AVIS-IBIS

Birds of Indian Subcontinent

Calcium in Grit Consumed by Hen Pheasants in East-Central Illinois

Publication Type:Journal Article
Year of Publication:1964
Authors:Harper, JA
Journal:The Journal of Wildlife Management
Volume:28
Issue:2
Date Published:1964
ISBN Number:0022541X
Keywords:Phasianidae, Phasianus, Phasianus colchicus
Abstract:This paper discusses the amount of calcium occurring in the grit from gizzards of 178 wild, adult pheasant hens (Phasianus colchicus) collected in east-central Illinois during the nesting cycle and during each month of the year. Grit was found in gizzards of hens collected in every month. Calcitic grit was found in the gizzards of hens in all months except December and January; calcite contained 35.6 percent calcium. Dolomitic grit was found in gizzards of hens in almost negligible quantities during April-July, only. The level of calcium in gizzard grit from wild hens was greatest during the nesting season, reaching a maximum of 3.0 percent in late May. Among hens with known egg-laying records, the amount of calcium in the gizzard grit did not reach a level exceeding 2.0 percent until after the sixth or seventh egg had been laid. The calcium level in the grit from gizzards of hens that had laid six or seven eggs remained between 2.0 and 2.5 percent throughout egg laying and into the first few days of incubation, and then declined to near negligible amounts during the remainder of the 23-day incubation period. Calcium in gizzard grit of hens was less than 1.0 percent during the brooding season of July and August. Calcium in the grit from gizzards of wild hens increased from 0.1 percent in August to 2.6 percent in September and remained near this level during October and November; this increase in calcium ingestion in fall may be associated with a sexual recrudescence among both hens and cocks. Calcium was absent from gizzard grit during December and January and was found only at levels of 0.2 percent in February and 0.1 percent in March. Wild hens demonstrated the ability not only to select calcareous grit from noncalcareous grit but also to ingest selectively calcium-rich limestone; the grit in gizzards contained disproportionately more calcite than dolomite with respect to their ratio of availability.
URL:http://www.jstor.org/stable/3798087
Short Title:The Journal of Wildlife Management
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith