Town roo, country roo: a comparison of behaviour in eastern grey kangaroos Macropus giganteus in developed and natural landscapes

Abstract

Many species have adapted their behaviour to survive in anthropogenically developed environments (hereafter referred to as developed). Eastern grey kangaroos Macropus giganteus are common in developed areas, however very few studies have evaluated their behavioural adaptations to developed landscapes. This study compared the behaviour of eastern grey kangaroos in a developed environment to those surrounded by a natural environment. Data were collected using infra-red camera traps that recorded one minute videos. Population density was calculated using pellet counts. The population of eastern grey kangaroos at the developed site had a higher density, spent more time in larger groups, and had an earlier peak activity time than those at the natural site. More vigilance and less feeding were observed at the developed site. A positive relationship between population density and group size was observed. The higher population density at the developed site is likely to be due to increased resources and restricted dispersal. Kangaroos in developed environments may be active earlier in the day in response to human activity occurring later in the day, and artificial lighting (street lighting) likely impacted nocturnal activity. Increased vigilance may be due to increased human activity, and visual barriers in developed landscapes that reduce the line of sight. Reduced feeding time is probably due to the increased nutritional content of pasture grasses at the developed site. Knowledge of the behavioural differences of kangaroos in developed areas will assist in designing management strategies.

Eastern Grey Kangaroo (Macropus giganteus) Vigilance Behaviour Varies between Human-Modified and Natural Environments

“…Prior to this study, the effects of urbanization on eastern grey kangaroos vigilance has only been investigated once, when comparing two populations that were found in close proximity to each other [28]. The results from our study concur with the former study, which observed a higher time being spent vigilant at the developed site as compared to the natural.…”

The genetic relatedness of a peri-urban population of eastern grey kangaroos

“…Research was conducted at Yarramundi Paddocks (33°36′47.85″S/150°43′47.429″E), Western Sydney University’s (WSU) Hawkesbury campus as described previously [ 15 , 19 – 21 ].…”

“…Unfortunately, the kangaroos at the study site had a very large flight distance and were extremely difficult to capture to obtain blood samples, hence tissue samples were obtained opportunistically from road-killed kangaroos, which proved to be a more effective and non-invasive method of collecting samples for DNA extraction. The population density of kangaroos inhabiting the site was previously estimated as 4.6 kangaroos/ha [ 21 ], hence 1416 kangaroos were estimated to be utilizing the site. Based on the estimated population size at the site, this sample size accounts for less than 2% of the population, hence as this is a small sample of the larger population the high level of relatedness between individuals was not expected.…”

Kangaroos in peri‐urban areas: A fool’s paradise?

“…2018b), although this may have been influenced by the short tracking duration (≤2 months). Green‐Barber and Old (2018) reported larger ranges (˜170 ha) for two males tracked for almost two years in Richmond NSW.…”

“…There is also some evidence of kangaroos adapting to the peri‐urban environment by modifying their activity patterns. Kangaroos became active earlier in the morning at a peri‐urban site than at a more natural site (Green‐Barber & Old, 2018), but data from additional sites are needed to confirm a general adaptive response.…”