Small-bodied Species Research Articles

Outcome of competition between two Daphnia species in the absence of predators: laboratory experiment findings support field observations

Zooplankton communities are typically comprised of smaller-bodied species when size-selective fish predators are abundant, but become dominated by large-bodied species when fish predators are scarce. Superiority by larger-bodied grazers over smaller-bodied species in competition for algal resources has been proposed to be the mechanism responsible for this observed pattern. To investigate this mechanism, we performed a laboratory experiment with two freshwater zooplankton species, the larger-bodied Daphnia pulicaria and smaller-bodied D. mendotae, obtained from Square Lake (Washington County, Minnesota). The Daphnia species were grown in monoculture and in combination over a 24-day period to assess the outcome of competition between the two species and their effect on algae cell densities. We hypothesized that the larger-bodied D. pulicaria species would outcompete D. mendotae, and that D. pulicaria would exert greater control on algae levels than would D. mendotae. Results of the experiment strongly supported these hypotheses, and were consistent with findings of a recently completed field study of Square Lake that discovered that terminating the program of stocking rainbow trout (a zooplanktivorous predator) in the lake resulted in D. pulicaria replacing D. mendotae as the dominant Daphnia species and in the reduction of algae levels in the lake's surface waters.

Ensuring the Sustainability of Coastal Small-Scale Fisheries at Pitcairn Island (South Pacific) Within a Large Scale No-Take MPA

The Pitcairn Islands, located in the central South Pacific, contain near-pristine marine ecosystems which support unique fish assemblages, together with both endemic and threatened species. Pitcairn itself is the only inhabited island in the group and, before this study, the environmental impact of local fisheries was unclear, with little data to inform conservation and management. In 2014–2015 coastal fish populations were assessed using a mixed methods approach: a newly introduced system of fishers’ catch monitoring and Baited Remote Underwater Video Systems (BRUVS). Thirty-nine BRUVS deployments recorded 88 species in total, with small-bodied herbivores (e.g., Kyphosus pacificus) and mesopredators (e.g., Xanthichthys mento) dominating a “bottom heavy” assemblage. Several large pelagic predators were recorded, but reef-associated predators were rare with only one shark observed. Pitcairn’s top predator assemblage was relatively impoverished compared to global “pristine” sites, including other islands within the Pitcairn group. Top predator scarcity may be explained by local artisanal fisheries, which have historically targeted sharks and other large reef carnivores, and these taxa may not have recovered despite subsequent declines in fishing pressure. The dominant small-bodied species may have proliferated as a result of diminished top predator populations. Subsequent to BRUVS sampling, a local fisheries officer post was created to collate catch data from coastal fishers. Regular returns were obtained from over half of the active fishers (representing approximately 80% of catches), with K. pacificus also dominating catches and the small grouper Epinephelus fasciatus frequently targeted. Thirty fish species were represented in the recorded catch over a 12 month period. Results were shared with the local community, providing a basis for the cooperative design of a Fisheries Management Plan. This plan ensured traditional fisheries could continue in a sustainable manner within Coastal Conservation Zones around each of the four Pitcairn Islands, established within the large, no-take Marine Protected Area designated in 2016, covering the entire Pitcairn Exclusive Economic Zone. Monitoring of Pitcairn’s artisanal fisheries should be continued beyond this one-off study in order to inform adjustment of the Fisheries Management Plan, as the ongoing island fishery may still have consequences for long-term sustainability, particularly for pelagic species caught in coastal waters which remain a significant data gap.

