CIE Spotlight: Decision-Making in Conservation and Natural Resource Management: Models for Interdisciplinary Approaches

Edited by: Nils Bunnefeld, Emily Nicholson, EJ Milner-Gulland

Source: Conservation Biology (Cambridge University Press), Volume: 22, August 2017

Brief summary of the book: Making decisions about the management and conservation of nature is necessarily complex, with many competing pressures on natural systems, opportunities and benefits for different groups of people and a varying, uncertain social and ecological environment.

An approach which is narrowly focused on either human development or environmental protection cannot deliver sustainable solutions. Decision-Making in Conservation and Natural Resource Management provides frameworks for improving the integration of natural resource management with conservation and supporting stronger collaboration between researchers and practitioners in developed and developing countries.

Novel approaches are required when ecological and social dynamics are highly interdependent. A structured, participatory, model-based approach to decision-making for biodiversity conservation has been proven to produce real-world change. There are surprisingly few successful case studies, however; some of the best are presented here, from fisheries, pest management and conservation. Researchers and practitioners need this interdisciplinary approach, focused on quantitative tools that have been tested and applied, and learning from success.

CIE Spotlight: Virtual palaeontology: the effects of mineral composition and texture of fossil shell and hosting rock on the quality of X-ray microtomography (XMT) outcomes using Palaeozoic brachiopods

Guang S.

Authors: Lee, Sangmin; Shi, G. R.; Park, Tae-Yoon S.; Oh, Jae-Ryong; Mii, Horng-Sheng; Lee, Mirinae

Source: PALAEONTOLOGIA ELECTRONICA, 20 (2):2017

Brief summary of the paper: X-ray microtomography (XMT) has become a popular tool for detailed investigations of a diverse range of fossils. However, XMT has not always guaranteed a satisfactory result, as the resolution of XMT images critically depends on the contrast between the fossil and its hosting rock.

In this paper, XMT was applied to 11 Palaeozoic brachiopod specimens selected from a range of sedimentary rocks in order to investigate the extent of effects of mineral composition and texture in the rock and fossil shell on the quality of XMT outcomes.

Our study shows that sufficient contrast in mineral composition and texture between the brachiopod shell and its infilling material is required to reproduce high-quality XMT results. Specifically, brachiopod specimens with their original calcium carbonate shell, infilled mainly with quartz grains, appear to produce the best XMT results characterized by sharply defined shell internal structures.

We also found that diagenesis is significant in determining the XMT quality. Diagenetic processes including silicification and recrystallization in the brachiopod shell and/or the infilling material generally tends to diminish the resolution of the XMT results, although this impact is considerably complicated by the degree and aspect of diagenesis. Another factor of minor significance concerns the presence of bioclasts scattered in the hosting sediment that potentially could be confused with genuine shell internal structures.

CIE Spotlight: Sediment microbes mediate the impact of nutrient loading on blue carbon sequestration by mixed seagrass meadows

Pic by James St. John

Authors: Liu, Songlin; Jiang, Zhijian; Zhang, Jingping; Wu, Yunchao; Huang, Xiaoping; Macreadie, Peter I.

Source: SCIENCE OF THE TOTAL ENVIRONMENT, 599 1479-1484, DEC 1 2017

Brief summary of the paper: Recent studies have reported significant variability in sediment organic carbon (SOC) storage capacity among seagrass species, but the factors driving this variability are poorly understood, limiting our ability to make informed decisions about which seagrass types are optimal for carbon offsetting and why.

Here we show that differences in SOC storage capacity among species within the same geomorphic environment can be explained (in part) by below-ground processes in response to nutrient load; specifically, differences in the activity of microbes harboured by morphologically-different seagrass species.

We found that increasing nutrient load enhanced the relative contribution of seagrass and algal sources to SOC pools, boosting sediment microbial biomass and extracellular enzyme activity within mixed seagrass meadows composed of Thalassia hemprichii and Enhalus acoroides, and thus possibly weaken the seagrass blue carbon sequestration capacity. The relative contribution of seagrass plant material to sediment bacterial organic carbon (BOC) and the influencing SOC-decomposing enzymes in E. acoroides meadows were half that of T. hemprichii meadows living side-by-side, even though the mixed seagrass meadows received SOC from the same sources.

Overall this research suggests that microbial activity can vary significantly among seagrass species, thereby causing fine-scale (within-meadow) variability in SOC sequestration capacity in response to nutrient load.

CIE Spotlight: The current and future state of animal coloration research

John E.

Authors: Endler, John A.; Mappes, Johanna

Source: PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 372 (1724), JUL 5 2017

Brief summary of the paper: Animal colour patterns are a model system for understanding evolution because they are unusually accessible for study and experimental manipulation. This is possible because their functions are readily identifiable.

In this final paper of the symposium we provide a diagram of the processes affecting colour patterns and use this to summarize their functions and put the other papers in a broad context. This allows us to identify significant ‘holes’ in the field that only become obvious when we see the processes affecting colour patterns, and their interactions, as a whole.

