In a short amount of time, undergraduate student, Aaron Groves, and I were able to trek over to Point au Sable and perform just one point count along the shoreline before the downpour of rain began! Upon arriving at the Point, we noticed that the landscape had changed drastically since we had last been there a few months ago. The shoreline was completely covered in the invasive Phragmites australis, making it nearly impossible to view the bay of Green Bay. Regardless, many of the small passerines did not seem to mind this invasive. We found numerous Black-capped Chickadees, Song Sparrows, and one Myrtle (Yellow-rumped) Warbler foraging within the Phragmites and using it for cover. We also observed the following species: Great Egret, Great Blue Heron, Mallard Duck, Canada Geese, Ring-billed Gull, Red-winged Blackbird, Common Grackle, Ovenbird, Downy Woodpecker, Gray Catbird, White-breasted Nuthatch, American Crow, Blue Jay, and American Robin. Upon hearing the chatter of the Belted Kingfisher and the ever-present European Starling, the rain slowly started to pour, at which point Aaron and I left for the day. We observed a total of 19 species.
As I mentioned in one recent blog posting entitled “May 26, 2010 by Erin Gnass,” I performed bird surveys for the greater part of the month of June for my thesis project—the index of ecological condition model, as applied to northern hardwood forests of Wisconsin. In order to most appropriately create this model, I surveyed additional hardwood forested sites considered to be of poorer forest condition so as to sample across a wide range of environmental condition. This enables the model to be more accurate and effective at calculating forest condition. Therefore, I went in search of hardwood forest sites on both public and private lands near and within heavily managed, fragmented, and human-disturbed or developed areas. Within Brown, Kewaunee, Shawano, and Oconto counties here in east-central Wisconsin, I found 27 sites that I surveyed, with the much-appreciated assistance of Joan Berkopec (the same wonderful volunteer who helped with the Wild Rivers Legacy Forest surveys and the Nicolet National Forest Bird Survey that I described in the two previous posts).
From May 26 until June 24, I observed 49 total species at these 27 additional sites, including the following species of interest:
Seven warblers: Chestnut-sided, Common Yellowthroat, Mourning, Northern Waterthrush, Ovenbird (in moderate numbers), Pine, and Yellow Warblers
Seven woodpeckers: Downy, Hairy, Northern Flicker, Pileated, Red-bellied, Red-headed, and Yellow-bellied Sapsucker Woodpeckers
Four flycatchers: Eastern Phoebe, Eastern Wood-Pewee (in moderate numbers), Great Crested (in moderate numbers), and Least Flycatchers
Three thrushes: American Robin (in moderate numbers), Veery, and Wood Thurshes
And one vireo: Red-eyed Vireos (in large numbers)
Please feel free to look at the photographs that I took shown below:
Thank you to professional photojournalist, Scott Giese, my boyfriend, for taking these additional photographs of me while I completed a bird survey in Brown County:
Every year since 1987, a large group of ornithologists have performed breeding bird surveys within the Nicolet National Forest (NNF; see the Nicolet National Forest Bird Survey: (http://www.uwgb.edu/birds/nnf/) in northeastern Wisconsin, now contributing to well over 40,000 records of birds consisting of over 200 total bird species. Whether you are an ornithologist by profession, a volunteer, a student, a back-yard birder, the state’s best expert, or a complete novice who has never seen a Canada Goose in your life, absolutely anyone can come and assist in the survey! Luckily, I was able to be one of the group leaders and engage myself in the survey for the very first time. Having heard about how much fun and exciting it is to participate in such a wonderful annual event, I was not disappointed in the slightest!
On the first day of the survey, I led a small team birders consisting of a young couple and another woman to pine and hardwood forests and a few beautiful bogs. Although the sites were not as biodiversity rich as other sites within the Nicolet National Forest, we were able to observe many interesting but “usual suspect” birds, such as the Ovenbird, Red-eyed Vireo, Chipping Sparrow, Eastern Wood-Pewee, Rose-breasted Grosbeak, American Robin, Brown Creeper, Blue Jay, Black-capped Chickadee, Black-throated Green Warbler, Alder Flycatcher, Yellow-bellied Sapsucker, and many others. After this first morning of surveys, a large group of us, including (some of my favorite ecologist/biologist friends) UWGB undergraduate student, Aaron Groves, former UWGB Environmental Science & Policy graduate student, Kathryn Corio, Ron Eichhorn (who helped the Nature Conservancy and me with the WRLF project), and a few others went out to a bog near the NNF to look for interesting plants and birds. A few of us chased down a Palm Warbler while others observed uncommon plant species. Please see the photographs that I took down at the bottom of this posting. Thank you to all of the botanists in this group who showed me these beautiful plants.
