Annual Federal Aid Performance Report, W-136-R-02Report issued on: September 21, 2001Prepared for unspecified recipien

Brawn, Jeffrey D.

Heske, Edward J.

Seigrist, Joseph

English

Illinois Digital Environment for Access to Learning and Scholarship Repository

ILLINO SUNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGNPRODUCTION NOTEUniversity of Illinois atUrbana-Champaign LibraryLarge-scale Digitization Project, 2007.ILLINOIS NATURALHISTORY SURVEYCENTER FORWILDLIFE ECOLOGYEffects of Traditional Habitat and Ecosystem Management on thePopulation Ecology of the Northern BobwhiteW-136-R-02Annual Federal Aid Performance ReportPrepared by:Jeffrey D. BrawnEdward HeskeJoseph SeigristSubmitted by:Jeffrey D. BrawnIllinois Natural History Survey607 East Peabody DriveChampaign, Illinois 61820Executive SummaryIn 2000-2001, we continued a comprehensive study of the population ecology ofthe Northern Bobwhite at the Jim Edgar-Panther Creek State Fish and Wildlife Area(formerly known as "Site M") in Cass Co. IL. The primary objectives of this projectare: 1) to estimate and compare local densities in different habitat types where activemanagement for quail is occurring and on untillable sites where ecosystem managementis being employed, 2) to evaluate bobwhite nesting ecology 3) to investigate bobwhitebrood movements, and 4) to investigate how other components of avian biodiversityreact to different management strategies and land-use.Fieldwork was conducted during the entire segment. Fall, 2001 was devoted totrapping of quail throughout the study site using techniques that were developed inSegment 1. To date (since initiation of the study), 109 quail have been trapped. Ofthese, 69 have been fitted with radio collars and tracked. In Segment II, 71 quail-( 18subadult female, 1 adult female, 49 subadult male, 3 adult male) were captured. Overalltrapping effort through the end of Segment II includes 5000 trap hours using decoy trapsand 18,500 trap hours using bait (i.e. corn) traps. The efficiency of decoy trapping(which is effective only during the near or during the breeding season) was considerablygreater than that for bait trapping.Birds fitted with collars yielded over 1,800 telemetry locations by the end ofSegment II (we attempted to locate each bird every 3 days and 1 night / week; all2locations were triangulated). In cases where we lost contact, we conducted overflights toassess whether birds had dispersed unusually long distances.Preliminary analyses of habitat use during the breeding season were complex,but clearly indicated that permanent pasture and cropped fields were preferred habitatsfor quail. Conversely, habitat dominated by woodland and cool season grasses appearedto be used less than that expected based on availability. Patterns of habitat use duringthe non-breeding or covey season were similar, but cropped fields were the mostfrequently utilized cover-type.A major challenge for analysis of habitat use by quail (and by non-game birds orpredators) is modification and ground truthing of the GIS habitat classification maps.At present, in collaboration with cooperators from the Illinois Department of NaturalResources, we are modifying the cover maps. The process of modifying cover typeswill also be relevant to future analyses non-game birds and potential predators indifferent types of habitat.Annual survival of quail (age classes and sexes pooled) is estimated to beapproximately 20-25%. Severe winter weather, fall hunting, or both appear to beespecially influential during the non-breeding season. Predation on adults by birds ormammals appears to be an important source of mortality during the breeding season.To date, only 6 quail nests have been located. Despite intensive searching byexperienced field crews, the most productive mode of locating nests is through locationof radio-collared birds that are incubating. All 6 nests were successful in terms of hatch,but in 3 cases adults were preyed upon while they were leading young broods. The firstyear of a two-year artificial quail nest experiment was also carried out to assess therelationship between habitat structure and probability of predation. This experimentsuggested differences by habitats and over the course of the breeding season, butanother year of replication is needed to reach conclusions about these patterns.Censuses of non-game birds and predators revealed assemblages that are typicalof Illinois where there is considerable edge and diverse cover types. Over 400 nests ofnon-game birds (239 in Segment 2) have been located and monitored; rates of loss topredation have been notably high for nearly all species in