Distribution of an urban little penguin (Eudyptula minor) colony on the St Kilda breakwater
Key Words: Little penguins, Eudyptula minor, disturbance, human, nesting, St Kilda Breakwater, anthropogenic structure, urban habitat
There are many examples of native Australian animals exploiting resources in cities and inhabiting anthropogenic structures. An example of this is the
little penguin (Eudyptula minor) population living between the rocks on the St Kilda breakwater in Melbourne, attracted by safe hiding places, a lack of predators and the presence of prey. However, being close to urbanisation poses many specific threats for the colony, and the effects of human disturbance were analysed by comparing the number of penguins and breeding sites in the public and restricted areas of the breakwater. Penguin presence at night was recorded over several months, as well as presence and breeding site data collected between 1998 and 2006 by Earthcare St Kilda. The results showed a significantly lower number of penguins inhabiting and breeding per interval in the public region. This was expected, as many other studies have documented the detrimental effects of human presence on penguins. Saltbush distribution and the number of sites based on feather and guano deposits was also mapped, and showed no significant difference. There are examples of penguin colonies with large tourist numbers that do not affect breeding success, but all these have stricter control measures than the St Kilda breakwater. As the penguins are still doing extremely well in such an urbanised area it is concluded however that additional measures are not needed as a new fence has recently made the public region smaller, and the public region is useful for raising awareness and tourism.
Almost half the world’s rising population lives in urban areas, making urbanisation one of the greatest concerns for global biodiversity (Garden et al. 2006). Animals living in urban locations are subjected to a completely different range of threats than in their natural habitats (Koenig et al. 2002), which have caused large scale local extinctions in Australia. In Adelaide, 132 native plants and animals have become locally extinct in under 200 years due to urban expansion (Tait et al. 2005), and less than half of Melbourne’s mammal species are predicted to persist in the long term (van der Ree & McCarthy 2005). Although human disturbance is devastating for many species, cities can often produce extra food or protection that support other species, predominantly generalists (Chambers & Dickman 2002). The exploitation of urban areas and anthropogenic structures is often viewed as negative, particularly in the case of introduced pests, but there are many examples of native Australian animals being more tolerant to humans than previously thought.
Animals exploiting resources in urban regions of Melbourne, a city of 3.5 million people, include the grey-headed flying-fox camping in the Royal Botanical Gardens (van der Ree et al. 2006; Williams et al. 2006). It is likely they established this camp close to the city’s centre in 1986, attracted by the more reliable supply of food-providing trees and shrubs planted around the city than in their original geographic range (van der Ree et al. 2006). Possums are common in suburbia, eating garden flowers and plants, and causing problems by invading and sleeping in roofs (Temby 2004). There is also a large range of birds, including galahs, ibis, kookaburras, lorikeets, ducks and silver gulls attracted to urbanisation by seed feeding, garden water baths and pools, and human refuse in bins and tips (Smith 1992; Low 2002; Temby 2004). Many animals also live around or grow on anthropogenic structures in marine environments, for example submerged pontoons and pylons (Connell 2001; Lindegarth 2001). Considering Melbourne’s population, these examples demonstrate the extraordinary resilience and opportunistic nature of many native species.
Another example of the exploitation of anthropogenic structures by native species is the use of the St Kilda breakwater by little penguins (Eudyptula minor), which will be the focus of this paper. Also called the blue or fairy penguin, E. minor is the smallest species of penguin and is distributed over New Zealand and southern Australia. The penguins in this colony are nesting between the boulders of the anthropogenic structure adjacent to the St Kilda boat moorings, only kilometres from Melbourne’s central business district (Cullen et al. 1996). There is a region of the breakwater accessible to the general public, but access to the majority is restricted by locked gates and fences.
Large colonies of penguins in disturbed areas are not uncommon, and there are recordings of most penguin species being found in developed areas (McKay et al. 1999). These include jackass penguins in South Africa, magellanic penguins in Argentina, and magellanic, rockhopper and macaroni penguins on the Falkland Islands (McKay et al. 1999). E. minor is also often found in urban locations. In Australia, there is a small colony of little penguins in Sydney harbour, the countries busiest port (Raidal et al. 2006). New Zealand also has little penguins in close proximity to humans, including a colony breeding in a closed quarry at Oamaru since the 1970’s (Higham & Lück 2002), which are also using buildings and industrial areas to breed (Hocken 2000).
