Part 9: Playback and be damned
Interacting with birds: imitating, whistling and spishing
Much of what we have summarised in the second half of this book was researched by scientists playing sounds to birds and observing their response, a technique called playback. Birders, and especially bird tour leaders, sometimes use pre-recorded sounds or record an unseen bird and play its own sound back to it, hoping to bring the bird closer. This is also called playback or, more commonly, tape-luring. The technique has a chequered reputation, and at worst it is used by bird-catchers in countries like Cyprus to draw birds to their death.
Ringers regularly use playback to attract birds into their nets, and many ringing stations, especially in the Benelux countries, are arrayed with speakers pointing at the stars. Vagrants are sometimes tape-lured with song in an attempt to confirm their identification. Nearly all bird tour leaders will use it now and then hoping to show a highly sought-after bird to a holidaying group of birders as quickly as they can. Photographers sometimes use tape-luring in order to bring their subjects close, and they often betrayed themselves with images of over-excited birds. The effectiveness can vary enormously and Arnoud, when leading tours, believes that its success depends on the species and time of year. When tried in September in Morocco, it only works less than 10% of the time, whereas in Holland a Water Rail, Willow Tit or Short-toed Treecreeper will respond to Arnoud’s efforts at any time of year. Some sound recordists use it to improve their recordings, although in The Sound Approach database of 30 000 recordings until 2006, only 125 were tape-lured. In this publication, only the four mentioned below were lured, and not all by playback as we shall see.
Many birders consider playback distasteful on aesthetic grounds, especially if it is loud, wanting to enjoy peaceful surroundings, and natural sights and sounds. Others see it as sloppy technique or indeed cheating, like athletes secretly resorting to the use of steroids, but the most frequently voiced objections concern possible effects on the birds themselves. These usually suggest that birds desert territories, nests, or young, become an easy target for predators by getting in the open, or suffer long term stress, having been humiliated by a much louder competitor (the playback). It’s worth mentioning at this point that in many countries, interacting with a locally rare bird could contravene the law.
For scientists, however, playback has been used as an important experimental technique in thousands of field experiments, apparently without any of these negative effects. It is thought that when playback is used in a male bird’s territory the main effect is to raise his testosterone levels. Research has shown that when the song of a given species is played in an area where there are several territories, males will usually be concerned about another male fertilising their mate (Dabelsteen & McGregor 1996). Most songbirds are promiscuous, and when you play a song inside a pair’s territory you are behaving in a pretty insolent way. The male has various ways to respond to any interloper. He can stay silent close to the female, and research shows that when she is about to ovulate this is the normal strategy. Alternatively, he can fly towards the sound, singing or calling, and try to drive the newcomer from his territory. He will judge the distance to the intruder, and therefore the seriousness of the intrusion, by the degree of degradation of the sound, not by loudness. He will recognise whether the intruder is a neighbour by listening for any shared songs. A female may also be drawn to the newcomer in the hope of an extra-pair copulation, although research shows that females tend to be more discerning than males, so they are less easily fooled by playback. In natural circumstances, an unfamiliar, opportunistic challenger will tend to be a less experienced first-year male. If this is so, a resident male may be sufficiently emboldened to chase off the youngster, and a female will generally be less attracted to him.
Magnus experienced another aspect of tape-luring on the 8th of August 2004 while looking for migrant Aquatic Warblers in his patch at Kennemermeer near IJmuiden, the sea harbour 25 km west of Amsterdam. Setting off to look for one that had been found the day before, he was still 80 m from some other birders when he noticed a juvenile singing right beside him (CD2-88). Although he had seen quite a few juvenile Aquatics at this site before, this was the only time he had ever heard one singing. When the other birders joined him, it turned out that they had been playing an Aquatic tape, trying to lure another individual. So, their tape had the desired effect of bringing an Aquatic up out of the sedges and even stimulated it to sing. However, they had not noticed this because this happened too far from where they had been playing the sound. Shaun Robson experienced a similar situation when he and Bob Gifford were ringing in Shaun’s patch of Lytchett Bay in Poole. They had been using a tape to bring birds to the nets and having packed everything away were leaving the ringing site when they heard an Aquatic singing. Not believing his ears Shaun immediately thought I was hiding in the reeds playing a tape. In fact he still thinks this. As in much adult song of this species, the subsong in this recording is very simple and consists mainly of trrt notes. Without hearing the fine warbling between these notes, mainly heard later in the recording, one could be forgiven for dismissing the recording as a series of calls.
