a time for butterflies

In my travels lately, I've seen a lot of butterflies about the place.  It's seems to be the perfect time of year for them - not so hot as to cause dehydration, warm enough to fly, and fairly good sources of leaves and nectar available. 

Butterflies in Western Australia are not as flashy as those of some other parts of Australia.  Look at the magnificently iridescent show-offs of the tropics, such as the Cairns Birdwing and Ulysses Swallowtail.  

Our local butterflies are smaller, often cryptic (i.e. camouflaged), and typically sparing with bright colours.  Here's an example; the Western Xenica (Geitoneura minyas). 

Western Xenica - adult female

The adults are light orange-brown with dark brown markings.  The little green larvae (caterpillars) feed on grasses, so the adults are often seen looking for mates or resting in shady patches of grass under Acacia or Eucalypts. 

Once, when I was birdwatching in the shade of some eucalypts, a cheeky butterfly landed on my notepad and I managed to take several photos.  I think he was attracted to the white surface of the paper, for some reason - he would fly away, then return to rest on my notepad.

Western Xenica - adult male

If you're interested in finding out more about butterflies, you might need a field guide such as Michael Braby's "The Complete Field Guide to Butterflies of Australia", and a digital camera with macro capabilities so you can take photos of the beautiful little creatures you see.  

The days of catching butterflies in a net and pinning them to boards has long gone, although this method is still used by entomologists to help in their biological studies.

Pepper and salt, mistletoes and insect interactions

We're heading into the time of year in which the bushland lights up with a thousand shades of yellow, orange, pink, gold and purple, and I simply can't go for a bushwalk without my camera.  There are so many different flowers to delight the photographer; orchids, hibbertias, leschenaultia, hakeas, native peas, acacias, cottonheads and kangaroo paws, to name a few*.  

One plant I particularly like (among these hundreds of species) is known colloquially as "Pepper and Salt".  The scientific name for it is Philotheca spicata.  It isn't the most spectacular flower in the bush, not by a long shot, but it makes up for being somewhat photogenically challenged by having a pleasant and elusive perfume, and always seems to have a posse of insects flittering around the delicate flowers.

Flowers of "Pepper and Salt" (Philotheca spicata)

The plant itself grows as an upright shrub, usually no taller than 50cm, with a slightly weeping habit especially when in flower.  (The gracile branches seem to be weighed down by the flowers.)  It is fairly widespread in our local bushland such as the Bush Forever sites, in banksia woodland, or amongst jarrah and marri trees.

"Pepper and Salt" (Philotheca spicata)

Pepper and Salt is found along much of the Swan Coastal Plain and further south (at least where it hasn't been cleared for roads and buildings.)  It would make a fine addition to a bush garden, but in nurseries you might have to search for it, or order it, under the old botanical name of Eriostemon spicatus.

Satin-green Forester moth (Pollanisus viridipulverulenta)

The little moth in attendance could be mistaken for a butterfly - it moves around in broad daylight, its iridescent green, blue and copper wings glittering in patches of sunlight.  Due to its romance with the Philotheca flowers, and its general reluctance to move from a good position, I find this species not too difficult to photograph.  

Satin-green Forester Moth

According to my field guides, this species is the Satin-green Forester Moth (Pollanisus viridipulverulenta).  Entomologists, please correct me if I'm wrong! The wikipedia entry doesn't mention that it is found in WA, but the CSIRO website shows that it is. 

Insects such as butterflies and moths are usually reliant on specific plants for food and drink.  Some of these little animals are entirely dependent on just one or two species.  Some have had deserved scientific attention.  For example, caterpillars of the Satin Azure butterfly (Ogyris amaryllis) dine on mistletoe (Amyema species).  Unfortunately, many people remove mistletoes, believing that their parasitic qualities will weaken and kill their trees.  See this ABC website for a great expose on the myths and facts of mistletoe.

Here is a fact sheet you can download about the Satin Azure, written for South Australia.  Interestingly, although the Satin Azure is found across Australia, in each area it feeds on the local Amyema species available.  In the factsheet, it mentions Wireleaf Mistletoe (Amyema preissii) as a favourite food plant, and Stalked Mistletoe (A. miquelii) as a back-up; these are two mistletoe species we have around Perth.  The butterfly also needs "attendant" ants to complete its life-cycle.

Wireleaf Mistletoe (Amyema preissii) grows on Acacia trees

Can you see the ecological links here?  In this case, the butterfly lays its eggs on a plant that is totally reliant on another plant (i.e. wattle trees).  The caterpillars of the butterfly are protected from predators by the attendant ants .  Do the mistletoes benefit from this arrangement?  And what do we know about the ants' requirements?  What do they feed on?  Does the wattle provide an ideal habitat in the way of leaf litter?  What are the requirements of the wasps that might parasitise the caterpillars?  We know a little, but not very much really.  (At least there are a few articles of interesting research listed on the internet about this!)