There are many possible reasons why the little penguins inhabit the disturbed environment in St Kilda. There is evidence of little penguins once nesting more extensively on mainland Australia (Cullen et al. 1996), but they are now mainly restricted to offshore islands (Johannesen et al. 2002). This is most likely due to being safer on islands from human disturbance and introduced predators (Norman et al. 1992; Johannesen et al. 2002). One of the large Victorian colonies is found on Phillip Island, and it is thought that penguins from here first colonised the St Kilda breakwater prior to 1974 (Cullen et al. 1996). The St Kilda breakwater offers a nesting site very similar to an island, restricting access to most predators except dogs brought down the pier by their owners. The spaces between breakwater boulders also offer a labyrinth of possible hiding places and nesting sites well out of reach.
Probably the most important factor explaining the penguin’s affinity for the anthropogenic structure is the presence of prey. Weavers (1992) showed that many penguins from Phillip Island make long foraging trips through the Port Phillip heads and into the bay to feed during winter. These trips lasted for days, and many kilometres, due to pilchards and anchovy being more common in the bay during winter than in the waters around Phillip Island (Weavers 1992). Penguins nesting at St Kilda have much shorter distances to travel for food and therefore they have to spend much less energy on food acquisition.
Little penguins are normally faithful to their nest site and partner, and return to the same site to breed every season (Pledger & Bullen 1998; Bull 2000). This means that the St Kilda colony is now self-sustaining, although some birds do move between the breakwater and Phillip Island (Cullen et al. 1996). Johannesen et al. (2002) concluded that nest site fidelity was lower if breeding had not been successful, so penguins are more likely to move away from poor nesting sites on the breakwater, whilst those with good sites will return to the same nest year after year. It is an advantage to have a successful breeding site so time and energy does not need to be spent finding a nest at the start of the season, and breeding can begin earlier (Knight & Rogers 2004). As a result, the nesting density on the St Kilda breakwater will be greatest in areas of high breeding success.
Despite the advantages of St Kilda, there are many specific disturbances for the colony, and little is known about how human presence affects the penguins breeding on the breakwater. Being located in an area of dense human population exposes the penguins to bright lighting, increased noise levels, large amounts of boating activity and becoming tangled in litter and fishing gear. An oil spill has the potential to completely devastate the entire colony at once (Cullen et al. 1996). Another cause of mortality is starvation due to overfishing by humans of pilchard and anchovy (Harrigan 1992), and even just a decrease in food can reduce breeding success (Cullen et al. 1992). There are also disturbances that apply only to the penguins inhabiting the pubic region of the breakwater. People walk their dogs down the breakwater, sometimes without leashes, and people have senselessly killed penguins. Even just human presence has shown to stress some species of penguins (Ellenburg et al. 2006). The aim of this study is to determine whether human presence and activity in the public region of the breakwater is detrimental to the penguins. Previous studies have recorded lower little penguin densities in areas subjected to human disturbance (Klomp et al. 1991; Weerheim et al. 2003), which will be examined for the St Kilda colony by comparing penguin presence and nesting site numbers between the public and non-public access regions. It is predicted that there will be fewer penguins inhabiting and nesting in the public region.
Materials and Methods
The St Kilda breakwater is about 660 metres long and extends from the St Kilda pier in Melbourne. It was built for the Melbourne Olympic Games in 1956 to harbour boats and yachts. Earthcare St Kilda has developed a lettering system, where 33 letters are glued or sprayed on rocks along the breakwater at 20 metre intervals (Figure 1). Figure 1 also shows the gates (old and new) which mark the end up the public area of the breakwater. The new gate, which reduced the area open to the public, was built in November 2006, but was not functional until January 2007. Any specific location on the breakwater can be given by the mapping system, which uses a decimal point for distance between intervals and six zones across the breakwater’s width (Figure 2).
