Relationship between variables and response using a multivariate approach

The difference of introduction success response was significantly affected by the selected variables (Permutation test ANOVA, F 3,84 = 2.75, p = .022). Among the five variables considered, clutch size, time of size (i.e., > 5), failed to establish viable populations. This included the Chestnut-breasted manikin (Lonchura castaneothorax), which was recorded in the region up to 55 years after the initial release but has not been recorded thereafter. The remaining 32 species (32 / 40, 80%) that were introduced were successful in establishing successful self-sustaining populations. Three species have been successfully introduced during the late twentieth century but have subsequently been eradicated throughly human control.

Based on the assumption that an introduction attempt of more than 5 birds presents a full introduction effort (see Methods), there is a noticeable difference in the proportion of introduced species that subsequently became established, according to their continent of origin: European, Asian, African and Australian species had an establishment success of 82% (14 / 17), 100% (5 / 5), 100% (3 / 3) and 78% (7 / 9) respectively (Table 4.1). In contrast, North American species had a lower establishment success rate (20%, 2 / 6) in the Auckland region (Figure 4.1).

Based on the data for introduced species, the average time-lag for the establishment of a successful population for all bird species released in the Auckland region was 24.1 years (±28.6 years SD) and ranged from 1 to 104 years (K-W test = 5.66, df =5, p = .34). There was an observable difference in time-lag establishment response of species in relation to its continent of origin : European (10.1 ±12.3 years SD), Asian (42 ±36.2 years SD), Australia (19.7 ± 19.7 years SD), North America (20.5 ±19.1 years SD), and Africa (64.7 ±52.3 years SD) species (Figure 4.2).

Around half of the species (46.9%) that were successfully introduced established viable populations in the Auckland region in less than 10 years (Figure 4.1). There was also no noticeable difference in the likelihood of establishment in less than 10 years for an introduced bird species according to its continent of origin: European, Asian, African, North American, and Australian species had an establishment success of 64.3% (9 / 14), 25% (1 / 4), 33.3% (1 / 3), 50% (1 / 2) and 43% (3 / 7) respectively (Figure 4.2) (X2 _{= 1.06,}

p = .90).

4.3.2 Relationship between variables and response using a multivariate approach

The difference of introduction success response was significantly affected by the selected variables (Permutation test ANOVA, F 3,84 = 2.75, p = .022). Among the five variables considered, clutch size, time of

human contact and number of release events have been observed to show results differing significantly in establishment success. The relative effect on the whole variable chosen showed that ‘time of human contact’ and ‘Number of release events’ variables perfectly discriminate the success of establishment response of avifauna in the Auckland Region with a probability of 0.75 and 0.68 respectively, when the "clutch size" variable seems to separate well the failure of the establishment response in the region (0.78, see Table 4.1).

The time-lag response in establishment success has not displayed an evident difference effect using the criteria selected (Permutation test ANOVA, F 3,67 = 2.38, p = .068).

Table 4.1: Relative variable effect value on response (in percentage) significant value (p >0.05) are in bold.

Time of human contact Time of industrial society Clutch size Number of propagules Number of releases

Establishment response Fail 25.1 43.0 78.1 53.9 32.1

Success 74.9 57.0 21.9 46.1 67.9

Time-response in the

establishment success Short (> 24.1 years) 69.7 75.8 53.8 35.4 71.2 Long

(< 24.1 years)

30.3 24.2 46.2 64.6 28.8

human contact and number of release events have been observed to show results differing significantly in establishment success. The relative effect on the whole variable chosen showed that ‘time of human contact’ and ‘Number of release events’ variables perfectly discriminate the success of establishment response of avifauna in the Auckland Region with a probability of 0.75 and 0.68 respectively, when the "clutch size" variable seems to separate well the failure of the establishment response in the region (0.78, see Table 4.1).

The time-lag response in establishment success has not displayed an evident difference effect using the criteria selected (Permutation test ANOVA, F 3,67 = 2.38, p = .068).

Table 4.1: Relative variable effect value on response (in percentage) significant value (p >0.05) are in bold.

