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We report on the occurrence of maternal uniparental disomy for chromosome 14 (mUPD14) in a 4-year-old girl with a de novo Robertsonian translocation, 45,XX,t (13q,14q). The child has arrested hydrocephalus, short stature, minor anomalies, small hands with hyperextensible joints, and mild to moderate developmental delay. Comparison of her phenotype with those of three previously described individuals show some common distinct traits which suggest a mUPD14 syndrome.

2004. Does maternal condition or predation risk influence small mammal population dynamics? Á/ Oikos 106: 176 Á/184.There is strong debate over whether the intrinsic traits of individuals or the extrinsic environment exert the greater influence on small mammal population dynamics. We test the roles of maternal effects (an intrinsic factor) and predation risk (an extrinsic factor) in the population dynamics of wild strain house mice using a 2-factor enclosure experiment. Pre-release supplemental feeding with a high-fat diet created female treatment founders that were 6 Á/10% heavier than controls, a condition that we predicted would be passed on as a maternal effect. Predation risk was enhanced using regular application of predator (red fox Vulpes vulpes ) scats. Founder populations of six females and six males released into eight, 15)/15 m enclosures showed near exponential population growth over 17 weeks (maximum 3 generations). But there were no responses to either treatment in terms of survival, inherited body weights, fecundity or population size. We suggest that elevated maternal condition may have only minor and transient intergenerational effects with little long-term consequence. We also suggest that the general significance of predator scats as a cue to predation risk to alter prey behaviour may have been overestimated. Hence our results question the role of either factor in causing long-term responses that influence condition to affect population processes.

Recent models indicate that coextinction events should be numerous but empirical support for coextinction is paradoxically scarce. I investigated whether the coextinction paradox is due to affiliates becoming extinct well ahead of their hosts, with the disjunction masking the coextinction event. Using psyllids (Hemiptera: Psylloidea) on acacias (Mimosaceae: Acacia) in southern Sydney as an example system, I compared the density of affiliate species and the proportion of specialists on threatened versus secure hosts. I observed reduced psyllid species densities on the threatened hosts Acacia pubescens and A. prominens relative to common, sympatric acacias, consistent with the loss of affiliates ahead of host plant extinction. However, contrary to predictions, I found no support for reduced affiliate specialisation on the threatened hosts. Rather, proximity to closely related hosts may be a stronger determinant of the proportion of specialised psyllid species on a host. In addition, generalists, as well as specialists, may be lost from declining plants due to loss of familiarity with rarely-encountered host plants.

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