These fauna-flora interactions are not widely studied, and have not been fully considered in our planning for conservation reserves, rehabilitation of industrial areas, and revegetation of urban landscapes.  Part of the problem in the past has been that people have studied plants (i.e. botany) or insects (i.e. entomology) and not the link between the two sciences (i.e. ecology).  In fact, botanists have tended to look askance at insects as a threat - something with the potential to destroy the perfect plant specimen, or wreck a photo of an ideal flower (where some little critter has chewed one of the petals, for example.) 

Horticulturists have moved one step further from nature, with their arsenal of poisons to deal with their unwanted fauna in the form of bug sprays.  It saddens me to think how many caterpillars might be being sprayed today in my suburb, because they are not recognised as being butterfly larvae.  Ecological links are broken.  No caterpillars; no birds to feed on them = Silent Spring.  (Yes, it's a book; read about it here.)

Entomologists have in the past sometimes lacked the botanical skills to record the plants on which their study animals have depended.  At the present, following little animals around in bushland still requires patience, time and a lot of skill, so it does not fare well in the cut-throat budgets and high-pressure timelines of a typical land "development" or mining project.  Why on earth would a high-flying developer think they need an entomologist?  Add in the "emotional care factor" (i.e. cute fluffy animals versus scaly ones or buzzy flitty ones) and it's difficult to get people to realise their importance.  Maybe in another fifty years we'll have a better idea of ecological links.  So our Bush Forever sites and little urban parks may be more precious than we yet realise, especially at their current rate of disappearance.

There is a lot more to be learnt about our local bushland. . . 

* Note to the people who maintain our local Public Open Spaces - August is NOT the time to prune these plants!  You will be removing the recent winter's growth and flower buds, and depriving us of our coming show of spring flowers.  Please wait until late summer or autumn next year before getting out your pruning equipment.

cats in Western Australia - where do we stand?

Debates about cats, the effects of cats on wildlife and the environment, and the rights of cat owners, have been on-going for many years.  There has been a lot of discussion in the media lately, regarding cat laws in Western Australia. 

The most recent discussion started late last year, when the City of Swan selected three public parks in Ellenbrook for a trial Cat-free Zone. The parks were Woodlake Park (in Woodlake), Mornington Park (in Coolamon) and Moulton Wetland Park (in Charlotte's Vineyard).  A survey conducted by City of Swan in the three areas found that more than three-quarters of local residents gave their support for the zoning.  You can read about the survey responses in this November 2010 article in The Advocate newspaper.  A further article in December 2010 in The Advocate talked about the use of warning signs, and the impounding of cats found wandering around in these parks.  

In June 2011,  Western Australia brought in state-wide Cat Laws, encouraging responsible pet ownership, You can download the new Cat Bill from this link.  The City of Swan put out a statement in June 2011 in The Advocate, outlining how the new Cat Bill makes it unnecessary for local councils to have Cat-free Zones.  They are therefore abandoning the three proposed Cat-free Zones in Ellenbrook.  However, the Cat Bill allows authorised persons to impound cats found in a public place, which includes parks, so it effectively gives the City of Swan the same level of control over cats in parks. 

In July 2011, the ABC picked up the story and conducted some interviews with people from various backgrounds.  Although I don't agree with some of their viewpoints, the article makes an interesting read.


You might be thinking, why am I so interested in all this?  

Well, as a passionate bushwalker and wildlife photographer, I often see cats in places where they shouldn't be.  

someone's pet in a bushland park in Ellenbrook

The problem isn't just in Ellenbrook, of course.  I have seen cats wandering around in bushland and parks all over Perth, and even further afield. 

Question: What's wrong with this picture of Burns Beach Nature Reserve?

Answer:  It contains a cat.

Most of these are obviously household moggies - well-fed, often with collars, and not really caring if I take their picture, so long as I don't get too close.  It wouldn't be so bad if this was all cats do, just sit around under bushes or on logs enjoying the view.  But even a cat owner should admit that cats aren't in the park just for the fresh air.  


A common misconception is that cats only hunt when they are hungry, and that well-fed cats don't kill birds, therefore pet cats don't do any damage in bushland.  This is just not true.  Cats hunt because they are cats, and hunting is what they do, hungry or not.  Another misconception is that cats hunt only at night.  Not true; if it was, cats would not hunt birds during the day (which they do).  A third urban myth is that belling a cat warns birds and other animals of the cat's presence.  Not true; the only bird that would associate the sound of the bell with a warning of impending danger would be the bird in the cat's mouth.  Too late for that bird.  But I digress....


