Coloration of Birds' Eggs

The Shapes of Birds' Eggs

Genetic Basis for Red Coloration in Birds

The yellow and red feather pigmentation of many bird species [1] plays pivotal roles in social signaling and mate choice [2, 3]. To produce red pigments, birds ingest yellow carotenoids and endogenously convert them into red ketocarotenoids via an oxidation reaction catalyzed by a previously unknown ketolase [4-6]. We investigated the genetic basis for red coloration in birds using whole-genome...

The Shapes of Birds' Eggs: Mathematical Aspects

--In the Handbook o! North American birds the description of egg sizes, and more particularly of egg shapes, proceeds on somewhat different lines from those of previous works. The present paper explains the methods of measuring and methods of "reducing" the observations. The elements actually measured are the conventional average length and breadth, plus the (unconventional) radii of the blunt ...

Tactical deception reduces predation on birds' eggs.

I n the months leading up to the 1973 Yom Kippur War, the Egyptian military staged 40 maneuvers on or near the Israeli border. Over time, the Israelis learned that Egyptian activity near the border was not necessarily a threat to respond to, and they ultimately let their guard down, only to be surprised one day when the tanks and troops crossed the border as part of a coordinated invasion (1, 2...

Responses of Birds to Broken Eggs in Their Nests’

We tested the responses of two bird species which nest on unmovable substrates (e.g., cavities and walls) to simulated and actual egg damage in their nest. Tree Swallows (Tachvcineta bicolor) and Barn Swallows (Hit-undo ruiticaj removed broken eggs and continued to incubate the rest of their clutch, but rcsponse times took up to 8 days, and observed rejection rates were lower than reported for ...