Mostrando recursos 121 - 140 de 1,676

  1. Monitoring and conservation of the largest loggerhead turtle (Caretta caretta) nesting population in Africa: successes and challenges.

    Varo Cruz, Nuria; López, Pedro; Vázquez, Cristina; Ballell-Valls, Lluis; Cejudo, Daniel; López-Jurado, Luis Felipe

    [EN] The Republic of Cape Verde is situated about 500 km off the coast of Senegal, West Africa. The islands of Sal, Boa Vista and Maio constitute the Eastern group and harbour the most important nesting beaches for loggerhead turtles in the Archipelago. During 1998-2004 nesting seasons, fieldwork has been focused on the eastern beaches of Boa Vista and, occasionally, in other beaches of Boa Vista and in the islands of Maio, Sal and Santa Luzia. The main study area includes a total extension of 3.1 km of suitable nesting beaches. All through these years, a tagging program has been...

  2. The size of the loggerhead nesting females in the Cape Verde islands

    Ballell-Valls, Lluis; López-Jurado, Luis Felipe

    [EN] The recently discovered nesting colony of Caretta caretta at the island ofBoavista (Cape Verde Islands, West Africa, FIGURE 1) is being subject ofresearch since 1998. A total number of 1,391 different females have been tagged during the 1998, 1999 and 2000 nesting seasons. Although more data are needed, these islands may represent one ofthe most important populations for the species in the North Atlantic (Brongersma, 1982; Ross, 1995; López-Jurado & Andreu, 1998). The present study shows a comparative analysis between the morphometric data collected at Boavista during the last 2000 nesting season and those recorded in the 1998 and...

  3. Injuries observed in nesting females of loggerhead turtles on Boavista island (Cabo Verde Archipelago)

    Vázquez, Cristina; Varo Cruz, Nuria; López, Óscar; Liria-Loza, Ana; López-Jurado, Luis Felipe

    [EN] Different kinds of physical anomalies are frequently observed in any sea turtle breeding population. Nesting beaches are an excellent place to study the injuries and defects that occur in adult females. The archipelago of Cape Verde is situated about 500 km of Senegal, West Africa. Boavista is the eastern most island and may constitute the most important nesting area for the loggerhead turtle in the archipelago. The studies conducted from 1998 to 2004 indicate that Cape Verde might account for one of the most important loggerheads populations in the eastern Atlantic. The nesting females in Boavista were surveyed during...

  4. Loggerhead nesting trend in three beaches of Boavista, Cape Verde archipelago

    Liria-Loza, Ana; Varo Cruz, Nuria; Medina Suárez, María E.; Jiménez Bordón, Saray; López-Jurado, Luis Felipe

    [EN] Nesting beach surveys are the most widely implemented monitoring tool in use by the global sea turtle community and are an important component of a comprehensive program to assess and monitor the status of sea turtle populations. These assessments are necessary to evaluate the effects of recovery and conservation activities that are being implemented at all life history stages. Monitoring techniques employed on nesting beaches range from highly structured standardized sampling to “snapshots” of nesting activity within a nesting season. Very long-term nest counts data (more than twenty years) were analyzed for some turtle populations.


  5. Synchrony on embryonic development of marine turtles: individual variability and environmental effects

    Pérez García, Héctor; García Cerdá, Rosa María; Fernández Gil, Belén; Marco, Adolfo; Abu Raya, Mara; López-Jurado, Luis Felipe

    [EN] For sea turtles, to hatch and emerge from the nest communally is essential to decrease hatchling mortality. Thus, it is very important within a nest the simultaneous fertilization and the synchronized embryonic development of all eggs. On loggerhead nesting beaches of Cape Verde we have studied the individual variability on developmental synchrony of embryos and the influence on this process of some biological, environmental and management factors. We have compared this trait within and between 34 nests naturally incubated on the beach and 34 nests relocated to a beach hatchery during the 2009 and 2010 nesting seasons.