Penguin Night Distribution
The distribution of little penguins (E. minor) was recorded after dusk along the St Kilda Breakwater in conjunction with Earthcare St Kilda. Data was collected over six Sunday nights in February, March and April 2007, from approximately 7.30pm or 8.30pm (after daylight savings time) by a team of 15 Earthcare volunteers. Penguins make their way onto the breakwater at dusk, and all sampling was done at least an hour after sunset, so it was assumed all penguins had returned. Volunteers were divided into three groups and the location of every penguin seen, heard, or caught was recorded. Penguins are caught to determine the gender and weight in order to observe trends in the population, but this is not covered here. Within these groups, three or four people spread out along the height of the landward side searching between the rocks with one person scribing, and everyone moved carefully along the breakwater length. The top section of the seaward side was also searched, but not many penguins nest on that side because it is exposed to wave action. Torches were used to locate penguins, which are often beyond reach deep in the rocks, and gardening gloves were worn for protection from possible infections and pecking penguins. They were recorded using the mapping system (Figure 2), which gives their location to within approximately a metre. The data from the groups was then collated.
Feather and Guano Mapping
The distribution of possible penguin nesting sites by the presence of moulted feathers and guano was completed during February and March 2007. This was done because breeding occurs from September to December (Fortescue 1999), which did not fall during the timeframe of this study, and therefore locations of eggs or nests could not be assessed. Potential nesting sites were found with the help of a volunteer, each taking half the height of the breakwater, and climbing slowly along its entire length. The location of each site was recorded on a data sheet. Penguin guano was mainly used as an indication to where large amount of moulted feathers would be found. It was distinguished from seagull guano as it is normally found running in a line, and often under rocks where other sea birds could not get to. A large amount of feathers in crevices between the rocks was defined as a possible nesting site, and is at least where a particular penguin spends the majority of its time on land. When large feather deposits were found in close proximity it was only labelled one site because the penguins move around.
Saltbush (Atriplex cinerea) Distribution
Saltbush (Atriplex cinerea) distribution on the breakwater was mapped out on a separate trip. The distribution along the breakwater and the zone which the saltbush extended into was recorded on a data sheet, as well as whether the bush was majority alive, or mainly dead and leafless.
Earthcare St Kilda Data Analysis
Aside from collecting data personally on the St Kilda breakwater, data collected by Earthcare St Kilda over previous years was also analysed. The presence of penguins (including adults and chicks) on Sundays nights during 2001-2, 2002-3, 2003- 4, 2004-5 and 2005-6 (penguin breeding year runs from May to April) in each letter interval was examined. The breeding sites of E. minor on the breakwater were also examined, by manually going through all the sightings or catches of adult pairs, chicks and eggs seen in a year. Data from the 1998-9 until the 2006-7 seasons (9 years) were used to look at nest site selection. Care was taken not to double count eggs or chicks being reared in the one location, which may be spotted over several months, but also to recognise another nest if the pair produced a second egg. Although the data back until 1986, the current breakwater mapping system was only implemented after 2001, and it would be extremely difficult to convert all the other data, as many of the locations are descriptive.
All the data was analysed using the computer program Microsoft Excel and the statistical software R. When comparing public and non-public access regions, the count data was subjected to a square root transformation for normalisation. Although the new gate is located at e.7, it was taken to be between e and f for statistical testing, because each region had to be the same length. The data is normal, however it is recognised that the letter intervals of the public and non-public regions are not independent samples because the penguins could easily move between them. This means the data does not meet all the assumptions of the parametric statistical tests performed, and therefore the results have limitations. It was more desirable to perform these analyses than none at all, because more complex statistics were beyond the scope of the study.
