Why white-tailed deer have spots

Why white-tailed deer have spots

About now a doe is searching among the shrubs and grasses. She is looking for a site to have her fawns.

White-tailed deer fawn season will peak in the summer across the Florida Panhandle. In the first weeks of life, fawns are not able to follow their mother and spend most of their time bedding. Although vulnerable, fawns can still rely on remarkable adaptations to survive. Their spotted coat provides excellent camouflage amidst the dappled sunlight filtering through the vegetation. To avoid being detected by predators, newborn fawns also have minimal scent and the ability to suppress their respiratory and cardiac systems when predators are nearby.

In addition to these critical adaptations, vegetation cover is essential to provide fawns the protection they need from predators. A lack of ground cover makes fawns very easy for predators to see, spots or not. This cover is also critical to protect fawns from heat, especially during Florida hot summers. Ideal fawning sites have thick and abundant vegetation. In particular, early successional sites where forbs (i.e., broad-leaved herbs) and native grasses are abundant are the perfect hiding cover for fawns. While forbs and grasses are important components of fawn cover, forbs can also help improve mother’s and fawns’ nutrition. In fact, forbs can be rich in crude protein and nutrient content, with some forbs reaching more than 30 percent crude protein content. The summer is a period of exceptionally high nutritional stress for mothers and fawns, and access to high-quality forage promotes fawn nutrition and growth. Because the mothers do not usually move far from their fawns, fawning sites rich in forbs can keep mothers healthy, and provide good forage for fawns.

Knowing the challenges fawns face, here are three things you can do to help:

First, if you find fawns, do not approach them – they are most likely not abandoned! Mothers leave fawns alone to avoid attracting predators close to the fawn bedding area, but they visit them throughout the day to nurse. Interacting with the fawn may cause them stress and, if fawns are relocated by humans, they may be permanently separated from their mothers.

Second, do not mow or pay close attention when mowing. Mowing can remove good fawn cover or, worse yet, endangering fawns.

Third, it is essential to promote good fawn cover. Landowners and managers can promote fawn cover by establishing or maintaining existing early successional sites such as forest openings. Thinning and prescribed fire can go a long way to promote this vegetation structure. However, remember that it takes time for the vegetation to respond and regrow after management practices have been applied. For example, mothers with fawns will likely avoid freshly burned areas unless they are close to other areas with better cover.

Helpful links to learn more:

EDIS white-tailed deer fact sheet: https://edis.ifas.ufl.edu/publication/UW121

Fire University Podcast, Fire as a tool to increase nutrient availability for fawns and lactating does: https://fireuniversity.libsyn.com/episode-27-fire-as-a-tool-to-increase-nutrient-availability-for-fawns-and-lactating-does-ft-dr-bronson-strickland

Deer University Podcast, Predator impacts: https://deeruniversity.libsyn.com/predator-impacts-part-2

Key deer mother lactating. White-tailed deer mothers leave fawns hiding, but visit them throughout the day to nurse. Photo: Michael Cove.
A Sea of Grass Part 8 Echinoderms

A Sea of Grass Part 8 Echinoderms

Sea urchins are one of the more commonly encountered creatures when snorkeling in our seagrass beds.  At times these little pin cushions can be found in great numbers.  In some locations there have been too many and community events have been developed to remove some.  In the western panhandle they have all but disappeared.  But for many parts of the panhandle, they are a noticeable member of the seagrass community. 

Long Spined Sea Urchin
According to the Florida Department of Health, most sea urchin species are not toxic but some Florida species like the Long Spined Sea Urchin have sharp spines can cause puncture injuries and have venom that can cause some stinging. Swim and step carefully when snorkeling as they usually are attached to rocks, both on the bottom and along jetty ledges. Photo by L Scott Jackson

Sea urchins belong to the phylum Echinodermata.  The term echinoderm means “spiny skin” and is a good name for this creature.  This group also includes the sand dollars, sea cucumbers, and the most famous member, the sea stars.  Echinoderms are considered advanced and primitive at the same time.  Advanced in the sense of organ development, sensory perception, and food gathering.  Primitive in the sense that they have radial symmetry, like many of the more primitive invertebrate groups; bilateral symmetry is considered more advanced.  The entire phylum is marine, they have no freshwater, nor terrestrial members, and they do like the water salty – at least 20 parts per thousand, and some need it higher than that. 

