Microplastic ingestion by common terns (Sterna hirundo) and their prey during the non-breeding season.

Current evidence demonstrates the presence and persistence of microplastics in the marine food web. Seabirds are predators in marine ecosystems and are highly exposed to marine plastic debris through the food. The aim of this work was to examine the presence of microplastics in a long-distance migratory seabird, the Common tern (Sterna hirundo) (n = 10), and in their prey (n = 53) during the non-breeding season. The study was conducted in Punta Rasa, Bahía Samborombón, province of Buenos Aires, which is an important resting and feeding location for migratory seabirds and shorebirds in South America. Microplastics were found in all the birds examined. The occurrence of microplastics in the gastrointestinal tract (GIT) of Common terns (n = 82) was higher than in regurgitated prey (RP) (n = 28), which is likely reflecting trophic transfer process. Almost all microplastics found were fibers and only 3 were fragments. Microplastics were sorted by color; transparent, black and blue-colored fibers were the most abundant plastic types. Characterization of the polymer type by Fourier Transform Infrared Spectrometry (FTIR) revealed that cellulose ester plastics, polyethylene terephtalate, polyacrylonitrile and polypropylene were the most abundant types found in both the gastrointestinal tract and prey. Our results highlight the high levels of ingested microplastics in Common terns and in their prey, and reflect a concern in this important location for migratory seabirds.

Abundancia, distribución espacial y temporal de aves playeras (Orden: Charadriiformes) en Marismas Nacionales, México

El noroeste de México alberga las mayores abundancias de aves playeras del país. Sin embargo, para muchos de estos humedales, información sobre comunidades de aves playeras, como abundancia, tendencias poblacionales y riqueza es limitada. Actualmente, los sitios de descanso son críticos para la conservación porque las poblaciones de aves playeras han decaído en las últimas décadas. Marismas Nacionales (MN) es un humedal tropical importante con un ecosistema dinámico donde los estudios de aves playeras están limitados a unos pocos censos aéreos y terrestres. Así el objetivo del trabajo fue describir la abundancia y distribución espacial y temporal de las aves playeras en MN (temporada 2010-2011). Se seleccionaron ocho unidades de muestreo en las que se llevaron a cabo censos mensuales (noviembre 2010 a junio 2011). Se determinaron las riquezas y abundancias por sitio-mes, además se realizó un análisis espacial y temporal de las especies dominantes. Se registraron 27 especies de aves playeras y un género, con un estimado mínimo de 136 236 individuos. Este número hace a MN uno de los humedales prioritarios para la conservación en México, pues alberga al 10 % de la abundancia general del noroeste. Las especies dominantes fueron el Playerito occidental (Calidris mauri, 33 % del total), la Avoceta americana (Recurvirostra americana, 31 %) y los Costureros (Limnodromus spp., 17 %). Espacialmente las lagunas de mayor importancia fueron: Chumbeño (37 % del total registrado), Las Garzas-Chahuin (24 %) y La Polca (24 %). Este trabajo actualiza la información sobre aves playeras que utilizan MN y podría permitir el establecimiento de un programa de monitoreo, lo cual es prioritario sobre todo porque el área es un Sitio de Importancia Internacional por parte de la Red Hemisférica de Reserva para las Aves Playeras.

Northwest Mexico is an important region for shorebirds associated with an extensive series of wetlands. However, for many of these wetlands, basic information about shorebirds communities like abundance, population trends, and richness are limited. Currently, wintering and stopover sites are critical for conservation because many populations of shorebirds have declined in the last decades. Marismas Nacionales (MN) is an important tropical wetland with a dynamic ecosystem and where shorebirds studies are limited to few wintering aerial and ground surveys. Our goals were analyzing shorebirds abundance and spatial and temporal distribution patterns in 2010-2011 season. We selected eight monitoring sites from two prospective visits to the study area. We observed shorebirds monthly between November 2010 and June 2011 to analyze richness and abundance patterns by site and month. Additionally, we describe specific spatial and temporal distribution for dominant species. A total of 27 shorebirds species and one genus, with a minimum global abundance of 136 236 individuals were found. Shorebird abundance at MN is among the most important in the region with around 10 % of total abundance in northwest Mexico; therefore, MN is a priority conservation site for this group of birds. Additionally, MN presents a suitable habitat for breeding of some shorebirds species such as Snowy and Wilson' Plover, Killdeer, Northern Jacana, Black-necked Stilt and Pacific American Oystercatcher. Dominant species were: Western Sandpiper (33.5 % of total in MN), American Avocet (31 %) and Dowitchers (17 %). These taxa are very common in others wetlands in Northwest Mexico region. Spatially, shorebirds were distributed in three sites: Chumbeño lagoon (37 % of abundance total), Las Garzas-Chihuin lagoons (24.2 %) and La Polca lagoon (24 %). The less used sites by shorebirds are located in the southern part of MN. Our results update MN information and can help to establish monitoring programs in the area.

