This conference on ecological and traditional approaches to memory was held in 1985, 100 years after the publication of Ebbinghaus's monograph (1885/1964) marking the beginnings of a science of memory. Although this happens to be a centennial coincidence rather than an observance, I want to emphasize some continuities between the tradition deriving from Ebbinghaus and more ecologically oriented research. There is a tendency to view the ecological approach to memory as contrasting sharply in both method and theory with the Ebbinghaus tradition. Indeed, some psychologists might see the research represented in this volume as exciting in direct proportion to the liberation it shows from the presumed dreariness and artificiality of the verbal learning tradition descending from Ebbinghaus. I argue here that this would be a mistake and, instead, suggest that there is much in common between laboratory studies of memory and the study of memory for events that did not occur in a psychology laboratory. Further, I believe that Ebbinghaus himself would have approved of most of what he would have heard at the conference.

Continuities across approaches

Verifiability

Ebbinghaus's most important methodological contribution to the scientific study of memory, in my opinion, is that he carefully controlled the conditions at encoding. In the Ebbinghaus tradition, the experimenter is present at the encoding and can therefore score for the accuracy of remembering later on. The problem of verifiability, as Brewer puts it, presents difficulties for the majority of studies of autobiographical memory.

One of the fundamental issues guiding work on autobiographical memory in recent years concerns the role of higher-order cognitive structures in these recollections. Presumably, the influence of such structures is a matter of degree, depending on such variables as the delay between the remembered event and the memory, the cues available at the time of recollection, and the character of the materials remembered. Boldly or timidly advanced, views that attribute a role to such structures require that at least some features of some autobiographical memories involve not the retrieval of mental copies of the original experiences but rather reconstructions based largely on our general knowledge of related everyday affairs. The teeth in this reconstructionist position show when its partisans employ it to explain even those memories that seem to subjects as if they did involve nothing more than the direct retrieval of mental copies.

Until quite recently, Craig Barclay and William Brewer both have defended relatively strong versions of the reconstructionist view of autobiographical memory. Now, apparently, only Barclay does. Both Brewer's chapter and Barclay and DeCooke's chapter respond to challenges to the sort of schema-based approach to mnemonic reconstruction that they have championed in the past. Barclay and DeCooke aim to improve on the previous research in order to offer additional evidence in support of this position. Brewer, by contrast, continues a recent trend toward a more moderate-sounding position (Brewer, 1986).

This chapter describes two empirical studies of autobiographical memory that focused on the personal memory component of autobiographical memory. These experiments investigated the characteristics of randomly sampled events and of events that subjects selected to be memorable. The autobiographical memory data in these experiments were obtained from naive subjects, not from the experimenter. Both experiments were designed so that it would be possible to study memory for thoughts independently from memory for actions. The second experiment was designed to study cued recall of verifiable autobiographical memories, and in this experiment systematic reports were obtained of the subjects' phenomenal experiences during the recall process.

The data from these two experiments were used to address a wide range of issues in the study of autobiographical memory. Memory for random events was compared with memory for subject-selected events, and memory for thoughts was compared with memory for actions. A number of analyses were carried out to uncover the relationships between the characteristics of the original events and memory for these events after various time intervals. The cued-recall data were used to study the accuracy of autobiographical recall and to work out the relations between the contents of the events and memory for the events. An analysis was carried out to study the relative effectiveness of various forms of cues for the retrieval of information from autobiographical memory. The data from the phenomenal memory scales were used to explore the subjects' experiences during the recall process.

This book represents an emerging theme in the field of memory research: a shift in focus from examining what memory is, a structural approach, to what memory is for, a functional approach (Bruce, 1985; Oakley, 1983). As Nelson points out, one of the primary and developmentally early functions of event memory is to organize our knowledge about the world, and as Barsalou's data demonstrate, this remains an important function of event memory throughout development. But there is another function of event memory. Event memory not only organizes our knowledge about the world, but also helps organize our knowledge about ourselves. Our sense of self and event memories are interwoven systems. We learn about ourselves by interacting with the world. Who we are is largely defined by what we do–the kinds of activities and events that we engage in.

Moreover, it is the sense of self that is crucial for autobiographical memory. Autobiographical memory is not simply memories of previously experienced events; it is memory of the self engaging in these activities. It is the sense of self that makes the memories cohere as a life history that expresses the essence of who we are. Whereas event memory serves the function of organizing our knowledge of the world, a predictive function, autobiographical memory serves the function of organizing our knowledge about ourselves, a self-defining function. I am not arguing for two separate memory systems, only for multiple functions.

There are a few people who think and write so clearly that their work is almost always influential. They can shape a whole field. What they say has to be taken very seriously. Failure to do so can waste a lot of time either because valuable insights are lost or because less-than-valuable insights are followed. Professor Neisser has shown himself to be such a person.

There are some problems that have “garden-path” solutions that are so seductive that psychologists repeatedly take them. Professor Neisser has warned us about many of these, including the reappearance hypothesis and the fact that the physical onset and offset of stimuli are not the psychological onset and offset of stimuli (Neisser, 1967). I think nesting is such a garden path, partly because it contains a kernel of truth and partly because we have been misled by similar concepts in the past. In Gibsonian ecological terms, nesting is a garden path because it makes a structure out of a process.