On the second day, graduate student, Nick Walton, joined our group and helped to lead the surveys. Near the end of one of the last surveys of the day, we heard a nearby soft chickadee-call where we discovered two Boreal Chickadees—the highlight of my entire summer. Not only did these individuals continue singing throughout the remainder survey, they flew low in the trees only ten meters away from us for quite a few minutes. Not many people have the opportunity to view this species in particular because they are considered an uncommon, northern U.S./Canada dwelling species. Thus, when we shared the news with other birders upon returning to the field houses, everyone expressed their surprise and excitement to us. What a thrilling day it was.
I look forward to next summer’s bird surveys at the Nicolet National Forest.
On a weekend in early August on a country road in Door Co., Wisconsin Mike Draney and I were surprised to find ourselves in a cloud of butterflies. Driving along County Road EE in Door County we were scaring up clouds of Clouded Sulfur butterflies (Colias philodice). We stopped and found that they were gathering by the hundreds in the wet mud of the stormwater ditches. We collected several dead butterflies, likely the victims of car traffic, and found that every individual we collected was a male.
Congregations of butterflies at mud puddles, animal dung, or carrion were first recognized in the early 1900s, but surprisingly, scientists still don’t know a lot about why they do it. It was long suspected the behavior was related to nutrients and salts. Flower nectar, while high in carbohydrates, is extremely low in nutrients like salts and amino acids. Experiments by chemical ecologists S. Smedley and T. Eisner conducted in 1995 confirmed that butterflies do prefer saltier puddles. And since them numerous studies have confirmed that butterflies are seeking sodium or proteins and sometimes other nutrients in the puddles that are scarce in nectar.
Females are not usually seen at puddles, even though it makes sense that they would also be in need these scarce nutrients to produce healthy eggs. In fact it has been demonstrated that males transfer some of the nutrients they collect at puddles to females as “nuptial gifts” during mating that she will then use to provision her eggs. In some cases may give away almost half of their total reserves. The gift is important because larvae that are born with higher amounts of nutrients probably have an advantage in surviving especially in low sodium environments. (See Molleman et al. 2005 for more information)
But why so many of this species? Clouded Sulphur caterpillars feed on legumes like alfalfa and clover, and there can be as many as 3 generations in favorable years, so it isn’t surprising to expect to see large numbers of them in agricultural areas in mid to late summer.
But Sulphurs aren’t the only butterflies you might see visiting puddles, many other species of terrestrial arthropods that have low salt diets including Blattodea, Diptera, Diplopoda, Hemiptera, Hymenoptera and Orthoptera have also been observed to puddle.
Molleman F, Grunsven RHA, Liefting M, Zwaan BJ, and Brakefield PM, 2005. Is male puddling behaviour of tropical butterflies targeted at sodium for nuptial gifts or activity? Biological journal of the linnean society. 86: 345-361
Smedley and Eisner, 1995. Sodium Uptake by Puddling in a Moth. Science. 270: 1816-1818
One of the many exciting bird research projects that I helped to investigate this summer was with the Nature Conservancy (TNC) in the Wild Rivers Legacy Forest (WRLF) north of Armstrong Creek in northern Wisconsin. With a field crew of eight people, many of us living in one field house, we not only gathered very useful bird survey data for TNC and my graduate thesis project, but we were also fortunate enough to listen to and observe many unique and beautiful bird species. Every afternoon or evening, we met as a group to decide how to break apart all of the required bird survey sites within the forest. Some of us went out in pairs while others surveyed independently to perform as many bird point counts as possible between the half hour prior to dawn until 9:30 AM (the short window of time that breeding birds are allowed to be surveyed). Depending on the terrain, distance between points (via car or on foot), and weather, many pairs or individuals performed as few as 5-6 surveys to as many as 12 in a morning! Therefore, we finished all 200 bird survey sites in the WRLF and the 23 additional sites of poor ecological forest condition in one week’s time!
