Aim We studied dynamics of four populations of New Zealand forest birds for 5–9 years after reintroduction to islands. We primarily aimed to predict whether these populations were viable, and what, if any, management was needed to maintain them. However, the small scale of these islands also provided an opportunity to study density‐dependent population growth over a short time frame. Location We studied New Zealand robin (toutouwai, Petroica australis) and stitchbird (hihi, Notiomystis cincta) populations reintroduced to Tiritiri Matangi, a 220‐ha offshore island near Auckland, and saddleback (tieke, Philesturnus carunculatus) and stitchbird populations reintroduced to Mokoia, a 135‐ha island in Lake Rotorua. These islands are free of mammalian predators, but have highly modified habitat following clearing and regeneration. Methods We closely monitored each population, individually marking all or most of the birds and in some cases experimentally manipulated population density or food supply. We used model selection procedures to understand factors affecting survival, fecundity and dispersal, and developed stochastic simulation models. Results The Tiritiri Matangi robin and Mokoia saddleback populations grew without management and appear to be viable. Both showed strong evidence of density‐dependent growth, with fecundity (saddlebacks) and juvenile survival (both populations) declining with increasing density. Neither stitchbird population appears viable without management and supplementation experiments showed reproduction and/or survival to be limited by food supply. The Tiritiri Matangi population appears viable as long as supplementary feeding continues. However, the Mokoia population has a high mortality rate regardless of supplementary feeding, resulting in tenuous viability even with intensive management. Mokoia stitchbirds suffer from infection by Aspergillus fumigatus, a pathogenic fungus that is prevalent in highly modified habitats and more abundant on Mokoia than Tiritiri Matangi. Main conclusions Some forest birds can thrive in regenerating forest on islands and strong evidence of density dependence can be detected in such populations in as little as 5 years. This allows density‐dependent models to be developed, providing guidance when island populations are harvested for further translocations. Other species are limited by food supply in regenerating environments, a problem potentially overcome by management. However, prevalence of A. fumigatus may render highly modified environments uninhabitable by some species regardless of management.

Summary 1.Reintroductions provide a good opportunity to study density-dependent population growth, as populations can be studied at a range of densities and the change in density is not confounded with environmental conditions. An understanding of density dependence is also necessary to predict dynamics of reintroduced populations under different management regimens, and assess the extent to which they can be harvested for further reintroductions. 2. We monitored a North Island saddleback ( Philesturnus rufusater ) population for 6 years after reintroduction to Mokoia, a 135 ha island in New Zealand that was made suitable for saddlebacks by eradicating introduced Norway rats ( Rattus norvegicus ). We modelled adult and juvenile survival using Program  , and modelled numbers of young fledged per pair using Proc Mixed in SAS with individual female as a random factor. 3. Juvenile survival clearly declined as the population increased, and the decline was closely correlated with the number of breeding pairs. Reproduction also showed a clear decline that was explained by two factors: a difference in quality between territories occupied immediately after reintroduction and those occupied later, and an overall decline as the number of pairs increased. Reproduction was also strongly affected by age, and this needed to be accounted for when modelling density dependence. 4. A stochastic simulation model incorporating these dynamics closely predicted the observed population growth. The equilibrium population size was insensitive to density dependence in reproduction, but highly sensitive to density dependence in juvenile survival. 5. The model is being used to plan management strategies for potential reintroductions of saddlebacks to mainland areas with predator control. The species is currently confined to predator-free islands and one fenced mainland sanctuary.

Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts’ immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites’ free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance) can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes is required to fully understand transmission dynamics. Understanding of both physiological and behavioural defence strategies will aid the development of novel approaches for control.

Background: There are limited clinical and epidemiological data on patients diagnosed with Bell’s palsy. While investigating an apparent clustering of Bell’s palsy, we sought to characterize the spectrum of illness in patients with this diagnosis. Methods: A telephone survey of persons with idiopathic facial (Bell’s) palsy in the Greater Toronto Area (GTA, population = 4.99 million) and Nova Scotia (population = 0.93 million) from August 1 to November 15, 1997 collected information on subject demographics, neurological symptoms, constitutional symptoms, medical investigation and management. Information regarding potential risks for exposure to infectious agents, past medical history, and family history of Bell’s palsy was also collected. Subjects with other secondary causes of facial palsy were excluded. Results: In the GTA and Nova Scotia, 222 and 36 patients were diagnosed with idiopathic facial (Bell’s) palsy, respectively. The crude annualized incidence of Bell’s palsy was 15.2 and 13.1 per 100,000 population in the GTA and Nova Scotia, respectively. There was no temporal or geographical clustering, and symptomatology did not differ significantly between the two samples. The mean age was 45 years, with 55% of subjects being female. The most common symptoms accompanying Bell’s palsy were increased tearing (63%), pain in or around the ear (63%), and taste abnormalities (52%). A significant number of patients reported neurological symptoms not attributable to the facial nerve. Conclusion: No clustering of cases of Bell’s palsy was observed to support an infectious etiology for the condition. Misdiagnosis of the etiology of facial weakness is common. Patients diagnosed with Bell’s palsy have a variety of neurological symptoms, many of which cannot be attributed to a facial nerve disorder.