I often find tracks of cats, both feral and domestic, in bushland, sometimes many kilometres from the nearest houses.  Lately I've made a habit of recording these, because they seem to be on the increase.

domestic cat tracks in moist sand, very easy to see

cat tracks in a Bush Forever site, a LONG way from the houses  
(dry sand makes the track indistinct and difficult to see)

I also see first-hand how irresponsible pet ownership impacts on bushland and its wildlife.  Sometimes the victims are not in bushland, they're in my garden.  It's not pretty, finding a patch of feathers or a piece of a deceased skink, or worse.   

I was going to put a gruesome photo of the remains of a bird killed by a cat in here, but I decided against it. Instead, here's a photo of a very-much-alive skink on a burnt-out tree stump.

Cats are famous for being very efficient predators of rats and mice, which endears them to the human race for their ability to keep vermin at manageable levels around our buildings and farms.  Amazingly, cats can kill animals up to the size of a rabbit.  But this ability also makes them quite good at killing a range of other animals as well, such as frogs, lizards, small snakes, pygopods (legless lizards), and of course, birds.


Unfortunately, much of our native wildlife is at risk, because it is in the same "size and weight range" as a rat or mouse.  In Ellenbrook, we have many marsupials, and small birds that like to feed and nest on or near the ground.  We have a large number of little frogs and lizards that live in leaf litter or burrows at ground level.  These are all susceptible to cat attack.

Here is a list of some of the animals in our local parks, at risk from cats:

Mammals (these are in our Bush Forever sites)

Quenda (Southern Brown Bandicoot)

Honey Possum

Brush-tailed Possum
Ash-grey Mouse (a native, not a pest)

Southern Bush-rat (a native, not a pest)

Water Rat (a native, not a pest)
White-striped Freetail Bat


Birds (in bushland, and some of these are in suburban gardens)


Painted Button-quail 

Red-capped Parrot

Crested Pigeon 

Common Bronzewing

Splendid Fairy-wren
Yellow-rumped Thornbill

Grey Fantail

Brown Honeyeater

White-cheeked Honeyeater

New Holland Honeyeater

Western Spinebill 
Silvereye



Reptiles (in bushland and suburban gardens)


Spiny-tailed Gecko

Burton's Legless Lizard
Fraser's Legless Lizard
Keeled Legless Lizard
Western Bluetongue

Fence Skink
Common Dwarf Skink
Western Pale-flecked Morethia (a skink)
Southern Pale-flecked Morethia (a skink)
West Coast Ctenotus (a skink)
West Coast Four-toed Lerista (another skink)
Western Bearded Dragon
Western Heath Dragon
Black-striped Snake (a small inoffensive creature)



Frogs (in bushland and, if you're lucky, in your garden)


Motorbike Frog
Banjo Frog (Pobblebonk)
Slender Tree Frog
Red-thighed Froglet
Moaning Frog
Squelching Froglet
Glauert's Froglet




Sadly, even if an animal survives the initial attack by a cat, it's very likely to succumb to post-attack shock or fatal infection from the wounds inflicted.  Cats carry a parasite called Toxoplasma gondii, which doesn't affect the cat itself, but can cause a disease called toxoplasmosis in other animals, as well as in people.  The effects of toxoplasmosis can be fatal.  The Australian Wildlife Health Network has an excellent factsheet which lists the effects that toxoplasmosis has on Australian wildlife. 

After all I've said, I still appreciate that cats are beautiful animals, and they make great pets.  Due to their intelligence and adaptability, they are undoubtedly one of the stars of the animal world.  But they don't belong in the Australian bushland, and they certainly don't have the "right" to go around killing our wildlife.  

If you have a cat, please follow the responsible pet ownership guidelines, and keep your pet on your property.  Don't let it loose to stray across roads, into other people's yards, and into parks, where it can get into trouble. 

birds watched at Woodlake

It was a cold breezy overcast day for our bird walk last week at Woodlake.  Despite that, a keen group gathered for a one-hour stroll around the lake perimeter.  The cold weather didn't deter the birds.

Here's a list of what we saw, with links for more information on each species.

Australian Magpies

Silvereyes
 

Western Wattlebirds (sometimes called Little Wattlebird)

"Twenty-eights" (Port Lincoln Parrots or Australian Ringnecks)

Galahs

White-cheeked Honeyeaters

Singing Honeyeaters

Brown Honeyeater

Eurasian Coots

Pacific Black Duck

Australasian Grebes

Spotted Turtledoves (an introduced species)

The bird highlight of the day, for me, though, occurred when returning to the carpark.  There in the shrubs was a Splendid Fairy-wren, shining out in his iridescent blue feathers.  We watched for a couple of minutes, then a female appeared and the pair descended to the ground to forage for insects.