Comparison of sexual performance and testicular characteristics of melatonin treated Kivircik and Charollais rams during the non-breeding season / Comparação de desempenho reprodutivo e características testiculares de carneiros Kivircik e Charollais tratados com melatonina durante a estação não reprodutiva

This study was conducted to investigate the effects of melatonin implantation on basic testicular characteristics and reproductive performance of Kivircik and Charollais rams and ewes during the non-breeding season. In this study, 8 Kivircik and 6 Charollais rams were used. Rams were implanted with 54 mg melatonin according to the manufacturer's instructions. At melatonin implantation and at ram introduction the reproductive performance and testicular characteristics were evaluated. Throughout the experimental period, rams were permanently kept outdoors under conditions of natural day length and at ambient temperature. The effects of exogenous melatonin treatments on the reproductive performances of rams and ewes, estrus response, pregnancy rate, litter size and twinning rate of ewes were evaluated in all groups. Libido values were significantly higher in Charollais rams compared to Kivircik rams (P<0.001). Testicular volume (TV) was increased in both ram breeds. Scrotal length (SL) was also increased in both Kivircik and Charollais rams (P<0.01). In conclusion, we showed that the treatment of rams with slow release melatonin implants increased scrotal diameters and testicular volumes in both Kivircik and Charollais rams. Furthermore, melatonin implantation improved the reproductive performances of ewes naturally mated with these melatonin implanted rams during non-breeding season.(AU)

Esse estudo foi conduzido para investigar os efeitos de implantação de melatonina em características testiculares básicas e desempenho reprodutivo de carneiros Kivircik e Charollais durante a estação não reprodutiva. Nesse estudo, oito carneiros Kivircik e 6 Charollais foram utilizados. Foi implantado 54 mg de melatonina nos cordeiros de acordo com as instruções do produtor. Ao implantar a melatonina e à introdução do carneiro, foram avaliados o desempenho reprodutivo e as características testiculares. Ao longo do período experimenta, os cordeiros foram mantidos em ambiente externo sob condições de luz e ritmo circadiano naturais e à temperatura ambiente. O efeito de tratamento com melatonina exógena no desempenho reprodutivo de carneiros e ovelhas, resposta estral, taxa de prenhez, tamanho de ninhada e taxa de gemelaridade foram avaliados em todos os grupos. Valores de libido foram significativamente maiores em Charollais comparados a Kivircik (P<0.001). Volume testicular (VT) estava aumentado em ambas as raças. Comprimento escrotal (CE) também estava aumentado tanto em Kivircik quanto em Charollais (P<0.01). Conclui-se que o tratamento de carneiros com implantes de liberação lenta de melatonina aumentou diâmetro e volume testiculares tanto em carneiros Kivircik quanto em Charollais. Ademais, implantação de melatonina melhorou o desempenho reprodutivo de ovelhas naturalmente cruzadas com esses carneiros implantados com melatonina durante o período não reprodutivo.(AU)

Comparison of sexual performance and testicular characteristics of melatonin treated Kivircik and Charollais rams during the non-breeding season / Comparação de desempenho reprodutivo e características testiculares de carneiros Kivircik e Charollais tratados com melatonina durante a estação não reprodutiva

This study was conducted to investigate the effects of melatonin implantation on basic testicular characteristics and reproductive performance of Kivircik and Charollais rams and ewes during the non-breeding season. In this study, 8 Kivircik and 6 Charollais rams were used. Rams were implanted with 54 mg melatonin according to the manufacturer's instructions. At melatonin implantation and at ram introduction the reproductive performance and testicular characteristics were evaluated. Throughout the experimental period, rams were permanently kept outdoors under conditions of natural day length and at ambient temperature. The effects of exogenous melatonin treatments on the reproductive performances of rams and ewes, estrus response, pregnancy rate, litter size and twinning rate of ewes were evaluated in all groups. Libido values were significantly higher in Charollais rams compared to Kivircik rams (P<0.001). Testicular volume (TV) was increased in both ram breeds. Scrotal length (SL) was also increased in both Kivircik and Charollais rams (P<0.01). In conclusion, we showed that the treatment of rams with slow release melatonin implants increased scrotal diameters and testicular volumes in both Kivircik and Charollais rams. Furthermore, melatonin implantation improved the reproductive performances of ewes naturally mated with these melatonin implanted rams during non-breeding season.(AU)

