Abstract

The New Zealand Threat Classification System (NZTCS) developed to assess the threat status of their taxa currently lists the little blue penguin (Eudyptula minor) as at risk declining. These birds often nest in suburban areas and face threats of lethal trauma from dogs, chick predation from cats, and mortality from vehicles on roads.¹ In an effort to mitigate these threats, a naturally ventilated purpose-built nest box (PBNB) design has been implemented in areas across New Zealand and Australia where suitable nesting sites are unavailable. While the boxes seem to be effective in protecting penguins from predators, potential noxious air parameters, particularly ammonia and carbon dioxide, in the artificial nest boxes have not been investigated. As a group, penguins are highly susceptible to air-borne fungal infections such as aspergillosis.^2,3 Infection of aspergillosis in penguins has been linked to substandard air quality, poorly ventilated housing, and elevated ammonia levels.² In housed poultry flocks, ammonia levels greater than 20 ppm have been linked to respiratory disease symptoms including coughing, upper and lower respiratory tract hemorrhage, excessive pulmonary secretions, inflammation, and increased susceptibility to infectious diseases.^4,5 Noxious gas levels were influenced by housing density, indoor temperature, and higher protein in the feed.⁴

Considering poultry as a model, this study set out to investigate the levels of two noxious gases in PBNBs of breeding little blue penguins. We hypothesized that living in small, artificial, one entry nest boxes, sometimes occupied by two adults and two chicks during the chick-rearing phase, in conjunction with a fish-based, high protein diet, would result in increased ammonia levels compared to poultry literature. We further predicted that carbon dioxide levels would increase with total penguin occupancy. The goal of this phase one pilot project was to measure the ammonia and carbon dioxide levels within purpose-built nest boxes of a little penguin colony in Kaikoura, New Zealand over 12 weeks during the breeding season. The highest elevation in ammonia was consistent with chick-rearing and carbon dioxide with total bird occupancy in the nest. While nest occupancy varied among nest boxes over the sampling period, the range of average ammonia levels was 12 ppm to 57 ppm with four of the six readings greater than 40 ppm. Carbon dioxide levels varied more widely among boxes, a discrepancy that may be impacted by the total time birds had been in or out of the nest when sampling occurred but reached levels of 1600 ppm when both chicks and adults were present. These numbers are supportive of noxious gas levels greater than recorded in poultry housing and warrant further investigation into its impacts on colony health. Further investigation of the results as a phase two study been delayed due to travel restrictions surrounding the current pandemic.

Acknowledgements

The authors would like to thank IAAAM for the Medway Scholarship that funded student travel, making this project possible, as well as the University of Florida’s Aquatic Health Program for the funding of this work. We extend a special thanks to the Kaikoura Ocean Research Institute (KORI) for their assistance in data collection and expertise on the colony in designing the study, especially to Alastair Judkins and Mallory Hackett for allowing access to the colony under KORI for data collection. We also send additional thank you to Chloe Cargill, Grant Ellis, and Laura Brush for their assistance in data collection.

*Presenting author

Literature Cited

1.  Flemming SA. 2013 [updated 2020]. Little penguin. In Miskelly CM editor. New Zealand Birds Online.

2.  AZA Penguin Taxon Advisory Group. 2014. Penguin (Spheniscidae) Care Manual. Silver Spring, MD: Association of Zoos and Aquariums.

3.  Seyedmousavi S, Guillot J, Arne P, de Hoog GS, Mouton JW, Melchers WJG, Verweij PE. 2015. Aspergillus and aspergilloses in wild and domestic animals: a global health concern with parallels to human disease. Int Soc Human Anim Mycol 52:765–797.

4.  Kilic I, Yaslioglu E. 2014. Ammonia and carbon dioxide concentrations in a layer house. Asian-Australas J Anim Sci 27(8 ):1211–1218.

5.  Taisistro AS, Ritz CW, Kissel DE. 2007. Ammonia emissions from broiler litter: response to bedding materials and acidifiers. Brit Poult Sci 48(4):399–405.