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.

In oscines, male song stimulates female reproduction and females are known to adjust both their sexual preferences and their maternal investment according to song quality.Female domestic canaries are especially responsive to wide frequency bandwidth (4 kHz) male songs emitted with a high-repetition syllable rate and low minimal frequencies (1 kHz). We previously showed that low-frequency urban noise decreases female sexual responsiveness for these low-frequency songs (1-5 kHz) through auditory masking. Based on the differential allocation hypothesis, we predicted that urban noise exposure will equally affect female maternal investment. Using a crossover design, we broadcast low-frequency songs to females either in an overlapping noise condition or in an alternating noise condition. Females decreased both their sexual responsiveness and their clutch size in the overlapping noise treatment relative to the alternative noise treatment. No differences were found concerning egg size or egg composition (yolk and albumen mass, testosterone concentration). Due to our experimental design, we can exclude a general impact of noisy conditions and thereby provide evidence for a detrimental effect through masking on avian courtship and reproductive output. These results suggest that noisy conditions may also affect avian communication in outdoor conditions, which may partly explain field reports on noisedependent breeding success and reduced breeding densities at noisy sites. K E Y W O R D Santhropogenic noise, birdsong, clutch size, domestic canary, maternal investment

In precocial bird species, the eggs represent a strong maternal allocation of resources and constitute most of the maternal investment since parents do not feed the young after they hatch. Females can differentially allocate resources in their eggs as a response to the environment experienced during the laying period, including the quality of their mate. To assess the importance of female selection on egg composition in the red-legged partridge, we tested breeding females in a choice trial in which they were allowed to choose between males. After the choice trials, the females were mated with their preferred male (P group), with a non-preferred one (NP group) or with a randomly selected male (RND group). Eggs laid by females of the three groups did not differ significantly in mass, shape, yolk, albumen or shell weight. Moreover, there was no significant difference in egg lysozyme concentration (an important albumen antimicrobial component). There was a significant difference in egg characteristics in relation to position in the laying order, with last-laid eggs being heavier and more spherical. Last-laid eggs contained more albumen but their shell was lighter and the albumen contained less lysozyme. This study shows that partner attractiveness may not influence the characteristics of egg quality, and that in this partridge species the females are able to invest in large clutches without a decrease of egg size but with a progressive decrease of egg quality.

The selection of habitat by macroinvertebrates living in running waters may be influenced by the physical characteristics of the substratum, as well as by the presence of other species. In this study, an artificial river with three different substrata (pebbles, detritus, and leaves) was utilized to analyze the microhabitat preference of two Plecoptera prey species (Amphinemura sulcicollis and Brachyptera risi), both in absence and in presence of a Plecoptera predator species (Perla marginata). In the absence of predators, both prey species showed a clear preference for the leaf microhabitat. When the predators were present, only Brachyptera risi showed a change of microhabitat selection, with a decrease of leaves and an increase of pebbles and detritus utilization. Amphinemura sulcicollis did not change their substratum utilization. This study demonstrates that the presence of a predator may affect microhabitat selection through a switch from the preferred to the less preferred substrata, although not all species change their habitat utilization in response to predator presence.

International audienceMaternal effects play an important role in mediating reproductive success; the different allocation of resources in eggs is considered a primary maternal effect. In oviparous vertebrates, there are several substances (hormones, immunoglobulins, antioxidants, antibacterial molecules) that females may allocate differentially. Mate choice is a key factor influencing female reproductive decisions and investment in eggs, but it is not clear to what extent the dominance status of the partner can influence the decision to invest differentially in the quality of eggs. In the grey partridge Perdix perdix, we ranked males for their social status after pairwise dominance tests. Then, females were paired experimentally with dominant or subordinate individuals. We measured testosterone, lysozyme and ovotransferrin concentrations in their eggs. Females paired with dominant males laid eggs with higher testosterone concentration, while egg mass, lysozyme and ovotransferrin concentrations did not differ. With regard to testosterone, because this hormone has been shown to elicit beneficial effects in offspring hatching from grey partridge eggs, our results are in line with the differential allocation hypothesis that females paired with high-quality males should invest more in the current reproductive event

Birds sometimes skip a day along the sequence of egg laying, which may vary the mass or the composition of delayed eggs compared with those that were laid consecutively. Our literature review shows that this has been interpreted as a short-term adaptation that enables females to overcome energetic constraints during the laying period, but other hypotheses implying the influence of weather, pollution, or hormonal cycles have also been proposed. We collected freshly laid Grey Partridge Perdix perdix eggs to determine the effects of laying gaps on egg characteristics. Egg shape, as well as egg components (beta-carotene, avidin and lysozyme concentrations) did not vary in relation to skipped days. Eggs were slightly heavier when one or two days were skipped (0.72% and 0.45%, respectively). However, when examining the hatching rate, we found a significant decrease in relation to skipped days, hence eggs following laying gaps showed a lower hatching rate than other eggs. The pattern observed could indicate the presence of some physiological stress that caused females to skip one or two days and to lay eggs that hatched less.