Penguin Night Distribution
A significant difference was detected between the number of penguins seen, heard or caught at night (n=6) in each letter region (20 metre intervals) along the breakwater (one-way ANOVA, F33,165 = 5.32, Pr(>F) < 0.001, Figure 3). This showed that the density of penguins along the breakwater was not equal in each of the 33 intervals. The distribution of E. minor on the public and non-public zones of the breakwater at night was analysed twice, for when the old gate determined the public region as well with the new gate in place. This is because it is unlikely the penguins have adapted to the lack of human presence behind the new gate which was only recently built. When the public region is defined by the old gate, therefore being from a to l, there was found to be a significantly lower mean number of penguins found per letter interval than in the non-public region (separate variances t-test, t126.90 = 7.12, p- value < 0.001, Figure 4). There was also a significant lower mean number of penguins seen, heard or caught per letter interval in the public area when it was defined as f to l by the new gate (separate variances t-test, t57.90 = 5.53, p-value < 0.001, Figure 5).
Feather and Guano Mapping
There was less variation in the number of feather and guano sites recorded in each location than was observed for the distribution of penguins at night (Figure 6). Analysis of the previous public region (gate between a and l) indicated there was no significant difference in the mean number of feather of guano sites per letter interval between the public and non-public access zones (separate variances t-test, t17.77 = 1.73, p-value = 0.101, Figure 7). There was also no significant difference observed when analysing the data with the new gate in place (separate variances t-test, t7.09 = 1.25, p-value = 0.250, Figure 8). It was observed that many penguins’ potential nests were found around the edges of, or in holes underneath the saltbush (Atriplex cinerea).
Saltbush (Atriplex cinerea) Distribution
Saltbush was planted on the breakwater by Earthcare, and the current distribution is shown in Figure 9. A relatively large amount of the A. cinerea has died since 2004 when it was last mapped (Zoe Hogg, pers. comm.), probably due to drought conditions. Other observations made whilst conducting mapping during daylight was the large amount of washed up litter and fishing gear between the rocks and on the edge of the breakwater.
Earthcare St Kilda Data Analysis
An overall significant difference was found for the total seen, heard or caught penguins on Sunday nights between the 33 intervals on the breakwater from the 2001-2 season until 2005-6 (n = 5 years, one-way ANOVA, F32,132= 12.38, Pr(>F) < 0.001, Figure 10). The mean number of penguins per letter interval was found to be significantly higher in the non-public access region (n = 5 years, separate variances t- test, t152.16 = 8.45, p-value < 0.001, Figure 11). This was only analysed for when the old gate was present, as the new fence had not been constructed.
The breeding site data collected by Earthcare St Kilda was also analysed just with the public region being letters l to a. Although it contains 2007 data when the fence was in place, breeding had almost been completely finished, and there would have been no time for adaptation to the new zoning. An ANOVA detected a significant difference in the mean number of breeding sites per season (n=9 years) between the 33 intervals of the breakwater (F32,264 = 11.59, p-value < 0.001, Figure 12). The mean number of breeding sites per letter interval was found to be significantly higher in the public region than in the non-public access zone (separate variances t-test, t292.91 = 9.13, p-value < 0.001, Figure 13).
The little penguin presence and nesting site results clearly show there are less penguins nesting per letter interval in the public region of the breakwater, especially directly adjacent to the pier (Figures 3 & 10). This result was hypothesised, and is supported by past studies. Klomp et al. (1991) found that nesting boxes were suitable for little penguin breeding on Penguin Island, Western Australia, but those subjected to human disturbance were used least. Weerheim et al. (2003) made similar conclusions, finding that little penguin nest density increased with distance from footpaths used regularly by tourist groups in New South Wales. Reports by Earthcare St Kilda also acknowledge the heterogenous distribution of penguins along the breakwater, and support the finding that there are fewer breeding sites per interval in the public region.
The avoidance of disturbed nesting areas is not surprising given the alarming effects of even just human presence that has been documented for many species of penguins. Woehler (1994) describes that an Antarctic colony of Adelie penguins is shifting away from it’s eastern periphery, which most visited by humans. This area has fewer penguins breeding, whilst the colony is extending towards the west with higher numbers of breeding pairs recorded there. Scientific nest checking and recreational visits to Adelie penguin colonies in Antarctica have also been found to reduced hatching success (Giese 1996). Yellow-eyed penguins in New Zealand have lower fledging weights on beaches with tourist activity compared to beaches without tourists, and the presence of humans deterred penguins from coming ashore after feeding (McClung et al. 2004). Several studies have found a behavioural or physiological change related to human presence. Regel & Pütz (1997) state that Adelie penguin heart rates increased when a person approached, meaning the penguin is being negatively affected even if it shows no external signs. This increase in heart rate occurs in Humbolt penguins even if a person approaches to within 150 metres, resulting in additional energy use and considerable recovery times (Ellenburg et al. 2006). Walker et al. (2005) found that magellanic penguin chicks in human visited areas had higher stress hormone levels than chicks in areas without human presence.
