Species-Specific Effects on OccupancyHighway Proximity and Predator Playback

AEC 501

Lina Aita, Emily Bruff, Khai Button, Colleen Grant, Kathryn

Nilsson, Ana Rivera-Burgos

Study AimsObtain baseline count of

species at the study siteWintering species in

North CarolinaMixed deciduous forest

Examine urbanization effectsin Wake County, NC

Highway infrastructureAvian community structure

NC Wildlife.org

ncwildlife.org

Proximity to infrastructure (buildings, highways, powerlines, etc) ≈ negative impact on bird populations

Stress, noise, barriers, habitat destruction, and fragmentation

Increasing urbanization in Wake County

Background

© WRAL

Graph and data compiled by Anora McGaha

Photo: Per Breiehagen

Changes in Avian communities

Responses to urban infrastructure?

Urban exploiter species (Palomino and Carrascal (2007)

Success of Screech Owls in Suburbs (GIll 2007)

Eastern Screech Owls prey on smaller birds

Background

PredictionsEastern Screech Owl

playback has the potential to increase or decrease occupancy & detection

Detection should increases if species alarm call in response

Occupancy should decreases if species hide/leave in response

Proximity to I-40 in Wake Co.Counts/detection should be

lower as proximity to I-40 increases

Not a screech owl, but it was near a highway.

Image Credit: Transport Quebec

Study AreaUmstead State Park

5,000 acres of mixed deciduous forest

Southern portion (study area) bordered by I-40 (yellow)

Study Area

Photo by Miguel Vieira

Umstead State Park

Protected since 1934

Originally farmland

Mixed hardwoods and pine

Photo by Stephanie Haines

Study AreaSchenck Forest

Managed forest (NCSU)

Adjacent to Umstead and I-40

Better proxy for natural forest

Controlled burns

Stratified forest

Methods20 sample points, 3x

Spaced 200m apart

5 minute unlimited radius count

Loblolly Trail

N

1050200

Methods40 additional points were

sampled by other groups

Points in Umstead State Park and Schenck Forest

Methods

© Sarah Wolfe, February 2011

Coin toss to determineplayback

Sound recorded at each site with a sound meter

Sites sampled over 15 days

8 am to 11am

Distance to I-40 calculated using ImageJ

Occupancy data analyzed using

Detection and occupancy models were calculated for five species of birds

© Kevin Shea, VA, January 2009

Carolina Chickadee

© Kevin Shea, VA, January 2009

Carolina Wren

Tufted Titmouse

© William Jobes, PA, January 2009

Northern Cardinal

© Judy Howle, December 2008

© Dawn Vornholt, GA, December 2009

Pine Warbler

Results

Results

Species Naive OccupancyLowest AIC Model AIC Value AIC Weight

Occupancy Detection

Carolina Chickadee 0.7500 Distance to I-40 1 246.00 0.2590

Carolina Wren 0.7833 1 1 247.52 0.4330

Eastern Tufted Titmouse 0.7167 Screech Owl 1 237.11 0.761

Northern Cardinal 0.7667 1 1 248.06 0.3666

Pine Warbler 0.8167 1 1 236.10 0.3242

Results

Species Naive OccupancyLowest AIC Model

AIC Value AIC Weight Occupancy Detection

Carolina Chickadee 0.7500 Distance to I-40 1 246.00 0.2590

Carolina Wren 0.7833 1 1 247.52 0.4330

Eastern Tufted Titmouse 0.7167 Screech Owl 1 237.11 0.761

Northern Cardinal 0.7667 1 1 248.06 0.3666

Pine Warbler 0.8167 1 1 236.10 0.3242

ResultsUntransformed Betas Transformed

Species Intercept Occupancy Detection Occupancy Detection

Carolina Chickadee

2.096 ±0.857 -0.774 ±0.557 1 0.877a 0.502

Eastern Tufted Titmouse

3.03 ±1.74 -2.53 ±1.75 1 0.954b 0.549

Mean ± S.E.M.

p= 0.164

p=0.1484

ResultsSignificant (p<.001) negative relationship, but effect was small

DiscussionSound readings decreased with distance

from I-40

Distance not correlated with the occupancy in 4 of the 5 most common species

Ambient noise likely not an important factor affecting bird occupancy in study area

Mobbing behavior of titmice (Hill 1986)

Discussion

Osprey being mobbed by starlings

© William Jobes, PA, January 2009

DiscussionEastern Screech Owl playback not correlated with detection

No effect on occupancy in 4 of 5 species

Volume of playback may beinsufficient to affect detection

Boldness of urban birds

Only auditory, not visual

Newsteam

Marvel Comics, 2012

DiscussionPoints most likely needed to be

closer to I-40

Previous studies showed the greatest effect on mean species abundance is within 500 m of a disturbance (Benítez-López et al. 2010)

Discussion

479m

DiscussionAccording to Lynch and Whigham (1984),

habitat fragmentation =species-specific effects

Other factors:Tree stratumPine abundanceFloristic diversityLand area and isolation

Results not easily explained due to complexity of bird behavior

Copyright © 2016 River Partners. All r ights reserved.

DiscussionUrbanization is also known to alter bird

behavior, survivorship, and response to predators (Gill 2007, Lowry et al. 2011) Umstead

S.P.

Schenck

Lake Crabtree County Park

Morrisville development

Sources of ErrorInconsistent noise

Joggers/dogs

Bicyclists

RDU?

Insufficient point separation?

Double counting -> false positives

Multiple independent observation assumption

Broad range of times and dates

Different conditions

ConclusionOverall the study provided litt le evidence of correlation between bird occupancy/detection and proximity to I-40 or Eastern Screech Owl playback.

Need to perform further studies to derive conclusive data

Account for edge effects and proximity to all major roads

Error in data due to

Inexperience identifying birds

False negative, misidentification (false positives)

Insufficient distance between sites

Difference in data collection procedure

Literature CitedBenítez-López, A., R. Alkemade, and P. A. Verweij (2010). The impacts of roads and other infrastructure on mammal and bird populations: A meta-analysis. Biological Conservation 143:1307–1316. doi: 10.1016/j.biocon.2010.02.009

Gill, F. B. (2007). Lifetime Reproductive Success - Life Tables. In Ornithology. 3rd edition. W. H. Freeman and Company, New York, pp. 506–510.

Hill, G. E. (1986). The function of distress calls given by tufted titmice (Parus bicolor): an experimental approach. Animal B ehavior. 34:590-598.

Hines, J. (2016). PRESENCE V. 10.7. (software). USGS.

Lowry, H., L. Alan, and B .B .M. Wong (2011). Tolerance of Auditory Disturbance by an Avian Urban Adapter, the Noisy Miner. Ethology. 117:490-497.

Lynch, J.F., and D.F. Whigham (1984). Effects of Forest Fragmentation on B reeding B ird Communities in Maryland, USA. B iological Conservation 28:287-324

Palomino, D., and L. M. Carrascal (2007). Threshold distances to nearby cities and roads influence the bird community of a mosaic landscape. Biological Conservation 140:100–109. doi: 10.1016/j.biocon.2007.07.029

Quay, T. L. (1940). The ecological succession of winter birds at Raleigh, North Carolina. M.S. thesis, State College of Agriculture and Engineering of the University of North Carolina.

Questions?