Sensor Housings for Avian Harnesses

VSI Harness housing attached to Ibis sp. during flight, a group of Ibis are seen in the back. The photo was taken from a ultralight plane
VSI sensor housing attached to Ibis sp. during migration, (C) Anne Schmalstieg, 2019

Various external attachment techniques have been developed that indirectly attach biologgers and transmitters to birds via a neck collar, backpack, harness or leg band. Neck collars and backpacks generally have excellent transmitter retention (often for the life of the bird). Various harness designs are available that provide better fits to particular species because poorly fitting harnesses may cause abrasions or impede wing movement. In addition, the design of a biologger housing, attached to the harness via a base plate, must often be adapted to specific species and the requirements set by the applied sensors, i.a. in terms of size and antenna positions. However, size and shape of sensor hoursing can have a significant impact on the drag coefficient. Here, a streamlined shape, proper dimensions, and a reduced frontal area may reduce drag. In an experimental wind tunnel setup, Obrecht et al. (1988) found that adding a rounded fairing to the front end and a pointed fairing behind helped reduce the drag of the transmitter by about one-third compared to a rectangular box. Recently, Mizrahy-Rewald et al. (2023) reported on how the shape of biologger housings can have a considerable effect on heart rate and VeDBA of Northern Bald Ibises - both parameters have been used as proxies for energy expenditure.

 

Please contact us to discuss your needs in sensor housings for avian harnesses. For adaptation to available sensors and harnesses, a detailed 3D-model or a hands-on test are strongly advisable. See this recent blog post on how biologging sensor housings have been used in research by Mizrahy-Rewald et al. (2023).

VSI Avian Sensor Housings

Images for illustration purposes only, design subject to change without notice

Selected Readings on External AttAchments for Birds

  • Bowlin, M.S., Henningsson, P., Muijres, F.T., Vleugels, R.H.E., Liechti, F., and Hedenström, A. (2010). The effects of geolocator drag and weight on the flight ranges of small migrants. Methods Ecol Evol. (4): 398–402
  • Chan, Y.-C., et al. (2016). "Testing an attachment method for solar-powered tracking devices on a long-distance migrating shorebird." Journal of Ornithology 157(1): 277-287
  • Fritz, J., Eberhard, B., Esterer, C., Goenner, B., Trobe, D., Unsoeld, M., et al. (2020). Biologging is suspect to cause corneal opacity in two populations of wild living Northern Bald Ibises (Geronticus eremita). Avian Res.11(1):38
  • Lewis, T. L. and P. L. Flint (2008). "Modified method for external attachment of transmitters to birds using two subcutaneous anchors." Journal of Field Ornithology 79(3): 336-341
  • Mizrahy-Rewald, O., Winkler, N., Amann, F. et al. (2023).The impact of shape and attachment position of biologging devices in Northern Bald Ibises. Anim Biotelemetry 11, 8
  • Obrecht, H.H. III, Pennycuick, C.J., and  Fuller, M.R. (1988). Wind tunnel experiments to assess the effect of back-mounted radio transmitters on bird body drag. J Exp Biol.;135(1): 265-273
  • Pennycuick, C.J., Fast, P.L.F., Ballerstädt, N., and Rattenborg, N. (2012). The effect of an external transmitter on the drag coefficient of a bird’s body, and hence on migration range, and energy reserves after migration. J Ornithol. 153(3): 633-644
  • Tomotani, B. M., et al. (2019). "Carrying a logger reduces escape flight speed in a passerine bird, but relative logger mass may be a misleading measure of this flight performance detriment." Methods in Ecology and Evolution 10(1): 70-79
  • Vandenabeele, S. P. (2013). Avian rucksacks for science: in search for minimum-impact tagging procedures for birds, Swansea University (United Kingdom)