Although the detrimental consequences of human presence and tourism at St Kilda has been shown, there are little penguins colonies where strict control measures have reduced or eliminated the effects of human disturbance. The Summerland Peninsula colony on Phillip Island has become a major tourist attraction, and the penguins have become accustomed to human presence and bright lighting which was built up gradually (Cullen et al. 1996). The thousands of people watching the ‘penguin parade’ are restricted to boardwalks present in only some areas of the colony, and are controlled by rangers (Dann 1992). The penguins have not moved away from tourist areas, and have a similar breeding success to penguins in regions without public access, suggesting there is little impact by human presence (Dann 1992). This is a very different situation to the rest of the island, where European modification for agriculture, recreation and housing, as well as erosion has caused a drastic decrease in population size over the past 90 years (Dann 1992). The Oamaru little penguin colony in New Zealand receives thousands of visitors each year, but they are also confined to viewing platforms and lighting outside the penguin’s visible spectrum is used (Higham & Lück 2002). Predators are controlled, and comparison with an undisturbed nearby colony has shown there has been no reduction breeding success due to the tourism. Tolerance has also been observed in other penguin species. Hull & Wilson (1996), contrary to many other studies, found that if care is taken whilst scientifically checking royal and rockhopper penguin nests there is no reduction in breeding success. Nimon et al. (1995) also found that tourism in Antarctica produced very little, if any, response in Adelie penguins if visitors are controlled and not disruptive.
Obviously the difference between these successful examples and the St Kilda colony is the lack of control in the public section of the breakwater. All the visitors are unregulated apart from one tourist operation running, but this is done by boat, so is likely not to have a large effect on the penguins given the number of boats already in the vicinity. The boardwalk can provide good viewing, but many people still climb over the rocks, and there are often large tourist groups. This is likely to stress penguins, although no research has looked at heart rate changes or stress hormone release in E. minor from human disturbance. Future research could include following the breeding site data in the newly restricted region between the gates (e – a) over the next few years, which would provide more evidence that the fewer penguins breeding in this area was due to human disturbance. This will be particularly valuable because other factors, for example the total number of sheltered holes, are unlikely to change. Although the findings show the public region supports fewer nesting little penguins, it still has value, and some penguins still successfully nest in the public region. There is a high public interest in the penguins, and information signs continue to raise awareness, which will hopefully reduce mortality from dogs and careless littering. No additional control is needed, as trying to further restrict the public with fences would just reduce interest, and the large non-public region is more than adequate to promote high breeding success. The St Kilda little penguins already have a higher breeding success and higher weights than the penguins at Phillip Island, indicating the colony is thriving (Fortescue 1999). The results suggest that constructing a new gate recently to make the public region smaller was worthwhile, and should increase the number of successfully nesting penguins. Increased breeding success is particularly important given the fear of reduced prey presence as a result of dredging in Port Phillip Bay. The new gate will also be much more successful in keeping people off the breakwater than the old one, as many fishers still got around it.
It was observed that the St Kilda penguins appear to have an affinity for nesting near saltbush (A. cinerea). Selecting nesting sites for their vegetation type has been observed before by Fortescue (1999), whom found little penguins had a higher nest density in woodland sites over grasses or introduced plants. However, the correlation at St Kilda was not readily apparent in the data. Some of the intervals with higher nesting site numbers, for example at C, F and O (Figure 12) also had high amounts of saltbush (Figure 9), but other intervals of high nesting density had little or no saltbush present. Possibly a smaller scale of analysis is needed to show a correlation, by comparing the exact location of nesting sites against the exact location of saltbush. However this would require examining the distance between intervals, and the zone for each nest, and was not undertaken because it is impossible to know if there are other factors involved. It may be that both the penguins and the saltbush are attracted to an unseen factor, for example amount of soil instead of rock, or that saltbush benefits from penguin guano deposits. In order to establish the preferential selection of saltbush protected sites by penguins a completely different experiment would have to be designed.