both Segments I and II.STUDY 101: Estimation of northern bobwhite densities in different habitat types.Job 101.1 - Selection of focal study sites.Selection of focal study sites was accomplished in Segment I and we continuedto use these sites that cover the 3 primary management units on the area and virtually allhabitat types. Our original objective to compare of tillable and untillable areas will besomewhat hampered owing to the small amount of untillable acreage on the site. Ascommented upon on in the Executive Summary, the cover maps supplied to us byIllinois Department of Natural Resources (IDNR) will need to be modified and groundtruthed. The modification process has been initiated in consultation with John Cole ofthe IDNRJob 101.2 - Censuses and population studies of quail in different habitats duringthe breeding and non-breeding season.Estimation of quail abundances throughout the site was accomplished in threeways. First, point counts were conducted on 40 of the 70 sites discussed above. Eachpoint was visited twice during June. Each visit consisted of a five minute census duringwhich all quail vocalizations and visual registrations were recorded. Estimateddistance (we used unlimited distance counts) and direction of each registration wererecorded. Second, in cooperation with IDNR we continued roadside quail counts thathave been conducted for several years. Each census point was visited twice during June(one or two points could not be visited during each round owing to limited access fromroad maintenance). Third, all quail observations made during the course of trapping andtracking birds (see below) were mapped. Estimated quail abundances on the differentmanagement units is presented in Table 1. Subsequent to census efforts in Segment III,detailed analyses will be carried out to assess variation among the management unitsand variation owing to differences in habitat structure and land use. Again, closeanalyses of habitat effects on local abundances will need of follow modification of thecover maps. Roadside quail counts indicated similar patterns of variation in quailabundance.Table 1. Estimated abundances of Northern Bobwhites on the three major managementunits in Segments I and II.Management Unit Estimated Abundance (Avg. detections/ 10 points)Quail Management 8.3Controlled Hunting 6.5Open Unit 4.4Data on the frequency of quail encounters were collected via a survey form given tohunters in covey season 00-01. About 25 surveys were collected and these data arecurrently under analyses We believe the best estimates of spatial and temporal variationin abundances of quail during the non-breeding season will derive from the longer-terminformation on reported hunter harvest and reported hours afield. These data will beanalyzed in Segment III.6Job 101.3 - Characterization of habitat structure on focal study sites.The recent landcover classification was utilized in Segment II (see Fig. 1). Personnelwere trained in the use of these cover maps using ArcView GIS software. Habitatanalyses will be conducted in detail during Segment III subsequent to revision of thecover-types.Job 101.4 - Management and analyses of population dataFormat and entry forms for all datafiles (census, telemetry, and habitat structure) wereidentified. The standard file format will be a ".dbf' file (most likely using VisualFoxPro software). Data entry was initiated during the segment and virtually all thetelemetry data has been entered in to GIS software databases for spatial visualizationand analysis (all telemetry locations were determined via portable GPS units).STUDY 102: Determination of survival, nest and reproductive success, nestpredators, and habitat use of the northern bobwhite.Job 102.1 - Locating and monitoring the success of quail nests.Considerable effort (200 person hours in Segment I, 500 person hours in Segment II)has been devoted to locating quail nests. Based on 2 years of experience, we havedetermined that the most efficient mean of locating nests is through nocturnal telemetrylocation of males or females that are incubating. Standard search cues such as flushinghens and other behavioral cures have proved to be unproductive. To date we havemonitored 6 quail nests (see Table 2). We have also monitored quail nests with fieldvideo-infrared cameras.Nest found8/8/008/15/008/25/005/9/017/3/017/15/01# hatched?12151512126 week flushcount56Adult deadAdult deadContact lostpendingTable2. Summary of fates for 6 Northern bobwhite Quail nests and broods.Job 102.2 - Trapping and fitting bobwhites with radio transmitters.New or refitted radios were purchased and new project personnel were trained