Spotted Crake

Porzana porzana


Magnus Robb,
Lukas Pelikan &
The Sound Approach
NFC, Night flight calls
24th May 2020

Spotted Crake Porzana porzana Besh Barmag, Siazan, Azerbaijan, 02:52, 6 May 2005 (BB). Two flight calls of a nocturnal migrant; first call shown. For a zoomed-in version see a) below. Background: Common Nightingale Luscinia megarhynchos and Marsh Frogs Pelophylax ridibundus. 190506.MR.025232.01                                    Please use headphones

Among nocturnal flight calls, the kwitt of a Spotted Crake Porzana porzana is among the most distinctive, and yet also one of the most likely to provoke disbelief and strong doubts: “Could a Spotted Crake really fly over my house in suburbia?”

We know of only one type of nocturnal flight call, which closely resembles the song of this species, except that it is given singly, not repeated monotonously. By comparison to this familiar sound, NFCs of Spotted may sometimes sound a bit “off”, often being higher-pitched, squeakier or having a less tidy structure.

Spotted Crakes rarely fly any distance during the day, and we have no daytime flight calls for comparison. However, they do have a variety of call-types that are recognisably similar to individual units of song (Feindt 1968). In the example below, you can hear calls given by a migrant in a marsh.

Spotted Crake Porzana porzana Salinas de Alverca, Vila Franca de Xira, Portugal, 31 March 2012. Two calls of a migrant, reacting to a Common Moorhen Gallinula chloropus that called just before the recording started. 120331.MR.194656.02

You are far more likely to pick up a Spotted Crake in spring or early summer than in autumn. At Besh Barmag in Azerbaijan we have recorded up to twelve a night in spring, and it appeared on many more nights than in autumn, during which season we have recorded a maximum of four in one night.

Identification

kwitt calls

 

  • whiplash-like sound, similar to song but usually given just once
  • durations from 56 – 111 ms (90% range; median 85 ms; n = 37)
  • multiple bands give slightly squeaky timbre
  • 2nd lowest band is strongest; fundamental often disappears (e & f)
  • starts with a hook then rises sharply, like a capital in italics
  • wide variation in size of hook and steepness of slope
  • may show a small break in the rising part (a, d & g)
  • frequency of strongest 2nd band 1.2 – 4.4 kHz (mean min 2.0 kHz; mean max 3.6 kHz; n = 37)

 

a) Spotted Crake Porzana porzana Besh Barmag, Siyazan, Azerbaijan, 02:52, 6 May 2005 (BB). Two flight calls of a nocturnal migrant; first call shown. For a zoomed-out version see top of page. Background: Common Nightingale Luscinia megarhynchos and Marsh Frogs Pelophylax ridibundus. 190506.MR.025232.01

b) Spotted Crake Porzana porzana Ebro Delta, Tarragona, Spain, 01:28, 20 September 2019. Single flight call of a nocturnal migrant. Background: juvenile Little Egrets Egretta garzetta. 190920.MR.012842.01

c) Spotted Crake Porzana porzana Besh Barmag, Siyazan, Azerbaijan, 01:50, 3 April 2019 (BB). Single flight call of a nocturnal migrant. 190403.MR.015020.01

d) Spotted Crake Porzana porzana Chafford Hundred, Essex, England, 03:44, 1 April 2020 (David Darrell-Lambert). Single flight call of a nocturnal migrant passing over an urban garden on the outskirts of London.

 

e) Spotted Crake Porzana porzana Besh Barmag, Siyazan, Azerbaijan, 00:35, 3 April 2019 (BB). Two flight calls of a nocturnal migrant. Sonagram shows second call. 190403.MR.003546.11

f) Spotted Crake Porzana porzana Besh Barmag, Siyazan, Azerbaijan, 01:36, 3 April 2019 (BB). Single rather weak-sounding flight call of a nocturnal migrant. 190403.MR.013634.01

g) Spotted Crake Porzana porzana Besh Barmag, Siyazan, Azerbaijan, 03:09, 3 April 2019 (BB). Single flight call of a nocturnal migrant. 190403.MR.030912.01

h) Spotted Crake Porzana porzana Comino, Malta, 05:02, 3 May 2020 (Nicholas Galea). Single flight call of a nocturnal migrant.

Effects of recording quality

  • Closer calls show three or more bands, including the fundamental (a, c & h). The hook at the start is clearly visible, and it may be possible to see weak additional details before or after the main ‘leaning J’-shaped structure.
  • More distant calls will lose the fundamental; the initial hook may also disappear (e).

Similar NFCs

  • Pied Avocet Recurvirostra avosetta has rising NFCs in a similar frequency range but shaped differently, lacking a hook at the start, rising to a lesser degree, and with a slope that levels out or becomes an arch at around 2 – 2.5 kHz.
  • Common Quail Coturnix coturnix has wet-my-lips NFCs with a similar whiplash sound and rising shape, but usually given in triplets. Occasional NFCs with just one such note have only half the duration of a Spotted Crake NFC.
  • Black-winged Stilt Himantopus himantopus has nasal NFCs that can be slightly rising in pitch and may resemble those Spotted Crake NFCs that have a weak slope. However, they do not have a hook at the start, and show a more even distribution of energy across several bands, rather than a concentration on the second band from the bottom. Besides, it would be extremely unusual to hear a single call of this species in isolation.

Where and when?

  • anywhere: over towns, forests, deserts; but not known to call offshore
  • strictly nocturnal: no known diurnal flight call
  • can be heard all night, especially second half

Spotted Crake Porzana porzana Maximum estimates of calling individuals per night: low, medium and high activity. See introduction for a full explanation.

Note of caution

Given that most experiences of Spotted Crake NFCs involve only a single call, it can be difficult to be sure that the bird is in flight. Without the benefit of a series of calls increasing then decreasing in volume with Doppler effect changing the pitch, we are obliged to make an educated guess based on our location and the surrounding habitat.

Beside their well-known songs, both males and females on breeding grounds have calls that are similar to single song notes. This means females also have a call similar in timbre to the song (Ingold 1918). But we do not know how to separate the calls of the two sexes.

Literature

Feindt, P 1968. Vier europäische Rallenarten. Vinyl, 7″, 45 rpm, mono. Hildesheim.

Ingold, R 1918. Vom Tüpfel-Sumpfhühnchen, Porzana maruetta Briss. in Gefangenschaft. Ornithologischer Beobachter 15: 177-181.