Assessment of Waterbird Habitat Importance and Identification of Conservation Gaps in Anhui Province.

Wetlands are among the most important habitats of highly wetland-dependent waterbirds but are subject to ongoing habitat loss and degradation owing to intensified anthropogenic activities. The scarcity of human and natural resources makes effective habitat protection an important concern. Here, we aimed to investigate waterbird habitat protection methods for Anhui Province, China, a critical stopover and wintering area on the East Asian-Australasian Flyway that features rich wetland resources subject to significant habitat loss and degradation. We evaluated the status and importance of 306 wintering waterbird habitats and identified the key environmental influences and current protection gaps using the entropy weights method and generalized additive modeling. We found 73 important habitats for waterbirds in Anhui Province, which were classified into levels of importance (descending from I to V) according to the natural discontinuity method. Level I and Level II habitats were mainly located in the Yangtze River floodplain and Level IV habitats in the Huaihe River floodplain. The gap analysis showed that 42 important waterbird habitats had protection gaps, accounting for 57.53% of the total area. Waterbird habitat importance was significantly correlated with elevation, normalized vegetation index, lake area, and lake circumference but not with distance from roads or population density. The results of this study provide scientific information for waterbird habitat conservation planning, which is crucial for maintaining wetland ecosystem functions.

Climate-informed forecasts reveal dramatic local habitat shifts and population uncertainty for northern boreal caribou.

Most research on boreal populations of woodland caribou (Rangifer tarandus caribou) has been conducted in areas of high anthropogenic disturbance. However, a large portion of the species' range overlaps relatively pristine areas primarily affected by natural disturbances, such as wildfire. Climate-driven habitat change is a key concern for the conservation of boreal-dependent species, where management decisions have yet to consider knowledge from multiple ecological domains integrated into a cohesive and spatially explicit forecast of species-specific habitat and demography. We used a novel ecological forecasting framework to provide climate-sensitive projections of habitat and demography for five boreal caribou monitoring areas within the Northwest Territories (NWT), Canada, over 90 years. Importantly, we quantify uncertainty around forecasted mean values. Our results suggest habitat suitability may increase in central and southwest regions of the NWT's Taiga Plains ecozone but decrease in southern and northwestern regions driven by conversion of coniferous to deciduous forests. We do not project that boreal caribou population growth rates will change despite forecasted changes to habitat suitability. Our results emphasize the importance of efforts to protect and restore northern boreal caribou habitat despite climate uncertainty while highlighting expected spatial variations that are important considerations for local people who rely on them. An ability to reproduce previous work, and critical thought when incorporating sources of uncertainty, will be important to refine forecasts, derive management decisions, and improve conservation efficacy for northern species at risk.

Characterization and Interpolation of Sediment Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Resident Killer Whale Habitat along the Coast of British Columbia, Canada.

The northeastern Pacific northern and southern resident killer whale (Orcinus orca) populations are listed as threatened and endangered in Canada, respectively, with persistent, bioaccumulative contaminants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), posing threats to their recovery. Concentrations of PCBs and PBDEs in subtidal surface sediments collected from 97 sites along the British Columbia (BC) coast were used to identify their distribution and profiles, and to assess killer whale habitat quality. Victoria Harbour (VH3(site ID: 1) ) sediments exhibited the highest PCB and PBDE concentrations. For PCBs, PCB-138 was found at the highest concentration, followed by PCB-153, PCB-110, PCB-149, PCB-101, and PCB-118. For PBDEs, individual congeners were ranked as follows: BDE-209 > BDE-207 > BDE-206 > BDE-208 > BDE-47 > BDE-99. Principal component analyses (PCA) illustrated the variations in contaminant profiles, with PC1 for PCBs and PBDEs correlated with the octanol-water partition coefficient (log KOW , p < 0.003). Based on the PCA, sediment particle size, total organic carbon (TOC), and water depth at collection were other factors associated with the distribution of PBDEs, while PCB profiles were associated with TOC. Total PCB and PBDE concentrations at 100% and 34% of the sites, respectively, exceeded the recently adopted British Columbia's Ministry of Environment and Climate Change Strategy Working Sediment Quality Guidelines (PCBs 3.7 pg/g dry wt and PBDEs 1000 pg/g dry wt), considered protective of killer whales. Our findings suggest that the legacy of banned PCBs and PBDEs has the potential to constrain the recovery of killer whales as a result of their mobilization from sediments and consequent uptake by marine food webs. Environ Toxicol Chem 2022;41:2139-2151. © 2022 SETAC.

Donsol: an important reproductive habitat for the world's largest fish Rhincodon typus?

Little is known about the reproductive ecology of the whale shark Rhincodon typus. On 15 March 2020, a free-swimming neonate whale shark was found in the shallow, coastal waters of Donsol, Philippines. The total length of the male shark was 60 cm, falling within the species known size-at-birth. This is the third occurrence of neonatal whale sharks reported in the area, and coupled with the occurrence of juveniles and adults, and anecdotal mating and precopulatory behaviour reported herein, the importance of the site for this endangered species is highlighted.