As mentioned, the sea stars are the “star” of the group.  They usually have five arms that radiate from a central disk region.  On top there are usually small knobs or bumps which are the remnants of their “spiny skin”.  Some species, though none in our area, have elongated spines.  Beneath the arms is a radial canal which houses a series of gelatinous suckers called tube feet.  The sea star can fill these with water using a unique system called the water vascular system.  The tips of the tube feet or concave and, when full of water, can create a suction cup that is used for pulling themselves along the bottom and for grabbing food.  These canals all meet within the central disk in what is called a ring canal and the water that fills them is sucked in by the sea star through a screen-like structure on the top of the central disk called a madreporite (“screen sieve”).  The central disk is where the mouth is located, and it is located on the bottom.  Food is worked into the mouth, digested, and excreted through an anus on the top of the central disk.  Most species have some form of eye at the end of each arm and have a good sense of smell and taste. 

Sea stars are predators, collecting small organisms they are fast enough to catch (which is not many really).  But they can also take on larger slow prey, like shellfish.  When they approach an oyster, which is sessile and cannot run away, they will grab each of the valves (shells) of the oyster with one of their arms.  They will draw water into their water vascular system creating suction on the tube feet and “stick” onto the shells.  They will then force the oyster open.  Once open they will invert their digestive tract out of their body in a process called evisceration, consume the oyster, then retract the digestive tract leaving two empty shells on the seagrass bed floor.  These empty shells are often found by snorkelers – though there are other predators of bivalves. 

The Florida Orange Sea Star. Photo: Florida Sea Grant

Sea urchins differ from their sea star cousins in the way their body is laid out.  Imagine you had a five-armed sea star laying on the ocean floor.  Imagine taking each of the five arms and rolling them upwards so that the tips of each touch above the central disk.  Can you imagine this looking like a ball? A sphere?  Now cover the now exposed underside of the arms with long spines (quills) and the tube feet extend between the quills.  You have a sea urchin. 

Another difference would be the mouth.  At the terminus of each arm near the mouth is a single tooth.  With five arms, there would be five teeth.  Scientists call this set of five teeth Aristotle’s lantern and the urchin uses this to scrap algae from rocks, shells, and grass blades.  They are herbivores, moving along feeding on a variety of seaweed and seagrasses in the system. 

There is concern with many snorkelers that the quills (spines) of the sea urchin are venomous.  That is the case with some species around the world, but not in our area.  That said, they are sharp, and the purple urchin (more common in our rock jetties and artificial reefs) hurts.  Their quills are sharp and often break off in the skin causing discomfort, much like a splinter.  You do not want to handle them, but if you do – handle them with care. 

Sand dollars are close cousins of the sea urchin and are in the same class (Echinoidea).  If you can imagine taking a round sea urchin and squashing it flat like a pancake, you have a sand dollar.  There are also echinoderms in this group that are not as round as sea urchins, but not as flat as sand dollars and are called heart urchins, or sea biscuits.  These can be found in grassbeds at the eastern end of the panhandle, but are more common in south Florida. 

The sea cucumber is an echinoderm more often found in rocky or coral reef communities, but there are some found in the seagrass beds.  To see the relationship between them and their cousins, imagine taking a round sea urchin, lie it on its side, and extended the body so that it is no longer a round ball but an elongated worm-looking creature… sea cucumber.  These are primarily scavengers and deposit feeders within the community. 

long, round brownish invertebrate
Sea Cucumber Photo by: Amy Leath

Being a resident of the western panhandle, we have noticed a mass decline of echinoderms in our grassbeds.  As a kid in the 60s and 70s we never saw large numbers, as they do in the eastern panhandle, but we did see them. Now they are gone.  One suggestion as to why has been salinity.  Our bay system over here has more river discharge than those further east and the lower salinity may not support larger populations.  The increased development of the years, and the methods of dealing with stormwater, may have created a system that echinoderms do not like.  Whatever the reason, finding sea stars and sea urchins in our grassbeds is rare. 

The eastern panhandle still has them.  And, at times, too many.  In recent years there has been an increase in sea urchin populations in St. Joe Bay that has led to overgrazing of the turtle grass.  This could lead to a decline in suitable habitat for bay scallops, which the community depends on economically.  The state currently sponsors a “Sea Urchin Round Up” event using humans to help control the overabundance of sea urchins. 