Phylogeny and evolution of large body size in the rove beetle genus Phlaeopterus Motschulsky, 1853 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini)

Abstract The omaliine rove beetle genus Phlaeopterus Motschulsky, 1853 contains 22 species. The genus is distributed across northwestern North America and eastern Asia. These beetles occur primarily along the edges of alpine snowfields and streams, habitats that are particularly sensitive to the impacts of climate change. Two species have not been collected since 1979 and 1984, one of which, Phlaeopterus bakerensis Mullen and Campbell, 2018, is a contender for the largest-bodied species among the over 1,600 species of the subfamily Omaliinae. Here, we present the first phylogeny of the genus, using Bayesian and maximum likelihood analyses based on DNA sequences from the mitochondrial gene COI and morphological data. We tested previous taxonomic hypotheses and most were rejected by all three analyses. Phlaeopterus castaneus Casey, 1893 is non-monophyletic based on COI sequences and may have hybridized with P. loganensis Hatch, 1957. We found support for the monophyly of the genus Phlaeopterus. Our analyses suggest the common ancestor of the genus had small-bodied adults (maximum body size under 5 mm) with ocelli. Within this small-bodied radiation of species, ocelli were lost once and there were two separate evolutionary transitions to large-bodied adults. Although all the large-bodied species are snowfield-associated and only 25% of the small-bodied species are, we did not find statistical support for a relationship between large body size and use of snowfield habitats. These findings represent the first modern phylogenetic reconstruction of species-level relationships within the rove beetle subfamily Omaliinae using both morphological and molecular data.

Scaling the extinction vortex: Body size as a predictor of population dynamics close to extinction events.

Mutual reinforcement between abiotic and biotic factors can drive small populations into a catastrophic downward spiral to extinction—a process known as the “extinction vortex.” However, empirical studies investigating extinction dynamics in relation to species' traits have been lacking.We assembled a database of 35 vertebrate populations monitored to extirpation over a period of at least ten years, represented by 32 different species, including 25 birds, five mammals, and two reptiles. We supplemented these population time series with species‐specific mean adult body size to investigate whether this key intrinsic trait affects the dynamics of populations declining toward extinction.We performed three analyses to quantify the effects of adult body size on three characteristics of population dynamics: time to extinction, population growth rate, and residual variability in population growth rate.Our results provide support for the existence of extinction vortex dynamics in extirpated populations. We show that populations typically decline nonlinearly to extinction, while both the rate of population decline and variability in population growth rate increase as extinction is approached. Our results also suggest that smaller‐bodied species are particularly prone to the extinction vortex, with larger increases in rates of population decline and population growth rate variability when compared to larger‐bodied species.Our results reaffirm and extend our understanding of extinction dynamics in real‐life extirpated populations. In particular, we suggest that smaller‐bodied species may be at greater risk of rapid collapse to extinction than larger‐bodied species, and thus, management of smaller‐bodied species should focus on maintaining higher population abundances as a priority.

Temperature-associated decreases in demographic rates of Afrotropical bird species over 30years.

Tropical mountains harbor globally significant levels of biodiversity and endemism. Climate change threatens many tropical montane species, yet little research has assessed the effects of climate change on the demographic rates of tropical species, particularly in the Afrotropics. Here, we report on the demographic rates of 21 Afrotropical bird species over 30years in montane forests in Tanzania. We used mark-recapture analyses to model rates of population growth, recruitment, and apparent survival as functions of annual mean temperature and annual precipitation. For over one-half of focal species, decreasing population growth rates were associated with increasing temperature. Due to the trend in temperature over time, we substituted a time covariate for the temperature covariate in top-ranked population growth rate models. Temperature was a better explanatory covariate than time for 6 of the 12 species, or 29% of all focal species. Population growth rates were also lower for species found further below their elevational midpoint and for smaller-bodied species. Changes in population growth rates were more closely tied to changes in recruitment than to changes in apparent survival. There were no consistent associations between demographic rates and precipitation. This study demonstrates temperature-associated demographic impacts for 6 (29%) of 21 focal species in an Afrotropical understory bird community and highlights the need to incorporate the impacts of climate change on demographic rates into conservation planning across the tropics.