We make suggestions about new directions of research that will enhance our understanding of both the evolution of colour patterns and visual signalling but also illuminate how the evolution of multiple interacting traits works.

This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.

CIE Spotlight: Valley-floor censuses of the Critically Endangered Yellow-crested Cockatoo Cacatua sulphurea occidentalis on Komodo Island, East Nusa Tenggara province, Indonesia, point to a steep population decline over a six-year period

Pic by Ashleigh Thompson

Authors: Imansyah, M. Jeri; Purwandana, Deni; Ariefiandy, Achmad; Benu, Y. Jackson; Jessop, Tim S.; Trainor, Colin R.

Source: FORKTAIL, (32):66-71; December 2016

Brief summary of the paper: The population of the Critically Endangered Yellow-crested Cockatoo Cacatua sulphurea occidentalis in Komodo National Park, Komodo Island, East Nusa Tenggara province, Indonesia, is thought to be second largest, but has been little studied.

In September–October 2005, we surveyed cockatoos from vantage points overlooking five coastal valleys, each one on three consecutive days, and in September 2006 counted cockatoos in Loh Sebita valley on five consecutive days. Our method reduced the possibility of double-counting birds because on each day only the single largest count of cockatoos was used.

We compared our 2005 and 2006 data with population census counts from the same valleys using the same method in September–October 2000. We also collated opportunistic counts of the species on Komodo made between 1996 and 2015 and checked whether temporal trends were apparent between two 10-year periods. Nest and breeding data were also collected. A total of 137 cockatoos was recorded in 2005 compared with 340 in 2000, with census counts declining by an average of 60%.

In Loh Sebita valley the population declined by 41% between 2000 and 2006. A total of 19 active nests was located, with 25 nestlings/ juveniles recorded, mostly in tall and smooth-trunked Sterculia foetida, S. oblongata and Corypha utan trees, which are apparently selected to reduce nest predation.

Vantage point census counts are a suitable method on Komodo because inland topography renders cockatoo flocks easily detectable from ridges, although greater survey effort is needed to reduce margins of error.

The cause(s) of the sharp population decline remain unclear but trade is the most likely driver, with other factors such as breeding failure possibly involved. Annual population and habitat monitoring is needed on Komodo to confirm the causes of decline and specific patrolling is needed to monitor nests.

CIE Spotlight: Variability in the foraging range of Eudyptula minor across breeding sites in central New Zealand

Pic by JJ Harrison

Authors: Poupart, Timothee A.; Waugh, Susan M.; Bost, Caroline; Bost, Charles-Andre; Dennis, Todd; Lane, Reuben; Rogers, Karyne; Sugishita, Junichi; Taylor, Graeme A.; Wilson, Kerry-Jayne; Zhang, Jingjing; Arnould, John P. Y.

Source: NEW ZEALAND JOURNAL OF ZOOLOGY, 44 (3):225-244, 2017

Brief summary of the paper: The little penguin Eudyptula minor is primarily an inshore forager with its range generally limited to c. 30 km of breeding sites during the nesting period. However, exceptions with greater foraging distances have been recorded in Australia.

To investigate the foraging range plasticity in New Zealand we used GPS tracks gathered on 68 individuals in three regions of central New Zealand between 2011 and 2016. Foraging patterns varied between sites and between years. Tracks revealed that penguins can rely on distant foraging areas while incubating, with nesting birds travelling up to 214 km to feed.

Isotope analyses of blood samples showed that this distant food across deep waters (0–200 m) is likely to be squid dominated. During the chick rearing period, birds undertook a diet shift to a higher trophic level while foraging closer to their colony, and possibly near river plumes.

These findings highlight the need to consider the little penguins’ large potential foraging ranges when managing threats and changes to the environment.

CIE Spotlight: Subharmonics increase the auditory impact of female koala rejection calls

Authors: Charlton, Benjamin D.; Watchorn, Darcy J.; Whisson, Desley A.

Source: ETHOLOGY, 128 (8):571-579, AUG 2017

Brief summary of the paper: Although non-linear phenomena are common in human and non-human animal vocalisations, their functional relevance remains poorly understood.

One theory posits that non-linear phenomena generate unpredictability in vocalisations, which increases the auditory impact of vocal signals, and makes animals less likely to habituate to call repetition. Female koalas (Phascolarctos cinereus) produce vocal signals when they reject male copulation attempts that contain relatively high levels of non-linear phenomena, and thus may function as attention grabbing vocal signals during the breeding season.

To test this hypothesis, we used playback experiments: firstly, to determine whether female rejection calls induce heightened behavioural responses in free-ranging male koalas during the breeding season, and secondly, to examine how the relative amount of non-linear phenomena in rejection calls influences male behavioural response.

The results show that male koalas look for longer towards speakers broadcasting playback sequences of male bellows followed by a series of female rejection calls than those broadcasting only male bellows. In addition, female rejection call sequences with more subharmonics, higher harmonics-to-noise ratios, and less biphonation produced the greatest male looking responses.

Our findings support the hypothesis that female koala rejection calls function to grab male attention during the breeding season, and indicate that subharmonics are the main acoustic feature that increases the auditory impact of these vocal signals.