Echinoderms are a visible, and interesting, part of our seagrass community. 

The Evening Bats of the Florida Panhandle

The Evening Bats of the Florida Panhandle

My wife and I like to sit on our back porch and watch the sunset each day.  We do not make all of them, but we try to make as many as we can.  We often see small bats darting in all directions feeding on bugs.  Recently we were enjoying a particularly great sunset.  The sky was a light blue with streaking clouds of dark gray, purple, orange, and white.  It was amazing.  As the streetlight came on, we could see a swarm of termites gathering around it.  There were a lot of them, but we also noticed the increase in bats.  There was a dozen at least, probably more, zipping in and out, darting in all directions.  We enjoyed watching them and wondered where all of them were roosting. 

Bats sometimes move into buildings when they can’t find the natural structures they prefer (caves and large trees with cavities).

Many people are afraid of these creatures.  They have been associated with Halloween, horror, vampires, and rabies.  They are creatures of the night, and that is unsettling in itself for many.  But, as biologists say with most creatures, these stories and legends are just that… stories and legends.  Some members of their population do carry rabies, but most do not and the transmission of the disease to humans is rare.  The animals are small furry mammals that eat an enormous number of insects each evening, including flying termites and mosquitoes.  Many help pollinate plants and help disperse seeds.  They are really pretty cool. 

There are around 1400 species of bats worldwide1, 13 of these are from Florida2.  Though some species feed on fruit and nectar, most feed on insects and consume about half their body weight each evening doing so.  The Bat Conservation International states that insect consuming bats may save U.S. farmers $23 billion dollars a year in pesticide use due to their insectivorous diet1.  The agave plant, the one used to produce tequila, is primarily pollinated by bats.  The 13 species found in Florida are all insectivores feeding on beetles, mosquitos, moths, and other agriculture and garden pests.  They are truly beneficial. 

Bats are mammals, having fur covered bodies, live birth with young nursing on milk, and being endothermic (warm blooded).  Most connect bats with the mammalian order Rodentia (rodents) – often calling them “flying rats”, but – due to the type of teeth – they are actually in their own order Chiroptera.  They are the only true flying mammals in the world, the flying squirrel is actually a glider, not a true flyer.  They live in a variety of habitats in Florida including pine forests, hardwood forests, riverine systems, lakes, and in urban areas.  They most often roost in the crevices of dead trees, beneath the dead fronds of palms, and in Spanish moss.  But when available, they will use caves and are notorious for using buildings, culverts, and the underside of bridges. 

They fly using wings that are actually thin skin between their extremely elongated fingers.  They breed in the fall and give birth to a single pup in the spring.  One of the legends is that they are blind.  As mentioned above, this is a legend.  Bats can see well and see better than we do in dim light.  They do have the ability to use high frequency sounds to “echo” off objects in the dark (echolocation) which helps them find, and follow, their insect prey at night.  You can notice this hunting tactic as the sun sets and view the bats darting in all sorts of directions chasing their prey. 

Most of the 13 species of Florida bats can be found in the Florida panhandle, with the gray bat only found in Calhoun and Jackson counties and nowhere else in the state.  Rabies is a concern with bats, and it is true that an infected bat with the disease can transmit it to humans, but this is very rare.  That said, anyone who is bitten by a bat should seek medical attention.  The animal was also connected with the transmission of COVID during the early period of the pandemic3.  Bats, like many other mammals, can pass infectious diseases and there is also a fungal growth associated with their droppings that has caused medical problems with some humans.  If working in an area where bat guano is abundant, a mask is recommended.  If an injured animal is found in your yard, wear a pair of gloves and take it to your local wildlife rehabber. 

Florida bats do face problems in our state with the loss of habitat.  We often remove dead trees and cut dead fronds from palms.  The benefit we receive from them (consuming thousands of pest insects each night) leads to a need for their conservation.  To date, the white-nose syndrome, which has infected many bats north of us, has not reached Florida but is of concern.  Despite the fear many have of this animal, they are quite beneficial and should be allowed to exist in our panhandle habitats. 

Species found in Florida:

Mexican Free-tailed bat

Southeastern myotis

Evening bat

Eastern red bat

Seminole bat

Northern yellow bat

Tricolored bat

Gray bat – endangered; only found in Calhoun and Jackson counties.

Big brown bat

Rafinesque’s big-eared bat

Hoary bat

Velvety free-tailed bat – only found in the Keys.

