Dr Malcolm Burgess

A review of spatial patterns across species ranges to aid the targeting of conservation interventions

Conservation resources are limited and need to be used where they can be most effective. Deciding where within a species range to implement conservation interventions requires knowledge of where threats operate and consideration of multiple spatial issues concerning patterns in abundance across species' ranges, and geographical and environmental gradients in these and other traits across species' ranges. Although these biogeographical patterns have been of great interest to ecologists for many years, the implications of these patterns for conservation are often unclear. Here we review these patterns in the context of targeting spatial conservation. We find that an inconsistent use of terminology, a lack of consistent rules and the use of imperfect datasets, hampers us drawing firm conclusions on the nature of these patterns. Evidence that abundance and ecological traits change systematically towards range edges is inconclusive. Abundance variation is influenced by many factors independent of position within a species range, including habitat type, habitat quality, environment, interspecific competition, dispersal ecology and metapopulation dynamics. This results in complex textured abundance patterns compared to a simple theoretical core-edge gradient. We conclude that any conservation practitioner looking to target the location of interventions will need to examine these patterns and processes for the species of interest. Current knowledge does not adequately inform spatial conservation prioritization for single-species conservation programmes and incorporating the complexities of spatial processes is challenging. The development of tools to inform spatial targeting of resources for single- or multiple-species conservation is required urgently to enable better use of conservation resources.

Date

03 September 2020

RSPB Authors

Dr Malcolm Burgess, Dr Mark Eaton, Prof Richard Gregory

Published in

Biological Conservation

Latitudinal variation in arrival and breeding phenology of the pied flycatcher Ficedula hypoleuca using large-scale citizen science data

Many species have advanced the timing of annual reproductive cycles in response to climatic warming, sometimes leading to asynchrony between trophic levels, with negative population consequences. Long-distance migratory birds, reliant on short seasonal food pulses for breeding, are considered particularly susceptible to such disjunction because late arrival may preclude optimal timing of egg-laying. It is unknown whether the relative timing of arrival and egg-laying is sufficiently plastic, in time and space, to enable an adaptive response when arrival times change relative to local food resources. We used citizen science data, describing pied flycatcher Ficedula hypoleuca arrival and egg-laying dates, to explore temporal (2013–2016) and spatial (across Great Britain) variation in the phenology of arrival, laying and their difference. To assess the long-term trend in arrival and laying at a single location, we used data from a long-term field study. The arrival-laying interval was consistently shorter in the north, driven by the contrast between spatial variation in arrival date and spatial invariance in laying date. To understand whether a short arrival-laying interval may have consequences for productivity, we assessed the association between this interval and clutch size. We found no statistically significant correlation between these two variables. To examine long-term changes in arrival and laying dates, we focussed on a single location in southwestern England. Both dates of first male arrival and first egg laid in a season advanced since 1986, with no evidence of interval shortening. Together, our results demonstrate spatial and annual variation in the arrival-laying interval, with no detected effect on fecundity. Thus, the interval from arrival to laying is likely dictated by spatially and temporally varying local conditions, suggesting these migrant birds may have the ability to adapt this interval to align with local conditions and mitigate potential mismatch impacts.

Date

12 February 2021

RSPB Authors

Dr Malcolm Burgess

Authors

Nicolau, Pedro G Burgess, Malcolm D Marques, Tiago A Baillie, Stephen R Moran, Nick J Leech, Dave I Johnston, Alison

Published in

Journal of Avian Biology

Tritrophic phenological match-mismatch in space and time

Increasing temperatures associated with climate change may generate phenological mismatches that disrupt previously synchronous trophic interactions. Most work on mismatch has focused on temporal trends, whereas spatial variation in the degree...

Date

02 April 2018

RSPB Authors

Dr Malcolm Burgess

Authors

Burgess, M.D., Smith, K.W., Evans, K.L., Leech, D., Pearce-Higgins, J.W., Branston, C.J., Briggs, K., Clark, J.R., du Feu, C.R., Lewthwaite, K., Nager, R.G., Sheldon, B., Smith, J.A., Whytock, R.C., Willis, S.G. & Phillimore, A.B.

Published in

Nature Ecology & Evolution. 2 (6)

A new framework of spatial targeting for single-species conservation planning

Context
Organisations acting to conserve and protect species across large spatial scales prioritise to optimise use of resources. Spatial conservation prioritization tools typically focus on identifying areas containing species groups of interest, with few tools used to identify the best areas for single-species conservation, in particular, to conserve currently widespread but declining species.

Objective
A single-species prioritization framework, based on temporal and spatial patterns of occupancy and abundance, was developed to spatially prioritize conservation action for widespread species by identifying smaller areas to work within to achieve predefined conservation objectives.

Methods
We demonstrate our approach for 29 widespread bird species in the UK, using breeding bird atlas data from two periods to define distribution, relative abundance and change in relative abundance. We selected occupied 10-km squares with abundance trends that matched species conservation objectives relating to maintaining or increasing population size or range, and then identified spatial clusters of squares for each objective using a Getis-Ord-Gi* or near neighbour analysis.

Results
For each species, the framework identified clusters of 20-km squares that enabled us to identify small areas in which species recovery action could be prioritized.

Conclusions
Our approach identified a proportion of species’ ranges to prioritize for species recovery. This approach is a relatively quick process that can be used to inform single-species conservation for any taxa if sufficiently fine-scale occupancy and abundance information is available for two or more time periods. This is a relatively simple first step for planning single-species focussed conservation to help optimise resource use.

Date

22 October 2020

RSPB Authors

Dr Malcolm Burgess, Prof Richard Gregory, Prof Jeremy Wilson, Dr Mark Eaton

Authors

Burgess, Malcolm Gregory, Richard Wilson, Jeremy Gillings, Simon Evans, Andy Chisholm, Kenna Southern, Adrian Eaton, Mark

Published in

Landscape Ecology

Gradients in richness and turnover of a forest passerine's diet prior to breeding: A mixed model approach applied to faecal metabarcoding data

Rather little is known about the dietary richness and variation of generalist insectivorous species, including birds, due primarily to difficulties in prey identification. Using faecal metabarcoding, we provide the most comprehensive analysis of a passerine's diet to date, identifying the relative magnitudes of biogeographic, habitat and temporal trends in the richness and turnover in diet of Cyanistes caeruleus (blue tit) along a 39 site and 2° latitudinal transect in Scotland. Faecal samples were collected in 2014–2015 from adult birds roosting in nestboxes prior to nest building. DNA was extracted from 793 samples and we amplified COI and 16S minibarcodes. We identified 432 molecular operational taxonomic units that correspond to putative dietary items. Most dietary items were rare, with Lepidoptera being the most abundant and taxon-rich prey order. Here, we present a statistical approach for estimation of gradients and intersample variation in taxonomic richness and turnover using a generalised linear mixed model. We discuss the merits of this approach over existing tools and present methods for model-based estimation of repeatability, taxon richness and Jaccard indices. We found that dietary richness increases significantly as spring advances, but changes little with elevation, latitude or local tree composition. In comparison, dietary composition exhibits significant turnover along temporal and spatial gradients and among sites. Our study shows the promise of faecal metabarcoding for inferring the macroecology of food webs, but we also highlight the challenge posed by contamination and make recommendations of laboratory and statistical practices to minimise its impact on inference.

Date

20 February 2020

RSPB Authors

Dr Malcolm Burgess

Authors

Shutt, Jack D Nicholls, James A Trivedi, Urmi H Burgess, Malcolm D Stone, Graham N Hadfield, Jarrod D Phillimore, Albert B

Published in

Molecular Ecology