The thesis is divided into three parts. In part I the ecology and behaviour of the Jungle Babbler Turdoides striatus are described and in part II comparable data on the Common Babbler T.caudatus are given. In part III some observations on other species of Turdoides and on the Long-tailed Tit Aegithalos caudatus are described and a general model for the evolution of group territoriality and co-operative breeding is presented. A description of the habitat in which Turdoides studies were carried out is given in an introduction which includes data on seasonal cycles and a brief outline of the ecology of the resident avifauna. A summary is also given of the biology of Turdoides species, which live in permanent exclusive groups of 2-20 birds, holding common territories throughout the year. In most cases only one pair breeds during the season, but many non-breeding group members take part in nesting activities, particularly feeding the nestlings. The aims of the study are summarised in two questions: "What circumstances make it advantageous for more than two birds to share a territory?" "What circumstances make it advantageous for birds to assist in rearing conspecifics which are not their own offspring?" Part I contains four chapters. The first deals with the population dynamics of the Jungle Babblers within the main study area on the outskirts of Delhi, India. Methods used to estimate recruitment, survival, interchange between groups, group structure and the degree of relatedness between group members are described. Territories are classified into three types on the basis of the vegetation that they contain and differences are found between these categories in the number of young reared and the number of birds per group. Large groups, which occupy territories mainly in woodland, probably produce most of the recruitment into the adult population. Birds from these groups may move into territories outside woodland to breed, but breeders in woodland territories are probably recruited from territories of a similar type. Although woodland groups are large and have a high breeding success there is no evidence that the number of non-breeders in the group influences the reproductive success of the breeding pair directly. In Chapter 2 the territorial behaviour of the Jungle Babbler is described. Groups do not cover their home ranges evenly, but tend to concentrate their activities in a small portion, usually comprising closed-canopy woodland with a dense understorey, known as the 'core area'. This was arbitrarily defined as the area within which 50% of the observations of a particular group were made and it comprised about 17% of the total home range recorded. Use of different parts of the home range varies with the time of year and territorially appears to be most marked at the start of the two peaks of breeding activity. During the winter groups often forage together for periods of several hours. The size of core areas is correlated with the number of birds in the group. Groups which changed their numbers from one season to the next showed corresponding changes in the extent and quality of their core area. Taken in conjunction with evidence from Chapter 1, this suggests that large groups tend to be stable and persistent, while small groups are vulnerable to encroachment by others and hence tend to be ephermeral. Chapter 3 describes five aspects of intra-group behaviour in relation to the age, sex and breeding status of the participants. These are allo- preening, sentinel behaviour, leadership, play and roosting. A rough concordance was found between hierarchies based on participation in allo- preening, sentinel and leadership behaviour, but among non-breeding adults differences were found between the sexes. If these three behaviour patterns function partly to express the social status of the participants then differences between males and females are probably related to their respective breeding strategies; males striving to become breeder in their natal group, while females normally move elsewhere to breed. Play behaviour occurs mainly among first year birds, particularly between 2-4 months after fledging, and may be-associated with the establishment of dominance relations among siblings. At the same age they show various signs of social indiscipline which may contribute to the unsettled behaviour shown by some groups while going to roost. The behaviour of non-breeding birds during nesting is described in Chapter 4. All non-breeders more than one year old contribute to feeding the nestlings and driving off potential predators, but a greater share is taken by males than by females. Like the differences in other aspects of behaviour, this difference between the sexes may be attributable to differences in their strategies for breeding. Non-breeders also take some part in incubation, but do not participate in nest-building. The introduction to part II explains how limitations on the visibility of Common Babblers in the field led to an emphasis on different aspects of their behaviour. Chapter 5 covers population dynamics and movements, and also deals with seasonal weight changes. These suggest that some birds which were trapped in mid-winter may have been close to the minimum weight guaranteeing survival and it is possible that the availability of food at this season may be a factor controlling the population. The proportion of unrelated birds found in groups of Common Babblers appears to be higher than estimated for Jungle Babblers. Females leave their natal groups in their first summer and a few males were observed to breed at one year old. The population of Common Babblers in the study area declined throughout the period of the study and this may have affected observed rates of immigration. In some Common Babbler groups only one pair nests during the season, but in others the same male nests successively with two different females and in a third situation two pairs nest simultaneously. There are significant differences between groups exhibiting these three patterns in the number of birds per group and in the density of birds within the territory. In Chapter 6 the relationship between group size, population density and territorial area is described for the main study area and also for populations in the Salt Range, Pakistan. The results of some inconclusive removal experiments are described. Behaviour at the nest was studied in greater detail for the Common Babbler than for the Jungle Babbler and the results are described in Chapter7. Incubation is carried out mainly by the breeding female. Non-breeding females do not usually participate in feeding the nestlings, being driven from the vicinity of the nest by the breeding female. A correlation was found between the number of non-breeders assisting at the nest and the number of nestlings in the nest on day nine, but a causal relationship could not be established. In part III, Chapter 8, brief observations on five other species of Turdoides are described. A comparison between population densities and group sizes for all the populations of Turdoides studied reveals that there is a close correlation between these parameters. The variance in group size within populations is also similar, suggesting that factors controlling group size operate in a similar way on populations in different habitats and at a wide range of densities. The behaviour and ecology of the Long-tailed Tit, studied over a period of nine months in Wytham Wood, Oxford, are described in Chapter 9. In winter stable groups of 10-25 birds hold territories. In February these groups break up into pairs during the day although members of the same winter group continue to roost together.