Diversidad de murciélagos en la selva baja inundable del sureste de México / Diversity of bats inhabiting seasonally inundated forest in the Southeastern Mexico

Introducción: El tintal es un tipo de selva baja inundable característico del sureste de México, donde la especie dominante es el palo de tinte (Haematoxylum campechianum L.). Por sus características estructurales y las condiciones de las áreas donde se desarrollan, los tintales pueden funcionar como un hábitat crítico para muchas especies animales. Objetivo: El objetivo de esta investigación fue describir la diversidad local y regional de la quiropterofauna presente en tintales de diferentes áreas del sureste mexicano. Métodos: Se trabajó en ocho localidades con presencia de tintal en los estados de Campeche y Tabasco. En cada una se colocaron seis redes de nylon durante tres noches. Se calculó la riqueza observada y la estimada para cada localidad, así como la abundancia total. Se elaboraron curvas de rango de abundancia y de acumulación de especies. Se realizaron análisis de similitud entre localidades y se correlacionaron estas similitudes con la distancia geográfica entre ellas. Resultados: Se registraron 25 especies de murciélagos pertenecientes a cinco familias, de las cuales Phyllostomidae fue la mejor representada. La mayoría de las especies fueron insectívoras (44 % del total), mientras los frugívoros fueron los más abundantes. Entre estas destacan Artibeus lituratus y A. jamaicensis, las cuales se registraron en un mayor número de localidades. Mientras tanto, Glossophaga soricina fue la más abundante. En Oxpemul, se registró la mayor riqueza de especies (N= 12) y en Las Bodegas la menor (N= 4), aunque esta fue la tercera localidad con mayor cantidad de individuos. La riqueza estimada de especies para toda el área, según nuestros datos, osciló entre 29 y 34. Los ensamblajes menos equitativos fueron Las Bodegas y Tres Brazos. Las localidades más semejantes entre sí en cuanto a la estructura de la comunidad fueron La Toza y Las Bodegas y, en cuanto a la composición de especies Oxpemul y Atasta. Las similitudes entre las localidades no estuvieron correlacionadas con la cercanía geográfica. Conclusiones: La mayoría de las localidades de estudio están altamente antropizadas, pero la tolerancia de varias especies de murciélagos a estas modificaciones del paisaje les ha permitido hacer uso de estas. La elevada abundancia de las especies consumidoras de frutos encontrada apoya la idea de la importancia de los murciélagos en la recuperación de la vegetación arbórea en zonas alteradas del sureste de México y el valor de los tintales dentro de estas áreas para la conservación de la biodiversidad.

Introduction: The "tintal" is a type of seasonally inundated forest where the dominant species is Haematoxylum campechianum L. Due to its structural characteristics and the conditions of the areas where it develops, it could work as a critical habitat for many animal species. Objective: This work aimed at describing the regional and local diversity of the chiropterofauna inhabiting tintal along different areas in the Southeastern Mexico. Methods: The research was carried out in eight localities with presence of tintal in the states of Campeche and Tabasco, Mexico. In each site, six mist nets were placed during three nights. The observed and expected richness were calculated for each site, as well as the total abundance. Rank-abundance and species accumulation curves were generated. Similarity analyses between localities were performed and correlated with the geographical distance between them. Results: We recorded 25 bat species belonging to five families, where Phyllostomidae was the most represented. Most registered species were insectivorous (44 % of the total), while frugivorous were the most abundant. Frugivorous Artibeus lituratus and A. jamaicensis were the species recorded in a greater number of localities, and Glossophaga soricina was the most abundant. The highest richness of species was registered in Oxpemul (N= 12), while in Las Bodegas we found the lowest (N= 4), although the latter was the third locality with the highest number of individuals. The estimated richness of species for the whole area varied between 29 and 34. The least even assemblages were Las Bodegas and Tres Brazos. The most similar localities in terms of the structure of the assemblages were La Toza and Las Bodegas and, in terms of the species composition, Oxpemul and Atasta. The similarities between the localities were not correlated with geographical proximity. Conclusions: Most of the researched localities were highly anthropized, but the tolerance of several bat species to these landscape modifications has allowed them to make use of such areas. The high abundance of the frugivorous species registered supports that bats may play a key role in the recovery of tree vegetation in altered areas in Southeastern Mexico, and emphasizes the value of the tintal along this area for the conservation of biodiversity.

Distinct habitat use strategies of sympatric rorqual whales within a fjord system.

