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Army ant invasion of leatherback nests in Gabon

Egg mortality is one of the main factors affecting life history and conservation of oviparous species. A massive and cryptic colonisation of many leatherback turtle (Dermochelys coriacea) eggs is presented in the most important rookery for the species in Gabon. A total of 163 nests were exhumed at Kingere beach, revealing that only 16.7% of eggs produced hatchlings. In the 59% of the nests, more than half of the eggs were dead and attacked by invertebrates and 94% had at least one egg affected by invertebrates. The rate of eggs and SAGs (yolkless eggs) affected by invertebrates within a clutch ranged from 0% to 100%, with an average proportion of 39% and 52%, respectively. The most common invertebrates interacting with the eggs were ghost crabs and insects that affected 51% and 82% of the nests, respectively. Crab and insect co-occurred in 33% of the affected nests. Ants, identified as Dorylus spininodis (Emery 1901) were found in 56% of the excavated nests. However, it was not possible to determine if the ants predated alive eggs or scavenged dead eggs. Very often, hundreds of ants were found drowned within dead eggs. Termites and other invertebrates were associated with the clutch environment and identified as opportunistic feeders, being this is the first record of interaction between termites and sea turtle eggs. An unusual ecological interaction within the leatherback clutches between termites and ants was found in 11% of the nests. The abrupt transition between the soil forest and the beach might be favouring a thriving microbial and invertebrate activity in the sand profile that colonises the nests. informacion[at]ebd.csic.es: Ikaran et al (2020) Cryptic massive nest colonisation by ants and termites in the world's largest leatherback turtle rookery Ethol Ecol Evol 2020. Doi 10.1080/03949370.2020.1715487


https://www.tandfonline.com/doi/abs/10.1080/03949370.2020.1715487
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Human impact is changing the way biodiversity is organized

Human impact is changing the way biodiversity is organized

Zoogeographical regions, or zooregions, are areas of the Earth defined by species pools that reflect ecological, historical and evolutionary processes acting over millions of years. Consequently, researchers have assumed that zooregions are robust and unlikely to change on a human timescale. However, the increasing number of human mediated introductions and extinctions can challenge this assumption. By delineating zooregions with a network?based algorithm, this study, focused on the bioregions defined by amphibians, mammals, and birds, shows that introductions and extinctions are altering the zooregions known today. Introductions are homogenising the Eurasian and African mammal zooregions and also triggering less intuitive effects in birds and amphibians, such as dividing and redefining zooregions representing the Old and New World. Furthermore, these Old and New World amphibian zooregions are no longer detected when considering introductions plus extinctions of the most threatened species. Unfortunately, these changes can be increased if the currently threatened species become extinct. Results suggest that the human being is altering historical, ecological, and evolutionary signals that informed us of the processes that have shaped life on Earth. These findings highlight the profound and far?reaching impact of human activity and call for identifying and protecting the uniqueness of biotic assemblages. informacion[at]ebd.csic.es: Bernardo-Madrid et al (2019) Human activity is altering the world's zoogeographical regions. Ecol Lett https://doi.org/10.1111/ele.13321


https://onlinelibrary.wiley.com/doi/full/10.1111/ele.13321