A flock of 370 Dorset x Romney ewes with up to 96% autumn lambtng was developed without the aid of hormones. Data from flock and experimental records were used to compare the performance of autumnand spring-born lambs and their dams. Preliminary findings for three seasons show that ewes lambed in autumn had a greater spread of lambing, lower litter size and fewer perinatal lamb deaths. Growth o...

Vigilance (scanning) and other behavior patterns were studied in free-ranging Evening Grosbeaks (Coccothraustes vespertinus) at feeders to assess how flock size and flock geometry influenced the behavior of individual birds. The present results indicate that the way in which individual grosbeaks are positioned with respect to one another effects many aspects of their behavior, especially when a...

Chimney swifts (Chaetura pelagica) are highly manoeuvrable birds notable for roosting overnight in chimneys, in groups of hundreds or thousands of birds, before and during their autumn migration. At dusk, birds gather in large numbers from surrounding areas near a roost site. The whole flock then employs an orderly, but dynamic, circling approach pattern before rapidly entering a small aperture...

The objectives of this study were to 1) evaluate the genetic diversity of Navajo-Churro sheep using pedigree information; 2) examine the distribution of the Navajo-Churro population; and 3) evaluate the effect of breeder dynamics on genetic conservation of the breed. Pedigree data and breeder information (city and state) were obtained from the Navajo-Churro Sheep Breed Association. Inbreeding c...

The objectives of this study were to 1) evaluate the genetic diversity of Navajo-Churro sheep using pedigree information; 2) examine the distribution of the Navajo-Churro population; and 3) evaluate the effect of breeder dynamics on genetic conservation of the breed. Pedigree data and breeder information (city and state) were obtained from the Navajo-Churro Sheep Breed Association. Inbreeding c...

The size and species composition of bird flocks in a mixed-conifer forest of the western Sierra Nevada was nearly identical over three winters. Golden-crowned Kinglets (Regulus satrapa), Chestnut-backed Chickadees (Parus rufescens), and Red-breasted Nuthatches (Sitta canadensis) had the highest number of individuals/flock. Kindets and nuthatches were the most frequent flockmembers, although the...

Since the 1980s, the prevalence of Salmonella in Belgian poultry layers and broilers has greatly fluctuated with a rise observed in 2003 and a significant decrease in 2005. In order to alleviate the risk at egg consumer level, it is crucial to understand the factors which influence the contamination and the spread of Salmonella in laying hens. To study such determinants we explored the Belgian ...