For some of the bird sighting highlights of this week during the first week of June, we viewed 73 total species within the WRLF including:
16 warblers: American Redstart, Black-and-white, Blackburnian (in large numbers), Black-throated Blue, Black-throated Green (in large numbers), Canada, Common Yellowthroat, Chestnut-sided, Magnolia, Mourning (in large numbers), Myrtle (the official name of the eastern population of the Yellow-rumped Warbler), Nashville, Northern Parula, Northern Waterthrush, Ovenbird (in large numbers), and Tennessee Warblers
Six flycatchers: Eastern Kingbird, Eastern Phoebe, Eastern Wood-Pewee (in large numbers), Great Crested, Least (in large numbers), and Yellow-bellied Flycatchers
Six woodpeckers: in comparison to last year’s data, we observed many more woodpecker individuals: Downy, Hairy, Northern Flicker, Pileated, Red-bellied, and Yellow-bellied Sapsucker (in large numbers) Woodpeckers
Five thrushes: American Robin (in large numbers), Hermit Thrush (in large numbers), Swainson’s, Veery, and Wood Thrushes
Four birds of prey: Broad-winged Hawk, American Kestrel, Barred Owl, and Red-shouldered Hawk
Two vireos: Red-eyed (in large numbers) and Blue-headed Vireos
And several other birds of interest included: Black-billed Cuckoo, Black-capped Chickadee (in large numbers), Blue Jay (in large numbers), Brown Creeper, Common Raven, Chimney Swift, Evening Grosbeak, Indigo Bunting, Purple Finch, Rose-breasted Grosbeak (in large numbers), Red-breasted Nuthatch, Scarlet Tanager (in large numbers), White-breasted Nuthatch, White-throated Sparrow (in large numbers), Winter Wren, and Yellow-billed Cuckoo.
In comparison to the 200 sites of the WRLF, we only observed 47 total species within the sites of poor ecological forest condition, including many of those observed within the WRLF. In these additional sites, however, we also observed the Eastern Bluebird, Eastern Meadowlark, Golden-winged Warbler, Ring-necked Pheasant, and Yellow-throated Vireo, which were not observed during point counts in the WRLF.
For fun in the afternoons, we would gather for lunch at a nearby lake, such as Savage Lake, and enjoy the Black Terns, Sandhill Cranes, and Common Loons, which foraged within a few hundred meters of us. Other days we searched for different bird species (e.g. Bobolink) and other walks of life, such as dozens of dragonfly species, as expertly identified by Ron and Joan. We ran into several deer and quite a few black bears, including one close call during a survey that I was conducting by myself. Around minute three of one ten-minute bird point count survey that I was doing, a large black bear peered through thick brush about 25 meters away from me. After shooing it away from me, it still remained close, only about 200 meters away. Upon completing the bird survey and heading back to my car, it stood on its back legs and kept a close watch over me! Thankfully, it continued to forage and stay clear of me.
In one short week’s time, our dedicated and tireless field crew performed many surveys, which provided this study with incredibly useful data that will contribute towards a vastly important conservation project for the future. Luckily, I had some of the most fun that I have ever had working on a bird field crew and am grateful to be a part of this project. Thank you to all of those expert birders on this crew who helped me to become a better birder!
Please take a look at some of the photographs that I took during this week.
One of the most common ways to try to control gypsy moth (Lymantria dispar) populations is to wrap tree trunks with control bands. These are simply burlap skirts that are wrapped around the tree. Gypsy moths feed on the leaves of the trees at night and then climb back down the tree trunk and hide under the bark or leaves during the day to avoid predators. The burlap skirts provide an ideal hiding spot for the caterpillars and they will congregate there in large numbers. This makes it easy to capture and kill them during the day. The burlap itself does not act as a trap, and actually increases the moth’s chance of surviving to adulthood, because it prevents predators like Blue Jays from seeing them. Burlap only works if the caterpillars are removed every few days. So if you are going to put up the burlap skirts, you must be committed to checking them every few days and killing the caterpillars by squishing them or by scraping them into a jar of soapy water so they drown.
We saw thousands of male gypsy moth flying around burlap skirted oak trees in one of the parks in Green Bay, Wisconsin in July of 2010. There were many females actually laying their eggs underneath the burlap. This is unfortunate because now there will be more work to remove egg masses this winter and spring.
Some Links on How to properly use burlap tree skirts:
- WI Gardener video clip http://www.uwex.edu/ces/gypsymoth/collectionband.cfm
- tips on controlling gypsy moth throughout the year: http://www.uwex.edu/ces/gypsymoth/index.cfm?mo=6
Keen-eyed botanist Gary Fewless spotted this American Bittern (Botaurus lentiginosus) in the Cofrin Arboretum. American Bitterns used to be fairly common in the large marshes on the west side of the Bay of Green Bay, nesting in cattails and in sedge meadows in Atkinson, Sensiba, and Peters marsh. In recent years, as Phragmites australis has invaded and replaced cattails in much of the marshes in northeast Wisconsin, we have seen a decline in the numbers of nesting pairs of American Bitterns.
The loss of large wetland areas to development and degradation by invasive plants like Phragmites and pollutants has taken a toll on bittern populations in the United States. Overall American Bitterns are half as common as they were 40 years ago.
