The Cook County, Illinois, Coyote Project

 

 

     
  Territories and Home Ranges  

 

 TERRITORIES & HOME RANGES

  • Activity Patterns in Urban Environments

  • Home Ranges and Territories

  • Solitary vs. Pack Coyotes

Radio-collars allow us to identify the location of coyotes throughout the day.  Coyote locations are recorded as coordinates and entered into a Geographic Information System (GIS) in order to determine the activity patterns, home ranges, territories, and habitat selection of coyotes.

 

ACTIVITY PATTERNS IN URBAN ENVIRONMENTS

We have found that coyotes in the Chicago metropolitan area confine most of their activity to nocturnal hours, which has been observed by virtually all studies of urban coyotes, whereas in natural areas, coyotes tend to be diurnal (active during the day) or crepuscular (active at dawn and dusk).

The activity patterns of coyotes depend upon many environmental and individual factors, such as the availability of prey, avoidance of predation or human-related activities, and life-history strategies, such as hunting strategies and social organization.

 

Fig. 1.-- Patterns of activity for radio collared coyotes in the Chicago metropolitan area from 2000 to 2002. Bars represent the proportion of locations in which a coyote was active per hour of radio telemetry. Dots/lines represent the number of locations recorded per hour.

Switching to nocturnal activity patterns in urban areas may be an adaptive response that allows coyotes to minimize contact with humans, reducing risks associated with encounters while still allowing them to exploit the environment.  However, coyotes are likely to individually vary in their responses to human activity even within the same population.

Coyote responses to people may depend upon the degree to which coyotes can habituate to humans or find shelter from them.

 

HOME RANGES & TERRITORIES

Home ranges are the areas used by animals to meet their daily needs and may overlap with home ranges of neighbors.  Home range size can be an important indicator of habitat quality or the distribution of resources.

Territories are also home ranges except that they are defended from other individuals and do not overlap.  In the case of coyotes, groups (or packs) defend their territories from other groups, whereas solitary coyotes do not defend their home ranges.  Other studies have also found that territory sizes of coyotes decrease with increased urbanization given adequate food is available. In general, studies have found that urban coyotes tend to have smaller territories than rural coyotes.

Many coyote territories are associated with large parks or forest preserves, which provide an abundance of cover and food.  In these cases, the boundaries of territories will often follow the park boundaries.

However, much to our surprise, other coyotes have been able to establish territories and form packs without the benefit of large blocks of habitats.  This formation of packs and territories can even occur in downtown areas, if parks or natural areas exist in scattered, small patches. In some cases, these are coyotes that have created territories in residential areas or complexes of small parks and golf courses.

In either case, coyotes manage to defend these territories so that the territories have very little overlap, which controls their density and spatial arrangement across the landscape. This is frequently called a land-tenure system. We still have much to learn about how coyotes maintain packs in downtown areas.  See Featured Territories for examples of how some coyotes live in downtown Chicago and suburban areas.

Figure 2 shows the territorial boundary of different packs across 260 square miles, an area encompassing at least 12 cities.

Fig. 2.-- Distribution of coyote packs during 2004. The area of the map encompasses at least 12 cities over 260 square miles. Each color represents the home range of an alpha male or female that represents the territorial boundary for the pack. Some territories are fragmented as a result of the computer model used to estimate the boundaries, but it is obvious that territories have only limited overlap.

 

SOLITARY VS. PACK COYOTES

Home-Range Size: Radio-tracking revealed two different types of movement patterns among coyotes in Cook County, and these differences were related to social behavior- whether a coyote was associated with a pack (Pack Coyotes) or not (Solitary Coyotes).

·         Pack coyotes, also known as resident coyotes, are those that belong to pack.  Coyotes in a pack share a territory, which they defend together.  In Cook County, we have found that pack coyotes have smaller territories than solitary coyotes, averaging less than 2 square miles (4.95 km2) but as large as 4.3 square miles (11.1km2).

