Camera traps are very useful to study temporal patterns of animals. However, most studies only take into account one or two temporal dimensions. We consider that, in most cases, there are at least four temporal cycles to be considered: day, week, month (lunar) and year. Therefore, the aim of this article is to analyze the importance of studying all four cycles, using data from a natural landmark as an example. We monitored the Pico del Aguila, in central Mexico, using camera traps for one year. We used the Hermans-Rasson test for distribution uniformity and calculated the overlap of activities between species for each temporal cycle. All four cycles affected the activity patterns of animal species. Activity peaks of ringtails and rodents coincide, suggesting the predation of the latter. Dogs and squirrels were affected by the week cycle, suggesting that interaction with humans is important for those species. Diurnal animals increased their activity during the new moon, and it raises the question: why are those animals affected by the moon? Using the year cycle, we established the Mexican Cottontail reproductive period. All four cycles provided useful information. We conclude that studying all four should be a common practice for camera-trap studies.
This is the first documented record of incidental hook ingestion in two endemic turtle species, the Nazas slider (Trachemys hartwegi) and the Durango mud turtle (Kinosternon durangoense), both with restricted distributions in northern Mexico and listed under threatened categories by the IUCN. The incidents, which occurred during the 2025 summer holiday period in the Nazas River, Durango, Mexico, highlight the presence of non-permitted recreational fishing in the area and underscore the need to strengthen surveillance and environmental education, as the loss of adults can have significant population-level consequences.
Mexico contains high insect biodiversity due to its diverse habitats and highly variable topography. However, our study found that insect observation, sampling, and collection efforts underrepresent the state's true insect biodiversity. This study examined total insect occurrence records and a subset of butterfly-only records from New Mexico and compared collections effort per area represented by both total records and number of taxa across ecoregions, mountain ranges, land management, and proximity to roads. We discovered that across ecoregions, the mountain regions were extensively sampled, while the Great Plains grasslands were poorly sampled. Among mountain ranges, those nearest to population centers were well sampled, while those located on state borders were poorly sampled. Finally, public land management designation had the most significant impact on collection bias. Land managed by the U.S. Forest Service was most extensively well sampled, and land managed by the Bureau of Land Management and Tribal entities were poorly sampled. Additionally, we found that nearly 80% of both all insect and butterfly-only occurrence records occurred within one kilometer of a road. Future insect surveys and collecting across underrepresented lands and ecoregions will provide better sampling information of biodiversity and the conservation status of New Mexico's insects. With this knowledge in mind, detailed observation, collection, and sampling recommendations are provided.
Water-holding tree holes are important phytotelma habitats for dipteran larvae, especially mosquitoes. In these systems, mosquito larvae serve as prey for diverse predators, many of which are specialists of tree hole microhabitats. Here, we report observations of underwater predation of mosquito larvae by a poorly known rove beetle, Hesperus arizonicus, in oak tree holes in the Sky Islands Region of southeastern Arizona. This terrestrial beetle was observed in the field walking into the water of a tree hole, remaining submerged for almost two minutes, and subsequently emerging from the water carrying a mosquito larva. In the laboratory, we prepared a mock tree hole microhabitat to better observe this behavior in captive beetles. We determined that, while underwater, the thorax and abdomens of these beetles are enveloped in a layer of air, that the beetles hunt for mosquito larvae underwater and, after seizing a larva, exit the water to consume their prey, and that the beetles can remain submerged for approximately eight minutes. Separately, we recorded the number of late instar (mosquitoes undergo four larval instars) mosquito larvae consumed by a beetle over a ten-day period, and found that, on average, approximately 20 mosquito larvae were consumed per day. These observations document details of the otherwise unknown natural history of H. arizonicus and suggest that this species is a specialist of tree hole phytotelmata where it may be a top predator. Underwater hunting for mosquito larvae among rove beetles has been documented previously, but these observations are noteworthy because H. arizonicus is the first species known to engage in this behavior in tree hole phytotelmata, and the only species known to do this outside of the tropics.
Fire's effect on in-stream communities varies depending on the intensity and frequency of the fire regime. As wildfire frequency increases, its effects are more important to understand. We sampled aquatic macroinvertebrates and fishes before and after the Marshall Fire in Coal Creek, Colorado at two sites within and downstream of the burn area and used biotic indices and direct examination of community composition to assess effects on these communities. We saw modest effects on macroinvertebrate communities with lower metric scores after the fire and an increase in four tolerant taxa, but we saw no substantive post-fire differences in the fish community other than differences in the presence of uncommon species. Our results are consistent with past studies showing higher sensitivity of macroinvertebrates to fire than fishes and that only high-intensity fires covering a high percentage of the basin have large effects on lotic community composition.
