Muna Maryam Azmy

Mechanism of human-hornet conflicts in an urban ecosystem

Towards Green Urbanization

Benefits of urban green space:-Decrease urban heat effects (Tsilini et al. 2015)

-Increase health (Lee et al. 2011)

-Mitigate water, air pollution (Nowak et al. 2006)

-Nature-based tourism opportunity (Broadbent et al. 2012)

-Wildlife habitat (McKinney 2008)

Due to these benefits, many cities (US, China, Japan) have implemented strategies to increase the supply of green space(Wolch et al. 2014)

Shinjuku Park,2014

Negative side effects of human-nature interaction

Human-wildlife conflictHuman-wildlife Human & Human-wildlife

Damage to infrastructureIn Iowa, deer-vehicle 220 collisions account for 13% of all crashes reported (Gkritza et al. 2014)

Increase in unwanted speciesIncrease in number of complaints from homeowners regarding damage to roof insulation due to inhabitants of martens (Herr et al. 2010)

Human DeathCoyote aggression towards people (n=3646) in Denver-Metro area of Colorado in 7 years. (Poessel et al. 2013)

Among stockholders managersDiffering responsibilities interpretations between agencies and landowners in red deer management (Davies& White 2012)

Conservation diversities97% of 100 articles were conflict between conservation and other human activities, particularly those associated with livelihoods (Redpath et al. 2015)

Stinging Insect Conflict: Japan

(Matsuura, 2010)

Average of death from 2005-2014

5 Snakes

18 Paper Wasp, Bee, Hornet

Stinging insects are considered as nuisance due to the damage inflicted by this species.

Eg. Death from wasp sting is rare but fatal incident often involves a single sting

Wasp attack in urban park , Florida

Stinging Insect Conflict

High consultation demand for stinging insects

Increasing demand for hornets consultation

Approximately half of the 53 local governments (excluding the isolated islands) financially or technically support nest removal from private homes, which normally costs between $100‒500 US per removal (Hosaka & Numata 2016).

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

02000400060008000

100001200014000

Paper wasp and hornet total consul-tations in Tokyo

Wasp Linear (Wasp)Year

No.

of

Cons

ul-

tatio

n

𝑟 𝑠=0.5 0∗

𝑟 𝑠=0. 8 2∗∗

* Significance at p<0.05, ** Significance at p<0.01Paper wasp

Pest Group Consultation in Tokyo 2010-2014Stinging insectsRatsNuisance animalsBlood-sucking insectsPoisonous insectsNuisance insectsSanitary pestsMitesWood pestsTree pestsFood pestsOthers

(Hosaka & Numata 2016)

What caused the conflict increase?

Tolerance of Human?

Abundance of Hornet?

Small habitat requirement (McKinney, 2008)

High temperature that induced hatching rate (Sirassmann and Orgren, 1983)

Availability of green spaces (Choi et al., 2012)

Physical disabilities during encounter among aging generation (Bjerke et al., 1998)

Lack of experience of younger generation of urban dwellers towards some nature (Soga et al., 2016)

Enhanced of communication technologies allows better news circulation

Horn

et

Year

Tole

ranc

e

Year

Aim of StudyTo identify factor influencing conflict between human and hornet in urban area

Hornet

Human

Conflict

Hornet’s Nest Removal report

Conflict

What is the environment prone for human-hornet conflict?

1) Where does hornet community mainly found?

2) Where does human-hornet conflict(HHC) mainly found?

Hornet Conflict

Prone environment

Human and hornet environment

+

Responses of hornet species to levels of urban greenness

Horn

etYear

Hornet: Species characteristics

There are 24 species of hornets (Vespa spp.) exclusively distributed throughout Asia, except for one found also in Europe (Ono, 2007)

Eight species are known to live in Japan (Matsuura and Yamane, 1990)

Hornets harmfulness to humans can differ among species (Matsuura 1984, 1990)

Hornet in Japan

FeaturesSpecies

V. mandarinia V. crabro V. analis V. ducalis

Body size (mm) 27-38 21-28 22-28 24-37

Nesting site underground,tree hollow

attic, underground, tree hollow

tree branch building eaves, rock wall

attic, underground, tree hollow

Preyvarious insects including other

hornetsmainly cicadas various insect and

spiders paper wasp

AggressivenessPoison

V. analisコガタスズメバチV. mandariniaオオスズメバチ V. crabroモンスズメバチ V. ducalisヒメスズメバチ

V. simillimaキイロスズメバチV. flavicepsクロスズメバチ

V. dybowskiチャイロスズメバチ

Matsuura (1984)

V. velutina

Increasing

V. mandariniaV. crabro

V. analisV. ducalis

Seasonal activity of hornetMated queens

survive outdoors

Nest-building

Nest maintainance by workers

New queens develop, summer colonies

dies

Winter

Spring

Summer

Autumn

Matsuura (1990)

Benefits of Hornet in Urban Ecosystem

Matsuura & Yamane (1990) ; pictures credited to Yamauchi H.

