Hi everyone, my apologies for getting this up several days late, thank you for patience.
For my first field visit of 2018 I decided to visit Turkey Flat near Yanco. I then proceeded to get myself all mixed up and ended up at McCaughey’s Lagoon instead.
It looked to be a nice little wetland-with-woodland area, and I could not get my brain to make sense of the actual map, which was oriented a different way to my mental map of the local area, so I decided to stay and check out McCaughey’s Lagoon instead, and try again for Turkey Flat another day.
McCaughey’s Lagoon is named after Sir Samuel McCaughey, a prominent pastoralist who owned a lot of property in the Narrandera-Yanco-Leeton area in the 1800s and early 1900s. Amongst his many notable achievements and contributions to the region and its communities, he started what became the Murrumbidgee Irrigation system, which now supports the 660,000 hectare Murrumbidgee Irrigation Area. If I had thought of it at the time I’d have headed into Yanco to get a photo of the statue of him in Yanco park. Maybe next time.
These days, McCaughey’s Lagoon is part of the MIA1 precinct of the Murrumbidgee Valley National Park. I visited a different part of MIA1 last year.
The lagoon itself is very small. Or at least, it was small during my visit, I don’t know if the site floods in high rainfall years or much about its management and hydrology.
It’s a very pretty little lagoon though, and there were a lot of small birds darting around – far too quickly for me to see what they were. Something that may have been an egret flew off when I arrived, and there was a moorhen (or similar-sized rail) that kept zooming under cover whenever I looked at it. Walking a distance into the trees didn’t raise any more bird sightings, so I turned the outing into a habitat-spotting trek.
Exhibit one: Cumbungi bordering shallow water and a mudflat. Excellent cover for the little twittery things I couldn’t see properly, and the rail that didn’t want to be friends, as well as other wading birds. Also good cover for frogs, and if there’s water up around the stems great for small fish as well.
Exhibit two: Rocks and logs. While exposed they’re good cover for frogs, and provide perching opportunities for birds looking for prey in and above the water, or just looking for a safe spot to dry wet feathers. They can be good sunning spots for turtles and other reptiles, especially when the surrounding water is deep enough to escape into if needed. When the water is high enough to submerge or partially submerge the rocks and logs they’re great shelter for fish and aquatic invertebrates (as well as frogs and reptiles again), and along with the cumbungi, can provide shelter and attachment points for fish and frog eggs (depending on species – some prefer open water or other locations).
Exhibit three: Deeper water. I don’t know how deep this water actually was, but it looked deeper and more open than on the other side of the regulator. The tracks through the floating vegetation may have been made by swimming or wading birds, depending on the actual depth. Deeper water is good for larger fish and turtles, as well as the water birds that like to hunt them, including diving species. Deep water is also good for very large waterbirds like pelicans. I expect they probably prefer somewhat deeper water than this was though.
Exhibit four: Trees beside waterbodies. Trees (and shrubs) beside waterbodies are great for providing shelter and nesting spots for small birds that eat insects over water. They’re also great for providing shade over the water, which affects water temperatures, which can be very important for fish and other aquatic species. Some waterbirds, including the Australian Wood Duck (Chenonetta jubata), also roost and nest in trees. Trees close enough to the water to have exposed roots at the water’s edge can also be important shelter for frogs, fish, and their eggs. Roots also contribute to bank stability, and leaves dropped into the water can provide nutrients.
Exhibit five: Tree hollows. Tree hollows are used by many species of birds, reptiles, mammals, insects, you name it. Great for providing protected nesting places. Some species are very particular about the size and shape of the hollows they prefer, and others will use anything they can fit into (even if that means making it bigger first). You can never have too many tree hollows.
Exhibit six: Flaky bark. Often overlooked, flaky bark is important habitat for many spiders and other invertebrates, as well as tiny bats. It can also be important for various species of small lizards, and some frogs. I always want to peek behind flaky bark to see who’s there, but as this would often require actually ripping it off altogether I restrain myself.
Exhibit seven: Fallen timber. As I’m sure I’ve mentioned before, fallen timber so often falls victim to ‘clean up’ efforts, bushfire fuel reduction efforts, and firewood collecting. This then leads to a massive loss of habitat in woodland areas. Fallen timber is essential habitat for small to medium-sized mammals, frogs, invertebrates, reptiles, certain birds, and even other plants, as well as a mosses and fungi. It contributes to soil moisture and nutrient levels; it provides protection for wildlife moving through areas, thus contributing to species movement at a landscape-scale; it influences airflow patterns close to the ground surface which can decrease wind-driven erosion; it helps slow the flow of surface water during rain events, thus allowing more water to penetrate into the soil. Fallen timber is important. Retain fallen timber in your woodland areas folks.
Exhibit eight: Standing dead timber. This is another one that a lot of people don’t realise is important. I have met people who know that live trees with hollows should be retained, and that fallen timber is important to keep around, but who will remove standing, dead trees because they’re dead and therefore worthless and unsightly. These people are incorrect. Standing dead trees are great for cracks and hollows (sometimes small, sometimes large), which makes them fantastic habitat for many of the same species that like flaky bark and tree hollows. A long narrow crack in a dead tree makes for a great roosting place for small bats, as well as nice protection for various reptile species (see also cracks in old timber fence posts). Larger hollows inside the trunks of dead trees will be used by birds and other species. Removing dead trees removes habitat just as surely as removing live trees does.
Exhibit nine: Leaf and bark litter. Ground litter is fantastic cover for tiny things: insects, spiders, and other invertebrates, small lizards and snakes, frogs, very small mammals of the non-winged variety. As with fallen timber, leaf and bark litter also contributes to how nutrients and water move through the landscape, including complex situations where a thick layer of litter can slow evaporation of soil moisture, whilst also slowing infiltration of rainwater into the soil, especially if the litter is quite hydrophobic. Studying all the ways in which leaf litter influences an ecosystem/landscape is fascinating.
Exhibit ten: Mistletoe. Mistletoe is another one that gets a bad rap. It’s parasitic, and parasites are ‘bad’. Except that mistletoes provide vital habitat and food for quite a lot of bird and insect species – including some that specialise in mistletoe (for example the Mistletoebird, Dicaeum hirundinaceum). A clump of mistletoe is an excellent place to nest if you’re a small bird, as the vegetation is often more dense than in the branches of the host plant. They also drop nutrient-rich leaves – often much more nutrient-rich than the leaves of the host plants – which has a huge impact on the nutrient levels of the leaf litter and soil below. So mistletoes are actually good!
And that concludes my little trip to McCaughey’s Lagoon – I’ll see you later in February.