CD2-88: Aquatic Warbler Acrocephalus paludicola IJmuiden, Noord-Holland, Netherlands, 08:00, 8 August 2004. Subsong of a juvenile that had been tape-lured by birders 80 m away. Background: begging calls of juvenile Common Reed Bunting Emberiza schoeniclus. 04.039.MR.14040.12
When he lured a male Black Woodpecker Dryocopus martius in the French Pyrenees, Arnoud used playback of a pre-recorded male’s song. Our bird flew in and sized us up from behind a nearby tree trunk but did not call, and after looking around it eventually flew off. As we then made our way through the woods some way from the original bird, we heard several male Black Woodpeckers calling and drumming. You can hear at least three of them in CD2-89. They had been quiet before, but now this displaying went on for hours.
CD2-89: Black Woodpecker Dryocopus martius Col de Spandelles, Hautes-Pyrenées, France, 15:34, 18 June 2002. Quiet drumming, and laughing song of a male at close range, answered by at least two distant birds. Background: Common Chiffchaff Phylloscopus collybita and Common Chaffinch Fringilla coelebs. 02.022.AB.10410b.11
This kind of reaction was described by S J Gray (in McGregor & Dabelsteen 1996). In his studies of male Zitting Cisticolas, Gray noticed that while these birds listened during playback sessions their neighbours were engaged in, they decreased their own vocal activity by 53%, and after playback stopped they increased it by 254% in an effort to stop the apparent interloper visiting their territories. Eavesdropping by pairs nearby can mean that playback has a ripple effect, resulting in more vocal activity across several territories.
Give a little whistle
Bird sounds are an aspect of behaviour, and we have to be very sharp observers if we want to achieve anything with them. This applies just as much whether we are trying to attract birds, or simply to identify them. Researchers, who can spend a lifetime studying their subjects, get to know exactly how they behave. Birders on the other hand tend to use playback in a rather haphazard way. This is less exact, often embarrassingly clumsy, and typically unsuccessful. If you impersonate bird calls instead, either by whistling or by using a bird whistle or other instrument, you can be more sensitive, and possibly more successful. Returning to Black Woodpecker, Dick often whistles them in by impersonating the male’s song (CD2-90). This usually works, and his tour groups are often astonished to see one hurtling towards them from a considerable distance. If you compare Dick’s imitation with the song of a real Black Woodpecker in the preceding track, you can hear that not only has Dick got the changes in speed and pitch right; he also waits about 25 seconds before doing his next series, just like a real Black Woodpecker.
CD2-90: Dick Forsman Homo sapiens Tvärminne, Hanko, Uusimaa, Finland, 27 March 2005. Dick whistles his imitation of a Black Woodpecker Dryocopus martius song. In this instance, there were two males squaring off on opposite sides of a nearby trunk (you can hear some very quiet calls and their claws scratching the bark), and Dick was trying to break the stalemate. Background: excitement calls of distant Glip Crossbills Loxia curvirostra type C. 05.001.DF.12339.10
TV and radio personality Percy Edwards could impersonate hundreds of birds (he also provided the voice of the alien in the film The Alien), and he used a variety of techniques to attract curious birds. He would whistle a bird’s song to get it to show itself, and sometimes use gentle tutting to decoy wheatears, stonechats, redstarts, flycatchers and others. By making a kissing sound by putting two fingers across his mouth and sucking, he also attracted inquisitive birds (Edwards & Watson 1986).
Pekka Pouttu is a sort of Percy Edwards of the Finnish forest, and like so many Finns he has a homemade owl-caller. He happily imitates Ural Owls, and attracts Eurasian Pygmy Owls by impersonating Tengmalm’s Owls Aegolius funereus. Here, using a leaf, Pekka does an amazing impersonation of a Northern Goshawk, which stimulates a Northern Bullfinch Pyrrhula pyrrhula pyrrhula to call (CD2-91).
Pekka Pouttu (right) teaching Killian Mullarney how to do an imitation of a Northern Goshawk Accipiter gentilis, Hauho, Kanta-Häme, Finland, 31 March 2002 (Mark Constantine). Same sound source as on CD2-91.
CD2-91: Pekka Pouttu Homo sapiens Hauho, Kanta-Häme, Finland, 31 March 2002. Pekka does an amazing imitation of a Northern Goshawk Accipiter gentilis, prompting responses from a male Northern Bullfinch Pyrrhula pyrrhula pyrrhula. In addition: chick-a-dee type calls of Great Tit Parus major, song of Eurasian Treecreeper Certhia familiaris, calls of distant Hooded Crows Corvus cornix and Yellowhammer Emberiza citrinella. 02.006.MC.00820.31
This kind of backwoodsmanship is also used widely in North America. Imitations of Eastern Screech-Owl O asio and Barred Owl S varia are so common during birdraces that it is a challenge not to tick another team by mistake. Another facet of attracting birds, especially in North America, is spishing or pishing. Often very effective, it involves making psssh psssh psssh sounds reminiscent of the calls of some birds when mobbing a predator. Bruce Mactavish, ‘Macspish’ to his friends, is an exponent with a famed ability to attract flocks of small passerines while hiding deep in the bushes. Bruce has also shown me that spishing can be equally effective on both sides of the Atlantic. In fact, many exciting rarities have been found in this way. Ireland’s second Hume’s Leaf Warbler P humei was found by Killian on Hook Head, Ireland, while spishing opportunistically at a series of bushes (CD2-92).
