Comparative diurnal and nocturnal foraging behaviour and energy intake of premigratory Grey Plovers Pluvialis squatarola and Whimbrels Numenius phaeopus in South Africa

Estimates of the energy budgets of nonbreeding waders (Charadrii) have frequently been hampered by ignorance of the birds' nocturnal activities. During the premigratory period (March), Grey Plovers Pluvialis squatarola and Whimbrels Numenius phaeopus at the Zwartkops estuary, South Africa, foraged throughout the nocturnal as well as the diurnal low-tide period. Although both species continued to forage visually at night, they exhibited behavioural changes to compensate for the reduced visibility. Both species foraged more slowly at night, taking fewer steps per minute, and Grey Plovers paused for longer to search for prey. Prey items were sighted from shorter distances at night than during the day. Energy intake rates, however, did not differ significantly by day and night for either species, and both achieved over 40% of their daily low-tide period intake at night. The energy intake rates and total daily intake of Grey Plovers, which fed exclusively on the study area, exceeded allometrically predicted values.     

The Effects of Actinomycin D,Gibberellin A7, and Cyclic AMP on Mating of Chlamydomonas reinhardtii*

SYNOPSIS. Gibberellin A7 and cyclic AMP increased mating efficiency of Chlamydomonas reinhardtii when the cells were treated during gametogenesis. No change in mating activity was observed when cells were treated with 5′-AMP. Actinomycin D inhibited both normal mating and gibberellin-stimulated mating.     

Isolation and characterization of 102 new microsatellite loci in Murray cod,Maccullochella peelii peelii (Percichthyidae), and assessment of cross‐amplification in 13 Australian native and six introduced freshwater species

We have isolated 102 polymorphic microsatellite loci from an enriched Murray cod DNA library and also assessed their amplification success in 13 native and six introduced freshwater fish species. The loci will serve the dual purpose of assessing wild population genetic structure for future conservation efforts, and for identifying markers for key quantitative trait loci important for aquaculture.     

Determining Observer Reliability in Counts of River Otter Tracks

ABSTRACT In many research projects, reliability of collected data is dependent on reliability of field observers. However, it is uncommon for observer reliability to be either measured or reported in wildlife research. We tested whether observer skill affected outcomes of a northern river otter (Lontra canadensis) track survey conducted by the Texas Parks and Wildlife Department. Observers recorded presence of tracks at bridge sites (n = 250) throughout a 27-county region in east Texas, USA. Logistic regression indicated that observers were significantly associated with frequency of reported otter tracks. Because observers were not assigned to bridges at random, we tested and found associations between the bridges surveyed by each observer (SURVEY ROUTE) and habitat variables (WATERSHED, VEGETATION-TYPE, WATER-TYPE, BRIDGE-AREA) that may have influenced otter presence and probability of detection. A standardized tracker evaluation procedure indicated that experienced observers (n = 7) misidentified 37% of otter tracks. Additionally, 26% of tracks from species determined to be “otter-like” were misidentified as otter tracks. We recommend that observer skill in identification of animal tracks and other indirect signs be measured to detect and reduce observer errors in wildlife monitoring.