Recovery of degraded lands in arid environments is especially challenging due to difficulty of matching ideal conditions to seed germination requirements and reduced native soil seed banks. Restoration practitioners try to overcome these challenges through seeding and site preparation treatments. In the McDowell Sonoran Preserve, Scottsdale, Arizona, the focus for restoring old roads was on seeding, cactus transplants, and soil treatments (either ripping or adding soil from nearby construction areas). Here we evaluated the success of these restoration sites 5–8 y after project completion. We compared vegetation and ground cover on eight roads that received a combination of these restoration treatments with adjacent reference areas. Plant cover was similar between the restoration and reference plots, but plant composition was different. The restoration plots contained more cacti due to cactus transplants, whereas the reference areas contained more shrub cover. The number of native plant species was greater in the reference areas than in the restoration plots. Seeding treatment had little effect, with only five of 11 seeded species appearing in plots, and only one species, Bouteloua aristidoides, appeared in both treatments that included seeding. Although cacti may have contributed to overall plant cover, they did not appear to aid establishment of other plants. Our findings suggest more interventions are likely required for the restoration and reference plant communities to converge in arid environments. We suggest considering multiple seeding treatments that will maximize the potential for ideal germination conditions and additional local interventions that may help accumulate litter and protect seeds.

Oak-pine barrens ecosystems provide critical habitat for the federally endangered Karner blue butterfly (Lycaeides melissa samuelis). Wild lupine (Lupinus perennis), an herbaceous perennial in this ecosystem is the only food source for the butterfly's larvae. The range and quality of these ecosystems have declined significantly. Restoration in private lands can be key to expanding these habitats, but often there is limited or no follow-up to assess the recovery of the site following restoration treatments. We conducted a case study in a private property in Newaygo County, Michigan for which prescribed fire had been implemented every 2 y from 2007 through 2011 to promote recruitment of key understory vegetation, but there had been no follow-up recovery assessment. The burn treatment consisted of a section that was not burned, one that was burned twice, and one that was burned three times. We collected data on vegetation groups and site related factors along this fire gradient to examine differences as a function of fire frequency, as well as delineate factors driving patterns of understory plant recruitment. Results show little tree recruitment from seedlings, but high densities of tree saplings recruited via resprouting. Estimated cover of lupine was low across all treatments, whereas Pennsylvania sedge (Carex pensylvanica Lam,) was highest among species in both cover and biomass. Lupine exhibited a negative relationship with Pennsylvania sedge, litter, and sprouted tree saplings, but a positive relationship with moss cover. We make recommendations for additional restoration interventions and highlight the need for continued support of private landowners as they engage in conservation of imperiled species.

Fire suppression and hardwood encroachment are two of the most significant threats to the imperiled, fire-dependent montane longleaf pine ecosystem. We examined the effects of restoration of a montane longleaf pine forest in Paulding County, Georgia, U.S.A. on tree canopy, groundcover and bird communities over a decade. The restoration included a program of prescribed fire and selective thinning to reduce tree canopy density and reduce or remove offsite species. Several conservation goals were met including the recovery of characteristic tree composition and groundcover. Birds responded with sharp increases in richness and abundance, with many shrub and woodland dependent species of high conservation value detected post-restoration. Our research demonstrates these sites are easily restorable and such projects will likely yield significant gains for conservation.

In 2015 the entire breeding colony of nesting waterbirds on Seahorse Key (Florida, U.S.A.) unexpectedly abandoned the island and have not returned. These birds have a unique trophic relationship with a sympatric cottonmouth snake (Agkistrodon conanti) population, as well as potentially important positions within the entire insular food web. Species-interaction network analysis was used to compare two trophic networks; pre- and post-abandonment. Trophic data were used to create a weighted adjacency matrix for each network and the resulting network metrics were compared using the network analysis software package UCINET and visualized using NetDraw. Results for the pre-abandonment network indicated a large, complex, diffuse network with low centrality and seven sub-networks. Several species of colonial nesting birds were identified as holding important positions within the network for resource transfer from marine and intertidal environments to terrestrial trophic guilds, particularly to the snakes. Post-abandonment analysis showed the network significantly fractured with the terrestrial trophic guild that includes the snakes being smaller, more isolated and potentially less stable.

