderados os custos e esforços de campo despendidos para ambas metodologias. Obteve-se 20 registros fotográficos independentes e 42 visualizações que geraram estimativas de 0,98 e 1,06 ind./km² respectivamente. Ao contrário do censo aéreo, as armadilhas fotográficas permitiram a identificação individual dos machos galhados, a proporção sexual e a detecção de filhotes na população. O custo das armadilhas fotográficas foi 78% menor, porém demandou um esforço de campo 20 vezes maior. Avaliamos que as armadilhas fotográficas apresentaram uma relação custo-benefício superiores em relação aos levantamentos aéreos, por ser mais informativa e barata e com uma logística mais simples. Sua aplicação abre a possibilidade para o estudo de um número maior de populações e o monitoramento contínuo e de longo prazo.

Avaliação de dois métodos para condicionamento e coleta de sêmen em quatro espécies do gênero Mazama / Assessment of two methods for conditioning and semen collection in four species of Mazama genus

O desenvolvimento de técnicas não invasivas para a obtenção de sêmen de cervídeos facilita a criação de bancos genômicos, que são importantes instrumentos para a conservação ex situ e in situ. Este trabalho teve como objetivo criar uma metodologia não-invasiva de coleta de sêmen e comparar duas técnicas de coleta em quatro espécies do gênero Mazama: M. americana, M. gouazoubira, M. nana e M. nemorivaga. Para tanto, foram utilizados seis machos (M) e duas fêmeas (F) da espécie M. americana, 3M e 2F de M. gouazoubira, 1M e 1F de M. nana e 2M e 1F de M. nemorivaga. Para cada técnica testada, foi realizado um período de habituação dos animais ao manejo. Em seguida, duas técnicas de condicionamento e coleta foram avaliadas. Na primeira delas foi utilizada uma fêmea em estro com desvio lateral do pênis para vagina artificial (FEDL), obtendo-se a coleta de 50% dos indivíduos (100% dos machos de M. gouazoubira e 50% dos machos de M. americana), não obtendo ejaculados das demais espécies. Na segunda técnica, utilizando um manequim taxidermizado com urina de fêmea em estro (MUFE) não foi possível a coleta de nenhum ejaculado. Em todas as fases foi observado o comportamento do macho quanto ao tempo de interesse e aproximação, reflexo de "Flehmen", ato de cheirar ou lamber, exposição do pênis, ereção, número de falsas montas, tentativas de cópula e ocorrência de agressividade entre os animais.(AU)

The development of noninvasive techniques for obtaining semen from deer facilitates the creation of genome banks, which are important tools for ex situ and in situ conservation. This study aimed to establish a noninvasive method of semen collection and compare two techniques of collection in four species of the genus Mazama: M. americana, M. gouazoubira, M. nana and M. nemorivaga. To achieve this, 6 males (M) and 2 females (F) of the species M. Americana, 3M and 2F of M. gouazoubira, 1M and 1F of M. nana and 2M and 1F of M. nemorivaga were used. For each technique tested, a period of habituation to animal handling was conducted; then, the two conditioning techniques and collection were evaluated. In the first, a female in estrus was used with lateral deviation of the penis to an artificial vagina (FEDL), yielding collection from 50% of the males (100% from M. gouazoubira and 50% from M. americana), with no ejaculate from the remaining species. In the second technique, using a taxidermized dummy with urine from females in estrus (MUFE), no semen collection was possible. During all stages, male behavior was observed regarding the time of interest and approximation, the "Flehmen" response, the act of sniffing or licking, exposure of the penis, erection, number of false mounts, attempts at copulation and the occurrence of aggression between the deer.(AU)

Avaliação de dois métodos para condicionamento e coleta de sêmen em quatro espécies do gênero Mazama / Assessment of two methods for conditioning and semen collection in four species of Mazama genus