The evolution of the placenta in poeciliid fishes

How and why complex organs evolve is generally lost to history. The mammalian placenta, for example, was derived from a single common ancestor that lived over 100 million years ago.1-3 Therefore, the selective factors favoring this complex trait remain obscure. Species in the live-bearing fish family Poeciliidae have independently evolved placentas numerous times while retaining closely related non-placental sister species.4-7 This provides the raw material to test alternative hypotheses for the evolution of the placenta. We assemble an extensive species-level dataset on reproductive mode, life histories, and habitat, and then implement phylogenetic comparative methods to test adaptive hypotheses for the evolution of the placenta. We find no consistent family-wide associations between placentation and habitat. However, placental species exhibit significantly reduced reproductive allotment and have a higher likelihood of exhibiting superfetation (the ability to gestate multiple broods at different developmental stages). Both features potentially increase body streamlining and enhance locomotor performance during pregnancy, possibly providing selective advantage in performance-demanding environments such as those with high predation or fast water flow. Furthermore, we found significant interactions between body size and placentation for offspring size and fecundity. Relative to non-placental species, placentation is associated with higher fecundity and smaller offspring size in small-bodied species and lower fecundity and larger offspring size in large-bodied species. This pattern suggests that there may be two phenotypic adaptive peaks, corresponding to two selective optima, associated with placentation: one represented by small-bodied species that have fast life histories, and the second by large-bodied species with slow life histories.

Correlated evolution between herbivory and gastrointestinal tract in a prolific lizard adaptive radiation

Abstract Radiations of ectothermic vertebrates across cold climates depend on the coordinated evolution of multiple traits that compensate for the constraints imposed by limited and fluctuating resources, such as temperature, food and oxygen. One of nature’s most prolific such radiations, Liolaemus lizards, has diversified across the extreme cold climates of the Andes and Patagonia. Remarkably, the prevailing patterns of reptile herbivory are opposed by Liolaemus which, in contrast with lizards generally, have repeatedly evolved plant consumption across small-bodied species from cold climates. Herbivory is hypothesized to depend on the evolution of multiple traits that maximize absorption of nutrients from an intrinsically poor-quality diet, such as increases in gastrointestinal tract size and increases in the density of nematodes in the intestine that may assist with plant digestion. Here, a comparative phylogenetic approach across Liolaemus species is implemented to test these hypotheses, which have only been investigated nonphylogenetically. Results reveal that intestine length increases consistently with increasing herbivory, whereas stomach size or nematode load are not associated with plant consumption. Body size plays no role in herbivory either. Consequently, this evidence places emphasis on the enlargement of the intestine to facilitate the evolution of herbivory in cold climates.

Annual survival rate of tropical stingless bee colonies (Meliponini): variation among habitats at the landscape scale in the Brazilian Atlantic Forest

Stingless social bees live in perennial colonies whose longevity is influenced by various ecological factors. This study analyzed the influence of habitat anthropization and native forest regeneration stage on the longevity of natural colonies at the landscape scale. Random sampling of 25x25m plots, totaling 30ha per habitat type, located and monitored 118 nests of 14 species in the forest and 105 nests of six species in the anthropic habitat. Significant differences in colony longevity were observed between young and long-lived forests and between long-lived forests and anthropized habitat. Shorter longevities have generally been associated with a set of smaller-bodied species residing in anthropized habitats. The greatest longevities were associated with the three abundant and exclusive forest species, and was similar in the two forest regeneration stages: Melipona scutellaris, Scaptotrigona xanthotricha and Scaptotrigona bipunctata had high annual survival rates ranging from 87% to 93%. Another abundant species in the landscape was Tetragonisca angustula, a small habitat-generalist with short longevity (63%) that varied among habitats. Euclidean distance analysis based on this generalist placed young forest closest to anthropic habitat, and grouped the replicates of long-lived forest. Considering spatial variation in the life history traits, we infer that, among prospective landscape habitats, the Atlantic Forest favors stingless bees with high colonial longevity. On the other hand, generalists, such as T. angustula, with shorter colonial longevity and high reproduction rates are being favored by the expansion of anthropized habitats in place of deforested areas.

