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Impact of fisheries on sea turtles

The bycatch of sea turtles by industrial fisheries is receiving an increasing attention in recent years due to the high impact it causes on these endangered species. This issue was evaluated in southern Spain waters that harbors an important feeding ground of loggerhead and leatherback turtles, including the endangered Eastern Atlantic loggerhead population. To quantify the impact that different fisheries represents to sea turtles, 272 fishermen answered to detailed illustrated questionnaires in all the main ports of Andalusia and Murcia (Spain) during 2014. This study has updated the knowledge of turtle bycatch in the southwestern Mediterranean revealing a widespread impact of fisheries on sea turtles. Fishermen recognized an annual catch of 2.3 turtles per boat. Considering the census of industrial fishing boats in the study area (1182), more than 2840 sea turtles could be bycaught per year in the study area. Most of captures (96.2%) were produced during the summer. These results suggest a severe impact of most of legal fisheries (surface longline, pursue seine, trawling and small scale fisheries) on loggerhead feeding grounds in the southwestern Mediterranean. Fishermen suggests that drift fishing conducted by foreign or illegal fishermen and almadrabas are also causing a significant bycatch of turtles. Several measures such as reviewing compliance of current fishing and environmental regulations, modifying turtle technics to reduce turtle bycatch (e.g. reduction of the use of squid as bait and disposal of hooks deeper in the water column), facilitating the rescue and handle of wound turtles and their transport to the port for recovery, and recognizing the efforts of anglers to perform a more sustainable fishing, are recommended to mitigate this impact. informacion[at]ebd.csic.es: Marco et al (2020) Sea turtle bycatch by different types of fisheries in southern Spain. Basic and Applied Herpetology https://doi.org/10.11160/bah.187


http://ojs.herpetologica.org/index.php/bah/article/view/187
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Dynamic signalling in the greater flamingo

Dynamic signalling in the greater flamingo

Colourful plumage is typical of males in species with conventional sex roles, in which females care for offspring and males compete for females, as well as in many monogamous species in which both sexes care for offspring. Reversed sexual dichromatism—more colourful females than males—is predominant in species with sex role reversal. In the latter species, males care for offspring and females compete for mates, the mating system is mainly polyandrous and there is reversed size dimorphism—females are larger than males. Here, a case of reversed dichromatism, in the greater flamingo Phoenicopterus roseus is documented, in which there is no sex role reversal and no reversed size dimorphism. Although theoretical models postulate that cases of reversed dichromatism should be rare among monogamous ornamented birds, these findings show that the use of cosmetics might be a mechanism for the occurrence of more ornamented females than males. Indeed, the concentrations of carotenoids in the uropygial secretions used as make-up were higher in females than in males. Apparently, there was a trade-off between coloration and antioxidant defence, as the concentrations of carotenoids in the uropygial secretions were lower during chick provisioning than in other periods, contrary to those in plasma. In this system, the application of make-up would act as a dynamic signal, which would allow a rapid reallocation of resources used for signalling among functions depending on needs. Cases like this may have evolved to signal the ability to provide parental care when females are more physiologically stressed than males. informacion[at]ebd.csic.es: Amat et al (2018) Dynamic signalling using cosmetics may explain the reversed sexual dichromatism in the monogamous greater flamingo. Behav Ecol Sociobiol 72:135 Doi 10.1002/ece3.4335. https://doi.org/10.1007/s00265-018-2551-1


https://link.springer.com/article/10.1007%2Fs00265-018-2551-1#