Landscape scale planning for bats Prof. Fiona Mathews ... · University of Sussex...
Transcript of Landscape scale planning for bats Prof. Fiona Mathews ... · University of Sussex...
Landscape scale planning for batsProf. Fiona MathewsUniversity of Sussex
[email protected] @[email protected] @MathewsFiona
Since 1970
41%
33%
26%
Populations
27%
52%
21%
Distributions
0.5M new houses pa
1,600 mi new roads 2006-1850% increase in traffic by 2050
1% increase pa
What does strategic planning for bats look like?
Razgour et al. 2013
Habitat suitability modelling:
• Presence only data c.f. pseudo-absences• Predictors usually climate and land cover• Predicts PRESENCE = DISTRIBUTION• Does NOT predict density/popn size
P Wright, PhD thesis 2018
2,877 initial presence records 620
50 maternity colonies records, 84 males in hand, 486 other
HSM map from all data
Best modelAll
records
Male
records
Maternity roost
recordsAUC (higher=better) 0.88 0.92 0.83Contribution (%):Distance from woodlands 50.1 66.3 28.8Distance from ancient
woodland16.6 NA NA
Woodland type 15.2 NA 40.8Elevation 12.7 16.8 14.6Ancient woodland 3.2 NA NALand cover 2.2 9.6 15.8Distance from urban area NA 7.3 NA
What is the question?
Different filters=different maps
n=283 in hand records
• Record reliability?• Are records a random sample of population?• Where are the ‘pseudoabsences’? Tautology?• Always prefer analysis of surveyed absences• Beware widespread generalist and cryptic species
Areas of high POTENTIAL suitability may be INACCESSIBLE
Analyse movement and/or gene flow
Light Light
Habitat Habitat
RASTERS RESISTANCE LAYERS
Multivariate
0
500
1000
1500
2000
2500
3000
3500
<=25% 26-50% 51-75% >75
Pass
rat
e
Circuitscape current
Umbrella species?
Gene flow
High habitat suitability and low resistance
Accounting for constraints within the local plan
Add in weights for:• Conflicting land-use type• Future constraints• Improvement potential
Summary:
• HSMs useful for DISTRIBUTION not density• Consider connectivity• Be open minded about ‘value’ of habitats• Think about context and cumulative impacts• Share data
@MathewsFiona