A survey of beak morphological abnormalities was performed on 6,201 chickens (egg-laying hens and chickens for meat production belonging to 25 flocks) brought to a poultry processing plant. The observed abnormalities varied among flocks with occurrence rates ranging from 0.48 to 46.67%. The occurrence was high in flocks subjected to beak trimming and varied significantly according to chicken br...

Studies of Darwin's finches of the Galapagos Islands have provided pivotal insights into the interplay of ecological variation, natural selection, and morphological evolution. Here we document, across nine Darwin's finch species, correlations between morphological variation and bite force capacity. We find that bite force correlates strongly with beak depth and width but only weakly or not at a...

Migratory silvereyes treated with a strong magnetic pulse shift their headings by approximately 90 degrees , indicating an involvement of magnetite-based receptors in the orientation process. Structures containing superparamagnetic magnetite have been described in the inner skin at the edges of the upper beak of birds, while single-domain magnetite particles are indicated in the nasal cavity. T...

Garfish, which are found in the Indo-Pacific Ocean areas, have a long, spear-like beak with two marrow jaws and small pointed teeth. They often make sudden leaps while swimming, particularly when attracted by bright lights. In Papua New Guinea people often fish from canoes using a light at night, and serious injuries may be caused by a fish jumping and its beak piercing part of the body. The su...

With the exception of primates, most vertebrates have laterally placed eyes. Binocular vision in vertebrates has been implicated in several functions, including depth perception, contrast discrimination, etc. However, the blind area in front of the head that is proximal to the binocular visual field is often neglected. This anterior blind area is important when discussing the evolution of binoc...

An experiment was conducted to study the effects of arc beak trimming on feed consumption, weight gain, and feed wastage in males and females from two large-bodied strains and one medium-bodied strain of turkeys. Birds were placed in wire-floored battery cages from 3 to 8 wk of age and feed intake, weight gains, and feed spilled into dropping pans were recorded for each of the 5 wk of each tria...

Divergence and speciation can sometimes proceed in the face of, and even be enhanced by, ongoing gene flow. We here study divergence with gene flow in Darwin's finches, focusing on the role of ecological/adaptive differences in maintaining/promoting divergence and reproductive isolation. To this end, we survey allelic variation at 10 microsatellite loci for 989 medium ground finches (Geospiza f...

The influence of beak trimming of two strains of commercial male turkeys (Strains A and B) on behavior during the growing period was investigated. Poults were either left with beaks intact or arc beak trimmed at hatching. Strain by beak treatment interactions were generally lacking, indicating that these two strains responded similarly. Beak trimming did not influence tameness (as measured by r...

Darwin's finches are a classic example of species diversification by natural selection. Their impressive variation in beak morphology is associated with the exploitation of a variety of ecological niches, but its developmental basis is unknown. We performed a comparative analysis of expression patterns of various growth factors in species comprising the genus Geospiza. We found that expression ...

Grooming a bird refers to clipping wing feathers, trimming claws (nails), and on occasion, smoothing and trimming the beak. A veterinarian or experienced technician can perform this service on an otherwise healthy bird. Some disease states can result in nail and beak problems; consequently, all birds should be properly examined at regular intervals every 6 to 12 months.