Florida bonneted bat

References

1 Bats 101.  Bat Conservation International.  https://www.batcon.org/about-bats/bats-101/.

2 Bats. Florida Fish and Wildlife Conservation Commission. https://myfwc.com/wildlifehabitats/profiles/mammals/land/bats/#:~:text=In%20Florida%2C%20there%20are%2013,and%207%20%E2%80%9Caccidental%E2%80%9D%20species..

3 Origins of Coronaviruses.  National Institute of Allergy and Infectious Diseases.  https://www.niaid.nih.gov/diseases-conditions/origins-coronaviruses.

A Sea of Grass; Part 7 The Crustaceans

A Sea of Grass; Part 7 The Crustaceans

In terms of diversity and abundance, the Phylum Arthropoda is the most successful in the Animal Kingdom.  Between them all, there are over one million species.  They can be found in all habitats, from the deepest part of the ocean to the highest places in the mountains, from the polar region to the most extreme deserts.  Most are insects, but there are also arachnids, centipedes, millipedes, and the ones most common to the marine environment – the crustaceans.  With the numerous species within this group, and new ones being discovered all the time, the classification of arthropods is constantly changing.  Currently Crustacea is considered a subphylum and there are about 30,000 species within. 

Insects are one of the most abundant forms of life on the planet. Photo: Princeton University

There are several keys to the success of arthropods.  Number one, their shell.  It was seen with the mollusk that having a hardshell to protect your soft body was a winner.  However, mollusk make their shells from heavy calcium carbonate.  Though this provides excellent protection against most predators, it did slow them down considerably making it much easier for predators to catch them.  It is understood that in the world of defense, speed is important.  The arthropods make their shells from a strong, but much lighter material called chitin.  This material is strong but serves as the creatures’ exoskeleton and must be shed periodically as the animal grows. 

Number two, their legs.  The name “arthropod” means jointed foot and one glance at the legs of any of these, you will see why scientists call them this.  To increase speed animals, need to break contact with the surface of the ground.  Birds are the best, lifting off and flying – the fastest form of location there is.  The slug-like mollusks have their entire bodies in contact with the sediment, as the “slug” along the bottom of the sea.  Many creatures have developed legs and walk, this is the case of the arthropods.  Some hop great distances, like the flea.  Others can actually swim, like blue crabs.  And many of the insects have wings and can fly.  But these jointed legs, along with a lighter shell, have been very effective defense for these creatures.

Number three, their sense organs and brain.  Though not as intelligent as octopus and squid, arthropods are very aware of their environment and very quick to respond to trouble or a food source.  Drop a piece of cheese during a picnic and see just how fast the ants find it.  Heck don’t drop the piece of cheese and see how quickly they find it!  These animals have a series of hairs, bristles, and setae connected to their shell that can detect movement and pressure changes in the environment.  There are canals, slits, pits, or other openings in the shell that can detect odors.  And then they have their compound eyes.  Compound in the sense there are more than one lens.  Each lens does provide an image of the target (in other words, they do not see 100 images of you) but rather each provides a level of light intensity sort of like individual pixels in a computer image, or the image we see when the camera displays “squares” of light so that you cannot read someone’s license plate, or the logo on their t-shirt – we see this on TV news and shows often.  Compound eyes do not produce as clear an image as our eyes, but they are MUCH better at detecting motion, and there is an advantage to this.  Try stomping on a cockroach, or swatting a fly, and you will see what I mean. 

And number four, a high reproductive rate.  You see this in many of the “prey” type species.  Most arthropods are dioecious (males and females) and can produce millions of offspring at rates that you could never consume them all.  So, they survive and can quickly support gene flow and adaptation.  These are well designed animals. 

Blue crabs are one of the few crabs with swimming appendages. Photo: Molly O’Connor

In the crustacean world we find several groups.  They differ from their arthropod cousins in that they have 10 jointed legs, and two sets of antenna (one set long, the other short).  They include at least 30,000 species including the shrimplike cephalocarids, the shrimplike branchipods, the shrimplike ostracods (common in the deep sea), the roachlike copepod (part of the plankton we spoke about in another article in this series), the mystacocards, branchiurans, the familiar barnacles, krill, the roachlike isopods, flea like amphipods, and the most familiar of the group – the decapods – which includes the crabs, shrimps, and lobsters.  It is this last group we will focus on. 