CD2-92: Hume’s Leaf Warbler Phylloscopus humei Hook Head, Wexford, Ireland, 15:50, 28 December 2003. Calls given by a vagrant in response to spishing. 03.017.KM.01855.22
Hume’s Leaf Warbler Phylloscopus humei, Hook Head, Wexford, Ireland, 28 December 2003 (Killian Mullarney). Same bird as on CD2-92.
While I was travelling with Dick in Spain, we met an old friend, Gordon Wilson, who was on a birding holiday with a large group of his friends, some of whom were very keen to see a European Scops Owl. They had been trying playback without success for several evenings and wondered if we could help. We listened to their scops owl playback which, due to the tape copy, the machine itself or the speakers, was dreadful. After some debate we all drove off into the countryside, parked in a suitable spot, and Dick whistled the typical monotone song of a scops owl. Within a very short time he was engaged in a duet, answering back and forth.
It seems that the secret for successfully drawing birds towards you is to have experience of the way they use their vocabulary, and to listen carefully for any reaction. I often record with the help of a friend, so that one of us can do the recording while the other confirms the identity, age, sex and behaviour of the subject. When recording, it can be all too easy to lose perspective, and focus too much on operating the equipment. I think it can be the same with playback: by the time you have got the equipment working, set up the speakers, and found the right place on the tape, CD or mp3 player, you are no longer listening carefully to the interaction.
To sum up, whether you lure with playback, your voice or a whistle, consider what part of a bird’s repertoire you are using, and don’t go on for too long. If a bird doesn’t respond fairly quickly, try returning once or twice later that day or the next. This enables you to get the benefit of the priming process you have started (Smith 1996). The stimulated bird may sing more within a few hours as his hormone levels rise. At a shorter time scale, many species will search silently once the sound has stopped and will continue looking for up to half an hour, so using more than three or four phrases of playback is not necessary. If a bird sings in response, it will probably start to increase the pace of its songs and turn to face you. Birds often match the song you are producing, and may sing a simplified male-to-male variant of their song, lacking any female-attracting adornments. If you are already close, they may sing more faintly or approach silently. Females are more likely to be excited by impersonations than be led to desert their nests, although they will probably ignore it. Good quality sound is likely to be more effective than loudness, which just annoys other birders and gets in the way of listening. And bear in mind that the male to which the recording is being played may be less likely to sing back than his neighbours.
When actually tape-luring, basic procedure is to play two or more song types for a short time at least 20 m away from where the subject is expected to be at a volume that would sound natural at that distance. Remember that the bird is listening for degradation not loudness, and a poor loudspeaker or badly copied recording could degrade the sound beyond recognition. Try to emulate a natural intrusion into a territory: make sure the gaps between songs are as natural as possible (commercial recordings other than our own often have silences edited to save space), and if you have them, use songs of first-year males. Position the sound source near vegetation that could hide an intruder and if unsuccessful try again at a spot a little closer. If, having primed the birds, you still have no luck in drawing one into view, search the surrounding area, looking and listening for the silent male or his neighbours. If you have to come back later, don’t forget to listen for a while before you do any playback.
Bird song is a government indicator of quality of life in Britain (DETR 2001) and you would imagine that it’s either something that you are either blessed with in your area or not. This isn’t the case. When I first started visiting Mallorca there was little to no dawn chorus. Thrushes were shot in the winter for food and became rarities by springtime. At dawn in the countryside around Pollensa, Stone-curlew would join the cockerels and that would be it. Now, blackbirds, robins, rock thrushes Monticola and other chats all contribute to a reasonable dawn chorus. Back home, in the winter, I feed over 20 Common Blackbirds in my garden along with half a dozen Blackcaps and a host of other birds. At the time of writing (February) I have robins, blackbirds and Song Thrushes T philomelos singing, and Blackcap subsinging each morning. Further up and down the road there is no singing this early in the ayear. Birds have more time to sing when they need less time for foraging. They can also attract a mate earlier if they are well-fed and strong, and when a good source of food is nearby.