I investigated the spatial memory abilities of male rufous hummingbirds (<i>Selasphorus rufus</i>) on their breeding grounds, where birds can be readily trained to feed from artificial flowers presented in two- and three-dimensional arrays. I found that birds use height as a cue when encoding flower locations, preferring to visit taller flowers. Performance in three-dimensional arrays was not however consistently better than in 2-D arrays. I also examined the possibility that hummingbirds follow a fixed flight path when returning to an array of flowers, as has been seen in the Hymenoptera. By manipulating the number of doors by which a bird could enter an arena to feed on an array of flowers, I found some evidence that birds do use systematic movements when relocating rewarding sites. Rufous hummingbirds feed on floral nectar, a resource that varies in time as well as space. To determine whether these birds use time as a cue when foraging, I provided them with an array in which flowers were refilled after intervals of either ten or twenty minute. The birds were able to learn these intervals, as they returned to flowers on or shortly after their expected refill time. I used an analogous experiment to investigate timing abilities in coal tits (<i>Parus ater</i>), a food-storing species, and great tits (<i>P. major</i>), a non food-storing species, in the laboratory. Storers and non-storer might differ in their ability to time intervals due to the demands, on storers, of reliable cache recovery. Coal tits were able to track the availability of rewards in three different locations associated with reward schedules in the 30-120s range. I found no consistent differnces in the abilities of coal tits and great tits to time intervals in the 40-70s range. In conclusion, rufous hummingbirds were shown to use both spatial and temporal cues whilst foraging at flowers. Coal tits and great tits were able to time short intervals in the laboratory, but I found no overall differences in timing behaviour between the two species.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:652323 |
| Date | January 2004 |
| Creators | Henderson, Jonathan |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14049 |
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