fortelemetry tracking in Segment II, during which 71 quail-(18 subadult female, 1 adultfemale, 49 subadult male, 3 adult male) were captured. Overall trapping effort throughthe end of Segment II includes 5000 trap hours using decoy traps and 18,500 trap hoursusing bait (i.e. corn) traps. The efficiency of decoy trapping (which is effective onlyduring the near or during the breeding season) was considerably greater than that forbait trapping. Overall, 102 quail have been captured and banded; of these, 69 have beenfitted with transmitters and released. To date, we have 25 mortality events of knowncause (Table 1). We have experienced 15 cases of radio failure and in 12 cases thecause of mortality could not be determined. Natural mortality owing to avian andmammalian predators has, to date, been the most prevalent cause of death.Annual survival of quail is estimated to be about 25% based on preliminary analysesusing Kaplan-Meier estimation procedures (Fig 2.).Table 3. Summary of quail mortality events (lost birds and radio failures not listed).Likely Cause of Mortality Number of BirdsAvian predator 12Mammal 10Hunting 3Unknown 12Job 102.3: Experimental investigation of nest predation.In Segment II, we conducted the first round of an experiment to investigatepredation rates on artificial quail nests in different habitats sites with different recentland-use. We could not assess rates of predation in all habitat-types that are present onthe site (Fig. 1). Rather, we examined nest predation in five grassland dominatedhabitat that had or had not been burned recently. The five habitat types were: warmseason grasses, cool season grasses, permanent pasture, CRP, and "borders." Weidentified the bum history of each individual field and categorized it as recently burned(those within units burned the current or previous year) or successional. For eachtreatment combination we randomly selected 3 fields. Within each field selected, weplaced 5 artificial quail nests, each containing 10 quail eggs. We placed a total of 300artificial nests in the fields, 150 in May and 150 in July. We monitored these nestsevery 3 days for 10 days. We observed predation events on the artificial nests. Weobserved a total of 8 predation events in May (5.5%) and 24 in July (14.1%; 3 nestswere predated more than once). Fourteen predation events occurred in recently burnedfields, 18 in successional fields. Results are summarized in Table 4.Table 4. Predation Events on Artificial Quail Nests at Jim Edgar Panther Creek StateFish & Wildlife Area.Recently Burned SuccessionalGrasslands GrasslandsMAY JULY MAY JULYWarm Season FULL 0 2 0 0Grasses PARTIAL 0 0 0 1Cool Season FULL 0 4 0 0Grasses PARTIAL 1 1 0 3Permanent FULL 1 1 1 3Pasture PARTIAL 0 1 1 1Conservation FULL 0 1 1 1Reserve PARTIAL 0 1 1 0ProgramBorders FULL 0 1 2 2PARTIAL 0 0 0 1Predation events ranged from the removal of a single egg to the destruction of the nestand its contents. On 6 occasions, a single egg was removed cleanly from the nest; on 4occasions a single egg was crushed or punctured in the nest. One nest had 4-5 eggsremoved twice during the 10-day exposure period. Of the 20 nests that were fullypredated, we found shell remains in or around the nest at 13. Of those same 20 nests,the nest itself was moved from its original location or otherwise damaged on 11occasions. One nest was found dumped over with 8 of the 10 eggs punctured but noneeaten.10While inconclusive, it is possible to infer predator identity based on nestremains. Mammals generally leave shell fragments behind and are capable of tearingapart the nest itself. Snakes generally swallow eggs whole and therefore tend not toleave shell fragments. Birds often puncture eggs with their beaks leaving obvious clues.Based on these generalizations, we can infer that of the 32 predation events recorded,mammals predated 13-25 nests, snakes predated 6-13 nests, and birds 1-4 predatednests. We also found a carrion beetle in one of the nests with a single punctured egg.Job 102.4: Estimation of species diversity and abundances of nest predatorsAs in Segment I, predator abundance and distribution was sampled using baitedsand track stations at the 70 focal census stations. We alternated bait between fatty acidscent (FAS) tablets and salmon-flavored cat food. We recorded tracks present for 2-3consecutive nights at all 70 sampling points during May, June, and July. Track stationswere active for a total of 560 nights. We recorded 5 times as many raccoons asopossums, the second most common species, and more raccoons than all other predatorspecies combined. Raccoons were recorded at 46 of the 70 sampling points and