How much do domestic and wild animals compete?

Submitted by editor on 21 November 2017.

 Herfindal et al.

How does the overlap in the niche of wild and domestic animals vary in time, and are wild animals affected by the presence of domestic animals? Such questions have received increased focus in wildlife management, as the abundance of wild and domestic animals have increased. Both groups are of high economic importance, but negative interactions may occur due to for example resource competition and disease transmission. In our paper: Weather affects temporal niche partitioning between moose and livestock, we investigated niche relationships among a wild ungulate, the moose, and two free-ranging domestic ungulates, sheep and cattle, which are sharing the same range during summer.

In large parts of south-eastern Norway, moose, sheep and cattle use the same forest ranges during summer, and the droppings in this picture indicate they don’t mind being close. However, our data on habitat use tell a more complicated story.

Using data from GPS-collared individuals and a modification of the ecological niche factor analysis (ENFA), we quantified the width of each species' realised habitat niche and the distances between species' location in the realised habitat niche space. Moose and sheep were closer than moose and cattle, and the niche distances were longer during the twilight hours. However, these relationships were affected by the weather conditions, as niches of wild and domestic animals were closer at higher (during day) or lower temperatures (during night). In contrast, high precipitation was associated with the species niches being longer apart during daytime.

Mighty rather than flighty sheep? Our data suggest that sheep that are free-ranging on forest pastures may in fact partly displace moose from the habitat.

As moose habitat utilisation was closer to that of sheep than cattle, it was not surprising that the niche width of moose was more narrow when the niche distance to sheep was lower, while the niche distance to cattle did not affect moose niche width. This suggests that moose avoided certain habitats in periods when they were utilised by sheep.

Cattle are large-sized grazers and often used open patches of more pasture-like areas within the forest. Such areas have lower foraging value for browsers like moose, which may partly explain that we found a longer niche distance between the two species

In this study, we show the temporal variation in niche partitioning in an ungulate community, and document how the utilisation of habitats by a wild ungulate was modified by the habitat use of domestic ungulates. This is a first step in understanding the interactions between wild and domestic animals. However, further research is needed to understand the fitness consequences of the interactions observed. 

The study was part of the project "Intensified harvesting of forests – implications for enterprises related to wild and domestic ungulates", funded by the Research Council of Norway. Data on domestic animals was available through a close collaboration with local farmers, whereas moose data were from the moose marking project in Akershus, Norway. 

The authors through Ivar Herfindal

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