Time of human contact Time of industrial society Clutch size Number of propagules Number of releases

Establishment response Fail 25.1 43.0 78.1 53.9 32.1

Success 74.9 57.0 21.9 46.1 67.9

Time-response in the

establishment success Short (> 24.1 years) 69.7 75.8 53.8 35.4 71.2 Long

(< 24.1 years)

Table 4.2: The outcome of bird species introduced in the Auckland Region and their continent of origin (n = 41 species). Only introduction attempts of greater than 5 individuals were included. The numbers in brackets represent the number of species introductions that occurred after 1950 (See Suppl. 4, for full species lists).

Natural range No. of species introduced presenting a full introduction effort No. of unsuccessful species

Successful species and their time lag to establish < 10 years 10 ≤ x< 20_years ≤ 20 years Unknown

Australia 8 (1) 2 2 (1) 1 3 Europe 17 3 9 4 1 North America 6 4 1 1 Asia 3 (2) 0 (1) 1 2 (1) Africa 3 0 1 2 Total 37 (3) 9 13 (2) 6 9 (1)

Figure 4.1: Variation in rates of successful establishment for birds introduced to the Auckland Region, depending on the continent of origin and date of first contact with humans (kya: thousands of years ago) on their respective source continent.

Table 4.2: The outcome of bird species introduced in the Auckland Region and their continent of origin (n = 41 species). Only introduction attempts of greater than 5 individuals were included. The numbers in brackets represent the number of species introductions that occurred after 1950 (See Suppl. 4, for full species lists).

Natural range No. of species introduced presenting a full introduction effort No. of unsuccessful species

Successful species and their time lag to establish < 10 years 10 ≤ x< 20_years ≤ 20 years Unknown

Australia 8 (1) 2 2 (1) 1 3 Europe 17 3 9 4 1 North America 6 4 1 1 Asia 3 (2) 0 (1) 1 2 (1) Africa 3 0 1 2 Total 37 (3) 9 13 (2) 6 9 (1)

Figure 4.1: Variation in rates of successful establishment for birds introduced to the Auckland Region, depending on the continent of origin and date of first contact with humans (kya: thousands of years ago) on their respective source continent.

4.4 Discussion

Acclimatisation societies set up by European colonists during the late nineteenth century conducted the introductions of exotic species in many European colonies across the globe (Osborne 2000), including New Zealand (see Suppl. 5) to respond to economic and cultural factors in these new areas. New Zealand, and particularly the Auckland Region, has thus experienced a very high degree of flora and fauna introductions (Thomson 1922, McDowall 1994, Veltman et al. 1996, Duncan and Young 2000) and has hence displayed higher rates of introduction success, with notably 77.5% of birds species acclimated having been successfully introduced (31 of the 40 species). My results underlined a higher success level by the Auckland Acclimatisation Society in the introduction of bird species in the Auckland Region comparing New Zealand as a whole (20%, Veltman et al. 1996), with North America, where only 52.4% of European species were successfully introduced, and Europe where only 54.4% of the North American species have been able to establish a viable population (Jeschke and Straver 2005). Such variation in introduction success between countries and areas could be explained by a difference in propagule pressure lead by the European human population (Gibson 1973), notably by divergence in their population size and density during colonisation and their establishment in the landscape or habitat (Pyšek et al. 2010). The massive influx of humans has led environmental changes and created habitats that increased likelihood for species to succeed during the introduction, as observed in alien plant invasions in New Zealand (Aikio et al. 2010). Introduction attempts in the Auckland Region have mainly occurred in the late nineteenth century, shortly after the establishment of European settlement in New Zealand. The late introduction in the area also occurred after the early stage of European settlement, from mainly illegally releases of species by members of the public (e.g., Red-vented bulbul, Rainbow lorikeet, see Suppl. 5). The analysis of the successful establishment events in the Auckland Region during this period revealed that 50% of the bird species introduced during this early stage of the European settlement originated from Europe.