CIE Spotlight: Improved color constancy in honey bees enabled by parallel visual projections from dorsal ocelli

Pic by Wikimedia Commons: Rushenb

Authors: Jair E. Garcia, Yu-Shan Hung, Andrew D. Greentree, Marcello G. P. Rosa, John A. Endler, and Adrian G. Dyer

Source: Proceedings of the National Academy of Sciences of the United States of America (received for review March 1, 2017)

Brief summary of the paper: How can a pollinator, like the honey bee, perceive the same colors on visited flowers, despite continuous and rapid changes in ambient illumination and background color?

A hundred years ago, von Kries proposed an elegant solution to this problem, color constancy, which is currently incorporated in many imaging and technological applications. However, empirical evidence on how this method can operate on animal brains remains tenuous.

Our mathematical modeling proposes that the observed spectral tuning of simple ocellar photoreceptors in the honey bee allows for the necessary input for an optimal color constancy solution to most natural light environments. The model is fully supported by our detailed description of a neural pathway allowing for the integration of signals originating from the ocellar photoreceptors to the information processing regions in the bee brain.

These findings reveal a neural implementation to the classic color constancy problem that can be easily translated into artificial color imaging systems.

CIE Spotlight: Geochemical analyses reveal the importance of environmental history for blue carbon sequestration

Peter M.

Authors: J. J. Kelleway, N. Saintilan, P. I. Macreadie, J. A. Baldock, H. Heijnis, A. Zawadzki, P. Gadd, G. Jacobsen, P. J. Ralph

Source: Journal of Geophysical Research: Biogeosciences (published online: 30 June 2017)

Brief summary of the paper: Coastal habitats including saltmarshes and mangrove forests can accumulate and store significant blue carbon stocks, which may persist for millennia. Despite this implied stability, the distribution and structure of intertidal-supratidal wetlands is known to respond to changes imposed by geomorphic evolution, climatic, sea level and anthropogenic influences.

In this study, we reconstruct environmental histories and biogeochemical conditions in four wetlands of similar contemporary vegetation in SE Australia. The objective is to assess the importance of historic factors to contemporary organic carbon (C) stocks and accumulation rates.

Results from the four cores – two collected from marine influenced saltmarshes (WAP-M and POR-M) and two from fluvial influenced saltmarshes (WAP-F and POR-F) – highlight different environmental histories and preservation conditions. High C stocks are associated with the presence of a mangrove phase below the contemporary saltmarsh sediments in the POR-M and POR-F cores. 13C NMR analyses show this historic mangrove root C to be remarkably stable in its molecular composition despite its age, consistent with its position in deep sediments. WAP-M and WAP-F cores did not contain mangrove root C, however, significant preservation of char C (up to 46% of C in some depths) in WAP-F reveals the importance of historic catchment processes to this site.

Together, these results highlight the importance of integrating historic ecosystem and catchment factors into attempts to upscale C accounting to broader spatial scales.

CIE Spotlight: Species distribution models derived from citizen science data predict the fine scale movements of owls in an urbanizing landscape

Pic by Greg Sharkey

Authors: Nick Bradsworth, John G. White, Bronwyn Isaac, Raylene Cooke

Source: Biological Conservation, Volume 213, Part A, Pages 27–35, September 2017

Brief summary of the paper: Apex predators are critical to ecological function, however their life history traits are often not conducive to survival in urban environments. While this can result in the loss of some apex predators, others are able to inhabit and utilize urban environments.

Understanding predator resource requirements and the factors driving their distribution is often difficult due to their cryptic nature, however, this understanding is essential, given the current rate of urban expansion.

In this research we use a threatened apex predator, the powerful owl (Ninox strenua) as a case study. Specifically, we aim to (1) develop a Species Distribution Model (SDM) to ascertain environmental variables driving habitat suitability across an urban gradient (2) determine fine scale spatial movements of powerful owls using GPS telemetry; (3) validate the SDM against collected GPS movement data; and (4) evaluate habitat predicted by the SDM against current reserve systems to establish whether they are adequate for the future protection of this species.

We used MaxEnt and citizen science data to produce SDMs that predicted habitat suitability for powerful owls and identified the environmental variables driving habitat across the landscape. Fine-scale spatial movements for urban powerful owls, gained via GPS telemetry, were used to establish home-range sizes, validate models and assess the fit of telemetry data against SDM predictions.

Rivers, vegetation (particularly dense tree cover) and distance to riparian areas were the ecological variables driving predicted habitat for powerful owls across the urban gradient. There was a strong relationship between habitat predicted by the SDM and the fine scale movements of powerful owls in urbanized environments. Home-ranges within this urban study were notably smaller than previous estimates established for forested environments.

The powerful owls in our study were also shown to utilize considerable amounts of habitat outside of the reserve system. This has severe conservation implications because it is often the space outside of reserves that are at most risk from urban intensification.

Conservation of the powerful owl in urban environments, therefore, needs to focus on both habitat management within existing reserves, and on establishing clear vegetation management strategies in the surrounding urban matrix.