Cassin's Sparrow (Peucaea cassinii) is a resident species of the southwestern United States and northern Mexico. Like many aridland birds, Cassin's Sparrow is thought to be an opportunistic breeder, its movements and other aspects of its reproductive cycle influenced by favorable conditions rather than a fixed schedule. In this study, we used retrospective ecological niche modeling, environmental data from NASA's MERRA-2 reanalysis, and 40 years of eBird observations to examine short-term and long-term trends in climatic suitability for the species during its breeding season. We found a consistent east-to-west progression of climatic suitability for Cassin's Sparrow during the summer months, with an annual average northwesterly movement of similar to 613 km over the 40-year study period. These shifts, driven largely by surface wind speed and variability in temperature and precipitation, have diminished over time from similar to 922 km over the summer season in the mid-1980s to similar to 304 km in recent years. Spatial analysis revealed that the amount of change in suitability over the course of the breeding season is increasing in central and western parts of Cassin's Sparrow's range and decreasing in southeastern Texas. This regional variation aligns with reported changes in breeding phenology, suggesting that the magnitude of seasonal change in suitability itself might have an important influence on the species' breeding cycle. Our findings further suggest that Cassin's Sparrow's response to long-term climate change might increasingly depend on adapting to regional conditions rather than the opportunistic movements once thought to define its breeding strategy.
On 28 May 2025, we observed a Brown-crested Flycatcher (Myiarchus tyrannulus) preying on an adult Lucy's Warbler (Leiothlypis luciae) at a supplemental feeding station in Patagonia, Santa Cruz County, Arizona. This appears to be the first documented instance of a Brown-crested Flycatcher preying on an adult passerine. While this species has previously been observed preying on hummingbirds, such events are rare and often anecdotally associated with drought conditions. Our observation occurred during an unusually dry breeding season, and we summarized all known records of bird predation by Brown-crested Flycatchers to local January-July precipitation data from 1950-2025 to explore potential links with drought years. All known observations occurred in below-average rainfall years, and most during drought years, suggesting opportunistic predation might be a flexible foraging response to reduced food availability or water resources. This record also illustrates how modern documentation tools and community science can capture rare interactions in situ, providing valuable data for understanding behavioral plasticity, novel species interactions, and ecological responses to environmental change.
are a key species in tropical forests; however they require large natural areas with good connectivity to maintain their populations. This requirement is often challenged by the construction of transport roads and the subsequent fragmentation. One such example is the Calakmul Biological Reserve which is the largest area for jaguar conservation in Mexico, and it is fragmented by two roads and recently the Maya Train. Therefore, the aim of this article is to model the effect of fragmentation on the jaguar population in this reserve. Twelve predictive models were built using the Vortex simulator and estimated the probability of persistence of jaguars depending on the fragment size. The models show that road fragmentation is affecting the probability of persistence of the population, but the addition of the fragmentation due to Maya Train has little direct effect on the jaguars. Jaguar populations are likely to persist for more than 100 years if the area they inhabit is bigger than 1000 km2. Overall, the Maya Train has moderate effect since it separates two big fragments that can maintain populations by themselves. however further fragmentation, especially combined with other human activities, could endanger the jaguars.
Headwater streams provide biodiversity, nutrients, and water to downstream river networks. The riparian communities of headwater streams differ greatly from the surrounding uplands, even along streams with little to no flow, providing habitat and other ecosystem services. This research compares the riparian plant communities of two headwater streams in Grand Staircase-Escalante National Monument, Utah, one perennial (Deer Creek) and one ephemeral (Long Canyon). We used remote sensing analysis, field collection of vegetation and soil data, and statistical analysis to determine the spatial distribution of riparian species and the environmental drivers of variations in riparian biodiversity and tree biomass. We observed significant differences in the riparian communities of the two streams, and variation in the environmental influences on vegetation. Along Deer Creek, remote sensing analysis revealed dense riparian vegetation throughout the study area, and sparse and patchy vegetation in Long Canyon. Percent sand was the primary control on tree biomass along Deer Creek, whereas valley width was more important in Long Canyon. Along Deer Creek, soil depth, elevation, and valley width were strong influences on biodiversity, whereas in Long Canyon, biodiversity was most influenced by elevation. This research provides evidence that riparian vegetation responds to different environmental factors in perennial and ephemeral headwater streams.