The results of the feather guano mapping contradicted the outcomes of all the other tests, possibly due to experimental errors. Not all the penguins would have starting moulting when the surveying was done, and some feathers may have already been washed away. It was also difficult to tell from the number of feathers whether the site was used by one penguin or more. The data collection by Earthcare St Kilda is done very thoroughly, but there may be difference in sampling effort on nights with more or less volunteers. A high number of penguins were always observed at the letters N, O, P and Q, which may be due to the fact that the breakwater gets wider as it goes around the bend (Figure 1), so there is more area for penguins per interval. The distribution of little penguins along the breakwater may also be due to uncontrollable factors unrelated to human presence, for example the presence of an area along the breakwater where penguins can easily climb up. The tests preformed also had known limitations, as stated previously.
Overall the little penguins are successfully exploiting this anthropogenic structure, and show a high resilience given the amount of disturbance placed on the entire colony by being in such close proximity to a major city. The penguins are being negatively affected from the direct contact in the public region, but this area is still productive and has high tourist interest.
I would like to thank Earthcare St Kilda, and in particular Zoe Hogg, for all their help with collecting data and allowing access to their data from previous years. Parks Victoria assisted with access to the St Kilda Breakwater. I would also like to acknowledge Richard Reina and Tiana Preston for help with project design and statistics, as well as volunteers for help with data collection.
Bull L. (2000) Fidelity and breeding success of the blue penguin Eudyptula minor on Matiu-Somes Island, Wellington, New Zealand. New Zealand Journal of Zoology, 27, 291-298
Chambers L.K. & Dickman C.R. (2002) Habitat selection of the long-nosed bandicoot, Perameles nasuta (Mammalia, Peramelidae), in a patchy urban environment. Austral Ecology, 27, 334 – 342
Connell S.D. (2001) Urban structures as marine habitats: an experimental comparison of the composition and abundance of subtidal epibiota among pilings, pontoons and rocky reefs. Marine Environmental Research, 52, 115 – 125
Cullen J.M., Montague T.L. & Hull C. (1992) Food of Little Penguins Eudyptula minor in Victoria: Comparison of Three Localities between 1985 and 1988. Emu, 91, 318-
Cullen M., Blake N. & Bickham M. (1996) Urban Penguins. Nature Australia, Winter (1), 22 – 28
Dann P. (1992) Distribution, population trends and factors influencing the population size of little penguins Eudyptula minor on Phillip Island, Victoria. Emu, 91, 263– 272
Ellenburg U., Mattern T., Seddon P.J. & Jorquera G.L. (2006) Physiological and reproductive consequences of human disturbance in Humbolt penguins: The need for species-specific visitor management. Biological Conservation, 133, 95- 106
Fortescue M. (1999) Temporal and spatial variation in breeding success of the Little Penguin Eudyptula minor on the east coast of Australia. Marine Ornithology, 27, 21 – 28
Garden J., McAlpine C., Peterson A., Jones D. & Possingham H. (2006) Review of the ecology of Australian urban fauna: A focus on spatially explicit processes. Austral Ecology, 21
Giese M. (1996) Effects of human activity on Adelie penguins Pygoscelis adeliae
breeding success. Biological Conservation, 75, 157-164
Harrigan K.E. (1992) Causes of Mortality of Little Penguins Eudyptula minor in Victoria.