4.4 Discussion

Acclimatisation societies set up by European colonists during the late nineteenth century conducted the introductions of exotic species in many European colonies across the globe (Osborne 2000), including New Zealand (see Suppl. 5) to respond to economic and cultural factors in these new areas. New Zealand, and particularly the Auckland Region, has thus experienced a very high degree of flora and fauna introductions (Thomson 1922, McDowall 1994, Veltman et al. 1996, Duncan and Young 2000) and has hence displayed higher rates of introduction success, with notably 77.5% of birds species acclimated having been successfully introduced (31 of the 40 species). My results underlined a higher success level by the Auckland Acclimatisation Society in the introduction of bird species in the Auckland Region comparing New Zealand as a whole (20%, Veltman et al. 1996), with North America, where only 52.4% of European species were successfully introduced, and Europe where only 54.4% of the North American species have been able to establish a viable population (Jeschke and Straver 2005). Such variation in introduction success between countries and areas could be explained by a difference in propagule pressure lead by the European human population (Gibson 1973), notably by divergence in their population size and density during colonisation and their establishment in the landscape or habitat (Pyšek et al. 2010). The massive influx of humans has led environmental changes and created habitats that increased likelihood for species to succeed during the introduction, as observed in alien plant invasions in New Zealand (Aikio et al. 2010). Introduction attempts in the Auckland Region have mainly occurred in the late nineteenth century, shortly after the establishment of European settlement in New Zealand. The late introduction in the area also occurred after the early stage of European settlement, from mainly illegally releases of species by members of the public (e.g., Red-vented bulbul, Rainbow lorikeet, see Suppl. 5). The analysis of the successful establishment events in the Auckland Region during this period revealed that 50% of the bird species introduced during this early stage of the European settlement originated from Europe.

Figure 4.2: Differences in time lag establishment response among bird species introduced to the Auckland Region in relation to their continent of origin. Only those species with known introduction and establishment dates were included (n = 31 species).

Figure 4.2: Differences in time lag establishment response among bird species introduced to the Auckland Region in relation to their continent of origin. Only those species with known introduction and establishment dates were included (n = 31 species).

My results support the first hypothesis outlined in the introduction. Human history is one of the element determinants of establishment success in Auckland Region, along with number of releases (Veltman et al. 1996) and clutch size (Green 1967, Cassey 2002). It is conceivable that the human history of species affects the establishment phase of the introduction by shaping and selecting key parameters. Through their evolutionary history with human society, species may be better prepared, notably via cue-response systems adapted to the human habitat transformations. Human transformation homogeneity over time provides stable and reliable environmental cues that should favour organisms with this evolutionary history to evolve optimal reaction norms or traits with higher flexibility or plasticity for species to respond to novel habitat transformations (Sih 2013). My observation reinforces previous observations (Crosby 1989, Jeschke and Strayer 2005) that European species are more likely to establish inside new regions, as per ‘Imperialism dogma’ (Crosby 1989). Imperialism dogma states that European species may have a higher invasion success due to their past experiences with a European society and in particular its ecological processes and environmental transformation (Crosby 1989). Here, I have demonstrated that in the Auckland Region, bird introductions tended to be more successful if the species had previously a long period of association with a human society, such as those in Europe and North America. But so far, the duration of the past-experience with human industrial society could not explain the success of the invasions and the rapidity of this process, in Auckland Region. Across the evolution of human society, industrial society has had the most marked effect on reshaping of the terrestrial biosphere (Steffen et al. 2007), most notably with the transformation of more than three-quarter of the terrestrial biosphere from biome to anthromes (Ellis 2010, 2013 and 2015). Despite the absence of significant result in this study, such aspects should be taken into account and tested at a larger scale in a future study because it has shown higher probability compared with a randomly chosen variable (see Table 4.1). Consequently, the finding at the Auckland Region level showed that species with a natural ecological niche in habitats transformed by human society may possess more suitable traits, potentially due to the species' evolutionary history (i.e., habitat filtering process, adaptive plasticity, optimal reaction norms). Such characteristics may allow them to cope with immediate ecological change during the establishment stage of the invasion (Sih et al. 2011). The approach offers substantial potential for the understanding of multiple cues involved in the invasiveness characteristics used to explain future success in My results support the first hypothesis outlined in the introduction. Human history is one of the element determinants of establishment success in Auckland Region, along with number of releases (Veltman et al. 1996) and clutch size (Green 1967, Cassey 2002). It is conceivable that the human history of species affects the establishment phase of the introduction by shaping and selecting key parameters. Through their evolutionary history with human society, species may be better prepared, notably via cue-response systems adapted to the human habitat transformations. Human transformation homogeneity over time provides stable and reliable environmental cues that should favour organisms with this evolutionary history to evolve optimal reaction norms or traits with higher flexibility or plasticity for species to respond to novel habitat transformations (Sih 2013). My observation reinforces previous observations (Crosby 1989, Jeschke and Strayer 2005) that European species are more likely to establish inside new regions, as per ‘Imperialism dogma’ (Crosby 1989). Imperialism dogma states that European species may have a higher invasion success due to their past experiences with a European society and in particular its ecological processes and environmental transformation (Crosby 1989). Here, I have demonstrated that in the Auckland Region, bird introductions tended to be more successful if the species had previously a long period of association with a human society, such as those in Europe and North America. But so far, the duration of the past-experience with human industrial society could not explain the success of the invasions and the rapidity of this process, in Auckland Region. Across the evolution of human society, industrial society has had the most marked effect on reshaping of the terrestrial biosphere (Steffen et al. 2007), most notably with the transformation of more than three-quarter of the terrestrial biosphere from biome to anthromes (Ellis 2010, 2013 and 2015). Despite the absence of significant result in this study, such aspects should be taken into account and tested at a larger scale in a future study because it has shown higher probability compared with a randomly chosen variable (see Table 4.1). Consequently, the finding at the Auckland Region level showed that species with a natural ecological niche in habitats transformed by human society may possess more suitable traits, potentially due to the species' evolutionary history (i.e., habitat filtering process, adaptive plasticity, optimal reaction norms). Such characteristics may allow them to cope with immediate ecological change during the establishment stage of the invasion (Sih et al. 2011). The approach offers substantial potential for the understanding of multiple cues involved in the invasiveness characteristics used to explain future success in