Pervasive duplication of tumor suppressors in Afrotherians during the evolution of large bodies and reduced cancer risk.

The risk of developing cancer is correlated with body size and lifespan within species. Between species, however, there is no correlation between cancer and either body size or lifespan, indicating that large, long-lived species have evolved enhanced cancer protection mechanisms. Elephants and their relatives (Proboscideans) are a particularly interesting lineage for the exploration of mechanisms underlying the evolution of augmented cancer resistance because they evolved large bodies recently within a clade of smaller-bodied species (Afrotherians). Here, we explore the contribution of gene duplication to body size and cancer risk in Afrotherians. Unexpectedly, we found that tumor suppressor duplication was pervasive in Afrotherian genomes, rather than restricted to Proboscideans. Proboscideans, however, have duplicates in unique pathways that may underlie some aspects of their remarkable anti-cancer cell biology. These data suggest that duplication of tumor suppressor genes facilitated the evolution of increased body size by compensating for decreasing intrinsic cancer risk.

Seasonal consumption of terrestrial prey by a threatened stream fish is influenced by riparian vegetation

The consumption of terrestrial prey by fishes highlights the functional value of terrestrial habitats, but such consumption is not well documented for many small-bodied species. We determined the diet and consumption of terrestrial prey by a threatened fish, silver shinerNotropis photogenis, using stomach content and stable isotope analyses to better understand the functional role of riparian habitat for the species. Results indicate silver shiner is a generalist drift feeder that consumes a wide range of aquatic and terrestrial prey. Both stomach content and stable isotope analyses indicated that terrestrial prey was commonly exploited and that terrestrial prey consumption was both seasonally and spatially variable. Based on stomach contents, the contribution of terrestrial prey was (average ± SD) 41.53 ± 32.35% in fall and 20.45 ± 20.45% in summer; based on stable isotopes it was 35.24 ± 4.41% in fall and 39.88 ± 12.34% in summer. During fall, when bankside terrestrial invertebrates were more abundant, silver shiner stomachs contained significantly more terrestrial prey in reaches where riparian vegetation cover was highest, indicating that intact riparian cover may facilitate access to high-quality prey. The consumption of terrestrial prey may be particularly important in fall, as it may promote increased growth and survival leading to more successful overwintering. Our findings suggest that terrestrial subsidies are ecologically valuable for silver shiner and that the protection of reaches with intact riparian habitats would likely improve conservation and recovery efforts by helping ensure access to key prey resources.

Animal remains from the Late Medieval kitchen of the Esztergom archdiocese, Hungary - the benefits of screening

Medieval animal remains from the Esztergom archbishopric (Hungary) were screened using 5 mm and 2 mm mesh sizes, aimed at the high-resolution study of fish and bird remains and helping to achieve better comparisons with documentary sources. This is the first medieval assemblage in Hungary recovered using screening. A total of 7,294 animal remains are studied here, representing the 14th and 15th century. The screening resulted in quantities of fish and bird bones. The large find numbers also multiplied the taxonomic diversity. In addition to the remains of new, small-bodied species, bones of young fish showed a diachronic increase in the contribution of carp and young pike to the diet. This seems consonant with the expansion of medieval fish farming. Remains of juvenile birds could also be identified. Some worked bones recovered by screening indicate the manufacturing or reparation of crossbows at the site. Thanks to these details, our material stands out among other contemporaneous animal bone assemblages from the Carpathian Basin. Comparisons between sites, however, must be done with caution, as our data are qualitatively different from others. Large bones of livestock and the near absence of those from large game may be interpreted in the light of other hand-collected samples, while fish and bird remains and even the abundance of brown hare need to be seen in part as a product of high-resolution recovery. The newly discovered spectrum of animal remains could be profitably interpreted in the light of late 15th century accounting books of the archbishop. Although these documentary sources slightly post-date our material, they shed light on the complexities of meat procurement between possibly local production and trade.