  6. Las puestas comunales de Hemidactylus boavistensis en la isla de Sal (Archipiélago de Cabo Verde)

    López-Jurado, Luis Felipe; Hernández-Acosta, C. Nayra; Geniez, Philippe; Mateo, José Antonio

    [ES]De acuerdo con Pough (1973), los requerimientos metabólicos de un saurio de pequeño tamaño determinan que su dieta deba ser básicamente insectívora. El mismo autor añadía que cuando el lagarto sobrepasa un determinado tamaño esa dieta basada en el consumo exclusivo de artrópodos ya no va a permitirle cubrir sus necesidades energéticas básicas y debe, por eso, buscar alternativas. Aunque en términos generales muchas especies se ajustan bastante bien a estas “reglas” ecofisiológicas, en los últimos 25 años han sido numerosos los trabajos publicados en los que se han recogido ejemplos que contravienen las previsiones de ese modelo, especialmente cuando...

  7. ¿Realmente importa tanto el tamaño? I: La dieta de las dos especies del género Tarentola de la Isla de Raso (Cabo Verde)

    Mateo, José Antonio; Geniez, Philippe; Hernández-Acosta, C. Nayra; López-Jurado, Luis Felipe

    [ES] La isla de Sal es, por su escaso relieve y por su posición geográfica, una de las islas más áridas del archipiélago de Cabo Verde (Chevalier, 1935). En ese escenario casi desértico vive Hemidactylus boavistensis, un geco endémico de las islas de Sal, Boavista y algunos islotes adyacentes (Arnold et al., 2008; Vasconcelos et al., 2013). Se trata de un saurio de pequeño tamaño (hasta 50 mm de longitud hocico cloaca; Figura 1a) relativamente abundante que durante el día suele refugiarse debajo de las piedras que descansan sobre el sustrato generalmente arenoso de la isla.


  8. ¿Realmente importa tanto el tamaño? II: La dieta de dos especies del género Tarentola en el Sáhara Occidental

    López-Jurado, Luis Felipe; Geniez, Philippe; Hernández-Acosta, C. Nayra; Mateo, José Antonio

    [ES] La Seguiat el Hamra es una cuenca hidrográfica árida situada en el extremo occidental del desierto del Sáhara. Si en su desembocadura la influencia del Océano Atlántico determina temperaturas tamponadas y cierta humedad ambiental, al este de Smara (26º44’29”N / 11º40’24”O) las condiciones bioclimáticas se endurecen (Ozenda, 1991), provocando un significativo cambio en la composición de las comunidades de vertebrados (Valverde, 1957; Geniez et al., 2004).


  9. Lost at sea: Genetic, oceanographic and meteorological evidence for storm-forced dispersal

    Monzón Argüello, Catalina; Dell’ Amico, F.; Morinière, P.; Marco, Adolfo; López-Jurado, Luis Felipe; Hays, Graeme; Scott, Rebecca; Marsh, Robert; Lee, Patricia

    [EN] For many species, there is broad-scale dispersal of juvenile stages and/or long-distance migration of individuals and hence the processes that drive these various wide-ranging move- ments have important life-history consequences. Sea turtles are one of these paradigmatic long-distance travellers, with hatchlings thought to be dispersed by ocean currents and adults often shuttling between distant breeding and foraging grounds. Here, we use multi- disciplinary oceanographic, atmospheric and genetic mixed stock analyses to show that juvenile turtles are encountered ‘downstream’ at sites predicted by currents. However, in some cases, unusual occurrences of juveniles are more readily explained by storm events and...

  10. Characterization of the intestinal microbiota of natural populations of Lutzomyia evansi: vector of visceral Leishmaniasis

    Vivero Gómez, Rafael José
    Abstract: Lutzomyia evansi (Diptera: Psychodidae) is a phlebotomine “sandfly” insect endemic to the Caribbean coast of Colombia with epidemiological significance for being the main vector of leishmaniasis disease, which is caused by Leishmania spp parasites. Sand flies (164 species in Colombia) in general are able to transmit other parasites as Bartonella spp, and virus mostly from vesiculovirus group, affecting human and animal health. This group of insects has been studied in Colombia in relation to vectorial role, geographical distribution and epidemiological importance, but vaccine absence for the most important disease they transmit (leishmaniasis) encourage the implementation of vector control measures as...

