City Nature Challenge: Greater Adelaide - Backyard Biodiversity


Current events will ensure this years City Nature Challenge will look very different to past years, with many people required to, or choosing to, stay at home. While this may be limiting in some respects it is also an opportunity to take the time to discover all the life present in our yards. Much of this life is almost invisible unless we take the time to look carefully for it. So now we have the time, let's make the most of it.
Exactly how many species can be found in a typical suburban backyard?

Consider your yard, and have a guess how many species you might be able to find in it. Don't count any cultivated or captive species. Obviously yards will range from courtyard to acreage, so your estimates will differ. Unless you are someone who regularly looks for life in their yard, your estimate could be out by a factor of 5 to 10.

This post will assume a typical suburban property of, let's say, 750m2 (as that is what I am most familiar with). Adjust your expectations of what you'll find up or down depending on your property size and location.

The Size of Life
Obviously the larger an organism the greater area of land is required to sustain a population of that species. You're unlikely to find a Kangaroo in your yard unless there is a large natural area nearby. While you will encounter a few Vertebrate species in your yard, predominantly Birds with a few Reptiles and Amphibians, the majority of species are going to be small Invertebrates. So be prepared to look closely.

How Much Life
This will all come down to Plants. The more you have in your yard (and surrounding area), the more species you will find. They draw in the herbivorous Invertebrates to chew the leaves, suck the sap, drink the nectar, and eat the fruit and seeds. These in turn attract the predatory Invertebrates and both will attract the insectivorous Vertebrates. The Plant litter feeds the ground and soil dwelling Invertebrates and encourages a diverse range of Fungi, whose fruiting bodies are consumed by various Invertebrates.



Time of Year
Not all species that can be found in your yard will be present at the same time. Many species of Insects have flight times in the warmer months. Some are only present in their adult forms for one month of the year. Some species are active at different times of the day and during the night. Some will only ever visit your yard if there is a food source available, i.e. flowering or fruiting Plants. To get a full count of species in your backyard, you'll need to be on the lookout throughout the year. With the City Nature Challenge spanning only four days, what you'll see in your yard is only small subset of the total.

Time of Day
Different creatures are active different times of the day. If during the City Nature Challenge you investigate your yard at the same time on each day, you'll only see a subset of what is actually there. Try to look around your yard at various times of the day, and after sunset. Turn on some outdoor lighting in the evening, put down a white sheet and join the Moth Night on the 26th. Keep an eye on birdbaths and any flowering Plants as these will have visiting Birds throughout the day, with some perhaps only visiting once per day. Take a powerful flashlight out after dark and search for nocturnal creatures. Don't forget the many nocturnal Invertebrates. Keep an eye out for the Grey-headed Flying-Foxes (Pteropus poliocephalus). These head out from the colony in Adelaide each evening. Each year in April/May I find them feeding in a local Palm around 22km from the colony, often around 10pm. So with luck these could be seen across much of Greater Adelaide.

Weather
Not only will inclement weather keep us inside, it will do the same for many creatures. Many Insects will be most active in the calmer and warmer parts of the day, however they can also be harder to photograph when most active. The Moth Night on the 26th will be most successful if the day/evening is warm and calm. If the weather is poor, try again another night. The difference the weather can make can be dramatic.

Resident, Visitor or Fly-By
Species seen in your yard fall into a few categories. 'Residents' that have their homes in your yard and spend most of their time there, 'Visitors' with homes elsewhere that come to your yard for food and other resources, and 'Fly-By' species that are passing through the physical space of your yard, but are not specifically interested in it. The number of Resident species will be determined by the size of your property and the available resources on it. The number of Visitors is dependent on the resources present in your yard and the homes available in the area surrounding your property. Fly-Bys are mostly chance encounters, but are higher when local surroundings are more diverse.


Surrounding Landscape
Most of the species observed in our yards won't be residents. They will be passing through, visiting and feeding. So the environment surrounding your property will have a large impact on the number of species you observe. If you have nearby natural areas and abundant food sources in your yard, you will get many visiting species. Newer suburbs with smaller backyards and less established vegetation will see less overall species.

Evidence of Organism
For an observation to be "Verifiable" in iNaturalist it must contain evidence of an organism. Most commonly a photo, but audio records are also suitable. Consider recording Frogs and Birds if you can hear them but can't locate them, or if they are too far away for your camera. You can also upload traces of the presence of organisms, for example feathers.

Finding Organisms - Observing
It is not difficult to find Rainbow Lorikeets in your yard. In fact it is hard to miss them. However keep an eye on established trees and shrubs, particularly if they are flowering, and you may spot some quieter species of Bird that have gone unnoticed. If the flowers are closer to the ground, keep an eye on them for visiting Insects. The longer you observe, the more species you'll likely spot. If you have a birdbath, keep an eye on it throughout the day. Some Birds may visit briefly only once every day or so.

Smaller creatures including Invertebrates tend to be rather more elusive. Evolved to avoid predation, they also avoid being seen by us as well. To find them you'll need to move slowly and look closely. Many Insects are at least partially camouflaged and are easily missed unless looking with intent. Some can see a surprising distance, will see us coming and hide on the underside of a leaf. Some species of Beetle will release their grip and drop to the ground if disturbed, often just as you get the camera in focus to take a shot. A quick method of finding Invertebrates in Plants is to place a sheet below a tree or shrub, shake the branches and record what falls out.

Although many of the Plant species in our yards will be 'Cultivated", there are likely dozens of small unassuming weed species popping up naturally. These can all be recorded and uploaded. Although not always the most appealing species, recording these will help to provide valuable information on the distribution of weed species in developed areas. Also don't forget the Moss species dotted around the yard.



Finding Organisms - Searching
If you have rocks or logs in the yard, don't forget to look under them. Have your camera ready as many species will try to hide when disturbed. Avoid lifting anything with your hands as Snakes/Spiders/Scorpions aren't going to be happy having their homes disturbed. Return the rocks and logs to their original positions when finished.

If you have a pond, have you considered what might be living in it, aside from Mosquito wrigglers? Sweep a fine mesh net through the water or collect some pond water in a jar and see what aquatic Invertebrates you can find.

Many Invertebrates can be found in leaf litter and soil. Consider collecting leaf litter and sifting through it on a white sheet to see what falls out. Soil can be dug from the ground to a spade depth and dropped into a bucket of water, where the Invertebrates will float to the surface and can be collected.



Finding Organisms - Attracting
Offering food sources can draw out resident species and attract additional visitors to your yard. Suitable vegetation can ensure food is available year round, but additional sources can be added temporarily during the City Nature Challenge. A birdbath or seed dish will attract a range of Birds, but will work best if established in advance so its availability is known to local Birds. Add a few large stones to the birdbath to give flying Insects a surface to land on before taking a drink.

Different Invertebrate species can be attracted using various substances from our fridges and cupboards. Try placing a range of substances in jar lids or bottle caps at locations around your yard, ideally in sheltered locations out of the rain. It may take a few hours or few days to be found. Leave them out for the four challenge days and move them around the yard. Keep them away from the house to avoid attracting pests. Sticky substances can also be applied to tree trunks and branches. Ant species will find sugary foods (i.e. honey, jam, sugar water) and fatty foods (i.e. bacon pieces, cheese, peanut butter). Other substances that can attract various Beetles, Flies, Moths and Plant Bugs include terpenes, alcohol and methanol, fermented fruits and rotting meat.



Finding Organisms - Attracting: Moth Night
Join the Australia wide Moth Night on the 26th by turning on some outdoor lighting, setting up a white sheet and recording the attracted species. The greatest number of species will be attracted with a bright UV light source and a white sheet hung nearby. However any outdoor lighting will attract some species and the sheet can be placed on a flat surface. i.e. table below the lighting if there is no option to hang the sheet. Consider temporarily replacing an outdoor light with a UV Blacklight. This will increase the number of species attracted significantly. The light will not only attract Moths, but also some Beetles, winged Ants, Katydids, Lacewings and various other taxa. You may also get some visiting predators such as Mantises attracted by the abundant food. Many more species will be out if the evening is warm and calm.

