Trends in Reproductive Indicators of Green and Hawksbill Sea Turtles over a 30-Year Monitoring Period in the Southern Gulf of Mexico and Their Conservation Implications.

Long-term monitoring programs of species at risk are efficacious tools to assess population changes, evaluate conservation strategies, and improve management practices to ensure populations reach levels at which they can fulfill their ecological roles. For sea turtles, annual nesting beach surveys are the most accessible method to estimating the population abundance and reproductive output, especially when these are done in primary nesting sites. However, little data exist on the long-term assessment of these parameters. Here, we present the trends of the nest abundance, female size, hatching, and emergence success of hawksbill (Eretmochelys imbricata) and green (Chelonia mydas) turtles at key nesting beaches in the southern Gulf of Mexico over 31 years (from 1990 to 2021). The nest abundance showed an increasing trend in both species as a result of the sustained protection and conservation effort, but there was no significant temporal trend in the annual female size, clutch size, hatching, and emergence success. However, these indicators showed decreasing mean values over the last decade and should be closely monitored. We suggest these decreases link to the combined effects of ocean warming and anthropogenic pressures affecting the sea turtle foraging grounds. Aside from protecting key nesting sites, protecting and restoring crucial foraging habitats should be an immediate priority requiring international cooperation.

Socioeconomic development and ecological traits as predictors of human-bird conflicts.

Because of the significant impacts on both human interests and bird conservation, it is imperative to identify patterns and anticipate drivers of human-bird conflicts (HBCs) worldwide. Through a global systematic review, following the PRISMA 2020 guidelines, we analyzed the socioeconomic factors and bird ecological traits driving the degree of knowledge and extent of HBCs. We included 166 articles published from 1971 to 2020 in our analyses through which we built a profile of the socioeconomic conditions of 52 countries with reported conflicts and the ecological traits of the 161 bird species involved in HBCs. Although HBC expanded worldwide, it had the greatest impact in less-developed countries (estimate 0. 66 [SE 0.13], p< 0.05), where agriculture is critical for rural livelihoods. Species with a relatively greater conflict extent had a relatively broader diet (estimate 0.80 [SE 0.22], p<0.05) and an increasing population trend (estimate 0.58 [SE 0.15], p<0.05) and affected human interests, such as agriculture and livestock raising. In countries with greater biodiversity, HBCs caused greater socioeconomic impacts than in more developed countries. Our results highlight the importance of understanding and addressing HBCs from multiple perspectives (ecological, sociocultural, and political) to effectively protect both biodiversity and local livelihoods.

El desarrollo socioeconómico y las características ecológicas como pronosticadores de los conflictos entre aves y humanos Resumen Debido a los impactos significativos sobre los intereses humanos y la conservación de las aves, es imperativo identificar patrones y anticiparse a las causas de los conflictos humano-aves (CHA) a nivel mundial. Por medio de una revisión sistemática, siguiendo los lineamientos de PRISMA 2020, analizamos los factores socioeconómicos y las características ecológicas de las aves que impulsan el grado de conocimiento y la extensión de los CHA. Incluimos 166 artículos publicados desde 1971 hasta 2020 en nuestros análisis, con los cuales construimos un perfil de las condiciones socioeconómicas de 52 países con reportes de conflictos y de las características ecológicas de 161 especies de aves involucradas en los CHA. Aunque los CHA se expandieron mundialmente, tuvieron un mayor impacto en los países menos desarrollados (estimado 0. 66 [ES 0.13], p< 0.05), en donde la agricultura es crítica para el sustento rural. Las especies con una extensión de conflicto relativamente más larga también contaban con una dieta más amplia (estimado 0.80 [ES 0.22], p<0.05) y una tendencia poblacional en aumento (estimado 0.58 [ES 0.15], p<0.05), lo que afectó los intereses humanos, como la agricultura y la cría de ganado. En los países con mayor biodiversidad, los CHA ocasionaron impactos socioeconómicos mayores que en los países más desarrollados. Nuestros resultados resaltan la importancia de abordar y entender los CHA desde múltiples perspectivas (ecológica, sociocultural, política) para proteger de manera efectiva tanto a la biodiversidad como a los sustentos locales.

Three decades of longlining in Bimini, Bahamas, reveals long-term trends in lemon shark Negaprion brevirostris (Carcharhinidae) catch per unit effort.

