Researchers uncover a large variation in the lifetime migratory decisions of young white storks.

Rooikrans Acacia cyclops is an aggressive invasive tree that threatens natural resources in South Africa. The seeds of A. cyclops have a prominent aril which attracts birds that ingest the seeds and disperse them endozoochorously. Two biological control agents, a Seed Weevil Melanterius servulus and a Flower‐galling Midge Dasineura dielsi, were released on A. cyclops in 1991 and 2002, respectively. Together these agents have substantially reduced seed production and generally far lower numbers of seeds are now available to birds. A consequence of this transition from historically bounteous quantities of seeds to scanty seed availability is that birds may no longer associate with the trees and seed dispersal may be disproportionately reduced. To assess whether this has happened, seed attrition was measured by comparing the amount of seeds that disappeared from two groups of branches, one available to birds and the other enclosed in bird netting. Other types of granivores (mainly field mice) were excluded from both groups of branches with a plastic funnel placed around the stems. Mature seeds were also harvested and fed to caged bird species to determine gut retention times and germination rates of ingested seeds. Attrition rates of seeds showed that birds continue to remove seeds but that only a proportion of the crop is taken. Only two frugivorous species (Knysna Turaco Tauraco corythaix and Red‐winged Starling Onychognathus morio) and two granivorous species (Red‐eyed Dove Streptopelia semitorquata and Laughing Dove Streptopelia sengalensis) ingested A. cyclops seeds during feeding trials. Ingestion by birds enhanced seed germination except for those ingested by Laughing Doves. There were no apparent effects of length of gut passage time and avian body size on seed germination rates. Despite the diminished seed resource due to biological control agents, birds continue to disperse A. cyclops seeds.

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Bird flight distances for the small Zosterops capensis, the medium-size Pycnonotus capensis and the large Colius striatus were extracted from these birds' initial ring and subsequent recapture locations and expressed on equivalent per km bases. The products of the bird-ring recapture records in nine different flight distance categories and daily consumption rates by these birds of seeds of two native (Chrysanthemoides monilifera and Olea europaea spp. africana) and two alien (Lantana camara and Solanum mauritianum) shrubs were used to construct seed dispersal curves. The dispersal distances to which ingested seeds were theoretically restricted were computed from the product of the retention time of seed in the birds' guts and their flight speeds using published functions. All three bird species displayed thin long-tailed seed dispersal curves characterized by peaks at distances below 1 km which declined progressively with increasing distances, the tails extending to distances of up to 400 km. Flight distances corresponding with predicted seed gut retention times were 9.4 km in the small Z. capensis, 17.8 km in the medium size P. capensis and 21.2 km in the large C. striatus. These potential seed dispersal distances were much greater that the frequently reported long distance seed dispersal threshold of 1 km by frugivorous birds in fragmented landscapes.

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Ecological interactions, especially those that are beneficial (i.e. mutualism) or detrimental (i.e. parasitism), play important roles during the establishment and spread of alien species. This chapter explores the role of these

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Environmental rehabilitation is mandatory for mining operations in many countries, including Lesotho. At Letšeng Diamond Mine in Lesotho, waste residues of kimberlite tailings create a hostile environment for the establishment of plant species during vegetation restoration. In this study, we investigated seed germination of native grassland species and tested the best performing species on different topsoil mixtures with kimberlite tailings in the Afro-alpine zone in Lesotho. Rapid germination tests showed highly significant differences in the number of seedlings that emerged for different plant species: the grass Tenaxia disticha (% mean AE SE: 80 AE 17%; n = 36) and the forb Hesperantha schelpeana (56 AE 14%) were highest but nonsignificantly different to each other, while other species were significantly lower and nonsignificantly different to each other. In all treatments, seed germination of T. disticha was significantly higher than the experimental control, while the treatments that were covered with topsoil did not differ significantly. In addition, T. disticha seedling height and basal width varied significantly over time with seedlings in all the treatments growing significantly taller than those in the experimental control. Also, seedling basal width showed significant increase during the third growing season while height remained constant. We concluded that kimberlite tailings ameliorated with topsoil encourage plant establishment and performance of T. disticha, and this medium could be used to stabilize disturbed mine landscapes in the Afro-alpine zone of Lesotho.