Seven introduced deer taxa are present in New Zealand and there is interest in the dynamics of these populations. Estimating the abundance of deer is problematic, but faecal pellet counts (an index of abundance) have been conducted on New Zealand's public conservation land since the 1950s. We compiled faecal pellet count data from published and unpublished sources, and used the most common data type (presenceÁabsence of pellets in plots along transects) to investigate decadal changes in the relative abundances of deer at the national, island (North and South) and Department of Conservation conservancy spatial scales. A quadratic model with different trends for each conservancy best explained the pellet frequency data for the period 1952Á2010: pellet frequencies were highest during the 1950sÁ1970s and then declined to minima in the 1980s and 1990s and then increased in the 2000s. The decline in pellet frequencies was likely caused by increasing commercial deer harvesting, and the recent increases in pellet frequencies in several conservancies are likely a consequence of reduced commercial harvesting. The key limitations of faecal pellet count data collected in New Zealand (i.e. spatial and temporal variability, and that only summary statistics are often available) are discussed.

Faecal pellet counts have been widely used to monitor the abundances of introduced ungulates in New Zealand, but ground-based sampling cannot be conducted safely in the steep non-forest habitats that are common in New Zealand's Southern Alps. Helicopter counts may be an effective technique for monitoring ungulates in steep non-forest habitat. We evaluated the relationship between faecal pellet and helicopter counts of ungulates (primarily feral goat Capra hircus) at 12 non-forest sites in the Southern Alps. Within each site we counted the numbers of ungulates from a helicopter on three occasions and the number of intact faecal pellets along 30 transects. Mean observed densities of feral goats derived from helicopter counts ranged from 0.0 to 20.2 km −2 . There was a positive curvilinear (concave down) relationship between faecal pellet and helicopter counts. Compared with faecal pellet counts, helicopter counts were cheaper, could identify ungulate species and provided estimates of absolute density. Helicopter counts are a cost-effective method for monitoring ungulates in the steep non-forest habitats of New Zealand's Southern Alps.

Specimens of Plagiorchis noblei from Tyrannus tyrannus and T. verticalis, were analyzed for morphological differences using multivariate techniques. Hotelling's T2-test showed a highly significant difference (P less than 0.001) between the two parasite populations. A stepwise discriminant analysis selected pharynx and testis as the characters that best separated the two populations, and correctly classified 69% of the specimens as to their host species. Plagiorchis gonzalchavezi was determined to be a junior subjective synonym of P. noblei.

Forty-six Tyrannus tyrannus (L.) and 35 Tyrannus verticalis Say from Delta Marsh, Manitoba, were examined for helminths during the summer of 1977. Eighty-three percent of T. tyrannus and 94% of T. verticalis were infected with at least one species of helminth. Nine helminth species (four trematodes, one cestode, three nematodes, and one acanthocephalan) were found, eight from T. tyrannus and seven from T. verticalis. Six species were common to both hosts. Six new host records are reported for Tyrannus tyrannus and seven for T. verticalis. Tyrannus verticalis had a significantly greater total helminth burden than T. tyrannus did. Plagiorchis noblei was the most abundant parasite in each species, accounting for 69% of the helminths of T. tyrannus and 96% of those for T. verticalis (this difference is significant). Plagiorchis noblei was the only helminth found in juvenile hosts.This study further supports the following hypotheses: (1) that P. noblei is a northern parasite transmitted only in breeding habitats of its hosts; (2) that juvenile birds show greater intensities of infection than adults; and (3) that the number of parasite species is greater in adult birds than in juveniles.

Forty-eight Tyrannus tyrannus (L.) and 35 T. verticalis Say from Delta Marsh, Manitoba, were examined for ectoparasites. Nine species of ectoparasites were found: five Mallophaga, three Acarina, and one Hippoboscidae. Five new host records for T. tyrannus and three for T. verticalis are reported. Fifty-two percent of T. tyrannus and 68% of T. verticalis were infested. Both prevalence and intensity of Mallophaga were significantly higher in T. verticalis (p < 0.05).