Had a morning scheduled off, forced myself to do a little paperwork, then went out to visit tortoises in the newer North summer pasture. At 9 am, many were still sleeping from the previous evening, some in mud, water or pushed up under palms. As soon as they see one, they usually come to check things out.
Young male who was physically picked up and moved a few weeks ago by the author. He continues to shun author. In the clip, author is ignored for the time period it takes for a female tortoise to wander over for attention.
Island rewilding with giant tortoises in an era of climate change. An opinion piece.
This article is part of the theme issue 'Trophic rewilding: consequences for ecosystems under global change'.
Replacing recently extinct endemic giant tortoises with extant, functional analogues provide the perhaps best examples of island rewilding to date. Yet, an efficient future application of this conservation action is challenging in an era of climate change. We here present and discuss a conceptual framework that can serve as a roadmap for the study and application of tortoise rewilding in an uncertain future. We focus on three main ecological functions mediated by giant tortoises, namely herbivory, seed dispersal and nutrient cycling, and discuss how climate change is likely to impact these. We then propose and discuss mitigation strategies such as artificial constructed shade sites and water holes that can help drive and maintain the ecosystem functions provided by the tortoises on a landscape scale. The application of the framework and the mitigation strategies are illustrated with examples from both wild and rewilded populations of the Aldabra giant tortoise, Aldabrachelys gigantea, in the Western Indian Ocean.
Abstract: Loss of key plant–animal interactions (e.g., disturbance, seed dispersal, and herbivory) due to extinctions of large herbivores has diminished ecosystem functioning nearly worldwide. Mitigating for the ecological consequences of large herbivore losses through the use of ecological replacements to fill extinct species’ niches and thereby replicate missing ecological functions has been proposed. It is unknown how different morphologically and ecologically a replacement can be from the extinct species and still provide similar functions. We studied niche equivalency between 2 phenotypes of Gala ́pagos giant tortoises (domed and saddlebacked) that were translocated to Pinta Island in the Gala ́pagos Archipelago as ecological replacements for the extinct saddlebacked giant tortoise (Chelonoidis abingdonii). Thirty-nine adult, nonreproductive tortoises were introduced to Pinta Island in May 2010, and we observed tortoise resource use in relation to phenotype during the first year following release. Domed tortoises settled in higher, moister elevations than saddlebacked tortoises, which favored lower elevation arid zones. The areas where the tortoises settled are consistent with the ecological conditions each phenotype occupies in its native range. Saddlebacked tortoises selected areas with high densities of the arboreal prickly pear cactus (Opuntia galapageia) and mostly foraged on the cactus, which likely relied on the extinct saddlebacked Pinta tortoise for seed dispersal. In contrast, domed tortoises did not select areas with cactus and therefore would not provide the same seed-dispersal functions for the cactus as the introduced or the original, now extinct, saddlebacked tortoises. Interchangeability of extant megaherbivores as replacements for extinct forms therefore should be scrutinized given the lack of equivalency we observed in closely related forms of giant tortoises. Our results also demonstrate the value of trial introductions of sterilized individuals to test niche equivalency among candidate analog species.
Project today was the continuing clean-up of winter pasture areas which were damaged by Irma last year. In the process, disturbed a couple of the sleepy-heads. Thought it might be of intrest to see where they chose to sleep last pm.
Afer hearing me, she decided to move. There were two others sleeping in the same manner in the same pond.
This young lady has wallowed out a small cave in the back of one of her mud wallows (now dry). Although they sleep nose in, she did turn around and grace us with her presence.