Males and ephippial females of Oriental Chydoridae (Cladocera: Anomopoda) from Cat Tien National Park, South Vietnam

Cladocera (Crustacea: Branchiopoda) of South-East Asia have been intensively investigated over the last decades, but males and ephippial females of many taxa remain unknown or poorly studied. Males and ephippial females of ten species of Chydoridae were collected by monthly sampling of eight water bodies during autumn-winter dry season in Сat Tien National Park, South Vietnam. Morphology of studied specimens is described and taxonomic status of studied species is discussed. Gamogenetic specimens were sparse in all studied taxa, contributing less than 8 % of the populations in samples. Gamogenetic specimens were found mostly during December–January, what suggests that daylight period is the main factor inducing a sexual reproduction in most studied species.

Seabirds as samplers of the marine environment – a case study of northern gannets

Understanding distribution patterns, activities, and foraging behaviours of seabirds requires interdisciplinary approaches. In this paper, we provide examples of the data and analytical procedures from a new study in the German Bight (North Sea) tracking northern gannets (Morus bassanus) at their breeding colony on the island of Heligoland. Individual adult northern gannets were equipped with different types of data loggers for several weeks, measuring geographic positions and other parameters mostly at 3–5 min intervals. Birds flew in all directions from the island to search for food, but most flights targeted areas to the (N)NW (north–northwest) of Heligoland. Foraging trips were remarkably variable in duration and distance; most trips lasted 1–15 h and extended from 3 to 80 km from the breeding colony on Heligoland. Dives of gannets were generally shallow, with more than half of the dives only reaching depths of 1–3 m. The maximum dive depth was 11.4 m. Gannets showed a clear diurnal rhythm in their diving activity, with dives being almost completely restricted to the daylight period. Most flight activity at sea occurred at an altitude between the sea surface and 40 m. Gannets mostly stayed away from the wind farms and passed around them much more frequently than flying through them. Detailed information on individual animals may provide important insights into processes that are not detectable at a community level.

Seabirds as samplers of the marine environment – a case study in Northern Gannets

Understanding distribution patterns, activities, and foraging behaviours of seabirds requires interdisciplinary approaches. In this paper, we provide examples of the data and analytical procedures from a new study in the German Bight, North Sea, tracking Northern Gannets (Morus bassanus) at their breeding colony on the island of Helgoland. Individual adult Northern Gannets were equipped with different types of data loggers for several weeks, measuring geographic positions and other parameters mostly at 3–5 min intervals. Birds flew in all directions from the island to search for food, but most flights targeted areas to the (N)NW of Helgoland. Foraging trips were remarkably variable in duration and distance; most trips lasted 1–15 h and extended from 3–80 km from the breeding colony on Helgoland. Dives of gannets were generally shallow, with more than half of the dives only reaching depths of 1–3 m. The maximum dive depth was 11.4 m. Gannets showed a clear diurnal rhythm in their diving activity, with dives being almost completely restricted to the daylight period. Most flight activity at sea occurred at an altitude between the sea surface and 40 m. Gannets mostly stayed away from the wind farms and passed around them much more frequently than flying through them. Detailed information on individual animals may provide important insights into various processes, based on multi-layer information.

Time budgets and habitat use of White-naped Cranes Grus vipio in the Ulz river valley, north-eastern Mongolia during the breeding season

Habitat loss and degradation are critical threats for the globally threatened White-naped Crane Grus vipio. We estimated the size of the area used per day and the time budgets of parental and non-parental White-naped Crane pairs in north-eastern Mongolia during 2000 and 2001. Six parental crane pairs used an area of 11–155 ha per day. The maximum distance of a focal parental crane from the roosting-site was 3,030 m. Habitat conservation measures for breeding White-naped Cranes need to be targeted to within at least 3 km of the roosting-site or nest-site. Parental cranes spent 79.6 ± 4.8% of the daylight period foraging and had reduced preening and resting behaviour to 4.4 ± 1.9%. Pairs without juveniles showed a pronounced period of resting and preening behaviour during midday, which was absent in parental cranes. This indicates that parental cranes may be time-stressed. We conclude that increases in feeding-related activities (e.g. caused by a decrease in food availability) are likely to be at the expense of parental vigilance. Conversely, increases in vigilance (due to e.g. increased disturbance) may have a negative impact on feeding-related activities. Both increases can potentially negatively affect reproductive success in this Vulnerable species.