Comparative Reproductive Allometry of Syntopic Black-Knobbed Sawbacks (Graptemys nigrinoda) and Alabama Map Turtles (Graptemys pulchra) in the Alabama River, with Comparison to Three Congeners

In many freshwater turtle species, increasing adult female body size is accompanied by increases in both clutch size and egg size. Because clutch size and egg size represent competing sinks for the increasing abdominal space that can be devoted to reproductive potential as a female grows larger, both are hypoallometrically related to body size, i.e., each increases at less than the rate at which body size is increasing. I studied the reproductive allometry of 2 species of the map turtle and sawback genus (Emydidae: Graptemys) in syntopy in the Alabama River. Relative to congeners, Graptemys nigrinoda is a small-bodied species and Graptemys pulchra is a large-bodied species. In the study populations, adult female G. pulchra were on average 23% larger in plastron length and 125% larger in body mass and there was no overlap in size. Both species had positive but hypoallometric relationships of both clutch size and egg size with body size, a pattern reported for 3 congeners previously, thus further demonstrating the competing sinks of increases in both variables and refuting the optimal egg size hypothesis. For interspecific comparisons using analysis of covariance, there was no significant effect of species on clutch size after accounting for the effect of plastron length. The effect of species on egg width and width of the pelvic aperture was significant, with G. pulchra having relatively wider eggs and pelvic apertures, perhaps related to the more domed carapace and larger body sizes of their hatchlings. Compared with 3 congeners, the 2 Alabama River species had relatively small clutches of relatively large eggs. Latitudinal effects on reproductive output may be important in Graptemys, with more-northerly populations tending toward larger clutches of smaller eggs. There is a need to analyze more data from more populations with log-log analyses of reproductive allometry to confirm the trend. There is also a need to consider shape allometry in future analyses; in particular, the hypoallometry of both shell height and shell width relative to shell length.

Catch composition and life history characteristics of sharks and rays (Elasmobranchii) landed in the Andaman and Nicobar Islands, India.

Detailed information on shark and ray fisheries in the Andaman and Nicobar Islands, India are limited, including information on the diversity and biological characteristics of these species. We carried out fish landing surveys in South Andamans from January 2017 to May 2018, a comprehensive and cost-effective way to fill this data gap. We sampled 5,742 individuals representing 57 shark and ray species landed from six types of fishing gears. Of the 36 species of sharks and 21 species of rays landed, six species of sharks (Loxodon macrorhinus, Carcharhinus amblyrhynchos, Sphyrna lewini, C. albimarginatus, C. brevipinna, and Paragaleus randalli) comprised 83.35% of shark landings, while three species of rays (Pateobatis jenkinsii, Himantura leoparda and H. tutul) comprised 48.82% of ray landings, suggesting a species dominance in the catch or fishing region. We provide insights into the biology of species with extensions in maximum size for seven shark species. Additionally, we document an increase in the known ray diversity for the islands and for India with three previously unreported ray species. We found that amongst sharks, mature individuals of small-bodied species (63.48% males of total landings of species less than 1.5 m total length when mature) and immature individuals of larger species (84.79% males of total landings of species larger than 1.5 m total length when mature) were mostly landed; whereas for rays, mature individuals were predominantly landed (80.71% males of total landings) likely reflecting differences in habitat preferences along life-history stages across species and fishing gear. The largest size range in sharks was recorded in landings from pelagic longlines and gillnets. Further, the study emphasizes the overlap between critical habitats and fishing grounds, where immature sharks and gravid females were landed in large quantities which might be unsustainable in the long-term. Landings were female-biased in C. amblyrhynchos, S. lewini and P. jenkinsii, and male-biased in L. macrorhinus and H. leoparda, indicating either spatio-temporal or gear-specific sexual segregation in these species. Understanding seasonal and biological variability in the shark and ray landings over a longer study period across different fisheries will inform future conservation and fishery management measures for these species in the Andaman and Nicobar Islands.

