DOI: 10.5061/dryad.xgxd254s7
title: Tree cover limits occupancy of a declining game bird

description: Open forest ecosystems are considered one of the most imperiled ecosystems
 in North America and many associated avian species are experiencing
 population declines. Management at large and impactful scales is
 challenging on private lands due to fragmentation and resource
 limitations, but public lands are often larger in scale and offer
 opportunities for landscape level conservation of species of conservation
 concern. Northern bobwhite (Colinus virginianus; bobwhite) is a popular
 but declining game bird which is often considered an umbrella and
 indicator species for savanna ecosystems. To evaluate the effects of tree
 canopy cover and prescribed fire frequency (1 Jan 2010 – 15 May 2024) on
 bobwhite occupancy we surveyed 144 sites 11 times during 15 May – 17 June
 2024 using acoustic recording units on the Sabine and Angelina National
 Forests of Texas. Probability of bobwhite occupancy decreased as canopy
 cover increased (βTree = -0.74, 95% CrI: -1.29 – -0.28); occupancy was
 over 19 times higher when canopy cover was 44% versus the mean observed
 value of 80.8% (range: 38–96%). Despite a well-established positive
 relationship of bobwhite and prescribed fire based on previous research,
 we found tree canopy obfuscated any effects of fire frequency on bobwhite
 occupancy (βFire = -0.09, 95% CrI: -0.57 – 0.43). Only 2 of 144 sites were
 characterized by low-moderate canopy cover (&lt;50%) with a moderate
 fire frequency (burned 5 and 7 times since 2010). Our results underscore
 the importance of forest thinning in addition to prescribed fire for
 managing species which require savanna conditions.
description: Acousting recording units. 20 minute surveys at 0700-0720 from 15
 May - 17 June 2024. Convolutional neural network adapted and trained
 building upon Wolfe et al. (2023). Occupancy model. 
description: # Tree cover limits occupancy of a declining game bird
 [https://doi.org/10.5061/dryad.xgxd254s7](https://doi.org/10.5061/dryad.xgxd254s7) ## Description of the data and file structure y.n = Bobwhite detected (1) or not detected (0) during 1 of 11 surveys. Data are in a stacked format.  c.n = number of bobwhite songs detected during survey n, based on output of CNN.  tree250= Percent tree cover within a 250m buffer of ARU as estimated by rangeland analysis platform.  firefreq250 = Average number of times a site had been burned in the last 15 years (1 Jan 2010 – 15 May 2024) based on local USFS database. playback.n = Indicates the presence or absence of an autonomous playback speaker at a site during a given survey.  Data listed as NA are due to ARU batteries dying, card malfunctions, or other logistic issues.  ## Access information Other publicly accessible locations of the data: Metadata not used in analyses.  | PointName | Presence | Playback | Deployment | Easting | Northing | | :-------- | :------- | :------- | :--------- | :------ | :------- | | A1 | 0 | 1 | 1 | 376607 | 3436455 | | A10 | 0 | 1 | 2 | 391589 | 3436481 | | A11 | 1 | 0 | 1 | 393100 | 3436481 | | A12 | 0 | 0 | 2 | 375121 | 3437986 | | A13 | 0 | 1 | 1 | 376601 | 3437967 | | A14 | 0 | 0 | 2 | 378093 | 3437992 | | A15 | 0 | 0 | 1 | 379621 | 3437960 | | A16 | 0 | 1 | 2 | 381089 | 3437977 | | A17 | 0 | 0 | 1 | 382603 | 3437993 | | A18 | 0 | 1 | 2 | 384095 | 3437961 | | A19 | 1 | 1 | 1 | 385592 | 3437943 | | A2 | 0 | 0 | 2 | 378115 | 3436475 | | A20 | 1 | 0 | 2 | 387104 | 3437959 | | A21 | 1 | 0 | 1 | 388595 | 3437961 | | A22 | 0 | 1 | 2 | 390089 | 3437967 | | A23 | 1 | 0 | 1 | 391593 | 3438001 | | A24 | 0 | 0 | 2 | 376597 | 3439468 | | A25 | 0 | 1 | 1 | 378089 | 3439462 | | A26 | 0 | 0 | 2 | 381087 | 3439477 | | A27 | 1 | 1 | 1 | 382593 | 3439437 | | A28 | 0 | 1 | 2 | 384090 | 3439455 | | A29 | 0 | 0 | 1 | 385587 | 3439450 | | A3 | 0 | 0 | 1 | 379605 | 3436501 | | A30 | 0 | 0 | 2 | 387091 | 3439483 | | A31 | 0 | 1 | 1 | 388597 | 3439439 | | A32 | 0 | 0 | 2 | 375095 | 3440981 | | A33 | 0 | 0 | 1 | 376599 | 3440975 | | A35 | 0 | 0 | 1 | 381083 | 3440996 | | A36 | 1 | 0 | 2 | 382599 | 3440963 | | A37 | 0 | 1 | 1 | 375101 | 3442474 | | A38 | 0 | 0 | 2 | 376575 | 3442471 | | A39 | 0 | 0 | 1 | 378100 | 3442486 | | A4 | 0 | 1 | 2 | 382607 | 3436449 | | A40 | 0 | 1 | 2 | 379623 | 3442472 | | A41 | 0 | 0 | 1 | 381107 | 3442481 | | A42 | 0 | 0 | 2 | 372089 | 3443985 | | A43 | 0 | 1 | 1 | 375098 | 3443984 | | A44 | 0 | 0 | 2 | 376605 | 3443963 | | A45 | 0 | 0 | 1 | 378103 | 3443971 | | A46 | 0 | 1 | 2 | 369100 | 3445463 | | A47 | 0 | 0 | 1 | 370595 | 3445473 | | A48 | 0 | 0 | 2 | 372097 | 3445473 | | A49 | 0 | 1 | 1 | 373593 | 3445478 | | A5 | 0 | 0 | 1 | 384101 | 3436469 | | A50 | 1 | 1 | 2 | 375093 | 3445433 | | A51 | 1 | 0 | 1 | 376595 | 3445483 | | A52 | 0 | 1 | 2 | 378094 | 3445423 | | A53 | 0 | 0 | 1 | 379602 | 3445457 | | A54 | 0 | 0 | 2 | 375095 | 3446975 | | A55 | 1 | 1 | 1 | 376593 | 3446987 | | A56 | 0 | 0 | 2 | 378110 | 3446971 | | A57 | 0 | 1 | 1 | 370590 | 3448460 | | A58 | 0 | 1 | 2 | 372090 | 3448443 | | A59 | 0 | 0 | 1 | 375095 | 3448473 | | A6 | 0 | 0 | 2 | 385603 | 3436473 | | A60 | 0 | 0 | 2 | 376595 | 3448476 | | A62 | 0 | 0 | 1 | 372094 | 3449977 | | A63 | 0 | 1 | 2 | 373597 | 3449946 | | A64 | 0 | 0 | 1 | 375098 | 3449977 | | A65 | 0 | 1 | 1 | 373595 | 3451464 | | A7 | 0 | 1 | 1 | 387074 | 3436502 | | A8 | 0 | 0 | 2 | 388588 | 3436472 | | A9 | 1 | 0 | 1 | 390093 | 3436483 | | S1 | 0 | 0 | 2 | 408222 | 3448463 | | S10 | 0 | 1 | 1 | 426139 | 3448401 | | S11 | 0 | 0 | 2 | 429105 | 3448639 | | S12 | 0 | 1 | 2 | 408102 | 3450005 | | S13 | 0 | 0 | 1 | 412757 | 3449895 | | S14 | 0 | 0 | 2 | 418602 | 3449981 | | S15 | 0 | 1 | 1 | 420082 | 3449951 | | S16 | 0 | 0 | 2 | 421584 | 3449972 | | S17 | 0 | 0 | 1 | 423140 | 3450132 | | S18 | 0 | 1 | 2 | 424606 | 3449968 | | S19 | 0 | 1 | 2 | 430594 | 3449979 | | S2 | 0 | 0 | 1 | 409600 | 3448475 | | S23 | 0 | 0 | 2 | 411102 | 3451468 | | S24 | 0 | 0 | 1 | 421589 | 3451484 | | S25 | 0 | 0 | 2 | 424578 | 3451486 | | S26 | 0 | 1 | 1 | 426165 | 3451402 | | S27 | 0 | 0 | 2 | 427588 | 3451505 | | S28 | 0 | 1 | 1 | 408081 | 3452964 | | S29 | 1 | 1 | 2 | 412617 | 3452972 | | S3 | 0 | 0 | 2 | 412601 | 