Emu, 91, 273 – 277
Higham J. & Lück M. (2002) Urban Ecotourism: A Contradiction in Terms? Journal of Ecotourism, 1, 36 – 51
Hocken A.G. (2000) Cause of death in blue penguins (Eudyptula m. minor) in North Otago, New Zealand. New Zealand Journal of Zoology, 27, 305 – 309
Hull C.L. & Wilson J. (1996) The effect of investigators on the breeding success of royal, Eueyptes schlegeli, and rockhopper penguins, E. chrysocome, at Macquarie Island. Polar Biology, 16, 335 – 337
Johannesen E., Perriman L. & Steen H. (2002) The effect of breeding success and colony fidelity in the little penguin (Eudyptula minor) in Otago, New Zealand. Emu, 102, 241-247
Klomp N.J., Meathrel C.E., Wienecke B.C. & Woodler R.D. (1991) Surface nesting by little penguins on Penguin Island, Western Australia. Emu, 91, 190 -193
Knight C. & Rogers T. (2004) Factors influencing fledging production in little penguins (Eudyptula minor). Wildlife Research, 339-344
Koenig K., Shine R. & Shea G. (2002) The Dangers of Life in the City: Patterns of Activity, Injury and Mortality in Suburban Lizards (Tiliqua scincoides). Journal of Herpetology, 36, 62 – 68
Lindegarth M. (2001) Assemblages of animals around urban structures: testing hypotheses of patterns in sediments under boat-mooring pontoons. Marine Environmental Research, 51, 289 – 300
Low T. (2002) The New Nature. Penguin Publishers, Camberwell, Victoria.
McClung M.R., Seddon P.J., Massaro M. & Setiawen A.N. (2004) Nature-based tourism impacts on yellow-eyed penguins Megadyptes antipodes: does unregulated visitor access affect fledging weight and juvenile survival? Biological Conservation, 199, 279-285
McKay R., Lalas C., McKay D. & McConkey S. (1999) Nest-site selection by yellow- eyed penguins Megadyptes antipodes on grazed farmland. Marine Ornithology, 27, 29 – 35
Nimon A.J., Schroter R.C. & Stonehouse B. (1995) Heart rate of disturbed penguins.
Nature, 374, 415
Norman F.I., Cullen J.M. & Dann P. (1992) Little penguins Eudyptula minor in Victoria: past, present and future. Emu, 91, 402-408
Pledger S. & Bullen L. (1998) Tests for Mate and Nest Fidelity in Birds with Application to Little Blue Penguins (Eudyptula minor). Biometrics, 54, 61 – 66
Raidal S.R., Shearer P.L., Cannell B.L. & Norman R.J.d.B. (2006) Micromelia in Little Penguins (Eudyptula minor). Journal of Avian Medicine and Surgery, 20, 258 – 262
Regel J. & Pütz K. (1997) Effect of human disturbance on body temperature and energy expenditure in penguins. Polar Biology, 18, 246-253
Smith G.C. (1992) Silver Gulls and emerging problems from increasing abundance.
Corella, 16, 39-46
Tait C., Daniels C. & Hill R. (2005) Changes in species assemblages within the Adelaide Metropolitan Area, Australia, 1836-2002. Ecological Applications, 15, 346 – 359
Temby I.D. (2004) Urban wildlife issues in Australia. In: Proceedings of the 4th International symposium on urban wildlife conservation (ed. Shaw WW, Harris,
L.K. and Vandruff, L.), pp. 26-34
van der Ree R. & McCarthy M. (2005) Inferring persistence of indigenous mammals in response to urbanisation. The Zoological Society of London, 8, 309 – 319
van der Ree R., McDonnell M.J., Temby I., Nelson J. & Whittingham E. (2006) The establishment and dynamics of a recently established urban camp of flying foxes (Pteropus poliocephalus) outside their geographical range. Journal of Zoology 268, 177-185
Walker B.G., Boersma P.D. & Wingfield J.C. (2005) Physiological and Behavioral Differences in Magellanic Penguin Chicks in Undisturbed and Tourist-Visited Locations of a Colony. Conservation Biology, 19, 1571 – 1577
Weavers B.W. (1992) Seasonal foraging ranges and travels at sea of little penguins
Eudyptula minor, determined by radio tracking. Emu, 91, 302-317
Weerheim M.S., Klomp N.I., Brunsting A.M.H. & Nomdeur J. (2003) Population size, breeding habitat and nest site distribution of little penguins (Eudyptula minor) on Montague Island, New South Wales. Wildlife Research 30, 151-157
Williams N.S.G., McDonnell M.J., Phelan G.K., Keim L.D. & van der Ree R. (2006) Range expansion due to urbanization: Increased food resources attract Grey- headed Flying- foxes (Pteropus poliocephalus) to Melbourne. Austral Ecology, 31, 190-198
Woehler E.J., Penney R.L., Creet S.M. & Burton H.R. (1994) Impacts of human visitors on breeding success and long-term population trends in Adélie Penguins at Casey, Antarctica. Polar Biology, 14, 269 – 274
Figure 1. Map of the St Kilda breakwater, showing location of the pier, kiosk, new gate (e.7), and the old gate (A.0). Capital letters start from the old gate, and continue up to U, whilst lower case letters start at the old gate and count towards the kiosk. Each letter interval is 20 metres.