We assessed geographic and temporal variation in diets of wintering Northern Harriers (Circus hudsonius) in western Indiana, U.S.A., using multivariate regression on counts of prey from pellets collected at communal roosts. Because there is no uniform method for determining the minimum number of individuals (MNI) contained in a pellet, we also assessed whether application of four different counting methods influenced our conclusions. We collected 821 Northern Harrier pellets from four roosts in 2018 and 2019. Pellet contents differed between years, months, and roost sites. Voles (Microtus spp.) were the most commonly occurring prey group at all roosts and in both years (range: 45–73%), but were encountered 35% less frequently than reported on average by other studies in the midwestern U.S.A. Accordingly, other small mammal prey groups became more important dietary components than reported by most other midwestern studies, including mice (Peromyscus; 5–16%), western harvest mice (Reithrodontomys megalotis; 4–14%), and northern short-tailed shrews (Blarina brevicauda; 8–18%). The four methods of counting MNI produced no discernible effects on our conclusions concerning pellet contents between months or roosts. Northern Harriers in western Indiana exhibited great diet flexibility, which likely reflects local prey populations and constraints of life in intensive agroecosystems.

Pocket gophers (Geomyidae) require soils amenable to burrowing and vegetation communities that provide adequate foods. We examined the interplay of soil texture and vegetation structure in determining site occupancy of the southeastern pocket gopher (Geomys pinetis), a species of conservation concern throughout its range. Using a case-control sampling design, we compared vegetation structure and soil texture between occupied and unoccupied sites in southeastern Alabama. All occupied sites had soil clay content ≤8.05% at 0–20 cm depth. In logistic regression modeling, clay content had overwhelming support as the most important single habitat variable distinguishing occupied from unoccupied sites. Based on soil results, we focused our examination of vegetation structure on the subset of our sites with <10% clay at 0–20 cm depth. Relative odds of occupancy were highest at intermediate levels of canopy cover; however, canopy cover at occupied sites ranged widely. Compared to unoccupied sites, occupied sites contained less midstory cover and greater ground cover of graminoids and shrubs. Our results demonstrate that although vegetation structure is important in determining site suitability, soil texture may be an overriding constraint limiting potential habitat for this species. Conservation actions for southeastern pocket gophers such as habitat restoration and population translocations should ensure that target sites have suitable low-clay soils.

Bobcat (Lynx rufus) populations have increased in the midwestern U.S. since the 1980s after substantial declines and local extirpations into the mid-1900s. We monitored 38 radio-collared bobcats (25 males, 13 females) from 1998 to 2006 in a recovering population in south-central Indiana to investigate survival and mortality causes. Annual survival was high (Ŝ = 0.80, 95% CI = 0.71–0.89), comparable to results from other studies of bobcats in unexploited populations and higher than in harvested populations. Of 17 known deaths, vehicle collisions were the largest source of mortality (n = 9; 53%), followed by illegal shootings (n = 3; 18%). Higher values of habitat heterogeneity within home ranges were associated with lower risk of mortality. Estimates of survival and mortality sources in recovering populations provide an important context to compare management strategies to improve bobcat conservation.

We tested macroinvertebrate assemblages collected from 1979–2015 for temporal variation in structure and for impacts of the Clean Water Act of 1974. Collections were at ten sites on the mainstem of the West Fork White River. We used family-level taxonomy for macroinvertebrates that resulted in 77 families and 92,477 individuals. Macroinvertebrate families were further classified by trophic and tolerance traits and tested for temporal variation. We defined river reaches as upstream, urban, and downstream of Muncie, Indiana for analyses. Taxonomic richness increased over the study. A nonmetric multidimensional scaling (NMDS) analysis identified high temporal variation as assemblage structure differed among decades. Spatial analyses using NMDS indicated significant differences by river location upstream, urban, and downstream. NMDS and Analysis of Similarities (ANOSIM) by trophic relationship and tolerance values did not result in significant temporal or spatial patterns. Our results show the macroinvertebrate assemblages of the West Fork White River improved, likely due to implementation of the Clean Water Act.

