Expanding Survey Efforts and Refining Home Range Criteria

My study of moose populations in Wisconsin has reached an exciting milestone with new developments. Last week, I signed a volunteer researcher contract with Chequamegon-Nicolet National Forest, which will expand the scope of my survey efforts to include their vast and diverse landscapes. This new area presents exciting opportunities to explore new moose habitats, and I look forward to collecting data that will further inform our understanding of moose presence in Wisconsin.

I have also set out to create criteria to focus my survey efforts. Based on the reading I’ve done about moose movements and behaviors, I have established the following criteria to help define moose home ranges. These criteria are based on my current knowledge, and understanding and are intended to guide my efforts, but it’s important to note that this is still a work in progress. As new data is collected and more is learned, these criteria may evolve over time. It is also important to clarify that these criteria are specifically for guiding my survey efforts and do not directly correlate with the residency criteria used by the Wisconsin DNR. The DNR follows NatureServe criteria, and as I continue to learn more about the measures used within NatureServe, my approach may further adapt (NatureServe, n.d).

Criteria for Defining Moose Home Range

• Young-of-the-Year (YOY) Sightings (May–July): Observing calves during the birthing season suggests successful reproduction within the area, indicating a level of population stability.

• Multiple Moose Observed: Consistent sightings of multiple individuals in a specific area suggest that the habitat is suitable and has sufficient resources to support a resident population. This criterion is met via:

  • Multiple moose observed together in a single sighting.

  • Different sex or age classes (e.g., cow and bull, young-of-year and mature adult) documented in the same area.

  • Unique identifiers such as antler characteristics, scars, or other distinguishing markings.

• Multiple Years of Observations: Repeated sightings over several years suggests long-term habitat suitability and suggest a stable population.

• Consecutive Years of Observations: Annual sightings over consecutive years strengthen the evidence of a resident population. Although this criterion overlaps with "Multiple Years of Observations," consecutive-year observations add significant weight, making it a stronger indicator of home range and reinforcing the combined importance of both criteria.

• Observations Across Multiple Seasons:

  • Sightings in both Late Winter and Summer: Sightings in both late winter (January–February) and summer (June–August) within the same area suggest the possibility of a year-round home ranges.

  • Sightings in 3 of 4 Seasons: To account for migratory moose that may reside in the area seasonally, this criterion looks for moose in three of the four seasons. This ensures that both year-round residents and migratory moose are considered in the analysis.

  • Seasonal Definitions: For the purposes of this study, seasons are defined using meteorological timeframes:

    • Winter: December 1 – February 28 (or 29 in leap years)

    • Spring: March 1 – May 31

    • Summer: June 1 – August 31

    • Autumn: September 1 – November 30

    • Note: If a location meets both the late winter/summer and 3:4-season criteria, it will count only once toward the classification, ensuring each location is evaluated based on a single seasonal criterion.

• Observations Outside of Peak Migration Timeframes: Observing moose outside of key migration periods helps distinguish transitional ranges from potential home ranges.

  • Peak Migration Timeframes: For the purposes of this study, peak migration is defined as:

  • Peak Spring Migration: April

  • Peak “Fall” Migration: December

• Bull Observations Outside of Peak Breeding: Bull moose exhibit significantly larger movements during the rut, while cow movements remain more stable or may even show a reduction. Considering only those bull observations outside of peak breeding timeframes helps refine potential home range assessments by minimizing the influence of rut-driven movement patterns.

Scientific Basis for Home Range Criteria

• Young-of-the-Year (YOY) Sightings (May–July): YOY sightings during the birthing season are strong indicators of local home range, as female moose often select calving sites near their natal areas, supporting the concept of natal philopatry (Colson, White, & Hundertmark, 2016). In the first few weeks after parturition, cow-calf pairs exhibit restricted movement, staying close to the mother's established range. Over time, the calf's movement increases and reaches a "normal" home range after approximately six weeks (Hundertmark, 1997). Studies indicate that from June through August, cow-calf pairs make limited daily movements, averaging about 0.6 miles, reinforcing the validity of YOY sightings as an indicator of local residency (Phillips, Berg, & Siniff, 1973).