3448494 | | S30 | 0 | 0 | 1 | 420220 | 3452899 | | S31 | 0 | 1 | 2 | 423069 | 3452949 | | S32 | 0 | 1 | 1 | 409608 | 3454481 | | S33 | 0 | 0 | 2 | 411616 | 3454248 | | S34 | 0 | 0 | 1 | 414097 | 3454472 | | S35 | 0 | 1 | 2 | 415462 | 3454283 | | S36 | 0 | 0 | 1 | 422997 | 3454462 | | S37 | 0 | 0 | 2 | 424591 | 3454456 | | S38 | 0 | 1 | 1 | 428057 | 3454845 | | S39 | 0 | 0 | 2 | 429148 | 3454523 | | S4 | 0 | 0 | 1 | 414104 | 3448456 | | S40 | 0 | 0 | 1 | 409638 | 3455881 | | S41 | 0 | 1 | 2 | 411094 | 3455955 | | S42 | 0 | 0 | 1 | 412581 | 3455991 | | S43 | 1 | 0 | 2 | 420184 | 3455890 | | S44 | 0 | 1 | 2 | 422994 | 3455906 | | S46 | 0 | 0 | 1 | 429041 | 3455976 | | S47 | 0 | 0 | 2 | 430583 | 3455954 | | S48 | 1 | 0 | 1 | 412602 | 3457476 | | S49 | 0 | 0 | 2 | 414098 | 3457475 | | S50 | 0 | 1 | 1 | 415599 | 3457477 | | S51 | 1 | 1 | 2 | 417090 | 3457471 | | S52 | 1 | 0 | 1 | 418596 | 3457468 | | S53 | 1 | 0 | 2 | 419978 | 3457230 | | S54 | 0 | 0 | 1 | 423127 | 3457549 | | S55 | 0 | 0 | 2 | 424688 | 3457514 | | S56 | 1 | 1 | 1 | 411086 | 3458986 | | S57 | 0 | 0 | 2 | 412598 | 3458972 | | S58 | 1 | 0 | 1 | 414100 | 3458981 | | S59 | 1 | 1 | 2 | 415597 | 3458974 | | S6 | 0 | 1 | 1 | 418586 | 3448478 | | S60 | 0 | 0 | 1 | 417173 | 3459004 | | S61 | 1 | 0 | 2 | 418598 | 3458974 | | S62 | 0 | 1 | 1 | 420104 | 3458952 | | S63 | 0 | 0 | 2 | 421577 | 3458935 | | S64 | 0 | 0 | 1 | 422967 | 3459066 | | S65 | 0 | 1 | 2 | 424725 | 3458945 | | S66 | 0 | 0 | 1 | 426037 | 3458946 | | S67 | 0 | 0 | 2 | 427618 | 3459009 | | S68 | 0 | 1 | 1 | 429129 | 3459095 | | S69 | 0 | 0 | 2 | 430706 | 3459011 | | S7 | 0 | 0 | 2 | 421591 | 3448473 | | S70 | 0 | 0 | 1 | 432129 | 3458947 | | S71 | 0 | 1 | 2 | 434516 | 3459285 | | S72 | 1 | 1 | 1 | 411158 | 3460494 | | S73 | 1 | 0 | 2 | 412607 | 3460471 | | S74 | 1 | 1 | 1 | 414097 | 3460477 | | S75 | 1 | 0 | 2 | 415604 | 3460480 | | S77 | 0 | 1 | 2 | 418602 | 3460441 | | S78 | 0 | 0 | 1 | 420037 | 3460474 | | S79 | 0 | 0 | 2 | 421601 | 3460457 | | S8 | 0 | 0 | 1 | 423526 | 3448201 | | S80 | 0 | 1 | 2 | 423101 | 3460421 | | S82 | 0 | 0 | 1 | 427551 | 3460458 | | S83 | 0 | 1 | 2 | 430620 | 3460418 | | S84 | 0 | 0 | 1 | 432226 | 3460513 | | S85 | 0 | 0 | 2 | 433538 | 3460227 | | S86 | 0 | 1 | 1 | 412587 | 3461973 | | S87 | 0 | 1 | 2 | 417098 | 3461973 | | S88 | 0 | 0 | 1 | 418599 | 3461980 | | S9 | 0 | 1 | 2 | 424594 | 3448457 | Data was derived from the following sources: * Rangeland Analysis Platform 2023. * United States Forest Service Local Database Occ sim is an annotated R script modified from Kery and Shaub (2011) which is a simulation across a range of detection probabilities, number of survey sites, and temporal replicates to evaluate parameter stability given the variation in survey sites and temporal replicates. Value inputs are based on expert opinion of bobwhite detection (0 &lt; p &lt; 1), logistical constraints (i.e., more more than 160 survey sites given 80 ARUs per deployment), and closure (i.e., no more than 12 surveys or less than 2 weeks). Plots are made and followed by a simple occupancy model structure to evaluate performance.