American wildlife ecologist Craig Downer says wild horses and donkeys can make valuable contributions to Australian ecosystems in many different ways. He described them in this poster presentation at the Ecological Society of Australia annual conference in 2014.

Wild horses can complement an ecosystem, or life community, in many direct and obvious as well as more subtle ways. This they do when permitted their natural freedom to move and interrelate over a sufficiently extensive intact habitat and time period.

Dietary benefits, buildings, dispersing viable seeds

Equids possess a caecal, or post-gastric, digestive system. This enables them to take advantage of coarser, drier vegetation and, through symbiotic microbial activity, to break down cellulose cell walls to derive sufficient nutrients from the inner cell without overtaxing their metabolism. In drier regions, this can give equids a distinct advantage.

Consumption by equids of coarser, drier vegetation can greatly benefit sympatric, pre-gastric (ruminant) herbivores, and energize and enrich the ecosystem as a whole. By recycling chiefly the coarse, dry grasses as well as other dry, withered herbs, forbs and bush foliage, the horses and burros expose the seedlings of many diverse species to more sun, water and air, thus permitting them to flourish. The latter can then be consumed by ruminants (see R.H.V. Bell 1970).

Of great importance is the contribution by wild equids of significant quantities of partially degraded vegetation in the form of feces deposited on the land. These droppings provide fodder for myriad soil microorganisms; the resulting fecal decomposition builds the humus component of soils, lending ecologically valuable texture and cohesiveness. As feces slowly decompose, they gradually release their nutrients over all seasons and, thus, feed the fungal garden that exists in soils, thereby increasing the soil’s absorption of water – that vital limiting factor in semi-arid and arid regions.

Equid feces lend more sustenance to decomposers and food webs that involve mutually sustaining exchanges among all classes of organisms. The latter include many diverse insects, birds, rodents, reptiles, etc. This could help bolster many native species in Australia.

The less degraded feces of equids contain many more seeds that are intact and capable of germination and from many more types/species of plants when compared with ruminant grazers. Thus, the horses’ wide-ranging lifestyles can greatly assist many plants, including Australian natives, in dispersing far and wide and, so, in filling their respective ecological niches. This enriches the food web and allows a greater diversity of animal species, including Australian natives.

Behavioral benefits

Horses aid myriad plant and animal species by their physical actions. As an example, breaking of ice with their hooves during winter freezes allows other animals to access forage and water. Many of these would otherwise perish. Similarly, they open trails in heavy snow or through heavy brush, allowing smaller animals to move about in search of food, water, mineral salts, shelter, warmer areas, mates, etc.

A little-recognized fact is that the wallowing habit of wild equids creates natural ponds whose impacted surfaces become catchments for scant precipitation or summer cloudbursts. These provide a longer-lasting source of water for a wide diversity of plants and animals. This can even help to create an intermittent riparian habitat for desert amphibians and many other desert species including those of the Australian Outback. Ephemeral plants that quickly flower and set seed, including many composites, are benefited from these catchments – especially valuable in regions with clayey soils.

Wild horses also locate water seeps through their keen sense of smell and enlarge these through pawing during critical dry periods of the year, even digging down to the sources at rocky fissures. This allows many other species to access water, species whose individual members would otherwise perish. For these and many other reasons, wild equids should be treated as keystone species that contribute positively in a variety of ecological settings.

Role as prey

Wild horses are natural prey of certain carnivores and omnivores including in Australia dingoes, crocodiles, and wild dog packs.

Late today the Legislative Council in the Parliament of Victoria moved and passed a motion to cease the Labor Government and Parks Victoria's policy of shooting Brumbies in our National Parks.

It is a significant step for all of us who have fought to save these iconic high-country horses.

This vote in effect says and sends a very clear message to both the Labor Government and Parks Victoria to get back to the table and engage and consult with Victorians. To engage and consult with the organisations who have in the past and are willing to continue into the future to offer solutions that balance the environmental imperatives and the cultural and historical significance of these horses. I too am ready to engage in that process in a mature and considered way in order to find an appropriate way to manage our brumby population.

Some of those organisations have been pleading with the Government and Parks Victoria to do just that including and not exclusive to; Australian Brumby Alliance, Alpine Brumby Management Assoc, Benambra Brumby Runners, Barmah Brumby Preservation Group, Australian Brumby Association, Victorian Brumby Association plus a number of other qualified professional horse breakers and managers.

This is a small victory in this battle but we should celebrate and acknowledge all those people from all walks of life, from across the nation and indeed the globe who have stood up to be counted, who have continued to offer reasoned debate in the face of the massive and well-oiled machinery of government. And especially to my parliamentary colleagues in the Legislative Council whose eloquence and passion won the day.