(In or coming out of water)
Figure 2. Diagram of the St Kilda Breakwater, showing the system of letters along the length of the breakwater, and the zones going across the breakwater width. A site is recorded and mapped as a letter, then a decimal place to distinguish how far along that letter, then another decimal place to give the zone. For example, the grey dot is at A.8.3.
Figure 3. Mean (± S.E.) number of penguins found on each sampling night (n=6) during February, March and April in each letter zone. The kiosk is at l, the old gate is located between a and A, while the new gate (operational January 2007) is between e and f.
Figure 4. Mean (± S.E.) number of penguins seen, caught and heard at night per letter interval in the public and non-public regions on each of six sampling nights. Based on the old public zone from l to a (12 intervals), and the non-public zone from A to U (21 intervals). Grey bars show the mean for the public access region, and white bars indicate the non-public access region.
Figure 5. Mean (± S.E.) number of penguins seen, caught and heard at night per letter interval in the public and non-public regions on each of six sampling nights. Based on the new public zone from l to f (7 intervals), and the non-public zone from e to U (26 intervals). Grey bars show the mean for the public access region, and white bars indicate the non-public access region.
Figure 6. Number of possible nesting sites determined by feather and guano nesting in each letter interval on the St Kilda breakwater. The kiosk is at l, the old gate is located between a and A, while the new gate (operational January 2007) is between e and f.
Figure 7. Mean (± S.E.) number of feather or guano sites per letter interval between the public and non-public access regions on the St Kilda breakwater. Based on the old public zone from l to a (12 intervals), and the non-public zone from A to U (21 intervals).
Figure 8. Mean (± S.E.) number of feather or guano sites per letter interval between the public and non-public access regions on the St Kilda breakwater. Based on the new public zone from l to f (7 intervals), and the non-public zone from e to U (26 intervals).
Figure 9. Distribution of saltbush (Atriplex cinerea) on the St Kilda breakwater from the kiosk (l) to the end (U). Dark grey represents living saltbush, whilst light grey shows the location of dead saltbush.
Figure 10. Mean (± S.E.) number of penguins heard, seen or caught on Sunday nights in each interval by Earthcare St Kilda during the 2001-2 to 2005-6 seasons (n=5 years). The kiosk is at l, the old gate located between a and A, while the new gate (operational January 2007) is between e and f.
Figure 11. Mean (± S.E.) number of penguins heard, seen or caught on Sunday nights in each region by Earthcare St Kilda during the 2001-2 to 2006-7 seasons. Grey bars indicate the public access region (l – a, 12 intervals), and white bars represent the non-public access region (A – U, 21 intervals).
Figure 12. Mean (± S.E.) number of breeding sites recorded by Earthcare St Kilda between the 1998-9 and 2006-7 breeding seasons (n=9 years). The kiosk is at l, the old gate located between a and A, while the new gate (operational January 2007) is between e and f.
Figure 13. Mean (± S.E.) number of breeding sites per letter interval in each region by Earthcare St Kilda from the 1998-9 until the 2006-7 breeding seasons (n=9 years). Grey bars indicate the public access region (l – a, 12 intervals), and white bars represent the non-public access region (A – U, 21 intervals).