Esse estudo foi conduzido para investigar os efeitos de implantação de melatonina em características testiculares básicas e desempenho reprodutivo de carneiros Kivircik e Charollais durante a estação não reprodutiva. Nesse estudo, oito carneiros Kivircik e 6 Charollais foram utilizados. Foi implantado 54 mg de melatonina nos cordeiros de acordo com as instruções do produtor. Ao implantar a melatonina e à introdução do carneiro, foram avaliados o desempenho reprodutivo e as características testiculares. Ao longo do período experimenta, os cordeiros foram mantidos em ambiente externo sob condições de luz e ritmo circadiano naturais e à temperatura ambiente. O efeito de tratamento com melatonina exógena no desempenho reprodutivo de carneiros e ovelhas, resposta estral, taxa de prenhez, tamanho de ninhada e taxa de gemelaridade foram avaliados em todos os grupos. Valores de libido foram significativamente maiores em Charollais comparados a Kivircik (P<0.001). Volume testicular (VT) estava aumentado em ambas as raças. Comprimento escrotal (CE) também estava aumentado tanto em Kivircik quanto em Charollais (P<0.01). Conclui-se que o tratamento de carneiros com implantes de liberação lenta de melatonina aumentou diâmetro e volume testiculares tanto em carneiros Kivircik quanto em Charollais. Ademais, implantação de melatonina melhorou o desempenho reprodutivo de ovelhas naturalmente cruzadas com esses carneiros implantados com melatonina durante o período não reprodutivo.(AU)

Desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a protocolo hormonal a base de progestágeno e eCG, durante a contraestação reprodutiva / Reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season

Este trabalho teve como objetivo avaliar o desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a um protocolo hormonal a base de progestágeno e eCG durante a contraestação reprodutiva. Ovelhas mestiças (n=48), sem raça definida, foram divididas em dois tratamentos, considerando-se a presença (G-Lanada, n=25) ou ausência de lã (G-Deslanada, n=23). As ovelhas foram submetidas a um tratamento hormonal de indução/sincronização de estro, que consistiu na colocação do dispositivo intravaginal em dia aleatório do ciclo estral (D0). No D7, foi administrado eCG e d-cloprostenol. No D9, o dispositivo foi retirado e após 12 h os machos foram introduzidos no lote (proporção 1:6), nos dias 10, 11 e 12. Posteriormente, os machos foram separados das fêmeas por dez dias e então reintroduzidos no lote por mais 45 dias. A taxa de apresentação de estro e de prenhez resultantes da sincronização foi 84,0 e 36,0% vs. 87,0 e 56,6%, G-Lanada vs. G-Deslanada (p>0,05). A taxa de prenhez total, após repasse com os reprodutores foi 68,0 vs. 91,3%, G-Lanada vs. G-Deslanada (p<0,05). Conclui-se que ovelhas mestiças deslanadas tratadas com protocolo hormonal durante a contraestação apresentaram desempenho reprodutivo superior ao de ovelhas mestiças lanadas.

The aim of this study was to evaluate the reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season. Mixed breed ewes (n = 48) were assigned into two treatments considering the presence (G-Woolly, n = 25) or absence of wool (G-Hairless, n = 23). The ewes underwent hormone treatment to induction/synchronization of estrus, which consisted of the insertion of an intravaginal device randomly at the estrous cycle (D0). On Day 7, ewes were injected with eCG and d-cloprostenol. On Day 9, the device was removed and males were introduced into the herd (proportion of 1:6) twelve hours later during days 10, 11 and 12. After Day 12, males were separated from females for ten days and later reintroduced into the herd for 45 days. The rate of onset of estrus and the pregnancy rate from the synchronization was 84.0 and 36.0% vs. 87.0 and 56.6%, G-Woolly vs. G-Hairless (p> 0.05). The total pregnancy rate after male reintroduction was 68.0 vs. 91.3%, G-Woolly vs. G-Hairless (p< 0.05). In conclusion hairless crossbred ewes treated with the exogenous progestagen and eCG hormone during the non-breeding season presented higher reproductive performance compared to woolly crossbred ones.

Reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season / Desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a protocolo hormonal a base de progestágeno e eCG, durante a contraestação reprodutiva

The aim of this study was to evaluate the reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season. Mixed breed ewes (n = 48) were assigned into two treatments considering the presence (G-Woolly, n = 25) or absence of wool (G-Hairless, n = 23). The ewes underwent hormone treatment to induction/synchronization of estrus, which consisted of the insertion of an intravaginal device randomly at the estrous cycle (D0). On Day 7, ewes were injected with eCG and d-cloprostenol. On Day 9, the device was removed and males were introduced into the herd (proportion of 1:6) twelve hours later during days 10, 11 and 12. After Day 12, males were separated from females for ten days and later reintroduced into the herd for 45 days. The rate of onset of estrus and the pregnancy rate from the synchronization was 84.0 and 36.0% vs. 87.0 and 56.6%, G-Woolly vs. G-Hairless (p> 0.05). The total pregnancy rate after male reintroduction was 68.0 vs. 91.3%, G-Woolly vs. G-Hairless (p 0.05). In conclusion hairless crossbred ewes treated with the exogenous progestagen and eCG hormone during the non-breeding season presented higher reproductive performance compared to woolly crossbred ones.

