The relationship between defecation and feeding in nestling birds: observational and experimental evidence

Frontiers in Zoology

Eben Goodale²  Bo Wang¹  Huan Li¹  Rui-chang Quan¹ 

[1] Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden (XTBG), Chinese Academy of Sciences (CAS), Menglun, Mengla, Yunnan 666303, China;College of Forestry, Guangxi University, 100 Daxue Road, Nanning 530005, Guangxi, China

Others  :  1226116
DOI  :  10.1186/s12983-015-0116-y

 received in 2015-04-20, accepted in 2015-09-05,  发布年份 2015

【 摘 要 】

Background

Adult birds clean the nest by consuming or transporting feces, which is thought to be important in order to lower the levels of parasites, pathogens and predation at the nest. If nestlings were to defecate when parents were absent, however, feces could accumulate in the nest.

Results

To understand the mechanism by which nest sanitation is maintained, we studied the timing of defecation in nestling birds of common passerine species in southwest China. In 159 nests of 8 species at the nestling stage during 779 randomly timed observations, we never found fecal sacs present. Video recordings, totaling 455 h at five Pycnonotus jocosus nests in the field, showed almost all defecation after feedings, and only nestlings that were fed defecated. Six translocated P. jocosus nests were taken into captivity in order to manipulate the frequency of feeding. These nestlings defecated only after feeding, even when feeding intervals were extended to 60 and 120 min. The fecal sac weight also increased with extended feeding intervals, demonstrating a remarkable plasticity for nestlings to wait for feedings.

Conclusion

The evidence allows two major conclusions: 1) defecation in the nest occurs at a time that ensures nest sanitation, stimulated by feeding, rather than there being a set time of gut processing between feeding and excretion; 2) the strong plasticity in the timing of defecation and the possibility of negative repercussions (if defecation occurs when parents are absent) are important mechanisms underlying the efficiency of the feeding-defecation system.

【 授权许可】

   
2015 Quan et al.

【 图 表 】

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