Multiple lines of evidence suggest the persistence of the Ivory-billed Woodpecker (Campephilus principalis) in Louisiana

The history of the decline of the Ivory-billed Woodpecker is long and complex, but the status of the species since 1944, when the last widely accepted sighting in continental North America occurred, is particularly controversial. Reports of Ivory-billed Woodpeckers have continued, but none has reached the threshold of quality for general acceptance by ornithologists or the birdwatching public. In 2021, the U.S. Fish and Wildlife Service opened for public comment a proposal to declare the species extinct. Here, we present evidence suggesting the presence of the Ivory-billed Woodpecker at our study site, based on a variety of data collected over a 10-year search period, 2012-2022. These data are drawn from visual observations, ~70,000 h of recordings by 80-100 acoustic recording units, ~472,550 camera-hours by as many as 34 trail cameras, and ~1089 h of video drawn from ~3265 drone flights. Using multiple lines of evidence, the data suggest intermittent but repeated presence of multiple individual birds with field marks and behaviors consistent with those of Ivory-billed Woodpeckers. Data indicate repeated reuse of foraging sites and core habitat. Our findings, and the inferences drawn from them, suggest that not all is lost for the Ivory-billed Woodpecker, and that it is clearly premature for the species to be declared extinct.

Extreme tolerance for nocturnal emergence at low body temperatures in a high-latitude lizard: implications for future climate warming

High-latitude lizards live in environments where ambient air temperature at night is frequently below retreat temperatures, which likely has implications for nocturnal emergence and activity. However, patterns of lizard activity at night under current temperate climates are poorly understood, a situation that limits our understanding of potential effects of climate change. We investigated patterns of nocturnal emergence and activity in the cold-adapted, viviparous gecko (Woodworthia 'Otago/Southland'). We measured operative environmental temperature (T _e) available to geckos that emerged at night and simultaneously assessed nighttime emergence activity using time-lapse trail cameras. Also, we assessed field body temperature (T _b) of emerged geckos of various life history groups at night using thermography to understand how current weather conditions affect field T _b of emerged geckos. Our results show that T_e , nocturnal emergence activity and field-active T _b increased with nighttime air temperature. Nocturnal emergence was highest in spring and summer but also occurred in autumn and (unexpectedly) in winter. Geckos were active over a broad range of T _b down to 1.4°C (a new record low for lizards) and on rock surfaces typically warmer than air temperature or T _b. We conclude that this nocturnal, high-latitude lizard from the temperate zone is capable of activity at low winter temperatures, but that current climate limits emergence and activity at least in autumn and winter. Activity levels for cool-temperate reptiles will probably increase initially as climates warm, but the consequences of increased nocturnal activity under climate change will probably depend on how climate change affects predator populations as well as the focal species' biology.

Shell colour diversification induced by ecological release: A shift in natural selection after a migration event

Ecological release is often attributed to the rapid adaptive diversification of phenotypic traits. However, it is not well understood how natural selection changes its strength and direction through the process of ecological release. Herein, we demonstrated how shell colour of the Japanese land snail Euhadra peliomphala simodae has diversified via a shift in natural selection due to ecological release after migration from the mainland to an island. This snail's shell colour diversified on the island due to disruptive selection after migration from the mainland. We used trail camera traps to identify the cause of natural selection on both the mainland and the island. We then conducted a mark-recapture experiment while collecting microhabitat use data. In total, we captured and marked around 1,700 snails on the mainland, some of which were preyed upon by an unknown predator. The trail camera traps showed that the predator is the large Japanese field mouse Apodemus speciosus, and the predatory frequency was higher on the mainland than on the island. However, this predation did not correlate with shell colour. Microhabitat use on the island was more extensive than on the mainland, with snails on the island using both ground and arboreal microhabitats. A Bayesian estimation showed that the stabilizing selection on shell colour came from factors other than predation. Our results suggest that the course of natural selection was modified due to ecological release after migration from the mainland, explaining one cause of the phenotypic diversification.

