All the world's pet dogs weigh 10 times all the world's pet cats

Interested? Perhaps not but I think the statistic in the title is mildly interesting. Perhaps the more interesting statistic is that the weight of all humans on the planet at present is 18 times more than the weight of all land based wild mammals. 

But ants weigh about four times more than wild mammals! Those pesky ants are almost weightless as individuals but there are an awful lot of them.

Infographic my MikeB.

Perhaps the more extraordinary statistic from a study (The global biomass of wild mammals) by Prof Ron Milo and colleagues of the Weizmann Institute of Science in Israel is that the total biomass in tonnage of humans is almost 18 times more than all the wild mammals on the planet combined. 

To that perhaps remarkable statistic we have to add the 630 million tonnes of livestock kept by humans and other mammals that would not exist without us such as urban rats.

As the Infographic shows you, the biomass of all land-based wild mammals is about 22 million tonnes.

2 ways to reduce your cat's hunting behaviour

There are two ways to reduce your cat's hunting behaviour and they are: providing your cat with the highest quality wet cat food which is grain-free and playing with your cat as much as possible. The advice emerges from the conclusion of a sensible study by scientists of 335 participating domestic cats in 219 households.

Feeding domestic cats wet food which is grain-free and which derives protein from meat plus play reduces predation on birds and mammals. Image: the scientists who conducted the study and reproduced here under an implied license.

The cats were split into two groups and strategies to curb their hunting behaviour. They discovered that feeding the cats with a high quality commercial food in which the protein came from meat and not plants, i.e. it was grain-free reduced the number of prey animals that the cat brought home by 36%.

Also, playing with a domestic cat for between five and ten minutes daily resulted in a 25% reduction in the same behaviour. The study is published in the journal Current Biology.

Martina Cecchetti, a PhD student of Exeter University, who conducted the study, said that despite some foods claiming to be a complete diet, they might leave the cats with a nutritional deficiency in micronutrients which compels them to hunt.

Another member of the study team, Professor Robbie McDonald, of the same university, said: "Our study shows that with entirely non-invasive, non-restrictive methods, owners can change what the cats themselves want to do."

They also concluded that when a domestic cat wears a bell on their collar to warn birds that they were being stalked by the cat, there was no discernible reduction in the birds brought back home. Further, they decided that the brightly coloured collars that you can purchase for domestic cats to reduce predation on birds were effective by 42% but they did not have any impact on predation on mammals such as mice. In other words, there was a 42% reduction in the birds brought home when the collars were worn. I have an article on that you can read by clicking here.

The study is important in two respects (1) it possibly highlights an issue with high quality complete diet wet foods, which needs to be further investigated and no doubt will, (2) there is, it seems, a connection between appetite and hunting desire.

We have constantly heard the mantra that a domestic cat's hunger is completely dissociated from their desire to hunt. But this study indicates that there is a connection between what a cat eats and the desire to hunt. And essentially it seems to say that if you provide a cat with the highest possible wet cat food they will hunt less.

It is thought that some cat foods contain protein from soy which may leave a micronutrient deficiency which the cats try and make up through hunting.

There is a general concern from both sides of the divide i.e. from cat lovers and cat haters about the predation by domestic cats on wildlife because the environment and the protection of wildlife has become a priority in the minds of many people. 

Therefore, the domestic and feral cat is under fire from environmentalists, nature lovers and ornithologists, and indeed animal lovers of all kinds. The common advice is to keep your cat inside at all times, but this also produces a deficiency in their lifestyle because cat owners tend not to substitute the natural behaviour they enjoy by hunting with play.

This is borne out in the study because one third of the cat owners participating in the study indicated that they would not continue to play with their cats as they did in the study but they will continue to feed them with premium cat food. There is therefore a reluctance to play with domestic cats. That's because it is boring for the person. Notwithstanding that, it is highly enjoyable and necessary for the indoor cat.