The importance of position effects.
Gary Fitt, Brisbane.
Whenever we introduce new foods to our birds it can take time for some species to sample the new item and become familiar with its taste and texture. Some species readily accept anything new; Parrot finches or canaries are good examples, but many species are more finicky and take time to adapt.
In an earlier article on this topic Mike Fidler discussed the various techniques that can be used to introduce your birds to new foods, including supplements such as those from NFB –website- “Introducing-New-Food”. There is also a short video on the topic on the NFB website introduction of new foods. Here I explore an unusual factor you might need to consider when getting birds to try something new.
I have been using NFB supplements – PRIMA and MICRONUTRIENTS – for about 4 years with several of my aviaries. My daily feed consists of multiple choices of softfoods (frozen green seed + supplements), livefoods (maggots and mealworms), greenfoods and other food types.
These are fed in a tray on a ledge about 1.1 metres above the ground just inside a feeding door. Birds in most of my aviaries are happy to take their daily treats this way. Birds such as Parrot finches, longtails, or crimsons will eat anywhere you place their food.
However, during early 2017 I set up one of my 10 breeding aviaries with 4 pairs of Pictorellas and 4 pairs of White eared Masks. Surprisingly this aviary didn’t seem to touch it’s dish of frozen green seed mixed with PRIMA and MICRONUTRIENTS, where as every other aviary did. What was going on? I decided to experiment to find out.
I recalled that Pictorellas in particular feed on the ground and as Mike had mentioned previously some birds have a positional preference for where they feed. In the wild some species feed on the seed heads of growing grasses and are agile at perching on vertical stems to access the seeds (Yellowrumps, Chestnuts, Stars, Crimsons, Siskins all do this well). Others feed on fallen seed on the ground (Blackthroats, Painted, Pictorellas among others). So I tried placing their dish of frozen green seed and supplements on the ground, near their tub of crickets. Bingo, they ate the seed and supplement. I then decided to conduct a series of experiments to measure how much of the green seed and supplement was consumed in the two positions. I placed a measured amount of supplement mix (15-18 gms) into two dishes and placed one on the ledge and one on the floor and left for 24 hours. I then reweighed the remaining food in each tray. Because the frozen green seed/supplement mix is moist, part of the weight change over 24 hours could have simply been due to themix drying out. So I used a third dish as a control which also had a measured amount of supplement mix but simply sat outside the aviary. Any weight change of this dish was due to drying and I used that amount to adjust the final weights of the two test trays. So I was able to calculate % consumption of the supplement mix adjusted for natural weight loss in the two positions.
This simple experiment was repeated on 12 occasions from April 2017 to January 2018 to see how consistent the difference was. The figure below shows the results, with % consumption up on the ledge in blue and on the ground in orange. Obviously the rate of consumption will vary over time depending on whether the birds are breeding and how many there are in the aviary.
It is clear that consumption was greatest on every occasion from the food dish on the ground with between 30% and 75% of the food consumed as measured by weight change. By contrast the consumption from the dish on the ledge was always lower and ranged from 0% to 40% consumption. There were occasions where quite a bit was consumed on the ledge, but it was never more than 50% of what was consumed on the ground. Averaged over all the trials the daily consumption was 17% on the ledge and 60% on the ground.
So there was a strong positional effect of where these birds preferred to feed on supplements and this continued for many months and continues to this day (August 2018). The birds have not progressively adjusted to taking supplements on the ledge. Clearly this is another factor you might need to work on when getting your birds to try new foods. For some species it could be an important factor to consider.
The interesting thing about this aviary is that the Pictorellas, Masks and Jacarinis were quite happily consuming maggots on the ledge, but clearly like their softfood on the ground.