In this thesis, I try to proceed one step further towards an understanding of the biogeographic processes forming the distribution patterns of organisms that we see today. Babblers and warblers are diverse groups of passerines that are phylogenetically intermixed with other groups in the superfamily Sylvioidea. First, the gross phylogeny of the babblers and associated groups was estimated. Five major lineages of a well-supported monophyletic babbler radiation were recovered, and we proposed a new classification at family and subfamily level. Further, the genus Pnoepyga was excluded from Timaliidae, and we proposed the new family Pnoepygidae fam. nov. Second, the systematic position was investigated for the Albertine Rift taxon Hemitesia neumanni, which was found to be nested within the almost entirely Asian family Cettidae, and possible biogeographical scenarios were discussed. We concluded that the most plausible explanation involved late Miocene vicariance in combination with local extinctions. Third, the historical biogeography of a Leiothrichinae subclade, the Turdoides babblers and allies, was inferred. We concluded that the Middle East region probably played an important role in the early history of this clade, followed by local extinctions in this region. Fourth, a Bayesian method to reconstruct the historical biogeography under an event-based model was proposed, where the total biogeographic histories are sampled from its posterior probability distribution using Markov chains. In conclusion, I believe that, especially with more sophisticated methods available, we will see an increasing number of studies inferring biogeographic histories that lead to distribution patterns built up by a combination of dispersals and vicariance, but where these distributions have been extensively reshaped, or litterally demolished, by local extinctions. Therefore, my answer to the frequently asked question dispersal or vicariance? is both, but not the least: extinctions. / At the time of the doctoral defence the following papers were unpublished and had a status as follows; Papers 3 and 4: Manuscripts

Babblers together with the close related Timallidae are not very common inmates of the zoological gardens. In the Czech Republic they are only bred in the zoological gardens in Ohrada, Pilsen and Prague. The breeding in the zoological gardens is not generally very successful. The zoo in Prague with its number of species owns the largest collection of these birds in Europe. In the past the breeders in Prague were the first ones in Europe who managed to raise for example Rufous-fronted Laughingthrush, Sunda Laughingthrush, Barred Laughingthrush or Sumatran Laughingthrush (Black-and-white Laughingthrush). As the first ones in the Czech Republic they were able to reproduce the critically endagered Blue-crowned Laughingthrush (Courtois's Laughingthrush). The Blue-crowned Laughingthrush is so rare that for several years it was not clear at all if they still live in nature. In the year 2000 they were rediscovered in the number of 240 pieces. The quantity of them in the zoological gardens all over the world does not exceed 100 pieces. The zoo in Chester does a European breeding book of these pieces. Some birds in Prague reproduce repetitively and they prove that the right method of the breeding was found. Hopefully this method would lead to the birth of the securing population in the care of humans. This securing population is very important for the protection of these birds. The attempt of this work is to assess the links between the results of the breeding and their conditions, the comparison of the nesting activities of the two chosen species of babblers, then the summarizing of the expansion and the results of the breeding of the individual species and also the processing of the expansion, the development of the quantity and the problems of the protection of the babblers in nature. The following facts were found out: the breeding of the birds in the exposition or in its environment does not have an essential influence on their nesting activity. However, for the nesting activity it is more important if they are a newly formed couple or a couple paired for a longer time and at the forest babbler it is the female that has an important role in incubation period. However, at the Sumatran Laughingthrush there is a frequent changing in different time intervals. The work also shows that only 5 species out of 12, that showed the nesting activity, are able to build a nest without the help of the keepers. That can be attributed to their closer relational breeding and also to putting the higher number of artificially reared individuals into the breeding.