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Birds on the Range
July, 2023
Zachery Holmes, Graduate Student, UF/IFAS Range Cattle Research & Education
Center
Intended Message: How smart cattle management can
aid avian conservation.
Florida’s habitats and wildlife evolved with fire. As
the lightning capital of the world, it is not hard to imagine a time,
pre-European settlement, when frequent wildfires swept across peninsular
Florida. These fires kept hardwood encroachment at bay and maintained
landscapes such as wet and dry prairies, pine flatwoods, and longleaf pine
savannahs, landscapes that we broadly call grasslands. These grasslands
provided ecological niches for a variety of wildlife species. These species
thrived in areas with little to no canopy cover and a rich mosaic of low
growing groundcover. As human population continued to increase in Florida,
the rate of wildfires decreased through fire suppression by humans and many
of these landscapes became less suitable for grassland-dependent species.
For example, grassland birds are declining faster than any other type of
bird across North America. This is true in Florida as well, where several
grassland bird species are either state or federally endangered species, and
many others are experiencing declining populations.
From a conservation perspective, the potential solution
to these declining grassland avian populations comes from a surprising
source: cattle. In peninsular Florida, active cow/calf operations occupy
much of the land that were historically prairie and pine flatwood habitats.
Furthermore, having cattle on the land, in conjunction with typical land
management actions that occur with these operations, creates a similar
habitat structure that is conducive to many of these declining avian
species. However, like most things, it is complex. While cattle and land
management tasks do create suitable habitat conditions for many grassland
species, cattle operations can quickly become an ecological trap for species
that are already in decline. An ecological trap occurs when animals are
drawn to an area of apparent suitable habitat, only to be faced with
unsuitable conditions that might affect survival. For example, grassland
birds can be drawn into a pasture habitat only to perish because it was
mowed during the breeding season.
To
avoid ecological traps and allow pastures and rangelands to become suitable
habitat for grassland-dependent birds, simple changes can be made to
existing practices that can dramatically aid grassland bird populations. As
examples, I will illustrate this fact with three grassland bird species: the
crested caracara (Caracara cheriway), the southeastern American
kestrel (Falco sparvarius paulus), and the northern bobwhite (Colinus
virginiana). The crested caracara is a federally threatened species of
falcon that exclusively utilizes native prairie and early successional
habitats, including pastures and rangelands in south-central Florida. As a
large falcon species, they are frequently spotted, although little is known
about their full life history and reproduction. Caracaras nest almost
exclusively in live cabbage palm trees (Sabal palmetto), therefore
leaving these trees standing in the field can increase nesting opportunities
and aid overall population totals. Similarly, the southeastern American
kestrel is a state listed subspecies that breeds in Florida. Kestrels are
obligate secondary cavity nesters, meaning that they only nest in existing
cavities and do not make their own. Natural cavities are typically formed in
dead trees, called snags. Therefore, leaving dead trees on the landscape can
support all cavity nesters, including kestrels. An even more proactive
approach is erecting nest boxes that will encourage kestrel nesting
opportunities and population growth.
The
northern bobwhite quail historically had a wide range throughout Florida,
but the species has experienced significant declines due to fire suppression
and habitat degradation. Northern bobwhites are considered a grassland
species; however, their habitat preferences also include upland pine
habitats, scrub, and agricultural fields. During the breeding season, they
use early-successional shrubs and saw palmetto clumps to nest. As both a
declining species of conservation concern and a popular game species,
increasing bobwhite population numbers on the landscape is imperative. Land
management actions that encourage shrub growth during the breeding season
can increase northern bobwhite populations, such as allowing fence lines to
become shrubby or restricting mowing outside of the breeding season. These
are just a few examples of land management actions that can positively
affect declining grassland avifauna. Rural landowners and active cattle
operations can continue to provide refugia for these species.
As Florida continues to grow in population, many cattle
ranchers and rural landowners are facing ever-increasing pressure to sell
land for development and urban sprawl. Therefore, it is imperative that
rural landowners and cattle operators understand the significance of their
property from all perspectives, including the benefit to wildlife and
declining grassland bird populations. Furthermore, the conservation value
should add to the myriad of existing reasons to conserve active cattle
operations and rural land ownership. However, to claim their benefit to
wildlife and grassland birds, we must ensure smart cattle and land
management practices are implemented to avoid creating ecological traps.