In Bimini, Bahamas, the consistent employment of longlines, beginning in 1982, provided a rare opportunity to explore population trends for large resident sharks. This study assessed three shallow water longline survey periods at this location; 1982-1989, 1992-2002 and 2003-2014, with the aim of determining trends in annual catch per unit effort (CPUE) for an IUCN listed near-threatened species, the lemon shark Negaprion brevirostris. A general additive model (GAM) was used to analyse the non-linear annual CPUE values over the entire 32-year research period. The GAM displayed high variability of annual CPUE, with a peak value of 0·026 N. brevirostris per hook day (hooks day(-1) ) in 2000. The temporal pattern of CPUE indicated an abundance trend with a complete cycle, from trough to trough, occurring over a period of approximately 18 years. The 1982-1989 survey period saw the highest proportion of mature individuals (19·8%) and the smallest average pre-caudal length (LPC ; 124·8 cm). The 1992-2002 survey period had the highest average annual CPUE (0·018 hooks day(-1) ), while the 2003-2014 research period saw largest average LPC size (134·8 cm) and the lowest average CPUE values (0·009 hooks day(-1) ) of the entire research period. The long-term trend identified in this study provides a baseline for future assessment.

Actividad reproductiva de Chelonia mydas (Testudines: Cheloniidae) en Isla de Aves, Venezuela (2001-2008) / Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008)

Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008). The second major nesting-site for green turtles in the Caribbean is Isla de Aves, an island protected as a wildlife refuge since 1972, located at 650km Northeast from La Guaira, Venezuela. In this island, the nesting population monitoring started in 1972 and in a more continuous way after 1978, when a Scientific-Naval Station was established and scientific observations started. Since historical data show that female captures had severely affected population levels in this island before 1978, this study aim to describe recent reproductive activities. For this, during the nesting seasons of 2001-2002 and 2005-2008, nesting females were measured and tagged using metal flipper tags. A total of 458 nights were sampled observing 5 154 female emergences, with a maximum of 53 in a single night. Non-observed emergences were calculated fitting the temporal distribution of observed emergences to a normal curve. Total emergences estimated varied from =637.1±106.6 in 2001 to =2 853±42.5 in 2008 (ANOVA F(6.5df)=60.37, p<0.0001). Internesting interval in the same season was estimated in =10.71±1.32 days. Clutch frequency in a nesting season was calculated as =1.71±1.6 times per female and season. Estimated number of nesting females per year varied from =373±12.5 females in 2001 to =1 669±56.1 females in 2008 (ANOVA F (5.6df)=89.42, p<0.0001); with a positive and significant trend (r=0.842, p=0.036). Results show that nesting females numbers are increasing. We suggest that the protection of the nesting area for more than 30 years, has contributed with this population increase. Rev. Biol. Trp. 60 (2): 745-758. Epub 2012 June 01.

Isla de Aves, una isla a 650km de La Guaira, Venezuela, protegida como Refugio de Fauna Silvestre, constituye el segundo sitio de mayor anidación de la tortuga verde (Chelonia mydas) (Linnaeus 1758) en el Caribe. El seguimiento de la población comenzó en 1972 y de manera más continua desde 1978. Los datos históricos indican que la captura de hembras en la isla, afectó severamente la población hasta 1978, cuando fue construida una base científico-naval. Durante las temporadas de anidación entre 2001-2008 con excepción de 2003 y 2004, las hembras fueron marcadas con placas metálicas y medidas. Asimismo, se muestreó durante 458 noches, en donde se observaron 5 154 eventos, con un máximo de 53 por noche. Los posibles eventos no observados fueron calculados ajustando la distribución temporal de eventos observados a una curva normal. El total de eventos estimados varió de =637.1±106.6 en 2001 a =2 853±42.5 en 2008 (ANOVA F(6.5gl)=60.37, p<0.0001). El intervalo entre reanidaciones fue de =10.7±1.32 días. La frecuencia de anidación se calculó en =1.71±1.6 veces por hembra. El número de hembras estimadas varió entre =373±12.5 para 2001 y =1 669±56.1 para 2008 (ANOVA F(5.6gl)=89.42, p<0.0001). La tendencia es significativa (r=0.842, p=0.036). Los resultados indican que el número de hembras que anidan en Isla de Aves ha aumentado, y se sugiere que más de 30 años de protección del área de reproducción está resultando en un creciente número de hembras.