Cultural differences in ant-dipping tool length between neighbouring chimpanzee communities at Kalinzu, Uganda.

Cultural variation has been identified in a growing number of animal species ranging from primates to cetaceans. The principal method used to establish the presence of culture in wild populations is the method of exclusion. This method is problematic, since it cannot rule out the influence of genetics and ecology in geographically distant populations. A new approach to the study of culture compares neighbouring groups belonging to the same population. We applied this new approach by comparing ant-dipping tool length between two neighbouring communities of chimpanzees (Pan troglodytes schweinfurthii) in the Kalinzu Forest, Uganda. Ant-dipping tool length varies across chimpanzee study sites in relation to army ant species (Dorylus spp.) and dipping location (nest vs. trail). We compared the availability of army ant species and dipping tool length between the two communities. M-group tools were significantly longer than S-group tools, despite identical army ant target species availabilities. Moreover, tool length in S-group was shorter than at all other sites where chimpanzees prey on epigaeic ants at nests. Considering the lack of ecological differences between the two communities, the tool length difference appears to be cultural. Our findings highlight how cultural knowledge can generate small-scale cultural diversification in neighbouring chimpanzee communities

Hybridization in East African swarm-raiding army ants

<p>Abstract</p> <p>Background</p> <p>Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied hybridization in East African army ants (<it>Dorylus </it>subgenus <it>Anomma</it>) using morphology, mitochondrial DNA sequences, and nuclear microsatellites.</p> <p>Results</p> <p>While the mitochondrial phylogeny had a strong geographic signal, different species were not recovered as monophyletic. At our main study site at Kakamega Forest, a mitochondrial haplotype was shared between a "<it>Dorylus molestus</it>-like" and a "<it>Dorylus wilverthi</it>-like" form. This pattern is best explained by introgression following hybridization between <it>D. molestus </it>and <it>D. wilverthi</it>. Microsatellite data from workers showed that the two morphological forms correspond to two distinct genetic clusters, with a significant proportion of individuals being classified as hybrids.</p> <p>Conclusions</p> <p>We conclude that hybridization and gene-flow between the two army ant species <it>D. molestus </it>and <it>D. wilverthi </it>has occurred, and that mating between the two forms continues to regularly produce hybrid workers. Hybridization is particularly surprising in army ants because workers have control over which males are allowed to mate with a young virgin queen inside the colony.</p

