Reintroductions are essential in wildlife conservation, but their success depends not only on demographic outcomes such as survival and reproduction, but also on behavioral adjustments that determine integration into the wild. The Grey Crowned Crane (Balearica regulorum), an endangered species, has suffered dramatic declines due to habitat loss, disturbance, and illegal capture. In Rwanda, a large-scale amnesty rescued 242 cranes from captivity, with 166 rehabilitated and released into Akagera National Park. This study used GPS-GSM telemetry to investigate post-release movement of reintroduced captive-rescued cranes in comparison with wild individuals. Twenty-one cranes (10 reintroduced, 11 wild) were tracked for 5–1118 days, with 15 individuals meeting criteria for detailed analyses. Reintroduced cranes exhibited reduced dispersal, with only 2 of 7 dispersing compared to 7 of 9 wild cranes, and typically after much longer residence at the release site. Reintroduced cranes also had smaller maximum displacements (median 8.4 km) and smaller home ranges (median 3.3 km2) relative to those of wild cranes (median 24.0 km and median 22.6 km2, respectively). These findings suggest that supplemental feeding and extended captivity (2 days to 10 years) of reintroduced cranes strongly influenced their high site fidelity and movement patterns. While limited dispersal may benefit short-term survival, long-term monitoring of survival, reproduction, and demographic trends is critical for assessing whether reintroduction achieves population recovery.

Whale shark (Rhincodon typus) tourism is a growing industry, particularly at "El Azul" off the Yucat & aacute;n coast of Mexico, one of the largest known whale shark aggregation sites. Using aerial video footage acquired during unmanned aerial vehicle surveys in August 2016 and August 2022, this study assessed the frequency of regulatory violations of tour boat operators and clientele in proximity to whale sharks and the factors affecting non-compliance. The frequency of non-compliance incidents was driven by the number of boats, swimmers, and whale sharks present; as these numbers increased, so did the frequency of violations. We observed a high frequency of non-compliance by boats and swimmers even when the number of boats was far below the regulatory limit of 120 boats permitted for whale shark activities. The presence of a patrol boat had limited effectiveness in reducing the frequency of non-compliance activities. Our results demonstrate that the existing 120-boat limit and periodic enforcement are inadequate to ensure compliance, underscoring the need for stronger management measures. Additional ecological and social research are needed to develop more robust compliance and enforcement strategies for promoting responsible whale shark tourism, ensuring its long-term sustainability, and conserving whale shark populations in the Mexican Caribbean.

.Mangrove ecosystems are vulnerable to climate change impacts, which depend on species sensitivity and location. We studied the effects of climate change on three dominant mangrove species globally: red, black, and white mangroves. Using simulation, GIS, and statistical modeling, we evaluated spatially explicit changes in growth suitability resulting from climatic change. Our analysis shows that climate change has significant impacts on mangrove wetlands, with red and black mangroves being the most affected. Low precipitation can impact all species, with red, black, and white mangroves showing a 0.008%, 0.004%, and 0.008% decrease in growth suitability, respectively, for each one mm reduction in precipitation. Variability in climatic variables, such as a unit increase in CV, also significantly impacts mangroves. These results highlight the need to protect mangrove ecosystems for the sustainability of coastal ecosystems.

Sun bears (Helarctos malayanus) occur in various habitat types, ranging from dense natural forests to degraded forests and agricultural lands, such as oil palm plantations. Yet, the species population is declining due to habitat loss, hunting, and other threats, and the species is classified as threatened by the International Union for Conservation of Nature. In Myanmar, where the species' distribution is not well known, we conducted dryseason surveys using 120 camera-trap stations in a portion of the Htamanthi Wildlife Sanctuary (HWS) in northern Myanmar between 2016 and 2019 to identify the factors influencing sun bear distribution. From a total of 15,315 trap nights, we obtained 47 independent photo events of sun bears (0.31 captures/100 trap nights) at 9-16% of the stations. We analysed 12 factors that could potentially influence sun bear occupancy and detection probability. Sun bear occupancy increased as distance from patrol stations increased, but it was not affected by distance to roads. Sun bear detection probability increased when the probabilities of tigers (Panthera tigris), poachers, and field team presence were higher, but it was not affected by trespasser presence. Overall, our study did a poor job in identifying the ecological factors affecting sun bear occupancy in HWS. Instead, it highlighted several anthropogenic variables whose influences on sun bear distribution were counterintuitive. Further, many of our results contrasted with reports from other sun bear studies. Sun bears and other wildlife may be experiencing extremely low levels of human harassment and harvest in our study area. Thus, they may not be as sensitive to anthropogenic factors as reported elsewhere.