• Multiple Moose Observed: Moose are typically considered a quasi-solitary species, with most populations, except for Alces alces gigas in Alaska, avoiding conspecifics for much of the year, despite the absence of territorial behavior (Hundertmark, 1997). Given this tendency toward solitary living, the repeated observation of multiple individuals in a specific area may suggest that the habitat is suitable and provides enough resources to support a resident population. Therefore, sightings of multiple moose in the same location over time can be considered a potential indicator of a shared home range.

• Multiple Years of Observations & Consecutive Years of Observations: Moose exhibit strong philopatric tendencies, meaning they generally maintain a consistent home range over multiple years, influenced by the quality of the habitat and the availability of resources (Hundertmark, 1997). Repeated observations of moose in the same area over consecutive years suggest that the habitat meets the ecological needs for survival and reproduction, indicating long-term habitat suitability. The tendency for moose to return to the same seasonal ranges further supports the idea that repeated sightings across multiple years serve as evidence of a stable population and consistent home range use (Phillips, Berg, & Siniff, 1973).

• Observations Across Multiple Seasons: Moose show significant fidelity to their winter ranges, a behavior known as winter-range philopatry (Sweanor $ Sandegren, 1989). This tendency suggests that sightings across both winter and summer seasons may reflect a consistent, year-round home range. While some moose migrate between distinct winter and summer ranges, others maintain consistent home ranges year-round, with both migratory and resident individuals demonstrating philopatric tendencies (Hundertmark, 1997). This pattern of seasonal range fidelity is further supported by evidence that sightings across multiple seasons—whether the moose are migratory or resident—can reliably indicate home range use and patterns (Phillips, Berg, & Siniff, 1973).

Basis for Defining Migration Timing: April and December

Before reviewing the data supporting the removal of peak migration timeframes from home range criteria, I first want to outline my determination of “peak migration” timeframes.

The timing of moose migration is influenced by various factors, including environmental conditions such as snow depth, habitat availability, and the rut. Although migration patterns are variable, several studies consistently support April and December as key months for migration, specifically for spring and fall movements.

• Phillips, R. L., Berg, W. E., & Siniff, D. B. (1973) report that spring migration typically occurs in mid-April, with fall migration to winter ranges beginning in December. These timeframes align with environmental cues like snow depth and the need for rutting grounds.

• Chisholm et al. (2021) found that spring migration in British Columbia generally begins in April, with winter migration occurring between November and February, reinforcing the use of April for spring migration and December for “fall” migration. Cooley et al. (2019) also identify spring migration as starting in April, with winter migration varying from August to November depending on local snow conditions. I hypothesize that the earlier winter migration in Northern Yukon is due to deeper and earlier snowfall compared to other regions (such as Wisconsin), suggesting that local environmental factors may influence the exact start of winter migration.

• Garner and Porter (1990) observe that in the Adirondacks, spring-summer migration occurs from April to August, while fall migration, which includes the rut, spans from September to December. This aligns with the April and December migration periods identified in other studies.

In conclusion, the studies reviewed provide consistent evidence for using April and December as the peak migration months, despite some regional variability in migration timing. These months offer a reliable framework for defining migration periods across different populations.

• Observations Outside of Peak Migration Timeframes: Moose tend to follow established seasonal migration routes, with migrations influenced by environmental factors such as snow depth and forage availability. While the timing of these migrations can vary, the general patterns remain consistent, with moose moving between distinct summer and winter ranges (Hundertmark, 1997). By focusing on observations outside of peak migration periods, defined as April for spring migration and December for “fall” migration, this criterion helps differentiate between established home ranges and migration corridors. Moose consistently observed in an area outside these timeframes are more likely to be using the habitat as a year-round home range rather than merely passing through.

• Bull Observations Outside of Peak Breeding: Bull moose exhibit significantly increased movement during peak breeding times, with movement rates being as much as 10 times greater in the fall than in other seasons (Garner & Porter, 1990). This substantial increase in movement during the rut can skew observations of their home ranges, leading to their exclusion from home range analysis during peak breeding periods. Additionally, studies show that cows exhibit stable or reduced movement during the rut, making them suitable for inclusion in home range analysis during this period (Hundertmark, 1997; Phillips et al., 1973). The increased movement of bulls during breeding periods necessitates excluding bull observations from this timeframe to prevent misleading conclusions about home range use.