O desenvolvimento de técnicas não invasivas para a obtenção de sêmen de cervídeos facilita a criação de bancos genômicos, que são importantes instrumentos para a conservação ex situ e in situ. Este trabalho teve como objetivo criar uma metodologia não-invasiva de coleta de sêmen e comparar duas técnicas de coleta em quatro espécies do gênero Mazama: M. americana, M. gouazoubira, M. nana e M. nemorivaga. Para tanto, foram utilizados seis machos (M) e duas fêmeas (F) da espécie M. americana, 3M e 2F de M. gouazoubira, 1M e 1F de M. nana e 2M e 1F de M. nemorivaga. Para cada técnica testada, foi realizado um período de habituação dos animais ao manejo. Em seguida, duas técnicas de condicionamento e coleta foram avaliadas. Na primeira delas foi utilizada uma fêmea em estro com desvio lateral do pênis para vagina artificial (FEDL), obtendo-se a coleta de 50% dos indivíduos (100% dos machos de M. gouazoubira e 50% dos machos de M. americana), não obtendo ejaculados das demais espécies. Na segunda técnica, utilizando um manequim taxidermizado com urina de fêmea em estro (MUFE) não foi possível a coleta de nenhum ejaculado. Em todas as fases foi observado o comportamento do macho quanto ao tempo de interesse e aproximação, reflexo de "Flehmen", ato de cheirar ou lamber, exposição do pênis, ereção, número de falsas montas, tentativas de cópula e ocorrência de agressividade entre os animais.

The development of noninvasive techniques for obtaining semen from deer facilitates the creation of genome banks, which are important tools for ex situ and in situ conservation. This study aimed to establish a noninvasive method of semen collection and compare two techniques of collection in four species of the genus Mazama: M. americana, M. gouazoubira, M. nana and M. nemorivaga. To achieve this, 6 males (M) and 2 females (F) of the species M. Americana, 3M and 2F of M. gouazoubira, 1M and 1F of M. nana and 2M and 1F of M. nemorivaga were used. For each technique tested, a period of habituation to animal handling was conducted; then, the two conditioning techniques and collection were evaluated. In the first, a female in estrus was used with lateral deviation of the penis to an artificial vagina (FEDL), yielding collection from 50% of the males (100% from M. gouazoubira and 50% from M. americana), with no ejaculate from the remaining species. In the second technique, using a taxidermized dummy with urine from females in estrus (MUFE), no semen collection was possible. During all stages, male behavior was observed regarding the time of interest and approximation, the "Flehmen" response, the act of sniffing or licking, exposure of the penis, erection, number of false mounts, attempts at copulation and the occurrence of aggression between the deer.

Life cycle and host specificity of Amblyomma triste (Acari: Ixodidae) under laboratory conditions.

We report biological data of two generations of Amblyomma triste in laboratory and compared the suitability of different host species. Infestations by larval and nymphal stages were performed on guinea pigs (Cavia porcellus), chickens (Gallus gallus), rats (Rattus norvegicus), rabbits (Oryctolagus cuniculus), wild mice (Calomys callosus), dogs (Canis familiaris) and capybaras (Hydrochaeris hydrochaeris). Infestations by adult ticks were performed on dogs, capybaras and rabbits. Tick developmental periods were observed in an incubator at 27 degrees C and RH 90%. Guinea pigs were the most suitable hosts for larvae and nymphs, followed by chickens. The remaining host species were less suitable for immature ticks as fewer engorged ticks were recovered from them. Mean larval feeding periods varied from 3.8 to 4.7 d between different host species. Mean larval premolt periods ranged from 8.9 to 10.4 d. Nymphal mean feeding periods varied from 4.2 to 6.2 d for ticks fed on different host species. Premolt period of male nymphs (mean: 15.4 d) was significantly longer than that of female nymphs (14.7 d). Female nymphs were significantly heavier than male nymphs. The overall sex ratio of the adult ticks emerged from nymphs was 0.9:1 (M:F). Capybaras were the most suitable host for the tick adult stage as significantly more engorged females were recovered from them and these females were significantly heavier than those recovered from dogs or rabbits. The life cycle of A. triste in laboratory could be completed in an average period of 155 d. The potential role of guinea pigs, birds and capybaras, as hosts for A. triste in nature, is discussed.