This individual is the first to be sighted on the UWGB campus and is probably a young bird that is looking for suitable habitat as it prepares to migrate. According to Richter Museum Curator Tom Erdman, these individuals often return to a location they sampled the previous fall. So perhaps this one might return to nest in the spring.
And you thought growing up was tough…try metamorphosis. This unfortunate insect is probably a Spongillafly. It should have long lacy wings (see link for comparison), however, something must have happened as it emerged from its pupae.
When botanist Gary Fewless found this tiny creature, he had no idea just how unique it was. He found a spongillafly, an insect that is seldom collected as adults. And he found a living individual whose abdomen and wings were highly deformed.
At least we think it is a spongillafly. We are not completely sure of course, since we are making an identification from a photograph of a badly deformed specimen, but that is entomologist Mike Draney’s best guess, based on the size of the eyes and the pigmentation of the wings. And what exactly is a spongillafly? They are insects in the Order Nueroptera, which also include the more familiar lacewings and ant lions (aka doodlebugs if you’re from the South). Most Neuropterans are predators. However, spongillaflies are unique, because they are parasites that spend their larval stage underwater feeding on freshwater sponges. Only 6 species are found in the spongillafly family (Sisyridae) and only 3 of these, Climacia aerolaris, and Sisyra fuscata, and Sisyra vicaria are found in the Great Lakes region.
The adults look similar to brown lacewings. They spend their time flying, feeding and scavenging on other invertebrates, mating and laying eggs on vegetation overhanging streams and lakes usually at dusk or after dark, which is one reason they are so seldom collected. When the larvae hatch, they fall into the water and float around until the find a sponge. (Wait a minute…there are sponges in Wisconsin? Well—yes, but we’ll tackle that topic in a later blog. ) The spongillafly larvae use their piercing mouth parts to suck body fluids from the sponge tissues. They don’t kill the sponge and will stay with the same sponge until they are ready to pupate. It is likely our specimen spent its underwater time feeding on its sponge and generally enjoying life. When it was ready to metamorphose it climbed out of the water, found a site it liked under a rock or tree bark and then spun a silken cocoon around itself for protection. It remained in the cocoon all winter as a hibernating larva, waiting until the warm spring weather to even begin to pupate. And that is where something went terribly wrong.
What goes on in the pupa? From our perspective, pupation might seem like a pleasant rest in a bed of silk, this is hardly the case. Beneath its silken wrap, dropping levels of juvenile hormones trigger a cascade of changes in the developing insect. First, chemical signals are released that signal the epidermal cells to release enzymes that digest the larvae’s cuticle (skin). The cuticle is broken down into and reused to make new parts. Basically the larva is killing its own skin cells.
At the same time special clusters of cells in the body called imaginal discs become active and elongate, using the digested epidermis to build wings, eyes, antenna, and reproductive parts, as well as the new exoskeleton of the adult insect. These discs are aligned in pairs and their development is genetically controlled. Any mutation in these genes can result in malformations in the adult, so that a leg might grow where a wing should be. In fact, it was the study of mutations like these in fruit flies that greatly increased our understanding of how the process and genetic control of early developments occurs. If anything goes wrong during this period of genetic communication and rapid development the adult will not form properly.
Our insect has all its parts in the right places, so a genetic mutation is unlikely. It is more likely that the pupa was damaged from the outside as it was developing. If the pupa is crushed or bent during this period of radical re-arrangement, the underlying developing adult structures can also be damaged. The developing pupa does not have much capability to repair structures after they have formed.
Damage can also occur after the adult emerges, but before its exoskeleton dries and hardens. The newly emerged insect is soft and its wings are shortened and curled. It must pump fluid from its abdomen into the veins of the wings to enlarge and elongate them. (See this photo of a newly emerged brown lacewing. It has nearly finished uncurling its wings.) If the insect falls or is crushed while it is still soft, wings or legs can harden in bent positions. If the abdomen is damaged, internal injuries can result, and the insect will usually die.
Parasites can also cause improper development. Gregarine parasites are protozoa that live in the guts of many different insects including Nueroptera. The insects are infected by spores that fall onto the eggs as they are being laid. The spores are eaten by the insect larva and reproduce asexually inside the gut, absorbing nutrients through micropores in their wormlike bodies. During pupation the parasites switch to sexual reproduction, forming spores that are released through the pupal case and dust the body surface adults as they crawl out of the cocoon. They pass the spores onto their offspring when the spores fall onto the eggs as they are laid. Heavy gregarine infections are known to result in wing deformations in developing butterflies because the butterflies are too weak to hold themselves up or to inflate their wings.
