Observations

I only started using eBird after I moved to the US in the fall of 2016, and as of now, hardly any of my previous observations are on eBird. Before eBird, I used Artportalen while living in Sweden, and the Dutch websites waarneming.nl for observations in The Netherlands and observation.org for sightings elsewhere. One day, I'll need to get all of that – and older, non-digitally recorded observations – into eBird.

Sound Recordings

I have long been interested in bird vocalizations and have made thousands of sound recordings throughout the years, starting in 2006 with a little voice recorder… Over 900 of these recordings can be found on Xeno-Canto as of Jan. 2020. Several recordings have been published as audio accompanying books and articles.

Birding Trip Reports

All links are to pdf files hosted on the excellent Cloudbirders website:

  • TBA: China, May-June 2019. The Sichuan part of a custom tour put together by Steven An from China Dreams Tour while visiting China for a workshop at Duke Kunshan University.

  • TBA: NE Brazil, Dec 2017 - Jan 2018. With Sjoerd Radstaak, Pieter van Veelen, and Lars Buckx.

  • Morocco, Apr-May 2015. See also the accompanying map with GPS points here. With Vivian Jacobs, Marten Hornsveld, and Martijn Hammers.

  • Colombia, Feb-Mar 2015. Written by Rob Gordijn & Helen Rijkes. See also the accompanying map with GPS points here. With Rob Gordijn, Helen Rijkes, Janne Ouwehand, and Sander Bot.

  • Thailand, Jan 2014. See also the accompanying map with GPS points here. With Rutger Wilschut, Joachim Bouwmeester, and Thijs de Kruif.

  • Ethiopia, Jan-Feb 2011. Also available as a webpage on Birdtours.co.uk here. See also the accompanying map with GPS points here (Northern part) and here (Southern part). With Sander Bot, Rob Gordijn, Sjoerd Radstaak, and Bas van Schooten.

  • N Peru, Jun-Aug 2006. Written by Vincent van der Spek. With Arjan Dwarshuis and Vincent van der Spek.

Articles in Birding Journals

  • Poelstra, JW. Hybridization and speciation: the case of the Italian sparrow. Dutch Birding 37: 249-253, 2015. An article in the Dutch Birding's Trends in Systematics series summarizing papers on hybrid speciation in sparrows. As has long been suspected, and was recently confirmed by genomic data, the Italian Sparrow is a hybrid species. See here for a pdf.

  • Poelstra, JW. Olivaceous Warbler on the island of Björn. Fåglar i Uppland 38(3): 8-9. 2011. An article about the discovery of the 4th Olivaceous Warbler for Sweden. See here for a pdf.

  • Poelstra, JW. Speciation in shades of grey: the great grey shrike complex. Dutch Birding 32: 259-264, 2010. An article summarizing recent phylogenetic results on Great Grey Shrikes and discussing taxonomic implications. See here for a pdf.

Guiding

I have designed and guided two 5-day group birding tours to Central Sweden for Birding Breaks that took place in April 2016 and April 2017. Our main targets were owls (Great Grey, Ural, Pygmy, Hawk, and Tengmalm's), grouse (Capercaillie, Hazelhen, Rock Ptarmigan, and Willow Grouse), Siberian Jay, Siberian Tit, and Three-toed Woodpecker. I am set to lead a tour to the migrant traps along the northern shore of Lake Ontario in Canada in May 2020 (trip website here). See also my personal Birding Breaks page here.

The 2016 Birding Breaks tour in Sweden. Top: watching Gyr Falcons at Fulufjället, group picture at Rödhäll. Bottom: Watching a Great Grey Owl near Västerås.