Este trabalho teve como objetivo avaliar o desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a um protocolo hormonal a base de progestágeno e eCG durante a contraestação reprodutiva. Ovelhas mestiças (n=48), sem raça definida, foram divididas em dois tratamentos, considerando-se a presença (G-Lanada, n=25) ou ausência de lã (G-Deslanada, n=23). As ovelhas foram submetidas a um tratamento hormonal de indução/sincronização de estro, que consistiu na colocação do dispositivo intravaginal em dia aleatório do ciclo estral (D0). No D7, foi administrado eCG e d-cloprostenol. No D9, o dispositivo foi retirado e após 12 h os machos foram introduzidos no lote (proporção 1:6), nos dias 10, 11 e 12. Posteriormente, os machos foram separados das fêmeas por dez dias e então reintroduzidos no lote por mais 45 dias. A taxa de apresentação de estro e de prenhez resultantes da sincronização foi 84,0 e 36,0% vs. 87,0 e 56,6%, G-Lanada vs. G-Deslanada (p>0,05). A taxa de prenhez total, após repasse com os reprodutores foi 68,0 vs. 91,3%, G-Lanada vs. G-Deslanada (p 0,05).Conclui-se que ovelhas mestiças deslanadas tratadas com protocolo hormonal durante a contraestação apresentaram desempenho reprodutivo superior ao de ovelhas mestiças lanadas.

Reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season / Desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a protocolo hormonal a base de progestágeno e eCG, durante a contraestação reprodutiva

The aim of this study was to evaluate the reproductive performance of woolly and hairless crossbred ewes treated with an exogenous progestagen and eCG hormone during the non-breeding season. Mixed breed ewes (n = 48) were assigned into two treatments considering the presence (G-Woolly, n = 25) or absence of wool (G-Hairless, n = 23). The ewes underwent hormone treatment to induction/synchronization of estrus, which consisted of the insertion of an intravaginal device randomly at the estrous cycle (D0). On Day 7, ewes were injected with eCG and d-cloprostenol. On Day 9, the device was removed and males were introduced into the herd (proportion of 1:6) twelve hours later during days 10, 11 and 12. After Day 12, males were separated from females for ten days and later reintroduced into the herd for 45 days. The rate of onset of estrus and the pregnancy rate from the synchronization was 84.0 and 36.0% vs. 87.0 and 56.6%, G-Woolly vs. G-Hairless (p> 0.05). The total pregnancy rate after male reintroduction was 68.0 vs. 91.3%, G-Woolly vs. G-Hairless (p 0.05). In conclusion hairless crossbred ewes treated with the exogenous progestagen and eCG hormone during the non-breeding season presented higher reproductive performance compared to woolly crossbred ones.

Este trabalho teve como objetivo avaliar o desempenho reprodutivo de ovelhas mestiças lanadas e deslanadas submetidas a um protocolo hormonal a base de progestágeno e eCG durante a contraestação reprodutiva. Ovelhas mestiças (n=48), sem raça definida, foram divididas em dois tratamentos, considerando-se a presença (G-Lanada, n=25) ou ausência de lã (G-Deslanada, n=23). As ovelhas foram submetidas a um tratamento hormonal de indução/sincronização de estro, que consistiu na colocação do dispositivo intravaginal em dia aleatório do ciclo estral (D0). No D7, foi administrado eCG e d-cloprostenol. No D9, o dispositivo foi retirado e após 12 h os machos foram introduzidos no lote (proporção 1:6), nos dias 10, 11 e 12. Posteriormente, os machos foram separados das fêmeas por dez dias e então reintroduzidos no lote por mais 45 dias. A taxa de apresentação de estro e de prenhez resultantes da sincronização foi 84,0 e 36,0% vs. 87,0 e 56,6%, G-Lanada vs. G-Deslanada (p>0,05). A taxa de prenhez total, após repasse com os reprodutores foi 68,0 vs. 91,3%, G-Lanada vs. G-Deslanada (p 0,05).Conclui-se que ovelhas mestiças deslanadas tratadas com protocolo hormonal durante a contraestação apresentaram desempenho reprodutivo superior ao de ovelhas mestiças lanadas.