study describes a nectar barrier for birds in the hummingbird pollinated genus Anisacanthus (Acanthaceae). The most studied species is A. thurberi, but similar structures suggest a presence of a nectar barrier also in A. andersonii, A. junceus, A. linearis, A. pumilus, A. auadrifidus var. brevilobus, and A. auadrifidus var. wrightii. Similar structures were present but more weakly expressed in A. tetracaulis and A. puberulus, species that will need more detailed studies. When mimicking a hummingbird beak with a tweezer, I found that a visiting hummingbird would be able to move the style downwards in the nectar barrier to open a hole into the nectar chamber. I name the nectar barrier a Keyhole Barrier due to its appearance. A similar nectar barrier is present in Mexacanthus mcvaughii, a species now nested within Anisacanthus, and differences in that species could be due to an adaptation to insect pollination.
We report the first data confirming determinate growth in Texas River Cooters, Pseudemys texana, a freshwater turtle. We studied a four species community of freshwater turtles in Spring Lake, Hays County, TX, from 1995 to 2022 where we marked 2236 individuals. Accumulated data made it possible to ascertain whether determinate or indeterminate growth was evident. Data for 843 turtles confirmed that there was no inclination in the asymptotic phase of the general growth curve as determined by regression analysis. The mean difference in carapace lengths of turtles with a minimum of 10 years between first and last captures was less than two mm; thus, indeterminate growth was not observed. This research is important in that it confirms that not all freshwater turtles exhibit indeterminate growth, and that research into this topic would be productive.
A new geographic distributional record is documented for the avian coccidian, Isospora vanriperorum Levine, 1982 from a northern cardinal, Cardinalis cardinalis found dead in southwestern Arkansas, USA. The species was originally described from cardinalis from Hawaii and more recently reported from C. cardinalis from northeastern Texas. We also report information on an adelid pseudoparasite coccidian from the same cardinalis.
species diversity and abundance declined in the Central Arizona Project canal over 3.5 decades of increasing current velocities and lack of cover that prevented establishment of a viable fish community. The canal continues to have the potential to transfer non-native aquatic organisms across drainage boundaries and thus represents a continuing threat to native threatened and endangered species.
Gray Hawks (Buteo plagiatus) are generally considered migratory in much of their United States range, but recent telemetry research has demonstrated year-round residency of breeding adults in the Lower Rio Grande Valley of Texas. Whether this pattern extends farther upriver along the Rio Grande has remained uncertain. We used GPS telemetry from two adult male Gray Hawks tracked in Webb County, Texas, to document annual space use and evaluate evidence for residency outside the Lower Rio Grande Valley. Both individuals remained spatially constrained within a consistent area throughout the annual cycle, and seasonal analyses indicated use of the same general areas during winter months, with no evidence of long-distance seasonal migration. Winter community-science observations (2010-2025) further corroborate repeated Gray Hawk presence in the region. Together, these findings extend telemetry-based evidence of year-round residency approximately 170 km northward along the Rio Grande corridor and suggest a broader zone of non-migratory behavior in south Texas.
Golden Eagle is listed as endangered in Mexico. Despite the species' cultural value, human persecution, illegal trade, and collisions often produce impaired eagles. In Mexico, rescued and confiscated eagles must be first reported to the Federal Attorney's Office of Environmental Protection and sent to facilities for rehabilitation. The destination of these eagles are usually zoos or private repositories for educational purposes. However, it is highly relevant to evaluate whether these rehabilitated eagles possess any residual reproductive value to wild populations. We rescued 1 adult male Golden Eagle on 8 June 2021 with a broken wing, decreased body mass and signs of dehydration in the Municipality of Monte Escobedo in western Mexico. We provided veterinarian care to this eagle for 2 months until it was capable to perform short flights and fecal and blood clinical tests evidenced recovery. We released this eagle on 5 August 2021 at the location of rescue. We equipped the eagle with a satellite transmitter. The eagle maintained a home range of 6,724 km2 for 1 year 10 months after its release. Later, the eagle engaged in a 1.5-month roundtrip to central Chihuahua (700 km north). Upon arrival, the eagle maintained a home range of 132 km2, moving as a nesting bird, centered about 50 km from the release site from December 2023 to early April 2024. The eagle's transmitter frequently failed to provide GPS fixes and reported drained battery starting 14 April 2024, but we could not determine the survival fate of the eagle. A minimal survival time of 2 years 8 months, an extensive home range, a nonroutine long-distance movement, and reduced movements during the nesting season suggest that rescued eagles have reproductive potential to the conservation of wild populations in Mexico.
