Ex-Situ conservation Tidbinbilla
Depite its proximity, transport constraints meant that I had not visited Tidbinbilla since I began studying at ANU, however the prospect of work experience and exposure to the incredible native diversity so close to home was too good to pass up. Working alongside the Wildlife Team, was an informative behind the scenes look at ex-situ conservation in an Australian context. Having taken part in a decentralized breeding program for the Critically Endangered Lemur Leaf Frog back at home, I was especially excited to be involved with the breeding program for the Northern Corroboree Frog (Pseudophryne pengilleyi). As I was fortunate enough to experience however, the duties of Tidbinbilla’s Wildlife team are far from monofocused, ranging from felling trees to delicately sorting froglets all in the span of a few hours.
Figure 1: Koalas breed without much help within the park (author photo)
Tidbinbilla Nature Reserve
Tidbinbilla nature reserve is one of the naturally and historically richest conservation areas in the Canberra region, conserving an integral part of the ACT’s threatened subalpine landscapes (Act Government, 2017). In addition to the unique ecological communities protected within its boundaries, Tidbinbilla also protects important Aboriginal and European historical sites. Following extensive damage to the park during the 2003 wildfires, an additional focus was placed on ex-situ conservation and captive breeding of three critically endangered species or subspecies, the Northern Corroboree Frog (Pseudophryne pengilleyi), Southern Brush Tailed Rock Wallaby (Petrogale penicillata), and Eastern Bettong (Bettongia gaimardi). While fire exacted a toll on the landscape, it also created a management opportunity to redevelop infrastructure to suit its revised goals.To a greater extent than many of the regions conservation areas, public involvement, education and outreach is a key part of Tidbinbilla’s management. Not only does it boast guided activities, trails and an interesting information centre but it also actively engages with community volunteers.
Figure 2: Northern Corroboree Frogs (Pseudophryne pengilleyi), in growout tank (Author photo)
Wildlife Team- Why captive breeding?
At Tidbinbilla I worked alongside the Wildlife Team, who are in charge of managing the captive breeding programs in the park. While captive breeding has not always been a key focus in the park, its key flagship projects have been immensely successful. The ex-situ conservation program here serves both as an insurance population, but also to directly supply reintroduction efforts (Zippel et al. 2011).
All three species, but especially the Southern Brush Tailed Rock Wallaby and the Northern Corroboree Frog, are notable not only for their extremely limited geographical range but small population sizes (IUCN, 2017). This makes wild populations especially vulnerable to disturbances, either human induced or natural such as fire (Piggott et al. 2005) . If fire destroys their limited habitats, these species could quickly be lost forever. A poignant example threat is the Chytrid fungus, which has decimated P. pengilleyi populations throughout its range (Zippel et al. 2011). Maintaining a stable breeding population in captivity, can serve as an insurance policy for the eventuality of extinction in the wild, much the same way as the Tasmanian population of the Eastern Bettong served as an insurance for the now extinct mainland population (Short et al. 1992). With 70% of the global P. penicillata population, the largest population of P. pengilleyi and a diverse thriving group of B. gaimardi, Tidbinbilla is the cornerstone of their ex-situ conservation (ACT Government 2017.
Figure 3: Pseudophryne pengilleyi breeding setup (Author photo)
In captivity, high survival rates enable reintroduction where suitable. These reintroductions can bolster natural populations, further improving the odds of their continuing survival (Griffiths and Pavajeau, 2008). So far, reintroduction of all three species has been successful (ACT Government 2017). Reintroductions at Mulligans Flat have seen Bettongs roaming the natural landscape of the ACT for the first time in over 100 years (ibid). In a critical success, as of last season there is evidence that frogs born at Tidbinbilla and released into Namadgi have been able to successfully survive, and even breed in the wild.
AN important question in populations this small is genetic sustainability (Frankham, 1995), and careful work at Tidbinbilla has been able to maintain functional genetic diversity. By introducing these new species into the wild populations, the gene pool can expand and become more resilient, hopefully bettering their chances of their survival (Fraser, 2008). These species and projects are so important not only for how rare they are, but also for what good prospects these conservation efforts are showing.
A day in the life of a Wildlife Team member is not just directed at a singular species, but rather adapts to the needs of the park as a whole. The day began with cleaning and maintenance of Wallaby habitats. In the breeding pens, the small enclosure size means that droppings need to be removed daily. Then, we had to gather new food for the Koala population. Due to their fussy feeding habits, and preference for the youngest leaf tips this didn’t involve picking leaves, but rather the sawing down of over a dozen young trees. The paradoxical experience of quasi-logging within a protected area really made me think about how animal conservation, and landscape conservation can come to be at odds. One of the most notable features of the Koala habitat was an overabundance of rather tame Potoroos. While all but absent from the park proper, their population exploded within predator proof areas. This showed the devastating effects of invasive species predation, even when programs are in place to cull invasives. We later gave individual attention to the onsite reptile population before moving on to the Corroboree breeding center.
Figure 4: Two days’ worth of Koala Food (author photo)
Huge attention is paid to the genetic viability of the frog population, with each brood being separated and classified. The seriousness of this project for the survival of the species was evidenced by the numerous alarms, sirens and locks all protecting the population form intrusion or environmental fluctuation. We transferred newly metamorphosed froglets into their new grow-out enclosures. One of the most amazing things was the level of detail involved to ensure their health. Everything from the slant of the gravel, position and shape of the natural shelters, to the effect of proximity to the air conditioner on ambient humidity was accounted for. This delicate work was followed by an informative talk with one of the indigenous rangers, Kai, who not only contextualized the history of the landscape, but showed the importance of public education for the survival of the park.
Working at Tidbinbilla was eye opening, and valuable giving me an insight into how dynamic wildlife work can be. It demonstrated the conflicts between species, landscape and historical conservation and showed how important public interface is for all three, something I had not previously given enough thought. Not only did I learn practical skills, but conversations with staff gave valuable insights into researching Biodiversity as I explore the next steps in my academic life. And as a perfect way to round off, I was able to finish the day with my first sighting of a wild platypus, making me think again how important biodiversity is to the value of a landscape.
Work Date: 12/10/17 from 7:30 to 16:00.
Word Count: 1056
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