Evolutions- und Verhaltensökologie von Dorylus Treiberameisen

1\. Title 1 2\. Acknowledgements 3 3\. Table of contents 4 4\. Introduction 5 5\. Chapter 1 8 6\. Chapter 2 25 7\. Chapter 3 43 8\. General conclusions 58 9\. Summary 61 10\. Zusammenfassung 62 11\. References 64 12\. Curriculum vitae 75Dorylus army ants are considered to be keystone predator species in many afrotropical ecosystems. Yet our knowledge of the evolutionary and behavioural ecology of this fascinating group is still very sparse. Members of the subgenera Alaopone, Dichtadia, Dorylus s.str., Rhogmus and Typhlopone hunt and nest in the soil (hypogaeic life-style), while some Anomma species hunt in the leaf-litter (members of the gerstäckeri group, intermediate life-style) and the others conduct massive swarm raids on the surface and up into the vegetation (the fierce and famous driver ants, epigaeic life-style). According to an evolutionary scenario the hypogaeic life-style is the ancestral state in this group. To identify possible selection pressures driving the evolution of worker morphology in this genus, I have analysed the allometries of functionally important body traits in relation to life-style. There is a clear-cut trend of increasing relative size of eight out of nine studied characters from hypogaeic to intermediate to epigaeic species. The results strongly suggest that the ecological niche shifts necessitated adaptations in these traits. The degree of overall differentiation among species is more pronounced in larger than in smaller workers. The pattern of division of labour in the epigaeic D. molestus indicates that two factors that may have caused this phenomenon are new food habits and an increased need for colony defence of intermediate and epigaeic species respectively. In an attempt to clarify the functional value of long front and long hind legs which are among the traits that are very likely to represent adaptations to epigaeic foraging I analysed the food spectrum and food transport by the two epigaeic species D. molestus and D. wilverthi. I show that even within the category of epigaeic species front and hind legs correlate with foraging stratum use. While D. molestus searches in the vegetation, on the surface and intensely in the leaf- litter and top soil layers, the longer-legged D. wilverthi appears to restrict its hunting efforts to the vegetation and surface. D. wilverthi workers do not carry relatively larger food items and so it is concluded that other factors such as energy efficiency in locomotion or climbing ability may have selected for longer legs in this species. The migration behaviour of the army ant Dorylus molestus was studied in the montane forest of Mt Kenya. I found that stay duration in a nest is highly variable so that brood cycle as an underlying endogenous pattern generator can be ruled out. Local food depletion is likely to be the ultimate cause for migrations in this species, because migration distance is larger than foraging range and colonies move away from their nearest neighbours. A small percentage of migrations is triggered by pangolin attacks of nests. Despite fierce intraspecific competition colonies do not fight other colonies contrary to the prediction of a recently developed mathematical model for epigaeic swarm raiding Dorylus species.Treiberameisen der Gattung Dorylus werden als Schlüsselarten für verschiedene afrotropische Ökosysteme angesehen. Trotzdem ist unser Wissen über die Evolutions- und Verhaltensökologie dieser faszinierenden Gruppe sehr begrenzt. Arten der Untergattungen Alaopone, Dichtadia, Dorylus s.str., Rhogmus und Typhlopone jagen und nisten in der Erde (hypogäischer Lebensstil), wohingegen manche Anomma Arten in der Laubstreuschicht jagen (Arten der gerstäckeri � Gruppe, intermediärer Lebensstil) und andere massive Schwarm-jagden auf der Bodenoberfläche sowie bis hoch in die Vegetation unternehmen (die bekannten und gefürchteten Treiberameisen, epigäischer Lebensstil). Gemäß eines evolutionären Szenarios ist der hypogäischer Lebensstil in dieser Gruppe der ursprüngliche Zustand. Um mögliche Selektionsdrücke zu identifizieren, die eine Rolle in der Evolution der Arbeiterinnenmorphologie spielen, habe ich die Allometrien verschiedener funktionell relevanter Körpermerkmale im Zusammenhang mit den jeweiligen Lebensstilen analysiert. Dabei finde ich einen klaren Trend von zunehmender relativer Größe von hypogäischem zu intermediärem zu epigäischem Lebensstil bei acht von neun untersuchten Merkmalen. Die Ergebnisse deuten sehr stark darauf hin, dass die Wechsel der ökologischen Nische Anpassungen in den entsprechenden Merkmalen notwendig machten. Die Differenzierung zwischen den Arten ist bei den größeren Arbeiterinnen stärker ausgeprägt als bei kleineren. Das Muster der Arbeitsteilung in der epigäischen Art Dorylus molestus deutet darauf hin, dass dieses Phänomen durch Erfordernisse des neuen Futterspektrums und der Kolonieverteidigung von intermediären und epigäischen Arten hervorgerufen wurde. Sowohl lange Vorder- als auch lange Hinterbeine gehören zu den Merkmalen, die als Anpassungen an epigäische Lebensweise anzusehen sind. Um ihren funktionellen Wert aufzuzeigen, habe ich das Futterspektrum und den Futtertransport der beiden epigäischen Arten D. molestus and D. wilverthi untersucht. Dabei konnte ich zeigen, dass auch innerhalb der epigäischen Kategorie Vorderbein- und Hinterbeinlängen mit Jagdstratumnutzung korrelieren. Während D. molestus in der Vegetation, auf dem Boden sowie intensiv in der Laubstreuschicht und oberen Bodenschicht nach Beute sucht, beschränkt die langbeinigere D. wilverthi ihre Jagdaktivitäten auf die Vegetation und Bodenoberfläche. Trotz ihrer längeren Beine tragen D. wilverthi Arbeiterinnen aber nicht relativ größere Beutetierfragmente, so dass sich folgern lässt, dass andere Faktoren wie Energieeffizienz in der Lokomotion oder Kletterfähigkeit die längeren Beine selektiv gefördert haben müssen. Das Wanderverhalten der Art Dorylus molestus wurde in dem Bergwald am Mt Kenya untersucht. Ich fand heraus, dass die Aufenthaltsdauer in einem Nest sehr variabel war, so dass ein Brutzyklus als endogener Rhythmusgenerator für die Migrationen ausgeschlossen werden kann. Lokale Erschöpfung der Futterressourcen ist sehr wahrscheinlich die entscheidende Ursache für Wanderungen, weil Wanderdistanzen größer als Futterjagddistanzen sind, und Kolonien von ihren nächsten Nachbarn fortwandern. Ein kleiner Prozentsatz der Wanderungen wird durch Angriffe von Schuppentieren auf Nester verursacht. Trotz starker intraspezifischer Konkurrenz kämpfen Kolonien nicht gegeneinander im Gegensatz zu den Vorhersagen eines kürzlich für epigäische schwarmjagende Dorylus-Arten entwickelten mathematischen Modells

SNP dataset for 148 Kenyan, African and Eurasian honey bees (part 5)

This dataset contains the 13+ million SNPs that were detected between 148 Kenyan, African and Eurasian honey bees using FreeBayes and that passed quality filtering. Details for SNP processing, sample labels and quality control is provided in the paper and its supplementary information. The original 148_honeybees.vcf.gz input file has been split into fourteen numbered parts (0 to 13). After downloading all parts, they can be joined to recreate the original file using the follwing UNIX command: cat 148_honeybees.vcf.gz.{0..13}.split > 148_honeybees.vcf.gz The VCF file can then be unzipped using the UNIX command: gunzip 148_honeybees.vcf.g