There are three basic body parts to an arthropod.  The head, thorax, and abdomen.  In crustaceans the head and thorax are fused into one segment called the cephalothorax (the head of a shrimp or crawfish).  The abdomen is what most call the shrimp and crawfish tail (the part we usually eat). 

Insect body parts.

Crabs are the ones we most often encounter when exploring the seagrass beds.  Not that the others are not abundant, they are, they are just not seen.  They differ in that their abdomen is curled beneath their cephalothorax.  The most commonly encountered is the famous blue crab (Callinectes sapidus).  Most crabs have modified two of their 10 legs into chelipeds (claws) and most folks seeking crabs for dinner are aware of these claws.  The blue crab belongs to a group called the protunid crabs which have modified two additional legs into swimming paddles – they can swim.  They are often found crawling around the edges, and within, the seagrass searching for food.  When detected over sand, they quickly bury themselves and sometimes people step on them not knowing they are there.  When spooked they often will emerge with chelipeds extended and when the time is right, will scurry off running sideways with one cheliped pointed at you.  They can get quite large and are a popular fishing target for both recreational and commercial fishermen.  The males (the ones with the long then telson on their curled tailed) are more common in the upper estuaries.  The females (the ones with the more round telson) frequent the lower bay.  During breeding season, the males will move to the lower estuary to find a female.  Once found he will crawl on her back and “ride” for a couple of days in what commercial fishermen call “doublers”.  At some point the male will provide a tube filled with sperm called a spermatophore to the female.  He then moves on.  The female will store the spermatophore until she feels it is time to fertilize the eggs, then does so.  The eggs begin to develop beneath her abdomen in a spongy looking mass.  Early in development the mass is an orange color.  Closure to hatching it is brown.  Females carrying this spongy mass are called gravid and are illegal to harvest in Florida.  The larva will be released in the millions as tiny plankton and go through several life stages before becoming young crabs and starting the whole story again.  These popular crabs live for about five years. 

Male and female blue crabs. Photo:

Another crab found in the grassbeds is the spider crab (Libinia dubia).  This crab does resemble a spider, is slow moving, and very hard to see.  It has small chelipeds and feeds on debris and organic material collected by the grasses.  They too can get quite large and resemble the king crabs harvested in Alaska. 

Stone crabs (Menippe mercenaria) are more often associated with rocky bottoms, or artificial reefs, but they have been found in burrows and crevices within grassbeds.  The have wide-stocky chelipeds, which is a favorite with some seafood lovers.  Those in the grassbeds do not get as large as those found around the reefs of south Florida, where they support a large commercial and recreational fishery. 

The stone crab has been a popular seafood target in Florida for decades.

The hermit crab is a common resident of grassbeds.  The most frequently encountered is the striped hermit (Clibanarius vittatus).  Like all hermit crabs, they lack an external shell covering their abdomen and must cover their tail with an empty mollusk shell.  Their curled abdomen can grab and wrap around the columella within the mollusk shell and carry around their new home.  These hermits have been found in a variety of mollusk shells and are found roaming the beaches at low tide feeding on organic debris and cleaning the grassbeds. 

A room with a view: a stripped hermit crab sizes up a potential residence

One crab that is often associated with seagrasses is not actually a crab at all.  The horseshoe crab (Limulus polyphemus) lacks antenna and is more closely related to the arachnids.  This ancient mariner has been plowing the bottoms of estuaries for over 400 million years.  They resemble stingrays with their elongated telson and feed on a variety of small invertebrates both in the grassbeds, and in other estuarine habitats.  They are quite common in the eastern panhandle and seem to be making a recovery in the western end. 

A large horseshoe crab found in Little Sabine. Photo: Amanda Mattair

Though rarely seen, shrimp are very prolific in our seagrass beds.  Pulling a seine or dip net through the grass will expose their presence, usually in high numbers.  The most commonly collected species are those known as grass shrimp (Palaemonetes sp.).  There are a few species, and all are small and mostly translucent, though one is a brilliant green.  Feeding on organic debris within the grassbed these little guys are an important food source for the larger members of the community. 