Logging drives contrasting animal body-size effects on tropical forest mammal communities

Anthropogenic disturbance of tropical ecosystems can re-configure mammalian communities, frequently through a process of differential impact on animal species, whereby medium- and large-bodied animals are more impacted than small-bodied animals, which often are even favored. Here we examine if logging –a prevalent activity in the tropics– drives a pattern of differential defaunation in a Neotropical forest managed by a community of indigenous people. Using a match-paired design, we conducted mammalian surveys during four consecutive years in three independent sites, each one including (1) areas for logging practiced by Maya communities of the Yucatan Peninsula (selective and interspaced harvesting), and (2) adjacent areas set aside as reserves. We found that in logged areas the abundance of medium and large mammals decreased (4.3-fold, overall), while the abundance of small mammals increased (2.5-fold, overall). We posit that these changes result from a combination of factors, including: (1) facilitated access for hunters of medium- and large-sized game, comprising both predators (potentially leading to small-prey release) and competitors of small-bodied species; (2) changes in vegetation (e.g., more shelter and food for rodents); and (3) contrasting animal life history traits (population growth rate, home range size). We conclude that although non-intensive logging interventions have negative consequences for the mammalian community (for at least ten years after harvesting), the indigenous practices of rotational harvesting and maintaining reserves help to prevent the landscape-wide mammalian declines known to occur under large-scale industrial logging.

Temporal Dynamics of Fish Assemblages as a Reflection of Policy Shift from Fishing Concession to Co-Management in One of the World’s Largest Tropical Flood Pulse Fisheries

Inland fisheries management in Cambodia has undergone two major policy reforms over the last two decades. These reforms led to the abolishment of a century-old commercial fishing lot system in 2012 and the establishment of new fish sanctuary and community fishing areas. However, the status of fisheries and fish assemblages following the reforms is not well understood. Here, we investigated the temporal changes in fish catch weight and fish assemblage structure for the period 1995–2000 before fishing lot abolishment (BLA) and for the period 2012–2015 after the removal of all fishing lots (after lot abolishment-ALA) using time-series fish catch data recorded from the Tonle Sap Lake (TSL), one of the world largest inland fisheries. We found (i) mean catch trends vary seasonally, with stable catch trends during the BLA and decreasing catch trends during the ALA and (ii) significant shifts in fish assemblage composition, notably a shift from large-bodied, migratory, and/or predatory species during the BLA toward more short-distance migratory and/or floodplain, small-bodied species during the ALA. Fishing lot abolishment coincided with substantial changes to floodplain habitats and increases in fishing pressure, threatening TSL fish stocks. Flow alterations caused by dams and climate change may exacerbate the problem. Therefore, to realize the fisheries reform objectives, it is imperative to strengthen the fisheries’ governance and management system, including effective law enforcement, institutional strengthening, improved planning, cooperation, and coordination as well as clearly defined roles and responsibilities among concerned stakeholders at all levels.

Growth and maturation of three commercially important coral reef species from American Samoa

This study presents age-based life history information on three small-bodied species targeted in the American Samoan fishery: Chlorurus japanensis palecheek parrotfish/fuga-alosama, Lethrinus rubrioperculatus spotcheek emperor/fiola pa`o`omumu, and Naso lituratus orangespine unicornfish/ili`ilia. Age and reproductive information were derived from sagittal otoliths and gonads. Maximum observed ages were 7 years for C. japanensis, 10 years for L. rubrioperculatus, and 25 years for N. lituratus. Due to a limited numbers of immature samples, a proxy for size at 50% maturity (L50) was derived from the relationship between asymptotic fork length (L∞) and L50 based on data published for species from similar geographic regions and respective families. L50 was estimated at 20.9 cm for C. japanensis, 20.4 cm for L. rubrioperculatus, and 17.5 cm for N. lituratus. Derived estimates were within 1 % of the L50 calculated for C. japanensis and N. lituratus from the limited number of immature samples collected in this study, indicating that for regions where sampling ability is limited, derived relationships between L∞ and L50 can be used to calculate an appropriate proxy. Naso lituratus demonstrated a biphasic mortality schedule with a higher than expected total mortality rate in the first 7 years of life. The age-based demographic information presented here can be used for future stock assessments and ecosystem models, which should facilitate improved management.

