Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of...Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of particular interest, such as the age at which young can be safely ringed, or in choosing the best period to attain the most accurate calculation of laying or hatching dates.Methods: We constructed a photographic guide for aging European Bee-eaters(Merops apiaster) nestlings to 3-day age classes and evaluated the aging method by performing a validation exercise with several observers with no previous experience in aging bee-eater nestlings.Results: The aging guide for bee-eater nestlings allowed estimating age to within 3 days with an average accuracy of 0.85. We found the optimal period for aging nestlings was between days 13-18(with accuracy between 0.94 and 0.99), during which the status of feather development was more easily distinguishable from the preceding and subsequent age classes. During the first 3 days after hatching, nestlings could also be aged with high accuracy(0.93). The small size of the nestling in relation to the eggs and the nestling’s inability to raise its head during these first days allowed for good discrimination from the subsequent age class. Between days 25 and 28, nestlings were correctly aged in only half of assignments(0.55 sensitivity) and nestlings belonging to class 7(days 7-9) were the least correctly identified(0.38 sensitivity). However, by visiting the nests at 12 days intervals it is possible to achieve the highest accuracy in age estimation with the smallest disturbance and logistic investment.Conclusions: This study highlighted how indirect methods and a simple protocol can be established and employed to quickly estimate nestling age in cases where handling nestlings is challenging or impossible, while minimizing disturbance in and around the nest.展开更多
Pigments play an essential role in imparting colors to the various organs of invertebrates particularly,insects.Genetic evolution and adaptive pigmentation of invertebrates have been studied which depicted that ...Pigments play an essential role in imparting colors to the various organs of invertebrates particularly,insects.Genetic evolution and adaptive pigmentation of invertebrates have been studied which depicted that insect colors respond to the climatic changes.The physical,chemical and structural properties of insect pigments are being studied by researchers for years to elucidate their evolutionary aspects of physiology,metabolism,and economic importance for human welfare.Color development in insects varies within the species of different genera.In this state-of-the-art literature review,we discuss the variety of pigments other than visual ones found in different species of insects.The review also highlights the potential benefits or functions of pigments to insects.展开更多
基金funded by FCT with grants to JSC(SFRH/BD/113580/2015),JAA(SFRH/BPD/91527/2012),RC(SFRH/BPD/118635/2016)benefited from financial support to CESAM(UID/AMB/50017/2019),through national funds(FCT/MCTES).
文摘Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of particular interest, such as the age at which young can be safely ringed, or in choosing the best period to attain the most accurate calculation of laying or hatching dates.Methods: We constructed a photographic guide for aging European Bee-eaters(Merops apiaster) nestlings to 3-day age classes and evaluated the aging method by performing a validation exercise with several observers with no previous experience in aging bee-eater nestlings.Results: The aging guide for bee-eater nestlings allowed estimating age to within 3 days with an average accuracy of 0.85. We found the optimal period for aging nestlings was between days 13-18(with accuracy between 0.94 and 0.99), during which the status of feather development was more easily distinguishable from the preceding and subsequent age classes. During the first 3 days after hatching, nestlings could also be aged with high accuracy(0.93). The small size of the nestling in relation to the eggs and the nestling’s inability to raise its head during these first days allowed for good discrimination from the subsequent age class. Between days 25 and 28, nestlings were correctly aged in only half of assignments(0.55 sensitivity) and nestlings belonging to class 7(days 7-9) were the least correctly identified(0.38 sensitivity). However, by visiting the nests at 12 days intervals it is possible to achieve the highest accuracy in age estimation with the smallest disturbance and logistic investment.Conclusions: This study highlighted how indirect methods and a simple protocol can be established and employed to quickly estimate nestling age in cases where handling nestlings is challenging or impossible, while minimizing disturbance in and around the nest.
文摘Pigments play an essential role in imparting colors to the various organs of invertebrates particularly,insects.Genetic evolution and adaptive pigmentation of invertebrates have been studied which depicted that insect colors respond to the climatic changes.The physical,chemical and structural properties of insect pigments are being studied by researchers for years to elucidate their evolutionary aspects of physiology,metabolism,and economic importance for human welfare.Color development in insects varies within the species of different genera.In this state-of-the-art literature review,we discuss the variety of pigments other than visual ones found in different species of insects.The review also highlights the potential benefits or functions of pigments to insects.
