I realised, with a fright this morning, that I have been working with wildlife for 30 years. That means that my career as a zoologist is as old as AWMS is this year.
I have been reflecting on how wildlife management has changed in my time from student to researcher and teacher. I was sent out into the field with a notebook (paper version) and pencil. Today, we have access to technology and tricks that have expanded our horizons. Each advancement has opened up new opportunities and revealed more about the incredible wildlife that we seek to manage. The revolution of DNA methods, GPS trackers, accelerometers, remote sensing cameras, computers, and advanced statistical analyses are rapidly changing how we do our jobs.
At this year's conference, not only will we celebrate 30 years of AWMS, we'll also celebrate (or lament) the changes in wildlife management techniques. This year's conference is already shaping up to be a good one. We already have over 110 people registered to attend, plus numerous trade stalls and sponsors. We have a strong focus on students this year, with a student mentoring session and a writing workshop, along with our annual student dinner. For those of you interested in reintroduction's, don't miss the reintroduction workshop on Monday 4 December. See the conference page on our website for more details.
I look forward to celebrating 30 years of AWMS with you all in December, at Katoomba in the NSW mountains.
It's amazing how quickly one year and three issues of the AWMS newsletter goes past. It feels like just last month I was setting up the content for the March 2017 issue. Time flies when you're having fun they say...
The member-driven components of the newsletter are continuing to grow. We had such an overwhelming response to requests for abstracts from your publications, it's lucky that the newsletter is now electronic and the number of pages isn't an issue! It's great to see so much work from our membership being published each year.
In this issue we have the final report from last years Postgraduate Award Winner, Kathryn Strang, with her work on feral cats and sex-biases. This year there are also a number of Executive Committee positions up for nomination. If you would like to get more involved in AWMS, then this is a great way to do it. The only requirement is that you are an AWMS member and that your nomination for a position is supported by two existing members.
Our AGM is also coming up at this year's conference. If you have anything that you would like to put on the agenda, please contact the AWMS secretary, Lily (firstname.lastname@example.org). Finally, next year's conference is going to be held in Hobart. Look out Tassie, here we come! We were last in Tasmania in 2005, so it's about time we went back. If you would like to get involved in the organistion of next year's conference, please contact our Conference Liaison Officer Konnie (conference @awms.org.au) or catch up with her at this year's conference.
For those of you going, see you in Katoomba. For the rest of you...until March 2018 :)
Where: Library, The Carrington Hotel, Katoomba, NSW
This year sees a number of committee positions up for nomination. All committee positions become available every two years. Members who currently hold these committee positions are eligible to re-nominate. The following positions are open for nomination:
All candidates must be members of AWMS and all candidates require a member to nominate them. If you would like to nominate someone for a position, please ensure you speak to that person first to gauge their interest in the position. Please send all nominations, including letters/emails of acceptance of the nomination, to email@example.com
Sexing scats and investigating dietary differences between sexes in
Feral cats (Felis catus) are opportunistic and solitary hunters, which have become a worldwide problem (Lowe et al., 2000). Feral cats affect native wildlife by predation, competition, and the spread of diseases. In New Zealand, since their introduction mammalian predators have preyed on naïve native fauna as they were easy to detect and catch (Wilson, 2004). Predator control is focused mainly on mustelids, rodents, possums and rabbits, though they are only part of the problem. Feral cats are being identified as an issue; however, the public is often opposed to feral cat control. Feral cats prey mainly on the introduced ship rats (Rattus rattus) (Gillies & Fitzgerald, 2005) which are the most common rat species in New Zealand forests. Given that males are on average 1.5x heavier than females, we would expect males to be able to hunt and kill larger prey. We wanted to investigate whether there is a difference in diet between the sexes.
A sex-bias in scats collected has been found in jaguars and other felid species, which does not reflect the true sex ratio in the population (Palomares et al., 2012). Males may use scats as scent marks more than females. This would mean that more male scats are sampled, which may not accurately reflect the diet of the population. For these reasons, we also want to see if the sex ratio of scats collected reflects the true sex ratio of the population.
Scats and casts were collected opportunistically throughout the study site from January 2014 to April 2016. The study site is the southern end of Ponui Island (~600 ha), located in the Hauraki Gulf, and is a sheep and beef farm with a large piece of intact forest. Other than farm animals, feral cats, rats, and mice are the only mammals on the island. Samples were washed into a gradation of sieves. The contents were analysed under a microscope. Invertebrates were identified using an insect keys and invertebrate books. The vertebrate content of the scat was identified to species. When possible, morphological differences were used to identify any bones, hair, feathers, or skin found. Prey remains were collected around the study site when seen, and vertebrate material was compared to this.
Felid sex identification was based on the methods described by Pilgrim et al. (2005) on the amelogenin region, and were optimised for this study. Faecal and blood samples were collected from two cats at the Massey University Feline Unit. These samples were used to test and optimise the methods, and as a reference for the feral cat samples. Three hundred and ninety-six feral cat scat samples collected were used for this part of the study. Extraction of DNA from these samples and the reference (colony cats) faecal samples was with the ISOLATE Fecal DNA Kit (Bioline) using 100 – 150mg of faeces. DNA was amplified using PCR techniques, and a gel was run to visualise results.
Results & Discussion
Cat DNA was successfully extracted from 59% of the scats. The sex ratio of male to female scats was 2.82:1, where the true sex ratio of the cat population was 2:1 male:female. Males are likely using scats as a marker to other cats, which results in the sex ratio of scats overestimating the number of males in the area. If there is a dietary difference in diet, then this could lead to an underestimation of the effect of cats on small animal populations, as less female scats are picked up by researchers.
Males and females had similar frequency of occurrence of rats and mice in their scats. Males ate more birds and eggs than females, though females ate more Orthopterans. Females preyed more on passerines than males, but mainly the small and medium sized birds (fantails, Rhipidura fuliginosa; blackbirds, Turdus merula; grey warblers, Geygone igata), whereas males ate larger sized birds (pukeko, Porphyrio melanotus; ducks, Anas platyrhynchos; magpies, Gymnorhina tibicen). A large variety of bird species were eaten (Figures 1 & 2). These results have implications for understanding the effects feral cats have on native fauna. Males are able to hunt larger prey, and this is reflected in their diet. However, if we are collecting less female scats, then we may be underestimating the effect cats have on small animal populations, particularly passerines in New Zealand. The goal of Predator Free NZ 2050 is targeting mainly mustelids, rats and possums. Removing the main prey source of feral cats, as well as their competitors, could lead to increased prey switching to birds, having further detrimental effects on native wildlife populations.
Figure 1: Foot from a passerine Figure 2: Toes and claws from a morepork, Ninox novaseelandiae
Gillies, C. A., & Fitzgerald, B. M. (2005). Feral cat. In C. M. King (Ed.), The handbook of New Zealand mammals (2nd ed., pp. 307-326). Melbourne: Oxford University Press.
This newsletter reflects the opinions of the author(s) but not necessarily those of the AWMS Committee or membership. AWMS makes no claim as to the accuracy of stated claims and any party using this information does so at their own risk.