Parasitism of the deer ked, Lipoptena cervi, on the moose, Alces alces, in eastern Finland.

The deer ked, Lipoptena cervi L. (Diptera: Hippoboscidae), is an ectoparasitic fly that spread to Finland in the early 1960s from the southeast across the Soviet border. It is currently a common parasite of the moose, Alces alces (Artiodactyla: Cervidae), in the southern part of the country and its area of distribution is gradually spreading to Finnish Lapland, where it will come into contact with another potential cervid host, the semi-domesticated reindeer, Rangifer tarandus tarandus. The aim of this study was to determine the intensity of deer ked parasitism on the moose in eastern Finland. Whole skins of 23 moose were examined for the presence of deer keds, which were extracted and their total numbers estimated. The intensity of deer ked parasitism was correlated to the age, sex, skin area and anatomical region of the host. Bulls had the highest total number of keds (10616 ± 1375) and the highest deer ked density (35.7 ± 4.4 keds/dm(2) of skin). Cows had a higher total number of keds than calves (3549 ± 587 vs. 1730 ± 191), but ked densities on cows and calves were roughly equal (11.8 ± 1.7 vs. 9.4 ± 1.1 keds/dm(2) of skin). The density of keds was highest on the anterior back, followed by the posterior back, front limbs, abdomen, head and hind limbs. The sex ratio of deer keds was close to equal (male : female, 1.0 : 1.1). After they had consumed blood, male keds were heavier than females. As the total numbers and densities of deer keds were higher than reported previously on moose or for any other louse fly species, the effects of parasitism on the health of the host species should be determined.

Shared and unshared parental investment in the precocial goldeneye (Aves: Anatidae)

Lazarus & Inglis (Anim. Behav., 1986, 34, 1791-1804) introduced a model of the influence of brood size on the optimal level of parental investment and parent-offspring conflict and drew a distinction between shared and unshared types of parental investment. With respect to this division, we measured the parental costs in the goldeneye, Bucephala clangula, a precocial species with uniparental female care, in terms of time spent in vigilance and intraspecific aggression. We also compared levels of anti-predator vigilance and intraspecific aggression between females with and without broods. Females with broods spent considerably more time on both vigilance and intraspecific aggression, but anti-predator vigilance was independent of brood size. Furthermore, female behaviour was unaffected by brood reduction. Both these observations support the 'fixed-loss' model of unshared care, where the level of parental investment is predicted to be independent of brood size, since the predator is likely to take only a single offspring. In contrast, intraspecific aggression, mainly associated with defence of the brood's feeding area, increased with brood size. This supports the 'shared care' model where the level of parental investment increases with brood size, a type of care usually associated with altricial species. Copyright 1998 The Association for the Study of Animal Behaviour.