wereevenly distributed across the site. Results for all species surveyed are summarized inTable 5. In Segment III, These data will be used to analyze habitat use by these speciesat a variety of spatial scales.11Table 5. Abundance and Distribution of Mammalian Predators.Total # of Track stationstracks visited (x/70)recordedRaccoon Procyon lotor 118 46Opossum Didelphis virginiana 23 16Long-tailed weasel Mustela 20 10frenataFox Vulpes vulpes and 16 11UrocyoncineoargenteusFox squirrel Sciurus niger 15 12Striped skunk Mephitis 10 8mephitisCoyote Canis latrans 4 4Domestic cat Felis catus 1 1Domestic dog Canisfamiliaris 0 0Badger Taxidea taxus 0 0Mink Mustela vison 0 012Job 102.5: Characterization of habitat use by quail using GIS.As of this writing approximately 1,800 telemetry fixes have been recorded,georeferenced, and into the GIS data. These data have been summarized in two ways.First, home range maps for were constructed from data collected during the breedingand non-breeding (i.e., covey) seasons. Visual summaries of day to day movements ofindividual birds were also derived. Samples of these graphical summaries for covey arepresented in Figs. 3-4. Habitat use in relation to weather, time of year, and otherenvironmental factors will be assessed in Segment III subsequent to modification ofcovermap. To date, we have collected comprehensive data on 13 coveys.Preliminary analyses of habitat use during the breeding season were complex,but clearly indicated that permanent pasture and cropped fields were preferred habitatsfor quail (Figs 5-6). Conversely, habitat dominated by woodland and cool seasongrasses appeared to be used less than that expected based on availability. Patterns ofhabitat use during the non-breeding or covey season were similar, but cropped fieldswere the most frequently utilized cover-type. Comprehensive analyses of habitat use atdifferent spatial scales will be completed in Segment III.Study 103: Effects of habitat structure and different land-use practices onreproductive ecology and local abundances of nongame birds.Job 103.1: Characterization of nesting success of nongame birds in sitesundergoing traditional quail management versus and ecosystem restoration.13To date, 454 nongame bird nests have been located and monitored (239 nestwere detected in Segment II). This sample consisted of 32 species. As in Segment I,the sample was dominated by Red-winged Blackbirds, which was the most commonnesting songbird on the area (forest habitat was not sampled). A breakdown of the nestsby select species is presented in Table 6.Table 6. Rates of success of selected species for the 2001 breeding season.Species Number of Nest Located Number of Nests SuccessfulandEstimated Daily Success Rate(%)Red-winged Blackbird 31 3 /89%Field Sparrow 38 6 / 89%Dickcissel 18 1 / 87%Indigo Bunting 8 2 / 98%American Goldfinch 20 7 / 95%Gray Catbird 16 5/91%Job 103.2: Censusing of nongame birds in different habitat during the breedingand non-breeding season.Non-game birds (including raptors) were censused during the point counts discussedabove. As in Segment I, 40 points distributed throughout the site were visited 4 timeseach from late may through early July. To date over 80 species of birds have beendetected during these counts. This comparatively high diversity reflects the mix of14habitat types at the site (grassland, savanna, woodland, shrubland). The bird communityat the site is dominated by Red-winged Blackbirds, Dickcissels, Indigo Buntings, andField Sparrows. Community and population analyses regarding habitat structure andpatterns of co-variation between abundances of quail and non-game birds will beconducted in Segment III.Prospects for Segment 3.The major objectives for Segment III will be to implement GIS analyses ofhabitat structure and develop models to associate habitat with quail activity anddemography, increase samples sizes for quail telemetry tracking and habitat use,increase the number of located quail nests by allocating more resources to this effort,and conduct another round of artificial nest experiments. Based on Segment II, weexpect that samples sizes will be sufficient to provide robust analyses for all the studiesand jobs. An exception is the location and monitoring of quail nests. For Segment III,we intend to somewhat de-emphasize the study of non-game bird nesting biology anddevote more time and personnel to looking for quail nests.SUBMITTED BY:Jeffrey D. 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Effects of Traditional Habitat and Ecosystem Management on the Population Ecology of the Northern Bobwhite

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