Natural areas are vital for biodiversity and ecosystem health, but effective management is a delicate dance. While interventions are often crucial for establishing and maintaining thriving native habitats, they can also have unintended short-term impacts on wildlife.
The good news? With informed strategies and precise timing, we can achieve substantial long-term benefits for both the landscape and the incredible species that call it home, often mitigating those near-term impacts.
At Natural Communities, we specialize in ecological management that prioritizes both habitat restoration and wildlife protection. This article will delve into common management techniques and how to apply them intelligently to safeguard rare and endangered species.
Why Management is Non-Negotiable for Healthy Ecosystems
Imagine a beautiful prairie, teeming with life. Now, consider what happens if it's left completely alone. Often, without intervention, invasive species can quickly outcompete native plants, woody vegetation can creep in, and the very structure vital for specific wildlife can be lost.
This is where active management, such as mowing or invasive species removal, becomes critical.
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For Prairies: Establishing and maintaining healthy prairies, woodlands, and wetlands often requires active management. In the early stages of prairie establishment (first, second, and sometimes even third years), regular mowing is essential to control aggressive annual and biennial weeds, and even some perennial invaders. Without this crucial step, the desired native plant community may never take hold, leading to a degraded habitat.
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For Woodlands: Similarly, in woodlands, the removal of invasive woody material – be it non-native trees or brush – is paramount. This management often aims to foster the growth of large, mature native trees, such as oaks with their deeply furrowed bark. These specific characteristics are critical for providing ideal roosting habitat for federally endangered bat species, as we'll discuss below.
Ultimately, by managing natural areas, we ensure the correct structure, plant composition, and overall health that native wildlife depend on. Without this management, many imperiled species would face even greater threats to their survival.
Safeguarding Grassland Nesting Birds: Mowing with Purpose
Grassland nesting birds are among the most imperiled avian groups, largely due to habitat loss and fragmentation. These species require specific short-to-medium grass structures for successful nesting. Mowing, when done incorrectly, can be devastating to their nests and young. However, when strategically applied, it's a vital tool for creating and maintaining the very habitat they need.
The No-Mow Zone for Nesting:
Generally, mowing during the primary grassland bird nesting season should be avoided. In Illinois, the Illinois Department of Natural Resources (IDNR) recommends avoiding mowing between April 1st and August 15th to protect these vulnerable birds. For more detailed information, visit the IDNR website on grassland bird conservation: IDNR
The Cornell Lab of Ornithology also emphasizes the importance of leaving grasslands undisturbed during the breeding season, advocating for delaying mowing until after young birds have fledged. These dates are regionally specific, so it's always best to consult your local state wildlife agency for precise recommendations for your area.
Mowing for Establishment and Woody Control:
Sometimes, mowing during the traditional "growing season" is unavoidable, especially when establishing new prairies or controlling encroaching woody species. In these instances, informed techniques can minimize harm:
- Prairie Establishment: If you are establishing a new prairie and need to mow to control annual, biennial, or even perennial weeds, the best approach to avoid creating a "sink" situation (where birds nest and then their attempts are destroyed) is to start mowing early in the season, before April 1st, and continue mowing regularly throughout the growing season. This continuous disturbance makes the habitat temporarily unsuitable for nesting, thereby discouraging birds from setting up shop in an area that will be actively managed. In the long run, this established prairie will provide significantly more beneficial habitat.
- Controlling Woody Species: When controlling woody encroachment in a prairie using mowing, it's often possible to wait until after the primary nesting season for grassland birds. In Illinois, for instance, you can typically resume mowing for woody species control after August 15th, as per IDNR guidelines. This allows you to achieve your management goals while largely avoiding peak nesting activity.
Protecting the Rusty Patched Bumble Bee: Mindful Mowing in High Potential Zones
The Rusty Patched Bumble Bee (*Bombus affinis*) is a federally endangered species, and its survival depends on the availability of diverse floral resources throughout the growing season. If your property falls within a "high potential zone" for this critical pollinator (you can check the U.S. Fish and Wildlife Service's (USFWS) interactive map here: USFWS Rusty Patched Bumble Bee Map
Similar to grassland birds, while establishing a healthy prairie ultimately provides vital long-term benefits for Rusty Patched Bumble Bees, initial management can pose a risk. The goal is to make the habitat less suitable for nesting during critical periods:
Targeted Mowing: If you are in a high potential zone and need to mow for prairie establishment or invasive species control, the USFWS generally recommends beginning mowing **early in the season (around April 15th - *please verify exact dates on USFWS site*) and continuing through the end of the growing season (roughly September 1st - *please verify exact dates on USFWS site*).
Mower Specifications: To allow any foraging bees to escape, the USFWS recommends mowing at a speed of less than eight miles per hour. Additionally, mowing should be done at a height of above eight inches. This higher cut allows for some floral resources to remain and gives bees a better chance to avoid the mower.
Remember, the aim of this temporary mowing strategy is to prevent the area from becoming prime habitat during establishment, thus avoiding negative impacts. In the long run, a diverse and healthy prairie is substantially more beneficial for these critical pollinators.
Conserving Federally Endangered Bats: The Right Time for Tree Work
The Midwest and Mid-Atlantic regions are home to several federally endangered bat species, most notably the Indiana Bat (Myotis sodalis) and the Northern Long-eared Bat (Myotis septentrionalis). These bats rely on specific tree characteristics for their summer roosting (raising young) and foraging.
Cutting down trees, especially those with exfoliating bark or cavities, during their active season can be detrimental, as it can directly harm or kill bats and their pups.
Legal Protections and Recommendations:
The protection of these bats is not just a recommendation; it's often a legal requirement under the Endangered Species Act. The U.S. Fish and Wildlife Service (USFWS) provides strict guidelines for tree removal in areas where these bats are known or suspected to be present.
Avoid Active Season Tree Removal: Generally, the USFWS recommends avoiding the cutting of any woody material (trees or invasive brush) that could serve as bat roosting habitat during their active season, which typically runs from April 1st to October 31st. This is when bats are emerging from hibernation, migrating, forming maternity colonies, and raising their young.
Strategic Invasive Brush Removal:
While the restrictions might seem challenging, invasive brush removal is a critical management activity for creating healthy woodlands. By clearing out dense, non-native undergrowth, we can promote the growth of those large, mature native trees – particularly oaks with deep-furrowed bark – that are ideal roosting sites for these endangered bats.
Therefore, the key is to schedule invasive woody removal activities during the bats' hibernation period, typically from **November 1st through March 31st**. By conducting these essential management tasks during the dormant season, you ensure the health of the woodland for the long term while avoiding direct impacts on these protected species during their most vulnerable periods.
Informed Management for a Brighter Future
The examples above highlight that natural area management is not about choosing between healthy ecosystems and protected wildlife. Instead, it's about making informed, strategic decisions that consider both short-term impacts and long-term gains. By understanding the specific needs and vulnerabilities of species like grassland birds, the Rusty Patched Bumble Bee, and endangered bats, we can implement management techniques that are effective, responsible, and ultimately lead to thriving natural communities.
**Always remember:** Ecological recommendations and guidelines can change. Please check the **U.S. Fish and Wildlife Service website and your local state wildlife agency websites for the most current and regionally specific information.
Do you have specific questions about managing your natural area for particular species, or are you looking to establish a native habitat responsibly? At Natural Communities, we offer free phone consultations to help you navigate these complex but rewarding challenges.