In what follows, Gibson's use of the word ecological is taken specifically to include the following principle: Although we should always start by making a very good description of the environment before wondering how the animal interacts with the environment, we should not copy that description of the environment into the mind.

Taxonomy

Shelducks are intermediate between the true ducks and the geese, although they are usually placed with the ducks in the family Anatidae, where they join the sheldgeese in the tribe Tadornini (Johnsgard, 1961). There are seven species of shelducks: the common or northern shelduck Tadorna tadorna (L.), the ruddy shelduck T. ferruginea (Pallas), the Cape or South African shelduck T. cana (Gmelin), the Australian shelduck or mountain duck T. tadornoides (Jardine & Selby), the New Zealand or paradise shelduck T. varietaga (Gmelin), the radjah shelduck or burdekin duck T. radjah (Garnot) and the crested or Korean shelduck T. cristata (Kuroda) (which may be extinct). All are large brightly coloured ducks with many goose-like features. The lack of a camouflaged female plumage, the persistence of the pair bond and the prolonged parental behaviour shown by the male all resemble the geese, whereas the general morphology, voice and the existence of an eclipse plumage are duck-like. Johnsgard (1978) considered that, like the radjah shelduck, the common shelduck represents a rather isolated offshoot from the rest of the group. Both species are adapted for dabbling and feed chiefly on molluscs and other invertebrates, whereas the rest of the group are principally vegetarian.

The common shelduck was originally called Anas tadorna by Linnaeus in 1758, but has had a variety of other names including Tadorna cornuta (Saunders, 1889) Tadorna vulpanser and Tadorna bellonii (Yarrell, 1843).

Having selected a nest site, the breeding bird must build a nest, lay a clutch of eggs and incubate them. The number of young hatched will depend on the size of clutch which can be produced and success in hatching them, in the face of many factors which might cause failure. Incubating birds must divide their time between the eggs and the need to spend some time feeding, the balance depending on the fat reserves which can be lost over the incubation period. In this chapter I will discuss these and other problems encountered by laying and incubating shelducks.

The timing of laying

The date on which the first egg of the clutch is laid can only rarely be determined by direct observation during the egg-laying period, due to the inaccessibility of the nests and the birds' intolerance of disturbance. Instead, a number of indirect methods must be used. In a few nests, observed before laying is complete, the laying date of the first egg can be back-dated since normally one egg is laid per day (Hori, 1964a). If the hatching date and clutch size are known, the laying date can be estimated using the incubation period of 29–31 days (Hori, 1964a; Young, 1964a), plus one day for each egg in the clutch. More commonly the laying date is back-dated from the first sighting of the brood of ducklings, adding a further day which the young spend in the nest after hatching (mean of four nests observed at hatching by Young, 1964a).

Parental behaviour normally involves a number of different activities: feeding the young, providing them with shelter and protecting them from predators and other dangers. By investing time and energy in this behaviour, even at some risk to their own chance of survival, the adults enhance their genetic fitness by increasing the survival of their progeny. Shelducks, like other parents of precocial young, do not feed their broods but merely accompany them while they feed themselves. The parents do, however, actively provide shelter and protection as I shall describe in this chapter.

Leaving the nest

Newly hatched young shelducks stay in the nest for some time, usually for at least 12 h and up to four days if there is a wide spread of hatching date within the clutch (Hori, 1964a). During this period, ducklings and female call frequently. Hori was able to approach very close to a nest inside a shed and described a monosyllabic ‘aarrk’ and a soft running ‘ugg ugg ugg’ given continuously for long periods by the female. I installed a microphone in a nest burrow over the hatching period and heard similar calls, along with piping responses from the ducklings. All of the calls are given very softly and can only be heard at very close range. It is likely that the ducklings become imprinted on the mother's voice while in the nest (Gottlieb, 1965). Since the ducklings' first hours are spent in the dark, it is obviously functional to use auditory rather than visual characteristics of the mother as a basis for imprinting.

An animal can be said to show territorial behaviour when it has some attachment to a site (or occasionally to a moving object) and when it is aggressive towards other animals which approach that place. The resulting territory, around the site of attachment, has been defined in a variety of ways. Pitelka (1959) and Schoener (1968) emphasised the owner's exclusive use of an area, usually with defined boundaries, whereas Davies (1978) recognised territories wherever interactions between individual animals led to their being spaced apart more than would be expected from random settlement. Between these two extremes, I prefer the simple definition of territory as ‘a defended area’ (Noble, 1939; Nice, 1941). This embodies the essential features of a special place, around which there is aggressive defence, without implying particular features such as exclusive use or rigid boundaries, or particular consequences such as spacing out of the individuals, which may occur in many but not necessarily in all cases.

Territorial behaviour raises some interesting questions. Since aggressive defence of an area requires the expenditure of time and effort, there should be some corresponding benefit to the owner's fitness which outweighs the cost of territoriality (Davies, 1978). The spacing effect of territorial aggression would be expected to influence the dispersion pattern and density of populations. These possibilities are of particular interest in the shelduck since territorial defence, particularly by both members of the pair, is not common among ducks.

Shelduck territories

Towards the end of winter, from February to April, shelduck pairs detach themselves from the winter flock and scatter widely over muddy shores, or freshwater pools and creeks near the coast.