Mozingo Lake was sampled monthly for 4 y following its impoundment in order to further understand trophic upsurges and to refine the classic model of upsurges. Upsurge 1 occurred in Month 8, when lake area increased by 184% and inundated only floodplain with comparable coverages of forest, cropland, and grassland (30%–33% each). At this time nitrate increased dramatically and was related to both precipitation and lake area increase, likely due to ammonia-based fertilizers from the flooded cropland. Phytoplankton biovolume remained low, however, likely due to the abundance of Daphnia and other zooplankton grazers. After recovery, the lake expanded dramatically again in Month 21 (Upsurge 2); lake area increased by 36%, but this expansion flooded land with less floodplain (23%) and with different proportions of land use (45% grassland, 31% forest, 14% cropland). Upsurge 2 experienced initial increases in nitrate and zooplankton, but these were minor compared to Upsurge 1, and phytoplankton remained low. These initial responses were followed by substantial increases in phosphate, which related to lake area increase; cyanobacteria biovolume expanded, but zooplankton abundance declined. Therefore the two upsurges were driven by different factors: nitrate in Upsurge 1, but phosphate in Upsurge 2. These drivers, in turn, may reflect differences in the newly-flooded land, including differences in land use and in landscape position (i.e., slope). In addition to seasonal succession, the phytoplankton of Mozingo Lake exhibited longer-term primary succession that related first to nitrate, then to grazing, then to multiple factors, suggesting increases in food web complexity. In contrast to the classic model of upsurges, the biotic responses in Mozingo Lake were quite transitory, and the nature of the upsurges varied with the characteristics of the newly-inundated land. Therefore, it appears that trophic upsurge is more variable than the classic model suggests.

Herbivores can have nonconsumptive effects on ecosystems, including the redistribution of nutrients in their waste. In tallgrass prairie bison (Bison bison) historically increased soil nitrogen availability via labile waste deposits. White-tailed deer (Odocoileus virginianus) are now the dominant native large herbivore in prairie and have been shown to consume higher nutrient-content plants than those preferred by bison. Deer are also edge-dwelling species that reuse the trails they make as they move and browse throughout the prairie. Therefore, deer may differ from bison in their spatial patterns of nutrient content and redistribution of fecal matter. We examined the nutrient content and spatial distribution of deer pellets by measuring the number of deer pellet piles along deer trails and transects that were systematically placed at the forest border and in open prairie. We also measured the nitrogen content of deer pellets. White-tailed deer pellets had twofold greater nitrogen concentrations (3.43% N and 40.8% C) compared to values reported for bison fecal matter. Deer pellet piles were more concentrated on deer trails compared to the transects, resulting in fourfold greater N inputs on deer trails compared to areas off of trails. As a result, White-tailed deer have the potential to create patches of increased nutrient availability through their clumped distribution of nutrient rich fecal matter, with potential consequences for prairie plant communities.

During routine surveys of owl distributions on St. Catherines Island, we observed naturalized ring-tailed lemurs displaying antipredator responses to owl auditory cues. In the 32 y since the introduction of ring-tailed lemurs to the island, two successful depredation events by two different owl species have been documented. We investigated the behavioral response of ring-tailed lemurs to determine if they responded consistently to social calls from all three owl species present on St. Catherines Island despite size differences among the owl species that could affect the likelihood of them serving as predators on ring-tailed lemurs. We observed while ring-tailed lemurs responded to all the auditory owl calls, they exhibited more intense, longer and more consistent responses to the two larger owl species – the barred owl and great horned owl – relative to the small Eastern screech owl. These data suggest naturalized species are capable of learning threat-sensitive antipredator behaviors to novel predator communities.

