Sykes’s vs. Egyptian Nightjars

“Identical twins are endemically alike in many ways.” – Edward Norton

It was during my first trip to Oman, in November 2017. We arrived to Muntasar Oasis already in the evening and our main targets there were Grey Hypocolius and sandgrouse (we saw none). However, later at night, we did see a good number of Nightjars Caprimulgus sp.flying over and eventually landing by the grassy pools made out of water leaked from the main oasis. Most were European Nightjars Caprimulgus europaeus (we could not determine the subspecies), but among them there was one obviously paler and apparently bigger. After some confusion, we identified it as Egyptian Nightjar Caprimulgus aegyptius of the Eastern nominate race and finally managed to get really good views of the bird sat on the sand.

Figure 1. Egyptian Nightjar Caprimulgus aegyptius aegyptius. Muntasar Oasis, Oman, November 2017. © Marcel Gil Velasco

With such good photos in our memory cards, it was mandatory to compare them with the Sykes’s Nightjar photos some friends of us had managed at the very exact place the year before, in order to learn something about this poorly known species and hence be able to identify it in future occasions. To my surprise, the plumages stroke me as being virtually identical.

Today, old fellow Julien Mazenauer posted a photo of a Sykes’s Nightjar he saw (and what a sighting!) last January in Gujarat, India. I thought it would be interesting to include it here since it was taken in breeding grounds and he kindly provided a large version of the file. Here below you can find a comparison between the 3 birds

Figure 2. Profile comparison between 3 tricky Nightjar individuals. Top: Sykes’s Nightjar Caprimulgus mahrattensis. Gujarat, India, January 2019 © Julien Mazenauer. Middle: Egyptian Nightjar Caprimulgus aegyptius aegyptius. Muntasar Oasis, Oman, November 2017 © Marcel Gil Velasco. Bottom: Sykes’s Nightjar Caprimulgus mahrattensis. Muntasar Oasis, Oman, December 2016 © Albert Burgas.

The similarities are striking. Although Julien’s bird looks a bit more contrasted, in my opinion this impression is mainly due to light conditions (I’m sure he uses proper lenses and flashes for this; I don’t) and in fact the variation in that respect is large even within my own photos of the same bird, plus it’s easy to find photos of more uniform-looking Sykes’s Nightjars (for instance here and here). In the other hand, our bird looks exactly the same as the Sykes’s in 2016 at Muntasar, a bird identified on the basis of it having white spots in wings and tail.

Let’s focus on some details then, since they reveal even more resemblances. If we zoom in the head, we can see all three individuals share a buffy collar, especially broad under the cheeks and broken around the nape and the throat by some sparse black and white feathers. The loral area and the subtle supercilium also follow the same pattern and colouration, both contrasting with an almost uniform grey crown that only shows some fine dark stripes. This latter feature is listed by Grimmett, et al. 2013 as key to tell these two species apart, but it’s clearly overrated in my opinion.

Figure 3. Detail of the head of the same 3 Nightjars above. Top: Sykes’s Nightjar Caprimulgus mahrattensis. Gujarat, India, January 2019 © Julien Mazenauer. Middle: Egyptian Nightjar Caprimulgus aegyptius aegyptius. Muntasar Oasis, Oman, November 2017 © Marcel Gil Velasco. Bottom: Sykes’s Nightjar Caprimulgus mahrattensis. Muntasar Oasis, Oman, December 2016 © Albert Burgas

Then the wings. The pattern is nearly identical in all three birds. There are 2 darker areas overall: somewhere near the innermost median coverts and somewhere near the innermost scapulars. These median coverts share the pattern: short sickle-shaped black lines surrounding a paler yellowish centre of the feather. The scapulars are quite the same too, although this time the black area extends along the shaft and creates a bold arrow. The outer upper-wing coverts show a beautiful golden outer web, in some cases embellished by a fine black base, a pattern that is also visible in the outer scapulars. In some feathers, especially the outermost coverts, the golden area can also extend into the inner web.

Figure 4. Wing pattern of all 3 individuals showing the black stripped area in the inner median coverts and the golden spots on the outer web of the outer median coverts. Note some of these spots have a black stripe at the base. A: Sykes’s Nightjar Caprimulgus mahrattensis. Gujarat, India, January 2019 © Julien Mazenauer. B: Egyptian Nightjar Caprimulgus aegyptius aegyptius. Muntasar Oasis, Oman, November 2017 © Marcel Gil Velasco. C: Sykes’s Nightjar Caprimulgus mahrattensis. Muntasar Oasis, Oman, December 2016 © Albert Burgas

Flight feathers aren’t really visible in these photos, but, from what I can see in all 3 birds perched, they are also bloody similar. There are 2-3 bold stripes on the primary tips and then a very broad golden primary patch at the base. The tail of the birds from Oman shows at least 3 stripes, whereas only one is visible in the bird from Gujarat. However, the inner stripes are actually part of the overlapped upper-tail coverts, so the position of these feathers versus the tail feathers is key for the impression we get.

Conclusion

The differences in size and structure and Sykes’s white spots in tail (males only) and wings should still work, so flight views are due in order to guarantee the id, especially in a vagrant context. However, in my opinion, the extreme plumage similarities between ‘Eastern’ Egyptian and Sykes’s Nightjars make them virtually impossible to tell apart when perched and could probably be considered the most alike Nightjar species pair in the world. This, together with the fact that their ranges are contiguous but virtually not overlapping, makes me thing there must be a linkage of some sort between the two species. Porter, et al. (2013) statement that Indian Nightjar is the most similar species to Sykes’s isn’t true and it’s probably based on a historical exaggeration of the identification criterion. Moreover, given the potential vagrancy of Sykes’s Nightjar to the easternmost WP borders (in fact it has already happened within the extended WP framework) it’s worth properly checking every Middle Eastern Egyptian Nightjar we come across, just in case it shows some white spots in the wing.

Acknowledgements

Big thanks must go to Julien Mazenauer and Albert Burgas for having shared their precious Sykes’s Nightjar photos with this blog. Thanks also to Àlex Ollé and Stephen Menzie for the comments on the matter, and to Martí Franch and Marc Illa for the discussion in the field.

References

• Grimmett, R., Inskipp, C., & Inskipp, T. (2013). Birds of the Indian Subcontinent: India, Pakistan, Sri Lanka, Nepal, Bhutan, Bangladesh and the Maldives. Bloomsbury Publishing.

• Porter, R., & Aspinall, S. (2013). Birds of the Middle East. Bloomsbury Publishing.

•  Burgas, A. & Ollé, A. (2017). Sykes’s Nightjar at Muntasar oasis, Oman, in December 2016. Dutch Birding 39: 329-332.