Camera settings and biome influence the accuracy of citizen science approaches to camera trap image classification

Scientists are increasingly using volunteer efforts of citizen scientists to classify images captured by motion-activated trail cameras. The rising popularity of citizen science reflects its potential to engage the public in conservation science and accelerate processing of the large volume of images generated by trail cameras. While image classification accuracy by citizen scientists can vary across species, the influence of other factors on accuracy is poorly understood. Inaccuracy diminishes the value of citizen science derived data and prompts the need for specific best-practice protocols to decrease error. We compare the accuracy between three programs that use crowdsourced citizen scientists to process images online: Snapshot Serengeti, Wildwatch Kenya, and AmazonCam Tambopata. We hypothesized that habitat type and camera settings would influence accuracy. To evaluate these factors, each photograph was circulated to multiple volunteers. All volunteer classifications were aggregated to a single best answer for each photograph using a plurality algorithm. Subsequently, a subset of these images underwent expert review and were compared to the citizen scientist results. Classification errors were categorized by the nature of the error (e.g., false species or false empty), and reason for the false classification (e.g., misidentification). Our results show that Snapshot Serengeti had the highest accuracy (97.9%), followed by AmazonCam Tambopata (93.5%), then Wildwatch Kenya (83.4%). Error type was influenced by habitat, with false empty images more prevalent in open-grassy habitat (27%) compared to woodlands (10%). For medium to large animal surveys across all habitat types, our results suggest that to significantly improve accuracy in crowdsourced projects, researchers should use a trail camera set up protocol with a burst of three consecutive photographs, a short field of view, and determine camera sensitivity settings based on in situ testing. Accuracy level comparisons such as this study can improve reliability of future citizen science projects, and subsequently encourage the increased use of such data.

Framing pictures: A conceptual framework to identify and correct for biases in detection probability of camera traps enabling multi-species comparison

Obtaining reliable species observations is of great importance in animal ecology and wildlife conservation. An increasing number of studies use camera traps (CTs) to study wildlife communities, and an increasing effort is made to make better use and reuse of the large amounts of data that are produced. It is in these circumstances that it becomes paramount to correct for the species- and study-specific variation in imperfect detection within CTs. We reviewed the literature and used our own experience to compile a list of factors that affect CT detection of animals. We did this within a conceptual framework of six distinct scales separating out the influences of (a) animal characteristics, (b) CT specifications, (c) CT set-up protocols, and (d) environmental variables. We identified 40 factors that can potentially influence the detection of animals by CTs at these six scales. Many of these factors were related to only a few overarching parameters. Most of the animal characteristics scale with body mass and diet type, and most environmental characteristics differ with season or latitude such that remote sensing products like NDVI could be used as a proxy index to capture this variation. Factors that influence detection at the microsite and camera scales are probably the most important in determining CT detection of animals. The type of study and specific research question will determine which factors should be corrected. Corrections can be done by directly adjusting the CT metric of interest or by using covariates in a statistical framework. Our conceptual framework can be used to design better CT studies and help when analyzing CT data. Furthermore, it provides an overview of which factors should be reported in CT studies to make them repeatable, comparable, and their data reusable. This should greatly improve the possibilities for global scale analyses of (reused) CT data.

Mammal diversity and metacommunity dynamics in urban green spaces: implications for urban wildlife conservation

As urban growth expands and natural environments fragment, it is essential to understand the ecological roles fulfilled by urban green spaces. To evaluate how urban green spaces function as wildlife habitat, we estimated mammal diversity and metacommunity dynamics in city parks, cemeteries, golf courses, and natural areas throughout the greater Chicago, Illinois, USA region. We found similar α-diversity (with the exception of city parks), but remarkably dissimilar communities in different urban green spaces. Additionally, the type of urban green space greatly influenced species colonization and persistence rates. For example, coyotes (Canis latrans) had the highest, but white-tailed deer (Odocoileus virginianus) the lowest probability of persistence in golf courses compared to other green space types. Further, most species had a difficult time colonizing city parks even when sites were seemingly available. Our results indicate that urban green spaces contribute different, but collectively important, habitats for maintaining and conserving biodiversity in cities.