Recovery of degraded lands in arid environments is especially challenging due to difficulty of matching ideal conditions to seed germination requirements and reduced native soil seed banks. Restoration practitioners try to overcome these challenges through seeding and site preparation treatments. In the McDowell Sonoran Preserve, Scottsdale, Arizona, the focus for restoring old roads was on seeding, cactus transplants, and soil treatments (either ripping or adding soil from nearby construction areas). Here we evaluated the success of these restoration sites 5–8 y after project completion. We compared vegetation and ground cover on eight roads that received a combination of these restoration treatments with adjacent reference areas. Plant cover was similar between the restoration and reference plots, but plant composition was different. The restoration plots contained more cacti due to cactus transplants, whereas the reference areas contained more shrub cover. The number of native plant species was greater in the reference areas than in the restoration plots. Seeding treatment had little effect, with only five of 11 seeded species appearing in plots, and only one species, Bouteloua aristidoides, appeared in both treatments that included seeding. Although cacti may have contributed to overall plant cover, they did not appear to aid establishment of other plants. Our findings suggest more interventions are likely required for the restoration and reference plant communities to converge in arid environments. We suggest considering multiple seeding treatments that will maximize the potential for ideal germination conditions and additional local interventions that may help accumulate litter and protect seeds.

Oak-pine barrens ecosystems provide critical habitat for the federally endangered Karner blue butterfly (Lycaeides melissa samuelis). Wild lupine (Lupinus perennis), an herbaceous perennial in this ecosystem is the only food source for the butterfly's larvae. The range and quality of these ecosystems have declined significantly. Restoration in private lands can be key to expanding these habitats, but often there is limited or no follow-up to assess the recovery of the site following restoration treatments. We conducted a case study in a private property in Newaygo County, Michigan for which prescribed fire had been implemented every 2 y from 2007 through 2011 to promote recruitment of key understory vegetation, but there had been no follow-up recovery assessment. The burn treatment consisted of a section that was not burned, one that was burned twice, and one that was burned three times. We collected data on vegetation groups and site related factors along this fire gradient to examine differences as a function of fire frequency, as well as delineate factors driving patterns of understory plant recruitment. Results show little tree recruitment from seedlings, but high densities of tree saplings recruited via resprouting. Estimated cover of lupine was low across all treatments, whereas Pennsylvania sedge (Carex pensylvanica Lam,) was highest among species in both cover and biomass. Lupine exhibited a negative relationship with Pennsylvania sedge, litter, and sprouted tree saplings, but a positive relationship with moss cover. We make recommendations for additional restoration interventions and highlight the need for continued support of private landowners as they engage in conservation of imperiled species.

Fire suppression and hardwood encroachment are two of the most significant threats to the imperiled, fire-dependent montane longleaf pine ecosystem. We examined the effects of restoration of a montane longleaf pine forest in Paulding County, Georgia, U.S.A. on tree canopy, groundcover and bird communities over a decade. The restoration included a program of prescribed fire and selective thinning to reduce tree canopy density and reduce or remove offsite species. Several conservation goals were met including the recovery of characteristic tree composition and groundcover. Birds responded with sharp increases in richness and abundance, with many shrub and woodland dependent species of high conservation value detected post-restoration. Our research demonstrates these sites are easily restorable and such projects will likely yield significant gains for conservation.

In 2015 the entire breeding colony of nesting waterbirds on Seahorse Key (Florida, U.S.A.) unexpectedly abandoned the island and have not returned. These birds have a unique trophic relationship with a sympatric cottonmouth snake (Agkistrodon conanti) population, as well as potentially important positions within the entire insular food web. Species-interaction network analysis was used to compare two trophic networks; pre- and post-abandonment. Trophic data were used to create a weighted adjacency matrix for each network and the resulting network metrics were compared using the network analysis software package UCINET and visualized using NetDraw. Results for the pre-abandonment network indicated a large, complex, diffuse network with low centrality and seven sub-networks. Several species of colonial nesting birds were identified as holding important positions within the network for resource transfer from marine and intertidal environments to terrestrial trophic guilds, particularly to the snakes. Post-abandonment analysis showed the network significantly fractured with the terrestrial trophic guild that includes the snakes being smaller, more isolated and potentially less stable.

