Last Monday, I visited Biebrich Palace in Wiesbaden where I visited once but without a camera. The palace is surrounded by a large park where lots of parakeets can be seen. My aim was to take photos of those parakeets but it turned out to be way more productive than I expected. I spotted a pair of treecreepers as soon as I entered the park. I expected them to be the Short-toed Treecreeper and after following them for a while, I could be sure after hearing their calls.
The birds kept staying in the shades and rarely came out into the sun, so getting a good photo of them was extremely difficult. Not to mention that they almost always stayed on tree top and rarely came down to the lower trunks.
The most striking ID feature after the call was the long and slender bill.
The birds were very vocal and one of them was even singing! The song was a huge difference from that of the Eurasian Treecreeper.
The difference in bill length is pretty striking!
The wing patterns of the two are slightly different as well. The most striking difference is the alula pattern. In Short-toed, the outer edge of alula has thin buffish-white line connected to a large buffish-white spot at the tip, while in Eurasian, only a large buffish-white spot is apparent. The black and buff ‘steps’ on the wing are more even in Short-toed than in Eurasian as well. You can also see how the hind claw of Short-toed is slightly shorter than Eurasian from the above comparison photo as well, but I don’t think this is a very helpful field identification feature.
Another difference between the two treecreepers that I’ve found is the habitat choice. At my campus which is located in the montanous wooded area, I’ve only found Eurasian Treecreepers. Whereas in parks both in Frankfurt and Wiesbaden, I’ve only found Short-toed Treecreepers. So it seems like Short-toed is more of a bird of lowlands and parks, while Eurasian seems to prefer higher altitude and more forested areas.