The endangered Grey Crowned-Crane (Balearica regulorum) occurs extensively in agricultural areas and grasslands outside of protected areas in Tanzania, posing high potential for conflict with people. This study sought to determine the extent of crop depredation by cranes, extent of illegal crane trade, and attitudes towards and interactions of local people with Grey Crowned-Cranes. We interviewed 570 respondents (44% female) from 42 rural communities across four districts in Tanzania. Most of the respondents were farmers (n = 288), followed by livestock keepers (n = 169), businesspersons (n = 75), government employees (n = 24), and others (n = 14). Overall, 91% of the respondents indicated that Grey Crowned-Cranes were not a pest to crops but, for those reporting damage, farmers with mixed or other types of crops (maize, beans, bananas, tomatoes) reported the highest frequency of damage. The respondents had positive interactions with cranes, with 96% responding that they caused no harm to the cranes and 4% saying they used trapping and chasing of cranes to control crop damage. There was evidence of crane trade, with 6% of the respondents reporting having seen illegal collection of cranes or taking crane eggs or chicks. The reported illegal collection of cranes occurred mainly in the Mbeya Region for use in traditional medicine. Overall, respondents had positive attitudes towards Grey Crowned-Cranes, and we recommend that crane conservation education programs be developed and delivered to rural communities to enhance Grey Crowned-Crane conservation in Tanzania.

Grey Crowned Cranes (Balearica regulorum), an endangered species that occurs throughout eastern and south-central Africa, are generally well-protected within national parks but commonly occur outside protected areas where the landscape is largely used for agriculture, settlement, and grazing. Understanding a species' distribution and collecting information on its presence from people who have long-standing interactions in an area of interest (i.e. local ecological knowledge) can be cost-effective for conservation. Thus, during February-December 2015, we gathered local knowledge from villagers to help inform Grey Crowned Crane status, distribution, breeding, and seasonal habitat use outside protected areas in Tanzania. Via 560 in-person surveys in 41 villages, local people identified 46 locations where they reported seeing cranes. In two regions, the proportion of crane observations by local people was higher in the wet season than the dry season, but in two others the proportion of crane observations were high in both seasons. Little evidence of crane breeding was reported, but a high proportion of local people in the Kilimanjaro region reported seeing crane chicks relative to the other regions. We modelled the influence of land-cover types and demographic variables on the number of people who reported seeing Grey Crowned Cranes in their wards (subunits of regions). Residents were more likely to see cranes in areas that were less populated by people with few human activities. An increase in grassland habitats in a ward increased the chances of people sighting cranes. While seasonal wetlands are important crane habitats, the model indicated a negative relationship between number of people seeing cranes and the percentage of wetlands in their wards; this may be due to the occurrence of degraded (unsuitable) wetlands. Local knowledge can provide insights into species' distribution and ecology, but there is a need for more field monitoring of cranes.

There are few quantitative estimates of numbers of Africa's endangered grey crowned cranes (Balearica regulorum), yet conservation of this species will depend on such estimates. We used line-transect distance sampling on multiple 2-km segments of an existing road network to estimate the abundance of grey crowned cranes in a portion of the Ngorongoro Crater, Tanzania, during the wet (April) and dry (August) seasons of 2016. We analysed data from 106 transects on which we observed 174 groups of 1-61 cranes (median and mode = 2). Abundance and density estimates on the areas surveyed were best modelled without group size as a covariate and indicated that mean crane densities were significantly lower in the wet season (2.4/km(2)) than in the dry season (20.2 cranes/km(2)). Even based on survey areas of different size, minimum estimated numbers of cranes in the Crater (wet season: 108-133; dry season: 362-401) likely reflect the concentration of cranes in the nonbreeding (dry) season in the perennial wetlands of the Crater and reinforce the notion of the Crater being a key seasonal habitat for crane populations in northern Tanzania, as previously suggested in the literature.

Bonefish (Albula spp.) are a popular recreational gamefish; however, there is currently limited information on bonefish early life history stages. Here we examine the diet of juvenile bonefish (Albula vulpes) in Eleuthera, The Bahamas, and provide a comparison to previously collected data on bonefish (Albula spp., primarily A. goreensis) in Florida. In Eleuthera, amphipods and carideans were the most important prey items found in the digestive tracts of 111 juvenile bonefish collected in 2011 and 2012. There was no difference in the ranking of 14 prey taxa between years, however, there was a difference between sample locations on Eleuthera, The Bahamas, with fish being from either Rock Sound (west coast) or Savannah Sound and Half Sound (east coast). Prey species diversity, evenness, and richness were all lower on the west coast compared to the east coast of Eleuthera. There was also a higher probability of an empty stomach with larger bonefish on the west coast, higher amphipod and caridean abundances in juvenile bonefish on the west coast, and higher amphipod abundance with larger bonefish of Eleuthera. Differences may be related to variation in habitat structure and/or prey availability between the sample locations of the island. There was no statistical difference in ranking between the 17 prey taxa categories in Eleuthera A. vulpes and Florida A. spp (86% A. goreensis) juvenile bonefish stomachs; however, only one taxon (Amphipoda) occurred in the top-five-ranked taxa between the two studies. Results reported here provide the first insight into juvenile A. vulpes diet and how bonefish diet may vary across embayments, regions, and species.

