Playing Detective: Rainfall, Kangaroos, and the Lack of Native Flowers

Being new to this area, I don’t have a history of seasonal changes. What’s normal for these parts?  I simply don’t know.   When we arrived here in August 2012, the land abounded with native flowers, including ten species of native orchid flowering at one time.  This continued in early and  mid Spring, then as the weather warmed up, the flowers ceased to appear.  We often had orchid leaves, or tiny native plants appearing, but they didn’t seem to grow, let alone flower.  Sometimes they disappeared as quickly as they arrived. It’s just too hot, I thought. They’ll re-appear in Autumn. Again, we’ve had lots of leaves and tiny plants, but no flowers. So I’m starting to look for reasons. Picking up a fact here, a clue there, a bit of gossip to add to the mix, and just a tiny bit of science.  Am I on the right track, or does my theory lead to a red herring?  I guess I will have to wat to find out.

Here’s the plot so far:

When we arrived, everything was lush and green, we had no kangaroos on the property, and rain seemed plentiful.  As we moved through Spring and into the Summer months, the rain stopped, and everything dried to a crisp. It was hot, dam levels dropped, and I guess, so did food levels in the bush for kangaroos.   Now, we have at least four resident kangaroos.

This leaves three possible reasons for the lack of native flowers:

  1. We mainly have Winter and Spring flowering native flowers on our land.
  2. The kangaroos are eating them,
  3. There has been insufficient rain,

Let’s have a quick look at the evidence to support or discredit each of these possibilities.

1. We only have  Winter and Spring flowering plants

This may be true, but I think it is unlikely. Our bushland has never been grazed or mined. Similar sclerophyll forest in this region does have Summer and Autumn flowering plants, including native orchids.  So, in theory, ours should too.

2. The kangaroos are eating our native flowering plants

During a property inspection with the previous owners, I had asked if we would see kangaroos here.  “Very occasionally, we see a little black wallaby’ was their answer.   With this expectation, we were pleasantly surprised to see so many kangaroos so close to the house – not only the little Swamp Wallaby, but also Eastern Grey Kangaroos.

Our first inkling that this may not be normal was with the destruction of our orchard and front garden. When we arrived here, the garden was very healthy, with several years of growth evident on all of the plants. There were no barriers to prevent kangaroos from accessing the garden, so maybe they had not ventured into the garden before.  Perhaps this reflected the lack of food in their natural habitat.  Or maybe there were increased kangaroo numbers?

I asked a local person if there were more kangaroos around this year than in previous years.  “No, but they are in different places because of the fire.”   This makes a lot of sense. Kangaroos would have been forced to seek food elsewhere.

Looking around the bush this week, I can see plants which have bite marks at the tops of the stems and leaves, so I think this theory is partly true, but I don’t think it is the sole cause.

Kangaroo Food

This native plant has been nibbled to the ground

Kangaroo Food

Even the spiky-leaved native heath has been nibbled.

 

3. There has been insufficient rain

The Bureau of Meteorology released rainfall data at the end of May which confirmed the period from September 2012 to May 2013 had the lowest rainfalls since records began in Victoria.  We are lucky enough to have rainfall totals for the previous seven years here, left by the previous owners, and we can see that our May rainfall in 2013 was half that received in May 2012.  Prolonged lack of rain would also explain the lack of native flowers.

Almost as if to prove the point, we had a very wet introduction to Winter. The first few days of June were filled with rain, and over the past week, plants, leaves and fungi have been popping up all over the property.   Some tiny orchid leaves have begun to grow larger, and new patches of orchid leaves seem to spring up overnight.

Dry Ground

Orchid leaves are beginning to come up after the rain.

 

My theory?

While I can’t really arrive at a conclusive answer until I actually see some flowers, my feeling is that the rainfall has been the largest factor in the equation. With such a dry Summer, and so little food in the bushland, the kangaroos are obviously a factor too. They probably did eat the Summer and Autumn flowering plants that appeared.  The poor things were probably starving when they came so close to the house to eat the garden.

Time will tell. We still have the four Eastern Grey Kangaroos (I saw them this morning) and the plants continue to appear and to grow after each rain shower.  If we continue to get good Winter rain, I’m hopeful we’ll see a splendid array of native flowers in the coming months. Surely the kangaroos can’t eat all of them!?

Kangaroos

Two of our four resident kangaroos.

  One thought on “Playing Detective: Rainfall, Kangaroos, and the Lack of Native Flowers

  1. BJ
    14 June 2013 at 7:50 pm

    You are probably right on all counts. One of the major reasons, however, is the first, in that the majority of flowering occurs in spring, so that is when you will find the most. And since I spend so much time seeking orchids (!) I’ll comment that although there are autumn and winter flowering plants, they are fairly sparse in comparison to the spring abundance. So we wait impatiently for spring…..

    • 14 June 2013 at 10:15 pm

      Thanks – that’s good to know. Looking back at the photos I took after we moved in, the majority of them are taken in October and November, so that fits.
      Lisa

  2. johng
    25 June 2013 at 11:14 pm

    The “orchid leaves” you have photographed may be Hydrocotyle laxiflora, Stinking Pennywort. Keep watching the leaves – pennywort flowers in spring and the flowers have an offensive, putrid odour as described in Florqa of Victoria, vol 4.

    Many animals are moving further than usual in search of food. Swans and Coots are moving onto streets around Lake Wendouree. This often has fatal consequences as the birds are nottoo road smart.

    • 25 June 2013 at 11:52 pm

      Thanks for letting me know about the Stinking Pennywort. Also for the reference to Flora of Victoria. I’ll keep a look-out for this reference. Sounds like something I need to have handy.

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