We assessed geographic and temporal variation in diets of wintering Northern Harriers (Circus hudsonius) in western Indiana, U.S.A., using multivariate regression on counts of prey from pellets collected at communal roosts. Because there is no uniform method for determining the minimum number of individuals (MNI) contained in a pellet, we also assessed whether application of four different counting methods influenced our conclusions. We collected 821 Northern Harrier pellets from four roosts in 2018 and 2019. Pellet contents differed between years, months, and roost sites. Voles (Microtus spp.) were the most commonly occurring prey group at all roosts and in both years (range: 45–73%), but were encountered 35% less frequently than reported on average by other studies in the midwestern U.S.A. Accordingly, other small mammal prey groups became more important dietary components than reported by most other midwestern studies, including mice (Peromyscus; 5–16%), western harvest mice (Reithrodontomys megalotis; 4–14%), and northern short-tailed shrews (Blarina brevicauda; 8–18%). The four methods of counting MNI produced no discernible effects on our conclusions concerning pellet contents between months or roosts. Northern Harriers in western Indiana exhibited great diet flexibility, which likely reflects local prey populations and constraints of life in intensive agroecosystems.

Pocket gophers (Geomyidae) require soils amenable to burrowing and vegetation communities that provide adequate foods. We examined the interplay of soil texture and vegetation structure in determining site occupancy of the southeastern pocket gopher (Geomys pinetis), a species of conservation concern throughout its range. Using a case-control sampling design, we compared vegetation structure and soil texture between occupied and unoccupied sites in southeastern Alabama. All occupied sites had soil clay content ≤8.05% at 0–20 cm depth. In logistic regression modeling, clay content had overwhelming support as the most important single habitat variable distinguishing occupied from unoccupied sites. Based on soil results, we focused our examination of vegetation structure on the subset of our sites with <10% clay at 0–20 cm depth. Relative odds of occupancy were highest at intermediate levels of canopy cover; however, canopy cover at occupied sites ranged widely. Compared to unoccupied sites, occupied sites contained less midstory cover and greater ground cover of graminoids and shrubs. Our results demonstrate that although vegetation structure is important in determining site suitability, soil texture may be an overriding constraint limiting potential habitat for this species. Conservation actions for southeastern pocket gophers such as habitat restoration and population translocations should ensure that target sites have suitable low-clay soils.

Bobcat (Lynx rufus) populations have increased in the midwestern U.S. since the 1980s after substantial declines and local extirpations into the mid-1900s. We monitored 38 radio-collared bobcats (25 males, 13 females) from 1998 to 2006 in a recovering population in south-central Indiana to investigate survival and mortality causes. Annual survival was high (Ŝ = 0.80, 95% CI = 0.71–0.89), comparable to results from other studies of bobcats in unexploited populations and higher than in harvested populations. Of 17 known deaths, vehicle collisions were the largest source of mortality (n = 9; 53%), followed by illegal shootings (n = 3; 18%). Higher values of habitat heterogeneity within home ranges were associated with lower risk of mortality. Estimates of survival and mortality sources in recovering populations provide an important context to compare management strategies to improve bobcat conservation.

We tested macroinvertebrate assemblages collected from 1979–2015 for temporal variation in structure and for impacts of the Clean Water Act of 1974. Collections were at ten sites on the mainstem of the West Fork White River. We used family-level taxonomy for macroinvertebrates that resulted in 77 families and 92,477 individuals. Macroinvertebrate families were further classified by trophic and tolerance traits and tested for temporal variation. We defined river reaches as upstream, urban, and downstream of Muncie, Indiana for analyses. Taxonomic richness increased over the study. A nonmetric multidimensional scaling (NMDS) analysis identified high temporal variation as assemblage structure differed among decades. Spatial analyses using NMDS indicated significant differences by river location upstream, urban, and downstream. NMDS and Analysis of Similarities (ANOSIM) by trophic relationship and tolerance values did not result in significant temporal or spatial patterns. Our results show the macroinvertebrate assemblages of the West Fork White River improved, likely due to implementation of the Clean Water Act.