Natural pest control Unsanitary pest Agriculture pest

Food alternative Source of protein Exotic food supply

Health improvement Herbal medicine Sports drinks

Objective of Study• Hornet depend on green space, particularly forest space due to food and

nesting preferences (Matsuura, 1984; Ono, 2003).• Some hornet species have also become well-adapted to urban areas, as

they use garden trees and buildings for nesting places and use human waste as their food source (Choi et al., 2012; Ono, 2003).

• Quantitative analysis on hornet dependence on greenness level is lacking

Food

Low green areas?

Whichhornet

High green areas?

Nest

Aggressive

To understand hornet preferred environment using greenness level

Materials & Methodologies

1) Hornet sample

Data collection of hornet abundance from Nagoya City Living Hygiene Centre

Two trapping points located at each 11 locations

Bait: Funnel trap and attractant liquid (6:4 fermented sugar solution to water)

Trap: 3m above the ground were observed every week

Period: April to November in 2007 to 2014 Species of the hornets were identified and

recorded.

Nagoya

Example:Funnel trap

Materials & Methodologies2) Green spaces

Satellite variable : Normalized Difference Vegetation Index (NDVI) of Landsat-8

Date observation :14 August 2013 The images were acquired with 30-m spatial

resolution

NDVI Valid range: -1 to 1 (e.g 0.5-0.8 forest, -0.1-0.2 bare land) Greenness level based on photosynthetically

active biomass of plant canopies can remotely monitored using NDVI(Tucker 1979; Elmore et al. 2000)

Relevant at detecting vegetation change and forest cover dynamics (Mancino et al. 2014)

Moriyama, Nagoya

Tenpaku, Nagoya

100m radius

0.52

0.35

Materials & Methodologies2) Green spaces radius measurement

Average NDVI were measured at each locations within: o 100mo 500mo 1kmo 1.5kmo 2kmo 3kmo 4kmo 5kmo 6kmo 7kmo 8kmo 9kmo 10km

1)Do NDVI values correlate with the abundance and species composition of hornets?2)Are responses to NDVI values different among hornet species?3)Which spatial scale is the most effective at predicting hornet abundance and species composition?

Research Questions

Materials & Methodologies3) Data analysis

1.To examine the effect of green areas towards hornet abundanceGeneralized Linear Mixed Model(GLMM) *-Response : Hornet species abundance-Explanatory : Average NDVI within 100m, 500m, 1km,2km,…, 10km-Random effect: Location ID

2.To identify the scale to detect hornet abundance GLMM, Nonmetric-multidimensional Scaling (NMDS)*-Response : Hornet species composition at site (NMDS)-Explanatory : Average NDVI within 100m, 500m, 1km, 2km,…, 10km-Random effect: Location ID

3.To analyze temporal pattern of hornet abundance Spearman rank correlation-Variables: Year ~ Hornet abundance(Burnham and Anderson, 2002, Zuur et al., 2009)

* Based on AIC

Results?

Temporal pattern

Although some species showed high temporal increase, the results were not significant except for V. mandarinia

Long-term monitoring is crucial to understand temporal patterns of hornet abundance

Temporal pattern of abundance

Results

2007 2008 2009 2010 2011 2012 2013 2014 20150

2000

4000

6000

8000

10000

12000V.analis V.ducalisV. crabro V. mandariniaTotal

62

𝑟 𝑠=0.72∗

𝑟 𝑠=0. 3𝑟 𝑠=0. 08

𝑟 𝑠=0.17

V. analis29%

V. ducalis9%

V. crabro17%

V. mandarinia43%

Others1%

Species composition 2007-2015N=64569

YearAb

unda

nce

Species compositions were different among locations (F=17.175, p<0.001)

Species compositions were not different in years (F=0.6926, p=0.8093)

Suggesting strong drivers caused in spatial environmental (i.e land covers), besides temporally fluctuating factors (i.e. temperature and rainfall)

