„Spiders in Galapagos – diversity, biogeography and origin“ has been published in the Biological Journal of the Linnean Society. In this paper we present an up-to-date list of species of spiders of Galápagos. We also analysed the Galápagos spider fauna in terms of distribution within the archipelago and origin. Based on this, we discuss the mode of arrival, dispersal patterns and colonising abilities of the spider families and species found in Galápagos .
Working at the Charles Darwin Research Station again
Thanks to a research fellowship sponsored by the Schimper Stiftung I was able to go to the Galápagos in February. It was great to continue my work on the Scalesia restoration project in the highlands of Santa Cruz. After intensive work in the invertebrate lab we finished all spider and beetles identifications and counted all other invertebrates caught within the long-term monitoring. This program started in 2014 and invertebrates were caught in 34 plots using pitfall and Malaise traps. First results have been recently published but more detailed analyses will be available soon.
Restauración del bosque de Scalesia invadido por mora: Impactos en la vegetación, los invertebrados y las aves has been published in Informe Galápagos.
Authors Jäger H, S Buchholz, A Cimadom, S Tebbich, J Rodríguez, D Barrera, A Wolentowitz, M Breuer, A Carrión, C Sevilla & C Causton
Insects and spiders of Galápagos
Together with my colleagues from the invertebrate lab of the Charles Darwin Research Station I recently finished the identifications of the spider, beetle and bug samples from the Los Gemelos project. We found a number of very interesting endemic species such as the spiders Darwinneon crypticus, Galaporella thaleri or Olios galapagoensis as well as endemic beetles such as Anchonus galapagoensis, Ataenius aequatorialis or Mordellistena galapagoensis. It was a great experience for me to see all this new species – and of course to work with the awesome team. Many thanks! Back in Berlin again, I am going to run the statistical analyses – look out for coming publications. If you are already interested in some basic results from the Los Gemelos project please make a note of the following paper which will published in the Galápagos Report soon:
Restoration of the blackberry-invaded Scalesia forest: impacts on the vegetation, invertebrates and birds (by Jäger H, Cimadom A, Buchholz S, Tebbich S, Rodriguez J, Barrera D, Breuer M, Walentowitz A, Carrión A, Sevilla C & Causton C)
Sailing Isabela island with my binoculars
Last weekend I went to Isabela island and I am happy to add two more species to my birding-list: the Black-necked Stilt (Himantopus mexicanus, r) and the Galápagos Petrel (Pterodroma galapagensis, e). It was really amazing to snorkel with Galápagos penguins and dozens of Blue-footed Boobies …
On the move with my binoculars
Galápagos is a great place for birdwatching and thus during my field trips and boat cruises I spent some time with my binoculars to glass the islands and the ocean. Up to now, I saw 41 species – see my species-list. There are only about 60 resident species and 13 of these are the finches. The relative paucity of species is in reality one of the beauties of Galápagos birds. The finches and mockingbirds are excellent examples of adaptive radiation and I am now very happy to have some photos for my animal ecology lecture. The number of resident species is growing. Two species have been introduced: pigeons, which have now been eradicated, and the Smooth-billed Ani. The Cattle Egret has arrived unaided. In addition to the resident species, there are numerous regular visitors, mainly migratory waders from North America. Here are some pictures I took during my trips … Find more in the photo gallery!
Bird ringing at Los Gemelos
Together with Arno Cimadom, his team from the University of Vienna and researchers of the Charles Darwin Research Station I spent gorgeous morning hours in the highlands of Santa Cruz. We captured darwin finches (e.g. warbler and tree finches as well as the woodpecker finch) using mist nets and ringed them. The field work was part of the Los Gemelos research project which among others focuses on how control of the invasive blackberry affects darwin finches in the Scalesia forests. I usually work with invertebrates – not only in this project – and thus I was glad to do some ornithological work for a change.
Visiting the study sites at Los Gemelos
I had a very amazing field trip to the Scalesia forests at Los Gemelos. Scalesia species have been called „the Darwin’s finches of the plant world“ because they show a similarly dramatic pattern of adaptive radiation. These giant daisy trees have an entire vegetation zone named after them. Scalesia is a genus of the family Asteraceae that is endemic to the Galapagos Islands. They consist of 15 native shrubs and tree species with six subspecies and each of the species has adapted to the different vegetation zones across the different islands.
A zone in the highlands of some islands is referred to as the Scalesia Zone which is a lush cloud forest and home to the largest of the Scalesia species (S. pedunculata dominant on Santa Cruz). From a distance the vegetation looks like a hummocky bog land but under the canopy, mosses, bromeliads, epiphytes and orchids thrive. The whole Scalesia zone is most threatened by human settlement. The zone is some of the most fertile land area on the Islands and perfect for agriculture. This has led to much of the original Scalesia forest being chopped down and replaced. Furthermore, the spread of introduced species such as blackberry has adverse effects on the habitat.
Here is a very interesting article about Scalesia forests which was published in GALAPAGOS REPORT 2009 -2010.
I am looking forward to spend a glorious time in Galápagos. I am going to participate in a research project for three months …
Over the last 10 years, the Galápagos National Park Directorate has carried out manual and chemical control of the invasive blackberry in the Scalesia forests at Los Gemelos on Santa Cruz. It is possible that this management has changed the structure of the forests which is supposed to affect invertebrates and birds that live there. To analyse effects of the management on plants, invertebrates and birds, a multi-taxon monitoring has been established. My part in this project is to evaluate the efficacy of the blackberry control measures and the impacts on non-target invertebrate species.
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