The more famous of the shrimp group are the brown and white shrimp.  These are the species we find on our dinner plates and are one of the most popular commercial species in the country.  Brown shrimp (Farfantepenaeus aztectus) are also known as bay shrimp and “brownie”.  They are a darker brown than the white shrimp and their uropod (the fan on the tail of the shrimp) is lined in a red color.  They do not get as large as the whites and are very popular for fried and steamed dishes.  The white shrimp (Litopenaeus setiferus) is a larger shrimp, is lighter in color (“white”), and their uropod is lined with a neon green color.  Both of these commercially important species spend their juvenile and young adult days in the grassbeds of our estuaries.  Later in the fall the adults move into the nearshore waters of the Gulf where they spawn and die.  The planktonic larva drift back into the estuary with the incoming tide, finding the grassbeds and the cycle begins again. 

The famous Gulf Coast shrimp. Photo: Mississippi State University

The large diversity of crustaceans within the grassbeds speaks to the importance of this habitat to all marine life.  Many are commercially important to the local economy and depend on a healthy ecosystem to survive.  All the more reason to protect our grassbeds. 

The Emerald Coast Open Lionfish Tournament 2023: Combating an Invasive Species Through Sport

The Emerald Coast Open Lionfish Tournament 2023: Combating an Invasive Species Through Sport

The Emerald Coast Open Lionfish Tournament May 20-21, 2023, at HarborWalk Village in Destin, FL, is gearing up to tackle a pressing ecological challenge while showcasing the power of sport to make a positive impact. This unique tournament, held along the picturesque shores of the Emerald Coast, focuses on combating the invasive lionfish population in the region’s waters.

Lionfish, native to the Indo-Pacific region, have become a significant threat to the delicate balance of marine ecosystems in the Gulf of Mexico. With their voracious appetite and rapid reproduction, these invasive species pose a grave danger to native marine life. The Emerald Coast Open Lionfish Tournament aims to address this issue by encouraging divers and fishermen to actively hunt and remove lionfish from the waters.

Participants in the tournament will compete to catch the most lionfish, utilizing their skills in underwater navigation, spearfishing, and conservation. Sponsors provide cash and prizes for multiple categories including most caught, largest and smallest lionfish. The event provides an exciting platform for experienced divers and newcomers alike to contribute to the preservation of the marine environment.

Beyond the ecological significance, the tournament also offers a thrilling experience for both participants and spectators. Divers equipped with their spears dive into the depths, searching for lionfish while showcasing their prowess and bravery. The tournament fosters a sense of camaraderie and shared purpose among the participants, creating a community dedicated to the cause of protecting marine ecosystems.

In addition to the competitive aspect, the Emerald Coast Open Lionfish Tournament promotes education and awareness about the invasive species. Participants and attendees have the opportunity to learn about the impact of lionfish on local marine life and explore sustainable solutions to combat the issue at the free Lionfish Awareness Festival from 10:00-5:00 each day. Sign up to volunteer at the event if you want to join the fun. The week prior to the tournament is dedicated to Lionfish restaurant week where local restaurants practice the “eat ‘um to beat ‘um” philosophy and cook up the tasty fish using a variety of innovative recipes. 

The Emerald Coast Open Lionfish Tournament 2023 represents a unique fusion of sport, environmental conservation, and community engagement. By bringing together individuals passionate about marine conservation, this event serves as a powerful catalyst for change and a shining example of how sport can contribute to the preservation of our natural world.  Learn more at https://emeraldcoastopen.com.

A Lionfish Removal and Awareness Day festival volunteer sorts lionfish for weighing. (L. Tiu)

Written with assistance from ChatGPT

Late Spring is Time to Go Cogongrass Hunting

Late Spring is Time to Go Cogongrass Hunting

Donn Shilling and Eldridge Wynn look over a research field of cogongrass, which has become a problem for cattle ranchers.

Cogongrass is one of our larger invasive species here in the Panhandle, and spring is a good time to detect and treat it. If you know or suspect your property may have cogongrass, spring is the best time to hunt it down and locate the spots and infested areas. It is also a great time to patrol your property boundaries as well to see if you have any that may be coming onto your property from a neighbor or right of way. Cogongrass seems to love fencerows and right of ways as it spreads easily on equipment through its tough rhizomes. One of the best ways to prevent large infestations from taking over portions of your property and creating a significant control cost is to catch it early. The key to this is to identify and mark small spots before they expand; and then follow up with herbicide treatment once to twice a year. Spring is an excellent time to go and scout for cogongrass and get a jump on this invasive for several reasons.

