THE USE OF “PISHING” AND PLAYBACK TO INVESTIGATE TERRITORIAL BEHAVIOUR WITH A FOCUS ON NEOTROPICAL MIGRANT BY MARLON BEALE

INTRODUCTION Neotropical migrants breed in Canada and the United States during the summer and spend their winter in Mexico, Central America, South America or the Caribbean Islands. According to the strict definition, there are about 200 species of Neotropical migratory . The majorities are songbirds (such as warblers, thrushes, tanagers, and vireos), but there are also many shorebirds (such as sandpipers, plovers and terns), some raptors (such as hawks, kites and vultures) and a few waterfowl (such as teal). In the past several years the alarming downward population trends of many Neotropical species has been made known. The culprits are both the loss of wintering ground habitat and habitat fragmentation on the breeding grounds. Along with habitat fragmentation there also is parasitism by Cowbirds. Territorial behaviour or territoriality can be described as any of several ways that control access to essential sources, such as food or nesting sites. Males typically compete for territories; either fighting or performing ritual combats as tests of strength. Weaker individuals may be prevented from holding or be forced to occupy less desirable situations. Territoriality may distribute resources disproportionably to the strongest and so limit the reproduction of the less fit. It must be noted that territoriality is one of the many forms of competition, and in order to maximise territorial behaviour, the territory must be such that the resources present can be monopolised.

METHOD The exercise was done in the foothills of Long Mountain, St. Andrew, . The exercise consisted of sixteen (16, i.e. 8 x 2) point counts, each of six minutes duration, during which the investigators stood and recorded all the birds seen. Each point was about 100m apart and marked with flagging as a means of future identification. In the first instance the eight points were counted by sight once. A recount of the same eight points was then done, using Playbacks at four (4) points and Pishing at the other four points. The songs and ‘chips’ of the following Neotropical migrants were used in playback: Black and White Warbler, Black-throated Blue Warbler, Ovenbird, American Redstart, Prairie Warbler and Swainson’s Warbler. The playbacks and pishing were done alternately for these eight points i.e. on the return point counts, point eight was subject to playback, point seven to ‘pishing’ and so on. On the return point counts, ‘pishing’ or playback ensued for the duration of (6 minutes) of the count.

RESULTS The first set of eight point counts in which there was no playback or pishing is hereafter described as the ‘Walk Through’ (W.T.) while the second set of eight points is described as the Return’ (R).

BIRDS SEEN ON INITIAL WALK THROUGH BIRDS SEEN WITH PLAYBACK (PB) OR ‘PISHING’ PB OR POINT (NUMBERS) (PI) PI Prairie Warbler (3), American Redstart, Gtr. Antillean Prairie Warbler (2) Unidentified Warbler, Jamaica A Bullfinch, Northern Mockingbird, Jamaican Oriole, PI Euphonia Unidentified Warbler Jamaican Oriole, Bananaquit, Red-billed B Loggerhead , Gray Kingbird PB Streamertail Black-throated Blue Warbler, Unidentified Jamaican Oriole (3), Jamaican Tody, Loggerhead Waterthrush, American Redstart, Prairie Warbler (4), C Kingbird, Northern Mockingbird, Greater Antillean PI Northern Mockingbird (2), Black-Whiskered Vireo, Grackle Yellow-throated Warbler. D Common Ground Dove, Vervain Hummingbird, Prairie Warbler, Black and White Warbler, Red- PB Gray Kingbird, Unidentified Warblers (2) Billed Streamertail, Loggerhead Kingbird Loggerhead Kingbird, Jamaican Oriole, Caribbean E Jamaican Vireo, Prairie Warbler (3) PI Dove, Yellow-faced Grassquit Jamaican Vireo, Northern Mockingbird, F Unidentified Warblers (2), Loggerhead Kingbird, Prairie Warbler (2) PB Yellow-faced Grassquit G Loggerhead Kingbird (2), Jamaican Vireo, Prairie Warbler (3), Loggerhead Kingbird, PI Caribbean Dove, Yellow-faced Grassquit Bananaquit Jamaican Vireo, Greater Antillean Grackle Prairie Warbler (2), Ovenbird, Unidentified Warbler, H Bullfinch, Northern Mockingbird, Black & White Loggerhead Kingbird, Red-Billed Streamertail, Black PB Warbler, Caribbean Dove & White Warbler

Birds Observed During the Point Counts in Long Mountain

DISCUSSION The total number of birds observed was close to 100, inclusive of locals (resident and endemics species) and Neotropical migrants. There may have been double counting due to the initial walk through and the return to the initial eight points. Chart I shows the observed differences in numbers and types of birds observed. For the walk through more locals were observed with the return having more Neotropical migrants observed. Possible reasons for the observations are: For the walk-through - (i) Local birds are generally larger in size and easily observed than migrants & (ii) Greater number of local birds inhabits the area For the return – The use of playback and pishing techniques which target Neotropical migrants specifically. The playback technique exemplifies both Interspecific and intraspecific competition. Although not clearly shown in the results, use of playback should demonstrate the presence of a competitor in the ’s territory, especially if one of the same species, there would be defence of its territory protecting the resources necessary for survival. The use of pishing, serves to mimic a familiar North American predator of the migrants. The technique resulted in more birds being observed. Possibly the territorial behaviour is temporarily suppressed in the presence of danger. Birds become more agitated, more vocal as they approach the source of the pishing. Explanations for this include: (i) Investigation of the source of the threat; (ii) to spread the alarm & (iii) Use of a safety in numbers device or mobbing effect to deter the predator.

BIASES It was noted that during this part of the exercise certain biases were present and these were noted below: (i) The time of year : It was early in the migratory season and not a lot of birds may have arrived on the island. (ii) The time of day: birds are more active in the earlier hours of the day. At the time of day visited, it was not expected to see many birds. (iii) The wind : this may have resulted in the birds not hearing the playback calls or pishing. (iv) The volume of the calls : on the cassette there was a discernible difference in the volumes of the birdcalls, so other call heard louder and clearer than others. (v) The observer : it was noted that with time the observers got better at observing the birds in the area.

CONCLUSION Both ‘pishing’ and playback increased species detection in point counts over counts by sight only. The birds responded aggressively to playback of songs and chips because they are defensive of territory. However, pishing resulted in more birds being detected. Of the three methods used, pishing was more effective because not only did it attract more individuals to the observer, but apparently resulted in temporary relaxation of territorial behaviour.

REFERENCES Marra, P.P., Sherry, T.W. & Holmes, R.T. (1993). Territorial exclusion by a long – distance migrant warbler in Jamaica: A removal experiment with American Redstarts (Setophaga ruticilla) The Auk 110 (3): 565-572 Sliwa, A. & T.W. Sherry. (1992). Surveying winter warbler populations in Jamaica: Point counts with and without broadcast vocalisation. Condor 94:924-936.

N.B. This paper was a lab report submitted for the course Behavioural Ecology of Animals and reprinted in BirdLife Jamaica’s The Broadsheet no. 76 March 2001 pp 16 - 19

Contact Information: Marlon Beale Email - [email protected] Also of BirdLife Jamaica - [email protected] Post – Graduate Student Department of Life Sciences, UWI Mona