Where I am, in the cooler Northern hemisphere, thoughts are turning towards the winter for many bird keepers. That said, temperature is an issue for birds worldwide. As bird keepers is it time we start thinking about what feels good rather than just what permits survival?
The main focus of the conversation here will be around colder temperatures, mainly because this is the most common temperature related concern that crops up in aviary birds, often in temperate climates.
There has for a long time been a die hard section of aviculturists who seem intent on gloating about their birds being cold as if it were impressive. I have never understood this to be honest as it makes about as much sense as bragging about starving your birds to the lowest possible level. The first time I really became aware of this culture was reading an article many years ago where the late Clinton Keeling wrote about a disturbing example of hearing a bird keeper showboating about his Sunbirds pecking at their frozen water bowls trying to get to water. This for a serious bird keeper is not a flex as anyone who knows Sunbirds will know that beside the obvious cold exposure, as a (mainly) tropical nectivore, access to drinking water as well as nectar is important at all times - a dehydrated bird without access to water may attempt to hydrate with nectar and suffer a vitamin overdose as a result.
I am not hoping to reach the remaining few folks out there who think like this, but more the keepers who may be asking these questions and wondering what the answers are. The answers are simple and easy, there is no great wisdom to be learned here other than research and forward thinking.
First things first, I understand that heating an entire aviary or enclosure is not always possible or favourable, there are many outdoor experiences of value to our birds, wind, rain and stimulation, that they would miss in a completely controlled indoor environment. Add to that, birds are warm blooded and can generate their own body heat, so can safely and comfortably spend time outside in winter. It does seem to me however that offering an area, a "bubble" if you like, of wild conditions provides a great comfort to birds.
There is an ongoing myth that all birds can "acclimate" and those that cannot are somehow not "hardy", this is an old thought process derived from horticulture and has never really evolved beyond that for some. The reality is that some species can have their biology non-fatally shoehorned into certain conditions and the others?... well they die as they are not "hardy". It is odd that aviculture is one of, if not the only taxa that is treated in this peculiar way, and it is entirely cultural. If you were to leave a dog outside until the limits of frostbite, people would have some very serious things to say about it.
Many native birds from temperate regions are able to store large amounts of fat to help with cold or migrate, which tends to propagate the legend that all birds can or should do the same. In reality many of these birds are migrating purely to escape the cold, as it is clearly not where they are at their best. True, some species store fat and can bumble through a cold winter, but are more likely to reduce their activity levels, use up protein reserves from muscle before they use the fats - then come spring, are not in their best condition to breed, which in the end is unhelpful.
When teaching students about temperature and birds, my simplest line has always been "as a human you can sleep every night of winter on a park bench and survive it, but would you WANT to?"
Moving on from the negative ideas, lets look at how we can rethink temperature (which is not the only parameter to worry about, but the one we will focus on here). If we start from the ground up, like so many things in forward thinking bird care, it requires us to be honest with ourselves, and honest to what data shows us. Let me give you some examples of this.
Often we look for a golden temperature range for birds, but the truth is, each species has their own, and as you start looking at it objectively you will see how some species have fared better than others and this may be because of these specific tolerances.
To understand optimal conditions we have to reframe our approach in a simple way. We don't ask what do we think is correct, we don't ask what do others think is correct, we ask what conditions does this species encounter in the wild and decide a reasonable range from that.
When I'm stumped and want some scientific insight I rely on climate models and overlay natural known ranges, this tends to show interesting correlations that sometimes match up to the struggles specific species have in human care. A nice example is White cheeked turacos, a species that is probably the most common species of Turaco in temperate aviaries and seems to do very well compared to some of the others when kept without heat. Looking at it's wild distribution and habitat shows you that they tend to frequent cooler, more highland juniper forests, which might explain how it has fared so well as an aviary bird in temperate regions - it's natural adaptations have worked favourably in this case. A counter example is Marabou stork, these birds often struggle in colder temperatures and their wild distribution reflects this. Distribution mapped against climate shows a clear avoidance of more temperate zones in Africa - the general gist you can infer from that is that there's a good reason they don't want to be there when left to their own devices.
The most common issue is being too cold, truly tropical birds not given some access to warmth do not necessarily have the decency to die straight away like a reptile might, but they will slowly fail to thrive and likely sooner or later die from some mystery illness or parasite, by which point cold exposure may seem unconnected. The honest truth is a bird in good health has better immune resistance, and stable conditions will help facilitate this and take one extra worry off a the bird's plate so to speak.
Each species has it's own heating needs and your particular facilities will be subject to your own tailored approach with the technology you use. If you can be honest with yourself, this is easy to establish once you have your target numbers. You don't need to even heat the whole building, but maybe a 50% area of the right climate will suffice, keeping in mind that choice is the key to good welfare.
Outside of the dreaded cold, there are other extremes that can be an issue for some species. Conversely birds from cold climates suffer equally when exposed to too much heat, this is why it's so important to tailor your offerings by species. Antarctic penguins, some Arctic falcons and Snowy owls for example, are well known to be very vulnerable to Aspergillus infections in temperate and tropical climates, purely because the conditions they come from naturally are generally too cold to allow such pathogens to thrive. They also suffer heat stress in the hottest weather and in the same way that tropical birds suffer with the cold, they are liable to fall victim to stress and disease if not cooled sufficiently. Wealthy facility owners in hot countries like Saudi Arabia spend many millions building cooled indoor facilities to fly their temperate/Arctic falcons under normal conditions for them. Whilst we can't all be that wealthy, we can still tailor our husbandry and collection planning around this.
One unique example is found amongst waterbirds, which have unique realignments of the blood vessels in their legs to allow them to recycle heat back into their body rather than lose it via their feet in the water. This is often used as an excuse to allow birds to get very cold, but again, the honest, species specific approach still rings true, as these adaptations are evolved to counter water temperature and not air temperature.
Where does this bird come from? An Eider species form the Arctic will only want a simple shelter from extreme conditions, having brilliant adaptations to repel cold, but a tropical Pygmy goose by comparison will struggle in extreme cold and not thrive. The truth is that using taxa groupings such as "waterfowl" or "pheasants" to decide husbandry is old fashioned, lazy and erroneous. Each of these species have millions of years of evolution behind them designed to help them thrive in certain conditions that a few generations in human care will not undo.
I'm not going to delve into specific technology here as that is best done by the individual based on their species and circumstances, but I just want to put forward the idea that the answers we are looking for are there and easy to find if we just research and observe our birds. Using a lack of frostbite as your benchmark for cold tolerance is frankly very cruel.
There are a few other criteria that are important and connected to temperature, but they warrant their own conversations and can't be done justice here.
To simply recap this process -
Temperatures need to be species specific to allow for optimal biological process.
What would the comfortable temperature be in the wild and how can you offer an area of this?
What are your birds saying about it and why?
If you're still in doubt, ask yourself, if you offered a bird a simple heat lamp/source in a localised spot, would/do they use it? If they would/do then you have the honest answer right there.
Until next time, keep listening to the birds and giving them your best.
C.