·         Solitary coyotes, also known as transient coyotes, are those coyotes that do not yet belong to a pack and therefore do not have a territory that they defend.  In Cook County, solitary coyotes range over much larger areas and have home ranges averaging 10 square miles (26.8 km2).  Unlike home ranges of residents, we have found that home ranges of transients were not composed exclusively within natural fragments, although natural land cover was still the most used land-cover type (see The Study for a map of land-cover types in the Chicago metropolitan area).

Fig. 3.-- Distribution of coyote home ranges during 2004. Light green lines represent the home ranges of solitary coyotes, while the smaller colored areas represent the territorial boundaries of packs (as seen in the previous figure). O’Hare International Airport is located in the lower right corner. The large home ranges of solitary coyotes overlap territories of packs as well as home ranges of other solitary individuals.

As the Cook County Coyote Project has progressed, we have been able to follow individual coyotes as they change from solitary coyotes with large movement patterns to social groups with small territories (and vice versa). In some cases, these are coyotes that have created territories in residential areas or complexes of small parks and golf courses.

Approximately 50 percent of the coyotes radio-collared as subadults (one to two years of age) or adults have been solitary for at least a portion of the study.

The home ranges of solitary coyotes span large areas of the metropolitan area, and they overlap extensively with pack territories as well as other solitary coyotes.

Solitary coyotes use a wide variety of habitats and can be found in virtually any part of the metropolitan area, even in downtown areas. We have observed some solitary coyotes finding mates and establishing their own territories, whereas others eventually disperse and leave the area permanently. In a few cases, resident adult coyotes have left their territories after the death of a mate.

Given the large areas traversed by coyotes and the number of roads coyotes regularly cross during their activities, it is not surprising that vehicles are the most common cause of death. Some of the roads crossed by coyotes in our study have average traffic volumes of more than 100,000 vehicles every 24 hours.  See Coyote Mortality and Disease for more.

 

Habitat Selection:  Despite differences in the size of home ranges, resident and transient coyotes both rely on using natural areas heavily and avoid urban grass, residential and urban land areas (see Figure 4).

 

Fig. 4.-- Distribution of annual home ranges of resident (yellow lines) and transient (white lines) coyotes in the Chicago metropolitan area during 2004.

 

For example, in Cook County we have found that home ranges of resident coyotes are typically associated with natural habitats, and in many cases these home ranges exist almost completely within large habitat fragments.  In these cases, the boundaries of coyote home ranges followed the borders between parks and surrounding development

However, we have also found that individuals vary in their use of habitat; 29% of our collared coyotes have home ranges composed of less than 10% of natural land and 8% having no measurable patches of natural land within their home ranges.

Despite considerable differences in the size and composition of territories and home ranges of individual coyotes, we have found that both transient and residential coyotes avoid urbanized areas.  Locations of collared coyotes indicate that they avoid human areas either by restricting their movements to boundaries of natural habitat fragments or by focusing their activities within series of smaller patches of undeveloped areas within their home ranges.  These findings support previous diet studies in our study area, which found that food items associated with natural areas (such as rodents and fruit) dominate coyotes’ diet, rather than human-related food items.

The locations of radio-collared coyotes depicted in the maps below illustrate coyote selection of natural areas and avoidance of residential areas within their home ranges.

Fig. 5.-- Variability of landscape use among urban coyotes as illustrated by patterns of use within annual home-range boundaries for 3 resident coyotes during 2004 in the Chicago metropolitan area. Each color represents the locations of 95% minimum convex polygon of a resident coyote from 3 territories. Each coyote exhibits avoidance of developed areas, despite considerable differences in territory composition.

Fig. 6.-- Radiolocations of an alpha female coyote (yellow) with a territory located in a downtown area. Her locations reflect her use of small patches of habitat, but avoidance of residential areas. The purple dots are locations of an adjacent alpha female from another pack.

  

 Fig. 7.-- Radiolocations of an alpha female coyote associated with the Poplar Creek Forest Preserve during 2000. More than 99 percent of the radio-locations are located within the forest preserve, and the animal (and pack) rarely left the park for three years.


 
 

 

The Cook County, Illinois, Coyote Project


The Ohio State University