Results

Spatial species composition

-0.25

0.00

0.25

-0.50 -0.25 0.00 0.25 0.50NMDS1

NM

DS

2

WardpPoint 1

Point 10

Point 11

Point 2

Point 3

Point 4

Point 5

Point 6

Point 7

Point 8

Point 9

1

32

456

8

109

11

7

Locations

N=82 [(6years x10location)+(2yearsx11location)]

N=82

Spatial pattern

Effect of Greenness Level

NDVI within all radiuses from 100m to 10km significantly affect hornet abundance

Best model: NDVI within 1km (0.18-0.54)

Suggesting that the level of greenness in urban areas positively affected hornet abundance

Best estimate within 1km: consistent with hornets flying range (Matsuura, 1984)

Results

GLMM :Hornet abundance~ average NDVI within radius + *Ward ID*random effect

Different Response on Greenness

Two species significantly affected by green spaces

-V. mandarinia -V. crabro Difference in response are

likely related to the species-specific ecological characteristics

Results

***N = 82

***N = 82

2.913N = 82

*** Significance at p<0.001

NDVI within 1km radius

Abun

danc

e

GLMM :Species abundance~ average NDVI within 1 km radius+ *Ward ID V. analisV. mandarinia

V. ducalisV. crabro

*random effect

N=82 [(6years x10location)+(2yearsx11location)]

0.78N = 82

Different Effect of Greenness Level

Results

Species dominance based on greenness levelwithin 1km

Nesting and prey preference related: V. mandarinia: underground nests and

prey on a great number of large insects in forests

V. crabro: tree hollows and underground nesting, and they prey on cicadas

V. analis: generalists in regard to prey species and nesting sites

(Matsura 1984, Choi et al. 2012, Michelutti et al., 2013)

N = 82

0.31

Kita

0.54

Chikusa Minato

0.19

Summary

Important to consider the greenness level of landscapes rather than land use element(forest, parks) to predict hornet abundance

This study showed that possibilities of conflicts with hornets are likely to increase proportionally with the amount of green space especially the most venomous species

Useful information to be shared by urban park managers to improve awareness on public safety at urban green spaces

Green space and conflict

Non-forest

• V. mandarinia• V. crabro

Forest

• V. analis• V. ducalis

Impacts of environment on human - hornet conflict in urban ecosystem of

Nagoya

Tole

ranc

e

Year

Human

Human wildlife conflict

Hornet as urban’s nuisance insect has several times been discussed in previous studies (Matsuura and Yamane, 1990; Nakamura, 2007; Yamauchi H, 2009), but lack of quantitative approach has been done to understand the issue

Limited of studies has on human-insect conflict (Magle et al. 2012)

Since insects can adapt well to urban environment we need to understand how conflicts can be detrimental to human

What environment can drive conflict?

1) Where we can find high number of hornet?

2) Where we can find high number of wildlife conflict?

Human and hornet environment= green spacesfor some species

= residential areas

3) Who mostly dislike wildlife? = elder generation

4) Who have low tolerance to wildlife? = woman

Structure of species diversity and abundance can depend on species interaction, microclimate and availability of natural resources (Picket et al 2001)

Combination of increased human population in urbanized environment with human dynamic attitude, induce challenge in solving wildlife conflict (Jochum et al. 2014)

Objectives of Study

Removal report

Conflict

Social characteristics

To understand which factors strongly contribute to the conflict

Grassland

PopulationAgricultural land

Parks

Forest

Residential areas

Women

Elder generation

Spatial environment

Materials & Methodologies1) Hornet nest removal report

Study area: Nagoya city Source: Environmental Health Center of

Nagoya city Size: 16 wards Type of removal: Free of charge Period : 1990 to 2005 Five main hornet species identified: - Vespa mandarinia (オオスズメバチ ) - V. analis (コガタスズメバチ ) - V. ducalis (ヒメスズメバチ ) - V. crabro (モンスズメバチ ) - V. simillima (キイロスズメバチ )

Nagoya city

Period observed: 1990-2005 Source: Nagoya city demographic

report (Nagoya, 2015) Ratio of group :

Materials & Methodologies

Grassland Agricultural land Forest Residential areas Parks

Elder generation proportion Women proportion Population

Nagoya

2) Land use types 3) Social characteristics

Period observed: 1990-2005 Source: Nagoya city government Ratio of land use:

Land use areaWard area

% Group proportionWard proportion

%

Do number of removals 1) Increase temporally?2) Different spatially ?3) Affected by land use or social pattern?