Influence of diet on development and oviposition of Forficula auricularia (Dermaptera: Forficulidae)

In North America, the life cycle of the European earwig (Forficula auricularia L.) can be divided into a nesting phase (hypogean phase) and a free-foraging phase (epigean phase) (Crumb et al. 1941; Behura 1956; Lamb and Wellington 1975). Adults spend the nesting phase in the soil; females burrow into the ground at the onset of the cold weather, lay eggs, and then care for the eggs. Hatching occurs in spring; first- or second-instar nymphs move to the soil surface for the free-foraging period. The earwig, a nocturnal insect, spends the entire daylight period of hiding under trash or in dark crevices. Where two broods occur, females reenter the ground a second time (Lamb and Wellington 1975). Stomach content analyses (Crumb et al. 1941; Sunderland and Vickerman 1980) and food preference tests (McLeod and Chant 1952; Buxton and Madge 1976) revealed that the European earwig is omnivorous. Under laboratory conditions, nymphs fed freshly frozen aphids, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), survive better than those fed green algae or carrots, develop faster, and produce heavier females (Phillips 1981; Carrillo 1985).

Diurnal activity and sexual maturation of the South American fruit fly (Diptera: Tephritidae) in the laboratory

Locomotion and grooming in immature adult Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) occurred throughout the daylight period. Feeding seemed to be slightly higher in mated than in unmated flies. Ovipositing females showed territoriality and only mated females laid eggs. Males started to display courtship behavior at 5 days old, reaching the complete sexual maturation at day 10. About 54% of the virgin mature females copulated on the day they were paired with virgin males of the same age. Female A. fraterculus seemed to require more than 30 min of mating to supply all spermathecae with sperm, and the efficiency of sperm transference after first mating was 100%.

Role of prolactin in a pheromone-like sexual inhibition in the male lesser mouse lemur

ABSTRACT Sexual activity of the male lesser mouse lemur can be induced by a long photoperiod, and plasma testosterone concentrations increase from 20 to 220 nmol/l within 3 weeks of photoperiodic stimulation. When isolated males were exposed to the volatile compounds from the urine of an active dominant male for 4 weeks at the beginning of the long daylight period, they demonstrated a significant decrease in testosterone concentrations (134± 11 nmol/l) compared with controls (210 ± 26 nmol/l) within 2 weeks. Lowering concentrations of prolactin by daily injections of bromocriptine prevented the decrease in testosterone in males simultaneously exposed to the odorant stimulation. Increasing concentrations of prolactin by daily injections of sulpiride mimicked the effect of the odorant stimulation in males receiving only fresh non-odorized air. The decrease in testosterone was strengthened when sulpiride was administered concurrently with exposure to urine. These results support the conclusion that variations in the concentration of prolactin are involved in the neuroendocrinological process mediating the pheromone-like sexual inhibition in the male lesser mouse lemur. However, daily injections of bromocriptine in males which were photoperiodically stimulated but not exposed to dominant male urine odour, also induced a significant decrease in testosterone concentrations. This finding suggests that two different systems involving prolactin and leading to opposite effects might be implicated in the regulation by environmental factors of sexual activity in the male lesser mouse lemur. J. Endocr. (1987) 114, 279–287

Wettertrupp Haudegen: the last German Arctic weather station of World War II: Part 2

On 23 February the uppermost edge of the sun appeared briefly for the first time over the southern horizon; by 1 March the sun's full disc had appeared, and thereafter the daylight period lengthened rapidly. Apart from some minor cases of insomnia, lack of appetite and lassitude, the long period of darkness had had little effect on the wintering party in terms of either morale or physical health. Most importantly, there had been absolutely no sign of scurvy, undoubtedly due to the regular dose of vitamins which Dege insisted his men take, and to a substantial intake of reindeer meat over the winter.