habitat colonisation of a species.

4.5 Conclusion

I have highlighted that the European exotic species introduced in the Auckland Region have had a higher rate of establishment success compared to species from other countries or areas. My findings suggest the influence of past-experience with human society may influence the potential of a species success when introduced to habitats recently colonised by humans (e.g., Sih et al. 2011). Indeed, my approach has highlighted the role of the duration of the past-experience with humans in introduction success across the Auckland Region but this may need to be explored at a broader level (e.g., in an island system or at country level). Further research should be conducted in order to understand the role of evolutionary history with human society in species invasions by studying how evolutionary history with humans has shaped key animal traits or behaviours. This knowledge could help to predict and produce a better understanding of species when introduced to new area.

Acknowledgments

I am grateful for the funding of Institute of Natural and Mathematical Sciences of Massey University. I thank particularly W. Ji, M. G. Anderson and S. D. Hill for their improvement in the chapter through their edits and suggestions

habitat colonisation of a species.

4.5 Conclusion

I have highlighted that the European exotic species introduced in the Auckland Region have had a higher rate of establishment success compared to species from other countries or areas. My findings suggest the influence of past-experience with human society may influence the potential of a species success when introduced to habitats recently colonised by humans (e.g., Sih et al. 2011). Indeed, my approach has highlighted the role of the duration of the past-experience with humans in introduction success across the Auckland Region but this may need to be explored at a broader level (e.g., in an island system or at country level). Further research should be conducted in order to understand the role of evolutionary history with human society in species invasions by studying how evolutionary history with humans has shaped key animal traits or behaviours. This knowledge could help to predict and produce a better understanding of species when introduced to new area.

Acknowledgments

I am grateful for the funding of Institute of Natural and Mathematical Sciences of Massey University. I thank particularly W. Ji, M. G. Anderson and S. D. Hill for their improvement in the chapter through their edits and suggestions

Supplementary forms

Suppl. 5 : Avian species introduced to the Auckland area after European settlement. Exotic species introduced data for Auckland Area, including date and number of attempt, date of establishment or fail and times response.