Research Questions

Materials & Methodologies3) Data analysis

1.To examine the effect of spatial and towards hornet removalGeneralized Linear Mixed Model(GLMM) -Response : No. of removals-Explanatory :

-Random Effect : Ward ID

2.To analyze temporal pattern of hornet removalSpearman rank correlation-Variables: Year ~ No. hornet removal

(Burnham and Anderson, 2002, Zuur et al., 2009)

: Grassland: Parks: Elder generation

: Women proportion: Population: Year

: Residential areas : Agricultural land : Forest

Results?

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

0

200

400

600

800

1000

1200Trend of total removal

Year

Rem

oval

92

3221

Species Removed

V. analisV. ducalisV. crabroV. simillimaV. mandarinia

Number of removal significantly increased temporally Highly removed species is V. analis : expected to have high adaptability at various land covers

Temporal trend of removal

Results

𝑟 𝑠=0.86∗∗∗

** p. value significant at p<0.001, N=16

0

0.5

1

1.5

2

2.5

3

3.5

Year

Log

no o

f Rem

oval

Trend of Removal by Species

Results

𝑟 𝑠=0. 85∗∗∗

𝑟 𝑠=0.4 6𝑟 𝑠=0.72∗∗∗

𝑟 𝑠=−0.4 3*

Significance at *** p<0.001, N=16

Temporal removal for all species increased significantly except for V. ducalis and V. simillimaHighest increase in removal was on V. analis followed by V. mandariniaIncrease of conflict with V. mandarinia raise awareness on the negative effect of urban ecosystem

Spatial trend of removal

Results

Nakag

awa

Minato

Nakam

uraNish

iKita

Atsuta

MinamiNak

a

Higash

i

Mizuho

Showa

Midori

Tenpak

u

Chikusa

Meito

Moriyam

a0

0.00010.00020.00030.00040.00050.00060.00070.0008

Removal by ward 1990-2005

Rem

oval

/ po

pula

tion

Removal trend was spatially different On average from 1990- 2005 Highest : Moriyama Lowest : Nakagawa

Which factors associated with conflict?

Results

Variables Estimates(βi) P. values

Forest 0.69 <0.001

Year 0.45 <0.001

Grass 0.29 <0.001

Residential 0.28 <0.001

GLMM : Removal~ β1Forest + β2Residential Size+ β3Grassland+ β4Parks + β5Agricultural Land+ β6Population+β7Elder + β8Women+ β9Year + random effect(Ward ID)

N=216

Proportion of the forest highly associated with the number of removal

Which factors associated with conflict?: Species

ResultsEstimates significant at p<0.05 *, p<0.01 **, p<0.001 ***, N=216

Forest is the strongest estimate for all models except for V. ducalisAgricultural areas showed negative association for some species removals

Discussion

Consistent with previous study (Azmy et al 2016) where species like V. mandarinia and V. crabro were abundant at high green areas.Unexpected for the removal of V. analis, removal might related with residence that is located near forested areasNatural regulations might be useful to control the hornet population

Forest

Positively affect

Similar with previous study where green spaces and forest were related with stinging insect conflict. (Choi et al, 2012; Hosaka & Numata, 2016)

Forest

Discussion

Considering paper wasps as control agents of some agricultural activities(Gould and Jeanne 1984), it is interesting that the extermination of V. ducalis was negatively correlated with agricultural areas. Either the agricultural environment was unsuitable for the survival of this species or high tolerance towards this species due to its ability in controlling paper wasps in these areas.

Agricultural land

Negatively affect

Previous study suggested that hornet has been used for pest control pest. (Matsuura & Yamane 1990)

Forest

Agriculture

Summary

Trends in removals Trend of removal might plausibly increase in future

This study illustrates how conflict between human and different hornet species can occur near forest areas.

Negative element of ecosystem is important to be considered in urban development such as green spaces and residential areas

High correlation between hornet abundance and urban green space

High association between hornet-human conflict and urban forest

Future Implementation Suggestion

Demonstrates risk of conflict with hornet spatially within urban environment especially urban green spaces.

Consideration of negative effects of element on urban land covers should be taken account for urban planning management

Understanding risk of wildlife such as is also important for human in order to live in green environment

Conclusion

Incorporating aspect of biodiversity conservation in urban planning can be effective for human as well as wildlife when the positive and negative effects of the ecosystems were put into considerations.

Acknowledgement

We are highly grateful to Environment Health Center of Nagoya city that provided us of access to their report on hornet abudnance and extermination data. We also thank Nagoya government for their cooperation on the sharing of land characteristics data of Nagoya city. This work would not have been accomplished without their support.

The end