Home Range Scale Classification

To further explore potential moose home ranges in Wisconsin, I’ve classified home range sizes at different scales. These scales offer different views of the spatial distribution and home range patterns of moose across the region. The scales are as follows:

• Large-Scale (Township/Range - 93.24 km²/36 m²): This scale represents the broadest level of moose habitat analysis, covering large areas that may encompass several home ranges or multiple habitats. It provides insight into the general distribution of moose populations.

• Mid-Scale (Township/Range broken down into North and South divisions - 46.62 km²/18 miles²): This scale targets smaller, more localized areas and more closely aligns with the general home range size for moose, which can span up to 4000 hectares (40 km²) (NatureServe, 2021).

• Fine-Scale (~2.59 km²/1 m²): Fine-scale analysis zooms in on individual habitats, capturing home ranges within specific geographic areas. This scale is essential for understanding moose movement within their most immediate environment.

Results by Home Range Scale

Here are the current results based on the home range criteria classifications as outlined above:

• Large-Scale (Township/Range - 93.24 km²/36 m²):

  • 4 Potential, 9 Probable, and 18 Confirmed Current Home Ranges across 10 counties.

• Mid-Scale (Township/Range broken down into North and South divisions - 46.62 km²/18 miles²):

  • 4 Potential, 7 Probable, and 20 Confirmed Current Home Ranges across 8 counties.

• Fine-Scale (~2.59 km²/1 m²):

  • 6 Potential, 7 Probable, and 10 Confirmed Current Home Ranges across 8 counties.

Conclusion:

My criteria for evaluating potential moose residency in Wisconsin are still in development, informed by field observations and existing scientific research. As data collection and analysis progress, refining these criteria will be crucial to accurately understanding moose behavior and their spatial ecology in the region. The combination of sighting frequency, multi-year data, seasonal patterns, and the influence of migration periods will provide a clearer picture of moose presence and movement in Wisconsin.

Ongoing research into migration timing and home range scales will further inform the accuracy of these home range definitions. Collaborative efforts, including partnerships with entities like the Chequamegon-Nicolet National Forest, offer new opportunities to refine these criteria and expand understanding of moose in the area.

By continuing to analyze large-scale, mid-scale, and fine-scale distribution patterns, this research will help deepen our understanding of moose ecology and contribute valuable insights into their potential as a resident species. Ultimately, these efforts aim to strengthen the scientific basis for recognizing moose as a resident species in Northern Wisconsin, laying the groundwork for further investigation and providing a clearer direction for future research.

Works Cited:

Chisholm, J.D., Hodder, D.P., Crowley, S.M., et al. (2021). Seasonal movements of migratory and resident female moose (Alces alces) in North-Central British Columbia, Canada. Mammalian Research, 66, 419–427. https://doi.org/10.1007/s13364-021-00575-6 

Colson, K. E., White, K. S., & Hundertmark, K. J. (2016). Parturition site selection in moose (Alces alces): Evidence for social structure. Journal of Mammalogy, xx(x), 1–10. https://doi.org/10.1093/jmammal/gyw006 

Cooley, D., Clarke, H., Graupe, S., et al. (2019). The seasonal movements of a migratory moose population in Northern Yukon. Alces, 55, 105–130.

Garner, D. L., & Porter, W. F. (1990). Movements and seasonal home ranges of bull moose in a pioneering Adirondack population. Alces, 26, 80–85. Retrieved from https://alcesjournal.org/index.php/alces/article/view/1155 

Hundertmark, K. J. (1997). Home range, dispersal, and migration. In Ecology and management of the North American moose (pp. 303–335). Wildlife Management Institute.

NatureServe. (2025). Alces alces (moose). NatureServeExplorer. Retrieved March 19,2025 from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.104982/Alces_alces 

NatureServe. (n.d.).Conservation status categorieshttps://explorer.natureserve.org/AboutTheData/DataTypes/ConservationStatusCategories 

Phillips, R. L., Berg, W. E., & Siniff, D. B. (1973). Moose movement patterns and range use in northwestern Minnesota. The Journal of Wildlife Management, 37(3), 266-278. Retrieved from https://www.jstor.org/stable/3800117 

Sweanor, P. Y., & Sandegren, F. (1989). Winter-range philopatry of seasonally migratory moose. Journal of Applied Ecology, 26(1), 25-33. https://doi.org/10.2307/2403648