The visitors can be photographed in place. Many Moth species can be IDed to species with a top down photo, but some may need profile and underside views. Don't forget the many smaller species 5mm long or less. With the camera as close as possible the flash may only illuminate one side of the specimen, so consider using a torch to light up the opposing side. This additional light will help to increase the shutter speed to ensure your photo is clear.

A total of 89 species of Moth have been recorded in April in the Greater Adelaide region. Familiarise yourself with some of the species you might find HERE.



Finding Organisms - Temporary Homes
In the days leading up to the challenge place wooden, cardboard or metal sheets on the ground around your yard. Some in cool and damp protected areas, some in exposed sunny areas. Various Invertebrate species will seek shelter under these and if lucky they will attract predators, in particular Lizard species. The sheets in cool damp areas may attract Frogs. The longer they are left in place, the more established the homes become.

Finding Organisms - Traps
There are many simple methods for trapping Invertebrates with varying degrees of success. A Pitfall Trap is a container or jar buried flush with the surface of the soil that Invertebrates crawl into but cannot get out. A simple Funnel Trap and Side-Door Trap can be made from empty soft drink bottles (See Traps section HERE for construction details).

Collecting & Photographing
Specimens can be photographed in situ, but this doesn't always allow for photos sufficiently clear or from the necessary angles for identification purposes. Consider having available a container to temporarily detain any Invertebrates found. These specimens can then be photographed on a white sheet or similar in more controlled lighting. For the more active specimens, place the container in the fridge for a while to slow them down. They will recover quickly as they warm up and can then be released after suitable photos have been taken.

Frequency of Observation
Although there is no official rule, it is generally considered that a species should only be recorded once per day at each location. There is little value in uploading a record of every single Bird that visits your yard each day. However if you do have males, females and juveniles visiting, each can form a separate observation. And there is nothing stopping you recording the same species in your yard at different times of the day. Perhaps you'll uncover the movement patterns of your local species.

Geoprivacy
If you wish to avoid having your property location visible, set all of your observations to "Obscured" when uploading them. You will still be able to see the exact location, but it won't be publicly visible. If you still wish to have the exact location available to those using the data for research and conservation efforts, go to your Profile, select "Edit Account Settings & Profile", scroll down and change your "iNaturalist Network Affiliation" to "iNaturalistAU". This will ensure the exact location is made available to the Atlas of Living Australia, but still remains private.

So how many species could be found in your yard?
The answer is probably a lot more than expected. Although I have not attempted many of the methods suggested above which would no doubt add many more species, I have recorded 291 species from a 750m2 suburban property with most of those being recorded in the last 18 months. 135 new species have been added in the first 101 days of this year. The total includes 18 Birds, 3 Reptiles, 2 Mammals, 18 Spiders, 35 Beetles, 6 Cockroaches, 24 Files, 17 True Bugs, 30 Ants, Bees and Wasps, 5 Butterflies, 113 Moths, 2 Mantises, and 5 Grasshoppers, Crickets and Katydids.

How many species will you find during the City Nature Challenge?
This will depend on many of the factors above and how much time you choose to put into it. Try a different approach on each challenge day. Spend an afternoon sitting in the sun watching your birdbath with your camera nearby. Get out your torch after dark and see what has come out of hiding. Spend some time with the flowering Plants in your yard spotting pollinators. Any way in which you choose to contribute to iNat and the City Nature Challenge is the right way. Let's see how many species we can record across Australia in only 4 days.

Posted by cobaltducks cobaltducks, April 16, 2020 05:37

Comments

Great information @cobaltducks. Lots of useful tips I can try.

Posted by adel_plainsgirl about 2 years ago (Flag)

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