Sometimes you get nothing but waving grass, or leaves gently blowing in the wind. Strong shadows in bright sunshine can also trigger a trail camera, as the sharp edges of a shadow trigger the movement sensor. Other times, it turns out just right and you catch a glimpse of that elusive animal you were hoping to discover.
Trail camera success can also come, not from a rare species, but from images of common species. Multiple images of animals repeatedly using an area provide more than just a species list, it begins to provide insight into what happens in the forest. This trail camera detected seven species of mammal, all of which are widespread in the forest – Mountain (or Short-eared) Brushtail Possum (Trichosurus cunninghami), Swamp Wallaby (Wallabia bicolor), Eastern Grey Kangaroo (Macropus giganteus), Common Wombat (Vombatus ursinus), Feral Cat (Felis catus), Red Fox (Vulpes vulpes) and Sambar Deer (Cervus elaphus). What’s interesting is how regular, even predictable, much of their behaviour is.
Here, I’ve merged 534 images into a 9 minute video; it’s the entire batch of images from the camera, taken near the Crystal Mines Tk from 15th May to 2nd August 2020. The site chosen included a variety of micro-habitats – plentiful leaf-litter, fallen branches and timber, trunks of living trees, open spaces, well-worn animal tracks and dense shrub-layer on the edge of the camera’s range. The camera captured some fauna activity on most days, but keep in mind that sequential photos might be hours or days apart (bottom right of window).
Though it’s hard to distinguish between different individuals of the same species in the images, it’s likely that only a small number of individuals are involved here. One of the more notable and disturbing observations is the high frequency of fox images, many of them blurred as the foxes run and jump through the frame. Whether it’s one fox or several, there would appear to be plenty of predation pressure from foxes in this part of the forest.
For those paying attention, the brushtail possum in the first few images looks somewhat like a Common Brushtail, with a tail much less bushy than usual, but the give-away is the length of the ears – they are short and only just longer than the pelage, identifying these as Mountain Brushtail Possums. These first images show that there are at least two Mountain Brushtail Possums using the area and they are on-screen regulars.
A few more things to note:
- There appears to be more than one Sambar Deer in the images – one with calf and one or more, without.
- The three Feral Cat occurrences appear to be similar looking animals and all following the same route along the log.
- The two Eastern Grey Kangaroos appear to both be males.
- All the Foxes appear in good condition – no mange visible.
- Species not encountered at this site, but that we might have expected on-camera, include – European Rabbit, Echidna, Agile Antechinus and a variety of birds (Pied Currawong, Eastern Yellow Robin, Grey Shrike-thrush.
The Strathbogie Forest Citizen Science project has used trail cameras extensively to survey forest fauna. The cameras provide distribution information for the species that are detected and also provide insight into how some species use the forest.