Mozingo Lake was sampled monthly for 4 y following its impoundment in order to further understand trophic upsurges and to refine the classic model of upsurges. Upsurge 1 occurred in Month 8, when lake area increased by 184% and inundated only floodplain with comparable coverages of forest, cropland, and grassland (30%–33% each). At this time nitrate increased dramatically and was related to both precipitation and lake area increase, likely due to ammonia-based fertilizers from the flooded cropland. Phytoplankton biovolume remained low, however, likely due to the abundance of Daphnia and other zooplankton grazers. After recovery, the lake expanded dramatically again in Month 21 (Upsurge 2); lake area increased by 36%, but this expansion flooded land with less floodplain (23%) and with different proportions of land use (45% grassland, 31% forest, 14% cropland). Upsurge 2 experienced initial increases in nitrate and zooplankton, but these were minor compared to Upsurge 1, and phytoplankton remained low. These initial responses were followed by substantial increases in phosphate, which related to lake area increase; cyanobacteria biovolume expanded, but zooplankton abundance declined. Therefore the two upsurges were driven by different factors: nitrate in Upsurge 1, but phosphate in Upsurge 2. These drivers, in turn, may reflect differences in the newly-flooded land, including differences in land use and in landscape position (i.e., slope). In addition to seasonal succession, the phytoplankton of Mozingo Lake exhibited longer-term primary succession that related first to nitrate, then to grazing, then to multiple factors, suggesting increases in food web complexity. In contrast to the classic model of upsurges, the biotic responses in Mozingo Lake were quite transitory, and the nature of the upsurges varied with the characteristics of the newly-inundated land. Therefore, it appears that trophic upsurge is more variable than the classic model suggests.

Herbivores can have nonconsumptive effects on ecosystems, including the redistribution of nutrients in their waste. In tallgrass prairie bison (Bison bison) historically increased soil nitrogen availability via labile waste deposits. White-tailed deer (Odocoileus virginianus) are now the dominant native large herbivore in prairie and have been shown to consume higher nutrient-content plants than those preferred by bison. Deer are also edge-dwelling species that reuse the trails they make as they move and browse throughout the prairie. Therefore, deer may differ from bison in their spatial patterns of nutrient content and redistribution of fecal matter. We examined the nutrient content and spatial distribution of deer pellets by measuring the number of deer pellet piles along deer trails and transects that were systematically placed at the forest border and in open prairie. We also measured the nitrogen content of deer pellets. White-tailed deer pellets had twofold greater nitrogen concentrations (3.43% N and 40.8% C) compared to values reported for bison fecal matter. Deer pellet piles were more concentrated on deer trails compared to the transects, resulting in fourfold greater N inputs on deer trails compared to areas off of trails. As a result, White-tailed deer have the potential to create patches of increased nutrient availability through their clumped distribution of nutrient rich fecal matter, with potential consequences for prairie plant communities.

During routine surveys of owl distributions on St. Catherines Island, we observed naturalized ring-tailed lemurs displaying antipredator responses to owl auditory cues. In the 32 y since the introduction of ring-tailed lemurs to the island, two successful depredation events by two different owl species have been documented. We investigated the behavioral response of ring-tailed lemurs to determine if they responded consistently to social calls from all three owl species present on St. Catherines Island despite size differences among the owl species that could affect the likelihood of them serving as predators on ring-tailed lemurs. We observed while ring-tailed lemurs responded to all the auditory owl calls, they exhibited more intense, longer and more consistent responses to the two larger owl species – the barred owl and great horned owl – relative to the small Eastern screech owl. These data suggest naturalized species are capable of learning threat-sensitive antipredator behaviors to novel predator communities.