Since the 1970s, the magnitude of turtle cold-stun strandings have increased dramatically within the northwestern Atlantic. Here, we examine oceanic, atmospheric, and biological factors that may affect the increasing trend of cold-stunned Kemp's ridleys in Cape Cod Bay, Massachusetts, United States of America. Using machine learning and Bayesian inference modeling techniques, we demonstrate higher cold-stunning years occur when the Gulf of Maine has warmer sea surface temperatures in late October through early November. Surprisingly, hatchling numbers in Mexico, a proxy for population abundance, was not identified as an important factor. Further, using our Bayesian count model and forecasted sea surface temperature projections, we predict more than 2,300 Kemp's ridley turtles may coldstun annually by 2031 as sea surface temperatures continue to increase within the Gulf of Maine. We suggest warmer sea surface temperatures may have modified the northerly distribution of Kemp's ridleys and act as an ecological bridge between the Gulf Stream and nearshore waters. While cold-stunning may currently account for a minor proportion of juvenile mortality, we recommend continuing efforts to rehabilitate cold-stunned individuals to maintain population resiliency for this critically endangered species in the face of a changing climate and continuing anthropogenic threats.

With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola's elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975-2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6-40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola's elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola's elephants face an uncertain future.

The use of digital VHF telemetry is expanding as a lightweight alternative to satellite-based technologies for tracking bird movements, though few studies have compared how they perform. During 2013, satellite telemetry and digital VHF telemetry were compared for estimating the length of stay and home ranges of American Oystercatchers (Haematopus palliatus) on their breeding grounds in Massachusetts; USA. American Oystercatchers (n = 5) were captured at their nest sites and tagged with a 9.5-g solar-powered satellite transmitter and a 1.0-g digitally coded VHF transmitter, and tracked using the Argos satellite system, an array of eight automated radio telemetry stations, and periodic land-based and aerial telemetry surveys. Estimates of mean minimum length of stay in the study area were slightly longer for satellite telemetry at 118 +/- 12 days vs. digital VHF telemetry at 108 11 days. Size estimates of mean (SE) fixed kernel 95% utilization distributions were similar for satellite telemetry (22.53 +/- 16.87 km(2)) and VHF telemetry (27.27 +/- 21.58 km(2)). Despite a small sample size, digital VHF telemetry, when combined with automated radio telemetry stations and telemetry surveys, performed similarly to satellite telemetry for estimating timing and home range size of shorebirds on their breeding grounds.

In animal surveys, detectability can vary widely across species. We hypothesized that detectability of animals should be a function of species traits such as mass, color, and mean herd size. We also hypothesized that models of detectability based on species traits can be used to predict detectability for new species not in the original data set, leading to substantial benefits for ecology and conservation. We tested these hypotheses with double-observer aerial surveys of 10 mammal species in northern Botswana. We combined all 10 species and modeled their detectability with species traits (mass, mean herd size, color) as predictors while controlling for observer effects, vegetation, and herd size. We found support for effects of mass and an interaction between herd size and mean herd size on detectability. This model accurately predicted the ratio of herds detected by two observers vs. one observer for 8 of 10 species. To test whether a model based on species traits could be applied to a new species, we serially deleted each species from the data set, fit a trait-based model to the remaining nine species, and used this model to predict detectability for the deleted species. The model was able to reproduce the species-trait model for seven species and accurately predicted the ratio of detections by one or two observers for a different set of seven species; the model was successful by both measures for five species. To our knowledge, this represents the first time that a mechanistic model for detectability of animals has been used to predict detectability for new species. Prediction failed for species with extreme values of traits, suggesting that predicting detectability is not possible near or beyond the boundaries of one's data set. The approach taken in this paper can potentially be used with a variety of taxa and may provide new opportunities to apply detectability corrections where they have not been possible before.

