The effect of clutch size on predation in birds Essay

The effect of clutch size on predation in birds - Essay Example Hypothetically, it is also logic to say that the bigger the clutch size, the more the mortality rate in birds. This is because the prey are large in number, hence, attracting more predators. Past studies on clutch size, have concentrated on the constant evolution in the size of the clutch. This has, therefore, guided researchers in coming up with theories such as the food limitation hypothesis of lack (Paul et al 824). This theory states that the clutch size gives a reflection on the relationship between the food limitation and the number of off springs that survive. In addition, another theory tries to explain how the clutch size is determined by parental behavior, for instance, the ability to feed and their success in reproduction. Nevertheless, predation patterns and the predators themselves are in more than one way affected by the clutch size. The effect of clutch size on predation in birds has been researched on in a number of models by different researchers since 1990s. However, there are two main models that act as the backbone to all other models. The first one explains how an increase in predation risk would be as a result of nestling begging, with or without spectral characteristics and avian mobbing (Paul et al 821). Parental behavior and nestling begging is usually seen a signal to increase in predation risk. This hypothesis was questioned since, in some cases, nestling begging could be there but the parents are also there to defend the young ones. To prove this, an experiment was carried out where bell miners Manorina melanophrys was observed and the cost of begging measured. The experiment was done by placing 168 attractive nests with wax egg and broadcasting speakers that produced sounds similar to the begging sound. Three conditions were put into considerations (Ekman 703). These conditions were silence, white noise pulses that was similar to the response no begging sounds and un-manipulated begging