Image from the NFDI4BIOIMAGE Calendar April 2025. This image shows the BIIGLE image and video annotation tool, which is a web-based software for collaborative research on large imaging datasets [1, 2]. It offers tools for manual and computer-assisted annotation, quality control and the collaboration on custom taxonomies to describe objects. BIIGLE is freely available and can be installed in cloud environments, a local network or on mobile platforms during research expeditions. A public instance can be found at biigle.de. The annotated image shows the coastline of Fernandina Island, Galapagos, which is the habitat of the Galapagos Marine Iguana (Amblyrhynchus cristatus). The image is a large mosaic that was stitched together from many individual images captured by a drone. The green annotations marking the iguanas were machine-generated as part of a feasibility study for the automatic analysis of the data in the project Iguanas from Above [3, 4]. [1] Langenkämper, D., Zurowietz, M., Schoening, T., & Nattkemper, T. W. (2017). BIIGLE 2.0-browsing and annotating large marine image collections. Frontiers in Marine Science, 4, 83. https://doi.org/10.3389/fmars.2017.00083 [2] Zurowietz, M., & Nattkemper, T. W. (2021). Current trends and future directions of large scale image and video annotation: Observations from four years of BIIGLE 2.0. Frontiers in Marine Science, 8, 760036. https://doi.org/10.3389/fmars.2021.760036 [3] Varela-Jaramillo, A., Rivas-Torres, G., Guayasamin, J. M., Steinfartz, S., & MacLeod, A. (2023). A pilot study to estimate the population size of endangered Galápagos marine iguanas using drones. Frontiers in Zoology, 20(1), 4. https://doi.org/10.1186/s12983-022-00478-5 [4] https://iguanasfromabove.com Project Iguanas from Above Location Fernandina Island, Galapagos Organism Amblyrhynchus cristatus Drone model DJI Mavic 2 Pro Camera Hasselblad L1D-20c Size 26,545 × 20,894 px Mosaic algorithm Agisoft Metashape Professional v.1.6 Submitted via NFDI4Biodiversity