Note – ? indicate absence of information, (+) indicates many birds introduces

References:

Thomson GM (1922) The naturalization of animals and plants in New Zealand. Cambridge University Press, Cambridge, UK.

Hutton FW (1869) On the introduction of the Pheasant into the Province of Auckland. Transactions and Proceedings of the Royal Society of New Zealand, 2, 80. Drummond J (1906) On introduced Birds. Transactions and Proceedings of the Royal Society of New Zealand, 39, 227-252.

Supplementary forms

Suppl. 5 : Avian species introduced to the Auckland area after European settlement. Exotic species introduced data for Auckland Area, including date and number of attempt, date of establishment or fail and times response.

Note – ? indicate absence of information, (+) indicates many birds introduces

References:

Thomson GM (1922) The naturalization of animals and plants in New Zealand. Cambridge University Press, Cambridge, UK.

Hutton FW (1869) On the introduction of the Pheasant into the Province of Auckland. Transactions and Proceedings of the Royal Society of New Zealand, 2, 80. Drummond J (1906) On introduced Birds. Transactions and Proceedings of the Royal Society of New Zealand, 39, 227-252.

Common names Scientific names recorded New scientific names Date of attempt (No of bird) clutch size

Successful introduction

Barbary dove Turtur risorius Streptopelia risoria Africa 1867 (5) 1972 I 1 5 2 Na

Chestnut-breasted manikin Munia castaneithorax Lonchura castaneothorax Australia 1867(4) 1869(+) 1871 (510) 1868 1922 I 1 1 5 Na

Indian peafowl Pavo cristatus Asia 1843 (+) 1860 (+) 1922 I many ~79 6 Na

African collared dove Streptopelia roseogrisea Africa 1867-80 (+) 1970 (+) 1971 I many 104 2 Na

Rock dove Columbia livia Europe 1860-65(+) 1922 I many 16 1,9 7

Eastern rosella Platycercus eximius Australia 1910 ( 1920 I many 10 3 5,6

Black bird Turdus merula Europe 1865 (8), 1867 (30), 1868 (132) 1868 I 3 2 3,8 3

House sparrow Passer domesticus Europe 1861 (?), 1867 (47) 1868 I 2 7 3,9 3

Eurasian Skylark Alauda arvensis Europe 1867 (10), 1868 (52) 1873 I 2 6 3,7 3

European goldfinch Fringilla carduelis Carduelis elegans Europe 1867 (11), 1871 (44) 1922 I 2 15 4,4 3

Spotted dove Streptopelia chinensis Asia 1920 1997 I many 67 2 3

Song thrush Turdus musicus Turdus philomelos Europe 1867 (30), 1868 (95) 1870 I 2 3 4,7 2

Common starling Sturnus vulgaris Europe 1865 (12), 1867 (15), 1868 (82) 1870 I 3 5 4,8 2

Common chaffinch Fringilla coelebs Europe 1864 (+), 1867(45), 1868 (68), 1969 (+) 1868 I 4 4 4,9 2

European greenfinch Fringilla chloris Europe 1865 (+), 1867 (18), 1868 (33) 1868 I 3 2 4,8 2

California quail Ortyx californicus Callipepla california North America 1862 (+) 1867 (113), 1877 (9) 1869 # 1870 I 3 7 14,2 2

Yellowhammer Embezia citrinella Europe1865 (8), 1867(4), 1868 (5), 1869 (?), 1870 (16), 1871 (312)1906 I 4 17 4 2

Dunnock Accentor modularis Europe 1867 (1) 1868(2) 1872 (7) 1874 (19) 1875(18) 1873 I 3 1 3,4 2

Common redpoll Linota rufescens Carduelis flammea Europe 1871(1) 1872(209) 1922 I 1 48 5 2

Brown quail Coturnix ypsilophora Australia 1867(4) 1869(+) 1871 (510) 1906 I 3 39 7 2

Australian magpie Gymnorhina tibicen Cracticus tibicen Australia 1867 (10), 1870 (1) 1870 I 1 3 4 1