Wednesday, June 26, 2013

Duetting Scops Owls

Earlier this month I was birding in Extremadura in western Spain, camping on the edge of Monfragüe National Park. Each morning I woke to the sounds of Hoopoes and Iberian (Azure-winged) Magpies. In the evening after sunset, Eurasian Scops Owls (Otus scops) began 'singing' and one evening I managed to locate a bird about 600 metres away on the road to Malpartida de Plasencia. 

Dehesa habitat around Monfragüe
What was most interesting was that from a distance it sounded like a single bird, but on getting closer it didn't sound like a typical Scops Owl. In fact, what I was hearing was both a male and female in perfect, overlapping synchronisation. Have a listen to the sound recordings below (and click the sonograms for a larger image). The male is producing the lower frequency sound at 1.23-1.94 kHz, with the female at 1.41-1.61 kHz.

Duetting pair with almost perfect synchronisation; the female is producing the second, quieter, shorter and higher-pitched part.

Detail from the above sonogram showing the duet detail: Male song in blue Female song in red

At times the female would drop out of the duet, and the sound clip and sonogram below shows the male vocalising alone. It appeared to produce a slightly longer note when not duetting.

Song/territorial call from the male.

Monday, June 10, 2013

Kindrogan Dawn Chorus Chronology

I've been noting the chronology of species joining the dawn chorus since 2003 at Kindrogan Field Centre in Perthshire, Scotland. This occurs in the first or second week of June when I’m present on a university field course. While this phenomenon of gradual song burst leading up to sunrise (approximately 04:28 on 5 June 2013) probably peaks sometime earlier in May, many species are still clearly defending territories from neighbouring males, guarding fertile females from extra pair copulations, or in some cases still attempting to attract a mate, or additional mates. Here is the chronology from a typical morning on 5 June 2013 with 50% cloud cover and almost no wind. Listen to an excerpt of the dawn chorus from a sound recording made that morning featuring Robin, Great Tit, Wren, Blackbird, Song Thrush, Goldcrest, and Treecreeper.  

Click the images to enlarge.

The chart shows the time at which the first song from each species was noted from the Robin starting at 03:05 to the final species, Spotted Flycatcher at 04:11. The waveform shows the relative sound intensity recorded with the built-in mics on my sound recorder.

The north-west end of Strathardle, looking south-east from Creag na Cuinneige. Straloch Loch is in the foreground, Kindrogan Hill on the right