Accurate counts of animals are critical for prioritizing conservation efforts. Past research, however, suggests that observers on aerial surveys may fail to detect all individuals of the target species present in the survey area. Such errors could bias population estimates low and confound trend estimation. We used two approaches to assess the accuracy of aerial surveys for African savanna elephants (Loxodonta africana) in northern Botswana. First, we used double-observer sampling, in which two observers make observations on the same herds, to estimate detectability of elephants and determine what variables affect it. Second, we compared total counts, a complete survey of the entire study area, against sample counts, in which only a portion of the study area is sampled. Total counts are often considered a complete census, so comparing total counts against sample counts can help to determine if sample counts are underestimating elephant numbers. We estimated that observers detected only 76% ± SE of 2% of elephant herds and 87 ± 1% of individual elephants present in survey strips. Detectability increased strongly with elephant herd size. Out of the four observers used in total, one observer had a lower detection probability than the other three, and detectability was higher in the rear row of seats than the front. The habitat immediately adjacent to animals also affected detectability, with detection more likely in more open habitats. Total counts were not statistically distinguishable from sample counts. Because, however, the double-observer samples revealed that observers missed 13% of elephants, we conclude that total counts may be undercounting elephants as well. These results suggest that elephant population estimates from both sample and total counts are biased low. Because factors such as observer and habitat affected detectability of elephants, comparisons of elephant populations across time or space may be confounded. We encourage survey teams to incorporate detectability analysis in all aerial surveys for mammals.

African elephants ( Loxodonta africana ) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants’ downward trajectory by preventing poaching and protecting habitat.

We applaud the 2015 report of Burke et al. to broaden the testing of habanero pepper powder as a potential deterrent to nest predation of turtle nests. Although we had much success in reducing nest predation rates by coyotes (Canis latrans) at loggerhead sea turtle (Caretta caretta) nests (LamarreDeJesus and Griffin 2013), our results were based on only 1 season of data at 1 beach location in South Carolina. We suspect that the dramatic difference in the efficacy of habanero pepper for reducing nest predation rates between our study for loggerheads and those reported by Burke et al. for diamondback terrapin (Malaclemys terrapin) may be related primarily to the predators involved.

As seabird nesting colonies have become concentrated on fewer managed islands, available nesting habitat for open-ground nesters such as Common Terns (Sterna hirundo) has rapidly become overgrown by guano-fertilized vegetation, leading managers to try various methods of vegetation control to open usable nesting habitat. Two of these methods, burning and synthetic weed barrier treatments, were tested in the summers of 2009 and 2010 to assess their ability to open and maintain Common Tern nesting habitat on two nearshore seabird nesting islands in Maine. Treatments were applied to overgrown habitat pre-nesting, and vegetation regrowth and Common Tern nest and fledging success were monitored in treated plots, untreated vegetation plots and occupied Common Tern nesting habitat. Burned areas did not remain open for the full nesting season, but regrew shortly after egg-laying, creating unsuitable vegetation structure and leading to near-complete nest failure in these plots. However, vegetation characteristics produced by the two different weed barrier treatments one a layer of muslin fabric overlaying newspaper mulch and the other a mosaic of synthetic turf and open ground were similar to vegetation in pre-existing Common Tern nesting habitat throughout the season. Common Tern nest and fledging success was similar in weed barrier plots (1.37 chicks/pair) and pre-existing Common Tern nesting habitat (1.38 chicks/pair). While burning may not be a useful technique for creating nesting habitat, synthetic weed barriers offer a promising short-term solution to vegetation overgrowth in nesting habitat of Common Terns and species with similar habitat requirements.

Increasingly, habitat fragmentation caused by agricultural and human development has forced Sumatran elephants into relatively small areas, but there is little information on how elephants use these areas and thus, how habitats can be managed to sustain elephants in the future. Using a Global Positioning System (GPS) collar and a land cover map developed from TM imagery, we identified the habitats used by a wild adult female elephant (Elephas maximus sumatranus) in the Seblat Elephant Conservation Center, Bengkulu Province, Sumatra during 2007–2008. The marked elephant (and presumably her 40–60 herd mates) used a home range that contained more than expected medium canopy and open canopy land cover. Further, within the home range, closed canopy forests were used more during the day than at night. When elephants were in closed canopy forests they were most often near the forest edge vs. in the forest interior. Effective elephant conservation strategies in Sumatra need to focus on forest restoration of cleared areas and providing a forest matrix that includes various canopy types.

Abstract We tested the effectiveness of nest screens and habanero pepper powder as deterrents for reducing depredation of loggerhead sea turtle (Caretta caretta) nests on Sand Island, South Carolina, including nest-screening (1 × 1-m plastic or metal mesh secured over the nest; n  =  33), surface-treatment (15 ml of habanero pepper powder sprinkled on the surface of the sand; n  =  10), bottom-treatment (15 ml of habanero pepper powder sprinkled 3 cm above the top egg; n  =  10), and 10 control nests. Twenty-two of 66 nests were partially or completely depredated by coyotes (Canis latrans), and nest survival rates varied from a high of 80% for surface-treated, 75% for screened, 45% for bottom-treated, and 32% for control nests. We propose that early surface-treatment of nests with pepper powder may provide an effective and more efficient management alternative to using screens, which are more difficult and costly to install, for reducing nest depredation at sea turtle nests.