Female condition, egg shape and hatchability: a study on the grey partridge

Abstract

Özet: Bu araştırmada, kınalı kekliklerin (Alectoris chukar) 5 aylık dönemdeki yumurta verimi farklı doğrusal olmayan modeller ile analiz edilmiştir. Kekliklerde yumurta verimini tanımlamak için Gamma, McNally, Modified Compartmental ve Adams-Bell modelleri kullanılmıştır. Modelleri karşılaştırmada Pseudo belirleme katsayısı (Pseudo-R 2), Akaike Bilgi Kriteri (AIC) ve Bayesci Bilgi Kriteri (BIC) kullanılmıştır. Gamma, McNally, Modified Compartmental ve Adams-Bell modellerinde Pseudo-R 2 değerleri sırasıyla 0.9994, 0.9995, 0.9972 ve 0.9855 olarak bulunmuştur. Bu modellere göre AIC ve BIC değerleri sırasıyla; 43.810, 49.810; 42.051, 49.051; 77.057, 87.057 ve 112.597, 122.597 olarak saptanmıştır. McNally modelinin kekliklerde yumurta verimini tanımlayan en iyi model olduğu, Adams-Bell modelinin ise en az tanımlayan model olduğu sonucu ortaya çıkmıştır. Abstract: The aim of this study was to investigate the egg yields of partridge with non-linear models in 5 mounts of lying period. Gamma, McNallay, Modified Compartmental and Adams-Bell models were used to describe egg yields of partridge. Pseudo-R 2 , Akaike Information Criteria (AIC) and Bias Information Criteria (BIC) were used to compare models. Pseudo-R 2 values were 0.9994, 0.9995, 0.9972 and 0.9855 for Gamma, McNally, Modified Compartmental and Adams-Bell, respectively. AIC and BIC values of these models were 43.810, 49.810; 42.051, 49.051; 77.057, 87.057 and 112.597, 122.597, respectively. As a result, it could be said that McNally is the best and Adams-Bell model is the least one to describe egg yields of partridges.

Egg Characteristics in Relation to Skipped Days of Laying in the Grey Partridge

“…From April to June, the hens laid a mean of 27.9 eggs, with a total of 5,209 eggs throughout the eight years. Most of the eggs laid were incubated for 26 days in a commercial incubator at 37.5 °C and 60% humidity, while 622 eggs (100 in 2002, 169 in 2003, 267 in 2005, and 86 in 2011) were brought to the lab for chemical analyses, and were analysed for concurrent studies (Cucco et al, 2012;Grenna et al, 2014).…”

“…We applied the method developed by Barta and Székely (1997) and Mónus and Barta (2005). We marked 22 points around the outline of the egg (Cucco et al, 2012), then we fitted second-order polynomials to the coordinates of the mark points and used three parameters of the polynomial to describe egg shape (Ban et al, 2011). The first (c 0 ) parameter is the compression ratio relative to a circle (sphericity): the smaller the c 0 , the more elongated the egg.…”

“…skipped eggs were not more elongated nor pointed or blunt rounded than average ones. An incorrect shape would have reproductive consequences, since hatchability has been shown to be higher with intermediate egg elongation values, while eggs with extreme elongations hatch less (Cucco et al, 2012). A change in shape could have been expected as the mechanical product of a longer stay if the egg remained in the oviduct in combination with longer laying intervals, but this event likely did not occur.…”

Influence of Male Dominance on Egg Testosterone and Antibacterial Substances in the Egg of Grey Partridges

“…We studied 20 pairs selected from a breeding farm stock in Ovada, NW Italy (Cucco et al. ). All birds were 1‐year‐olds and in their first reproductive season.…”

How the egg rolls: a morphological analysis of avian egg shape in the context of displacement dynamics

“…A substantial body of work exists exploring the adaptive values of the shell, including how the width and length contribute to structural robustness (Bain and Solomon, 1991) as well as how the shape of an egg contributes to efficient packing underneath the incubating parent for thermal stasis (Barta and Székely, 1997). Gas and moisture exchange have been speculated to be affected by a shell's shape and relative pore density over the surface (Birkhead et al, 2017a;Ar, 1991), and even the ease of hatching for young birds has been linked to egg morphology (Cucco et al, 2012;Igic et al, 2015). Some recent and exciting work has suggested flight ability as an adaptive driver for egg shape, with strong flyers being more likely to produce asymmetrical and elongated eggs (Stoddard et al, 2017), as well as climate and microhabitat having an effect on Australian bird egg morphology (Duursma et al, 2018).…”