We are not quite sure what went wrong with this individual. Regardless of what happened to this insect it is unlikely it survived very long after the photo was taken.
Because I have been in the process of preparing for my graduate thesis field work this summer, I have not had a chance to perform any additional bird surveys at Point au Sable. I will be heading to the northern hardwood forests of Wisconsin on Saturday to assist in performing over two-hundred bird surveys with the Nature Conservancy (TNC) for my thesis research. For my thesis project, I am developing a probability-based ecological indicator model for over 65,000 acres of forested land that is managed by TNC, the state of Wisconsin, and timber investment management organizations in the Wild Rivers Legacy Forest (WRLF). Based on an environmental gradient (ranging from degraded to pristine forest conditions), this ecological indicator will utilize the presence and absence of assemblages of bird species to indicate the ecological condition and conservation health of the forested lands of the WRLF. This indication of ecological condition will provide timber managers within the WRLF assistance in monitoring and managing these forests in a sustainable manner for both humans and wildlife.
In preparation for the model, TNC surveyed sites in the northern hardwoods of Wisconsin for forest bird species in the summer of 2009. This summer, I will be fortunate enough to join the team of ornithologists and survey the same sites as well as others, starting this Sunday. Additionally, in order to survey sites across the entire environmental gradient, my graduate advisor, Dr. Bob Howe, and I are surveying additional areas of varying forest condition including fragmented, isolated, and/or human-used areas in the Brown County area in order to most appropriately create this ecological indicator model. Therefore, we started these additional surveys yesterday morning in areas including and surrounding Brown County. All of this data will then ultimately contribute towards the conservation, protection, and sustainable use of northern Wisconsin hardwood forests.
Yesterday, we went to the managed forests of the Reforestation Camp in Suamico, Wisconsin and found 31 total bird species, including many species of particular interest: Mourning Warbler, Northern Waterthrush, Pileated Woodpecker, Scarlet Tanager, Veery, and Yellow-bellied Sapsucker. We also found American Crow, American Goldfinch, American Robin, Black-capped Chickadee, Blue-gray Gnatcatcher, Brown-headed Cowbird, Blue Jay, Canada Goose, Common Yellowthroat Warbler, Downy Woodpecker, Eastern Wood-Pewee, Great Crested Flycatcher, Gray Catbird, Hairy Woodpecker, House Wren, Indigo Bunting, Mourning Dove, Northern Cardinal, Ovenbird, Red-bellied Woodpecker, Red-eyed Vireo, Red-winged Blackbird, Sandhill Crane, White-breasted Nuthatch, and Wild Turkey.
Although I will be in northern Wisconsin for the next few weeks, I will provide a few reports about my thesis work and the annual Nicolet National Forest Bird Survey (June 11-13) when I return to Green Bay. Then, once I am back from field work, I will survey Point au Sable again and provide weekly updates. So please stay tuned!
With bright sunshine, nearly 60 degrees in temperature, and northerly winds over the weekend, we found many new species and the most total species observed for the season in one morning-a total of 59 species! We observed approximately a dozen Common Goldeneyes performing mating rituals off shore near a few American White Pelicans. A dozen Double-crested Cormorants, Canada Geese, Mallard Ducks, and screeching Caspian Terns passed along shore and overhead through the morning. Spotted Sandpipers and Sandhill Cranes also continue to use the Point. Despite many of the interesting species we observed today, we found a few broken American Robin egg shells, which we have found a few times around the Point. Sadly, the eggs might have blown out of different pair’s nests during some intense wind or rain storms that we have had this April and May.
Of the newest arrivals were Red-eyed Vireos, Yellow-throated Vireos, Least Flycatchers, and Yellow-bellied Flycatchers! While I stumbled upon a Northern Waterthrush out in the open, Aaron spotted our season’s first Black-billed Cuckoo high in an aspen tree, laying fairly still along a branch. We later found it lower in a shrub, perhaps resting after arriving to the Point overnight. And one short of our record of total warbler species observed in one day for the season, we observed 13 total warbler species this morning, including Northern Waterthrush, Tennessee, Golden-winged, Magnolia, American Redstart, Palm, Blackburnian, Yellow, Yellow-rumped, Common Yellowthroat, Black-and-white, Ovenbird, and Nashville Warblers. We continue to observe Warbling Vireos, Rose-breasted Grosbeaks, Swamp Sparrows, Blue-gray Gnatcatchers, House Wrens, Bald Eagles, Baltimore Orioles, Song Sparrows, and many more interesting and magnificent species of birds.
Observers: Erin Gnass and Aaron Groves (Thank you very much, Aaron, for accompanying and helping me this spring season and best of luck with your Cofrin student research summer field work!)