Mass procurement and prey rankings: insights from the European rabbit

In the archeological record, the presence of smaller-bodied species is often assumed to indicate a decline in higher-ranked, larger-bodied prey and broadening of the diet to include lower-ranked items with higher handling costs. This shift is typically considered to be a product of a “broad spectrum revolution” that gave rise in many regions to increased sedentism, subsistence intensification, and investments in farming at the Pleistocene/Holocene boundary. However, recent evidence suggests that the use of small, fast prey may have emerged much earlier in hominin evolution than previously appreciated. Here, we assess ethnographic, historical, and actualistic observations of European rabbit hunting to explore whether such small, fast prey are inherently lower-ranked than larger ones. We find that, in combination, the type of procurement method and the population density of rabbits substantially affect foraging returns and the definition of prey types. When rabbits are locally abundant and mass-captured in the open, on-encounter returns are predictably high, sometimes higher than those of large-bodied ungulates. We suggest that rabbit hunting may have been locally and intermittently common during the European Middle and Late Pleistocene as rabbit densities waxed and waned.

Warfare-induced mammal population declines in Southwestern Africa are mediated by species life history, habitat type and hunter preferences

Civil wars often coincide with global biodiversity hotspots and have plagued the everyday reality of many countries throughout human history. However, how do civil wars affect wildlife populations? Are these impacts the same in savannah and forest environments? How persistent are the post-war consequences on wildlife populations within and outside conflict zones? Long-term monitoring programs in war zones, which could answer these questions, are virtually nonexistent, not least due to the risks researchers are exposed to. In this context, only a few methodologies can provide data on wild populations during war conflicts. We used local ecological knowledge to assess the main consequences of a prolonged civil war (1975–2002) in Southwestern Africa on forest and savannah mammals. The post-war abundance in 20 of 26 (77%) mammal species considered in this study was lower in open savannah compared to the closed-canopy forest environments, with some species experiencing a decline of up to 80% of their pre-war baseline abundance. Large-bodied mammals were preferred targets and had been overhunted, but as their populations became increasingly depleted, the size structure of prey species gradually shifted towards smaller-bodied species. Finally, we present a general flow diagram of how civil wars in low-governance countries can have both positive and negative impacts on native wildlife populations at different scales of space and time.

Erratum

Erratum

Observations of Snakes Associated With Active Nests of Allegheny Mound Ant (Formica exsectoides) in Northeastern Pennsylvania

Refuge availability is an important component of snake ecology and conservation, yet we have limited understanding of the extent to which snakes use the nests of other animals for refuge. Despite their ubiquity in many forests, the use of ant nests as refuge by snakes has only been reported by a few publications. Between 15 September and 14 October 2019, we set out camera traps to assess whether snakes inhabited active ant mounds and the associated habitats engineered by Formica exsectoides (Allegheny Mound Ant) in northeastern Pennsylvania. We recorded a total of 44 snake images captured at 2 ant mounds, representing 24 individual encounters and 3 snake species. Species observed entering and emerging from mounds included Diadophis punctatus (Ring-necked Snake) and Storeria occipitomaculata (Red-bellied Snake). We observed both Ring-necked Snakes and Red-bellied Snakes briefly entering and exiting nests. The latter was also observed basking outside of a nest, and we observed both species enter a nest without resurfacing. These results suggest that active ant mounds constructed by Allegheny Mound Ants represent an underappreciated resource for these small-bodied snake species.