Stonechats – it’s all in the voice…

This is a good time of year for experiencing the considerable variety of Stonechat vocalisations. Both males and females utter a range of alarm and contact calls and song during the breeding season which mean specific things at different times of the cycle. Combined with visual clues gleaned from their behaviour, these vocalisations can help work out what stage of the breeding cycle each pair are at.

At the moment on Dersingham Bog NNR, we’re hearing just about every possible variation as our Stonechat pairs are at different stages of their nesting attempts, with some still on eggs, some with hatched young and some already with fledged juveniles.

Stonechat Roydon Les Bunyan

Photo courtesy of Les Bunyan

SONG
Only the male Stonechat sings and the peak song period is March and April. It can then cease, apart from brief peaks just prior to the start of each new nesting attempt but declines when the young hatch. Males can sing in good weather throughout the day and not necessarily at dawn. The frequency of song also depends on the nearness of neighbouring territories, with boundary disputes often triggering a burst of song from either male.

Song is also given by the male Stonechat as a distraction technique when observers are approaching a nest area, or are inadvertently sitting or standing too close, as a kind of ‘look at me’ technique by the male, or a distraction to allow the female to leave the nest unobserved. There is also a subdued version of the main song used in a similar fashion as a distraction.

CALLS
Both males and females utter a variety of calls, chiefly used as a warning or distraction. The warning call is usually a short, clear single note whit – often uttered by the male when observers are approaching the nest area and may be used to warn the female not to leave the nest. This is often followed by the male flying away from the nest area, leaving the female still sitting. It can also be used to warn young in the nest and recently fledged young to remain silent.

The distraction call is a harsh chack. Uttered by both sexes but more often by the male, it’s frequently heard when the incubating female is on a feeding circuit if observers are too close to the nest and may be preventing her from returning to it. This call is often accompanied by short flights and wing and tail flicking to try and distract observers away from the nest and towards the calling adult.

SC female unringed Stefan Oscarsson Thornham Feb 2019AThe whit call is most often used during incubation and the chacking call comes more into play when the young are hatched and being fed in the nest. All the calls increase in volume and frequency the closer an observer is to the nest and decline as the person moves away.

The whit call can also used by the male to call the incubating or brooding female from the nest for a feeding circuit if he perceives no threat – i.e. an observer is far enough from the nest area; although she may also be reluctant to leave the nest if the young are close to hatching. However, when the young have hatched, she can also leave the nest immediately upon hearing the call, so observing behaviour as well as listening to the calls becomes crucial at this stage in order to work out what’s going on.

There is also a much harsher double chack with a click-click note at the end which is given loudly and constantly by both sexes if observers are near a nest with well-grown young or recently fledged young. This is also accompanied by both parents trying to distract with wing and tail flicking and flying towards the observer and then away again, to try and ‘tempt’ the intruder away.

SC-Flat Nose Nth Male + 1st brood juv 2017 Benno Zeelte

Adult male with recently fledged juvenile. Photo courtesy of Benno Zeelte

Calls increase in volume and frequency as the young grow, reaching a peak when the young are near to fledging and continue after they fledge, particularly in their first week out of the nest. While the male continues to feed the young after fledging and will alarm if a person is near, the calls will gradually decrease as another nesting attempt begins when the female begins building another nest and the young from the previous brood leave their natal area or are chased off by the male. Fledged young also have a hoarser chack call which they give as begging calls for food or in response to an intruder; it’s a subtly different note from the adult’s chack call.

Each pair is different though and some we’ve found are very tolerant of a fairly close approach to the nest before they will alarm, regardless of what stage they’re at in the breeding cycle, while others will alarm when observers are some distance from the nest area. Pairs can also alarm when a ground predator is present or corvids but they rarely seem to alarm in response to the presence of birds of prey.

Both sexes can utter a variety of other interesting calls at different times, including a brief hoarse rattling krrrrr which is used in song flights or territorial defence and the thin seeseeseeseesee call is usually given by the female. Nestlings can sometimes be heard calling shree shree shree shree, although in practice it can be difficult to hear until a person is standing right over the nest or it’s a call they can give sometimes when they’re handled.

SC male Tranquil valley unringed2This only covers a fraction of the vocalisations Stonechats can produce. The song is especially varied and given in a variety of circumstances. We’ve just covered the ones which are helpful to our volunteers in their survey work, particularly in the nest-finding process, and helping to judge the relevant stage of the breeding cycle so volunteer time and effort can be planned more effectively. There’s a whole other article in trying to cover the display and song patterns and behaviour of this charismatic chat.

If you’re curious to listen to some of the vocalisations, Xeno Canto is quite a good resource for examples of the different calls and songs – https://www.xeno-canto.org/species/Saxicola-rubicola

Advertisements
This entry was posted in Uncategorized. Bookmark the permalink.