  11. Potencial de aislamientos fúngicos nativos para el manejo de Diaphorina citri (Hemiptera: Liviidae)

    Jaramillo Mazo, Claudia Yuliet
    Resumen: El cultivo de cítricos, representado principalmente por la naranja, la lima ácida y la mandarina, es considerado uno de los frutales más importantes a nivel mundial. La enfermedad causada por la bacteria Candidatus Liberibacter sp. y transmitida por el vector Diaphorina citri en América, es calificada como uno de los problemas fitosanitarios más devastadores en el cultivo. Una de las estrategias utilizadas para el control de la enfermedad hasta el momento, es el manejo del psílido asiático de los cítricos. Sin embargo, el principal método de control utilizado está relacionado con el uso de agroquímicos lo cual podría ocasionar...

  12. Producciónn xeno-free de Células Madre Mesenquimales derivadas de tejido adiposo, y evaluación de su secretoma neovasculairzante

    Escobar Soto, Carlos Hugo
    Introducción. Las moléculas de origen animal o bacteriano que habitualmente son usadas en los protocolos de extracción, cultivo y criopreservación de Células Madre derivadas de Tejido Adiposo humano (human Adipose derived Stem Cells, hASC) significan un riesgo de rechazo inmunológico contra las células trasplantadas y/o desarrollo de zoonosis. La capacidad de inducir la regeneración tisular de las ASC, depende al menos en parte, de factores de efecto paracrino liberados por ellas. Pero también se ha demostrado que la capacidad de inducir regeneración tisular, tiene una relación inversa con el pase al que se encuentran las células. Caracterizar el secretoma neovascularizante...

  13. High plasticity of loggerhead nesting site fidelity: from using repeatedly the same small beach during different seasons to deposit consecutive nests in different islands distant more than 100 km

    Abella Pérez, Elena; Sanz, Paula; Loureiro, Nuno de Santos; Cozens, Jacquie; Oujo-Alamo, Carolina; Martins, Samir; Marco, Adolfo; Varo Cruz, Nuria; López-Jurado, Luis Felipe

    [EN] Sea turtles exhibit a strong natal homing associated with a high nesting site philopatry. Mark-recapture and genetic studies confirm these patterns suggesting differences among and within species. In the present study, we have analysed the degree of nest site fidelity of a loggerhead population nesting on the islands of Cape Verde and have evaluated the existence of intrapopulational variability in this trait. The loggerhead is the only sea turtle species that nests in Cape Verde, and 15,000–25,000 nests per season have been estimated for the whole archipelago.


  14. Causes of extreme variability of nest density among close and similar beaches of Boavista island (Cape Verde): From 1 to 2000 annual nests per km.

    Marco, Adolfo; Liria-Loza, Ana; Martins, Samir; Abella Pérez, Elena; López-Jurado, Luis Felipe

    [EN] The 70 km of white sandy beaches of Boa Vista island in Cape Verde harbours one of the largest rookeries of the endangered loggerhead sea turtle, Caretta caretta. From middle June to early October, approximately 2000 to 4000 females lay up to 20000 nests annually. However, female beach selection, nesting success and nest density strongly varies among beaches and spatial patterns of nest abundance and distribution are relatively constant among seasons. The numbers of nesting activities and nests have been recorded along all beaches of the island during four nesting seasons (2007-2010)


  15. Climate change and the evolution of loggerhead sex-ratio in Cabo Verde

    Abella Pérez, Elena; Marco, Adolfo; López-Jurado, Luis Felipe

    [EN] Global warming can affect nesting success of sea turtles due to the rise of the sea level and the subsequent increased inundation or erosion of nesting beaches. Moreover, it can reduce male production to levels that can alter reproduction due to their temperature dependant sex determination (TSD). Now, mean nest temperatures all around the world predict a predominance of female hatchlings, and this trend may increase with global warming in the next decades.