A relatively new patch of cogongrass recently found in Washington County. Photo Credit: Mark Mauldin

One feature of cogongrass that is very distinctive is the seed head. In spring cogongrass flowers and puts up a cottony white seed head. These seed heads look like an elongated fluffy white tuft on a tall stalk. Once you have seen them for the first time you will instantly recognize this invasive grass. If cogongrass has been mowed, it can sometimes be hard to spot especially in a pasture. In spring the seed heads will quickly draw your attention to an area infested with this grass. It is very distinctive, and you do not see other grasses with this type of seed head the same time of year.

Other distinguishing features of cogongrass include a bright green color sometimes with red edges. In the spring the new growth of cogongrass is very prominent and stands out due to its bright color and usually faster growth compared to other grasses. The midrib of the grass blade is also usually offset to one side, another identifying feature. If you have a shovel handy you can dig up a small amount and you will notice thick rhizomes with sharp pointed tips. Once you learn to identify cogongrass and know what you are looking for; you can go out on your spring cogongrass patrol to identify any areas of infestation.

Cogongrass shown here with seedheads – more typically seen in the spring. If you suspect you have cogongrass in or around your food plots please consult your UF/IFAS Extension Agent how control options. Photo credit: Mark Mauldin

Once you have identified an infestation you need to do three things: mark the impacted area with a flag or other noticeable method, record the location (by description or GPS), and develop a treatment plan. Marking and recording the location of cogongrass infestations, especially a small spot that is new, is critical to the success of control efforts. Cogongrass is tough and requires multiple treatments with herbicide to effectively control it and hopefully eliminate the infestation. This means you need to know where a patch is, be able to relocate and monitor it, and consistently treat the same spot to ensure you achieved complete control. Cogongrass control is easier when the spot is small and has not become well established. With small spots it can be difficult to locate the spot again the next year, especially after a round of herbicide treatment, so good marking combined with a GPS location or description is essential. Once you have gone back to a spot several years and the spot has not come back after treatment; you can consider the spot controlled. If you stop treatment and monitoring before cogongrass has been controlled for several years, the infestation will return from remaining rhizomes and spread all over again.

Consistent treatment with effective herbicides is the best way to ensure cogongrass is controlled on your property. If you locate some while scouting this spring be prepared to start a treatment program. Cogongrass responds to herbicides with the active ingredients glyphosate or imazapyr. These can be used alone or in combination. The spring and fall are the two treatment windows that are most effective. If you treat in the early spring when new growth is vulnerable you can sometimes prevent seed heads from maturing. You can also get some control that can help prevent heavy growth over the summer, which can be an advantage if you have to mow or maintain the area. Spring treatment is usually best accomplished with glyphosate alone, imazapyr alone or a mixture of both can be used.

Once we progress into summer, treatments with herbicide will mostly top kill the grass and do not provide effective control. Treatment in the fall with imazapyr alone or in combination is the most effective treatment method. If you identify infestations in the spring you can mark them and come back in the fall to get the most bang for your buck with treatments. You can apply a spring and fall treatment in one year if you want to accomplish some control in the spring, but this method is not necessarily more effective than the fall treatment alone. When using imazapyr herbicide you should be aware that this is soil active and has the potential to damage surrounding vegetation and hardwood trees that are in and near the treatment area. Pines are tolerant of imazapyr but can be damaged if high rates are used, and longleaf pine is more sensitive than others. When treating cogongrass with imazapyr be aware that damage to other vegetation could occur. If the cogongrass is in an area with hardwood trees or other sensitive vegetation glyphosate alone is a good alternative herbicide treatment. When using any herbicide be sure to read and follow the label correctly, follow all label directions, and wear proper protective equipment. There are several IFAS EDIS publications on cogongrass control which provide more detailed information: for control in pasture areas follow this link SS-AGR-52/WG202: Cogongrass (Imperata cylindrica) Biology, Ecology, and Management in Florida Grazing Lands (ufl.edu) and for control in forested areas follow this link FR342/FR411: Biology and Control of Cogongrass (Imperata cylindrica) in Southern Forests (ufl.edu) . If you identify cogongrass on your property these publications will help you develop a treatment plan to control it. Early detection and treatment when infestations are small is key to getting this nasty invasive under control. Take advantage of this spring to identify, mark, and treat any cogongrass that may be getting a foothold on your property before it becomes a major infestation.