Impacts of the COVID-19 pandemic on population management in AZA.

Soon after the onset of the COVID-19 pandemic, almost all Association of Zoos and Aquariums (AZA) facilities closed to the public. Resulting cost-saving and safety measures led some facilities to temporarily cease or reduce animal breeding and/or transfers. We surveyed AZA facilities and Species Survival Plan® (SSP) Coordinators for AZA's cooperative population management programs to evaluate how widespread these decisions were, if impacts varied by taxa, and how the AZA community navigated related challenges during the pandemic. We found that 60% of responding facilities did not suspend breeding and 22% did not suspend transfers. About 50% of responding zoos increased their reliance on ground transportation to move animals, while aquariums reported no change to transportation methods. SSP Coordinators reported the main reason why breeding decreased, regardless of taxa, was due to canceled or delayed transfers. The reasons transfers decreased differed by taxa, such as limited financial resources and lack of access to air transportation. The majority of respondents for both surveys stated transfers were the greatest challenge they faced. To address this, facilities utilized alternative transportation methods and worked closely with nearby zoos and aquariums for the movement of animals, while SSP Coordinators issued alternative transfer recommendations. If another pandemic or other widespread facility closure occurs, our research highlights the importance of communication, collaboration, and flexibility to fulfill breeding and transfer recommendations to maintain sustainable zoo and aquarium populations.

Institutional networks in cooperative population management: Exploring patterns in transfer fulfillment.

Long-term sustainability of ex-situ animal populations is important for zoos and aquariums, but challenging due to inconsistent compliance with Breeding and Transfer Plans. Transfer recommendations are key to promoting the sustainability of ex-situ animal populations by ensuring cohesive populations, genetic diversity, and demographic stability, but factors affecting their fulfillment are poorly understood. We used a network analysis framework to analyze data compiled from PMCTrack from 2011 to 2019 for three taxonomic classes (mammals, birds, and reptiles/amphibians) within the Association of Zoos and Aquariums to assess factors affecting transfer recommendation fulfillment. Of 2505 compiled transfer recommendations spanning 330 Species Survival Plan® (SSP) Programs and 156 institutions, 1628 (65%) of them were fulfilled. Transfers were most likely to be fulfilled between institutions in close proximity with an established relationship. Annual operating budget, SSP Coordinator experience, number of staff, and diversity of Taxonomic Advisory Groups in which an institution participates also influenced transfer recommendations and/or fulfillment, but effects varied with taxonomic class. Our results suggest that current practices of focusing on transfers between institutions in close proximity are working to maximize transfer success and that institutions with larger budgets and some degree of taxonomic specialization play important roles in promoting success. Success could be further enhanced by building reciprocal transfer relationships and encouraging further development of relationships between smaller institutions and larger ones. These results emphasize the utility of examining animal transfers using a network approach, which accounts for attributes of both sending and receiving institutions, describing novel patterns otherwise left undetected.

Evolution of long-term coloration trends with biochemically unstable ingredients.

The evolutionarily persistent and widespread use of carotenoid pigments in animal coloration contrasts with their biochemical instability. Consequently, evolution of carotenoid-based displays should include mechanisms to accommodate or limit pigment degradation. In birds, this could involve two strategies: (i) evolution of a moult immediately prior to the mating season, enabling the use of particularly fast-degrading carotenoids and (ii) evolution of the ability to stabilize dietary carotenoids through metabolic modification or association with feather keratins. Here, we examine evolutionary lability and transitions between the two strategies across 126 species of birds. We report that species that express mostly unmodified, fast-degrading, carotenoids have pre-breeding moults, and a particularly short time between carotenoid deposition and the subsequent breeding season. Species that expressed mostly slow-degrading carotenoids in their plumage accomplished this through increased metabolic modification of dietary carotenoids, and the selective expression of these slow-degrading compounds. In these species, the timing of moult was not associated with carotenoid composition of plumage displays. Using repeated samples from individuals of one species, we found that metabolic modification of dietary carotenoids significantly slowed their degradation between moult and breeding season. Thus, the most complex and colourful ornamentation is likely the most biochemically stable in birds, and depends less on ecological factors, such as moult timing and migration tendency. We suggest that coevolution of metabolic modification, selective expression and biochemical stability of plumage carotenoids enables the use of unstable pigments in long-term evolutionary trends in plumage coloration.

The effects of iron fertilization on carbon sequestration in the Southern Ocean.

An unresolved issue in ocean and climate sciences is whether changes to the surface ocean input of the micronutrient iron can alter the flux of carbon to the deep ocean. During the Southern Ocean Iron Experiment, we measured an increase in the flux of particulate carbon from the surface mixed layer, as well as changes in particle cycling below the iron-fertilized patch. The flux of carbon was similar in magnitude to that of natural blooms in the Southern Ocean and thus small relative to global carbon budgets and proposed geoengineering plans to sequester atmospheric carbon dioxide in the deep sea.