  16. Why are egg fertilization rates not correlated with hatching success in sea turtles?

    Abella Pérez, Elena; Marco, Adolfo; López-Jurado, Luis Felipe

    [EN] The relative number of developing eggs is directly affected by fertilization rate, and unfertile eggs may indirectly negatively affect development of viable eggs within the nest. Thus, the number of viable eggs at laying should influence hatching success. We have studied both parameters in a nesting population of loggerhead turtles from Boavista Island (Republic of Cabo Verde). Fertility was estimated based on eggs excavated from nests within the first 96 hours after deposition. Our results confirm a high egg fertilization rate for the species, which exceeded an average of 94% fertility (95% confidence limits: 91.9 and 96.2%, N=43 nests).


  17. Sea turtles recovered at the Wild Fauna Recovery Center in Gran Canaria (Canary Islands, Spain)

    Calabuig, P.; Liria-Loza, Ana; López-Jurado, Luis Felipe

    [EN] Since the beginning of the 1990's, the Wild Fauna Recovery Center in Gran Canaria Canary Islands, Spain) has received a large number of injured animals for recovery. Apart from birds and mammals, a considerable number of sea turtles representing different species are gathered each year. During the last five years (1999-2003), more than 100 turtles were sheltered annually; more than 80% successfully recovered and were released.


  18. Satellite tracking of adult loggerheads (Caretta caretta L.) around waters of Cape Verde Archipielago (Western Africa)

    Cejudo, Daniel; Varo Cruz, Nuria; López, Óscar; López-Jurado, Luis Felipe

    [EN] During the 1999 nesting season (from June to October), four satellite transmitters were attached to two males and two females of Caretta caretta from Boavista Island (Cape Verde Archipelago, western Africa), where density of nesting females is the highest in the whole archipelago. Transmitters did not work as well as expected, resulting in a low number of locations, possibly due to the neritic behavior of adult loggerheads at reproductive habitat, with the antennae exposed to continuous rubbing. Therefore, we establish a conservative hypothesis about movements of C.caretta in Cape Verde.


  19. Preliminary approach to the hatchlings sex-ratio of a population of Caretta caretta of Boavista island, Cape Verde Archipielago (Western Africa).

    Delgado, Cláudia; Dellinger, Thomas; Varo Cruz, Nuria; Cejudo, Daniel; López-Jurado, Luis Felipe

    [EN] A nesting population of loggerhead sea turtles Caretta caretta has recently been described for Boa Vista Island, Cape Verde Archipelago (Western Africa). Since 1998, “Projecto Cabo Verde Natura 2000” has monitored three beaches during the turtle breeding season. The beaches being monitored - Calheta, Errata and Ponta Cosme - are located in the southeast part of Boa Vista Island. This work intends to give a first insight into the Boa Vista Island sea turtle population’s sex ratio using a histological approach, as sexual determination in sea turtles is known to be temperature-dependent (TSD or temperature-dependent sex determination).


  20. Comparative study of the epibionts on the pelagic and mature female loggerhead turtles on the Canary and Cape Verde islands

    Liria-Loza, Ana; López-Jurado, Luis Felipe

    [EN] Marine turtles commonly carry diverse forms of epizoa on their shells. The occurrence of a particular species may ultimately help to clarify certain questions about sea turtle natural life history. This paper gives a detailed and comparative list of epizoic species found on two populations of macaronesian loggerheads: pelagic and juveniles living around the Canary Islands and mature females nesting in Boavista Island, Cabo Verde. For the epizoic flora, the most important genera founded is Polysiphonia (Rhodophiceae); P. carettia for the pelagics and Polysiphonia sp. for the nesting animals.


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