We used ecosystem sampling during systematic surveys and opportunistic focal follows, comparison tests, and random forest models to evaluate fin whale (Balaenoptera physalus) and humpback whale (Megaptera novaeangliae) habitat associations within an inland feeding ground (Kitimat Fjord System, British Columbia, Canada). Though these species are sympatric and share a common prey source, they were attuned to different aspects of the local habitat. The fin whales were associated with habitat properties reminiscent of the open ocean. Humpback whales, in contrast, were associated with features more commonly associated with the inland waters of fjords. Fixed habitat features, such as seafloor depth and distance from the fjord mouth, were the most important predictors of fin whale presence, but fixed and dynamic variables, such as surface properties, predicted humpback whale presence with equal (moderate) success. With the exception of strong salinity gradients for humpback whales, habitat conditions were poor predictors of feeding state. Fin whales practiced a spatially confined, seasonally stable, and thus more predictable use of certain channels within the fjord system. These findings are compatible with site loyal behavior, which is interesting in light of the species' historical, unique use of this fjord system. The relatively lackluster performance of humpback-habitat models, coupled with the importance of oceanographic properties, makes the humpback's habitat use strategy more uncertain. The fact that two sympatric species sharing a common prey source exhibited different habitat use strategies suggests that at least one species was informed by something in addition to prey. Given that the two species are attuned to different aspects of the fjord habitat, their responses to habitat changes, including anthropogenic impacts, would likely be different in both nature and degree. Our findings highlight the value of comparative studies and the complexity of rorqual habitat use, which must be understood in order for critical habitat to be identified and protected.

Our use, misuse, and abandonment of a concept: Whither habitat?

The foundational concept of habitat lies at the very root of the entire science of ecology, but inaccurate use of the term compromises scientific rigor and communication among scientists and nonscientists. In 1997, Hall, Krausman & Morrison showed that 'habitat' was used correctly in only 55% of articles. We ask whether use of the term has been more accurate since their plea for standardization and whether use varies across the broader range of journals and taxa in the contemporary literature (1998-2012). We searched contemporary literature for 'habitat' and habitat-related terms, ranking usage as either correct or incorrect, following a simplified version of Hall et al.'s definitions. We used generalized linear models to compare use of the term in contemporary literature with the papers reviewed by Hall et al. and to test the effects of taxa, journal impact in the contemporary articles and effects due to authors that cited Hall et al. Use of the term 'habitat' has not improved; it was still only used correctly about 55% of the time in the contemporary data. Proportionately more correct uses occurred in articles that focused on animals compared to ones that included plants, and papers that cited Hall et al. did use the term correctly more often. However, journal impact had no effect. Some habitat terms are more likely to be misused than others, notably 'habitat type', usually used to refer to vegetation type, and 'suitable habitat' or 'unsuitable habitat', which are either redundant or nonsensical by definition. Inaccurate and inconsistent use of the term can lead to (1) misinterpretation of scientific findings; (2) inefficient use of conservation resources; (3) ineffective identification and prioritization of protected areas; (4) limited comparability among studies; and (5) miscommunication of science-based findings. Correct usage would improve communication with scientists and nonscientists, thereby benefiting conservation efforts, and ecology as a science.

A discrete-time model for population persistence in habitats with time-varying sizes.

In this paper, we use periodic and stochastic integrodifference models to study the persistence of a single-species population in a habitat with temporally varying sizes. We extend a persistence metric for integral operators on bounded domains to that of integral operators on unbounded domains. Using this metric in the periodic model, we present new perspectives of the critical habitat size problem in the case of dynamically changing habitat sizes. Specifically, we extend the concept of critical habitat size to that of lower minimal limit size in a period-2 scenario, and prove the existence of the lower minimal limit size. For the stochastic model, we point out the importance of considering multiple time scales in the temporal variability of the habitat size. The models are relevant to biological scenarios such as seasonal variability of wetland habitat sizes under precipitation variability.

Critical habitat for threatened and endangered species: how should the economic costs be evaluated?

The designation of critical habitat is a feature of endangered species protection laws in many countries. Under the U.S. Endangered Species Act, economics cannot enter into decisions to list species as threatened or endangered, but can be considered when critical habitat is designated. Areas can be excluded from proposed critical habitat if the economic cost of including them is determined to exceed the benefits of inclusion, and exclusion would not result in extinction of the species. The economic analysis done to support critical habitat exclusions has been controversial, and the focus of much litigation. We evaluate a sample of these analyses, and discuss the exclusions that were made in each case. We discuss how the methodology used to measure economic costs of critical habitat has changed over time and provide a critique of these alternative methods. We find that the approach currently in use is sound from an economic perspective. Nevertheless, quantification of the costs of critical habitat faces numerous challenges, including great uncertainty about future events, questions about the appropriate scale for the analysis, and the need to account for complex market feedbacks and values of non-market goods. For the studies we reviewed, there was no evidence that the results of the economic analyses provided information that was useful for making decisions about exemptions from critical habitat designations. If economics is to play a meaningful role in determining endangered species protections, an alternative would be to allow listing decisions to be based on economic as well as biological factors, as is typical for species conservation laws in other countries.

Severity of killer whale behavioral responses to ship noise: a dose-response study.

Critical habitats of at-risk populations of northeast Pacific "resident" killer whales can be heavily trafficked by large ships, with transits occurring on average once every hour in busy shipping lanes. We modeled behavioral responses of killer whales to ship transits during 35 "natural experiments" as a dose-response function of estimated received noise levels in both broadband and audiogram-weighted terms. Interpreting effects is contingent on a subjective and seemingly arbitrary decision about severity threshold indicating a response. Subtle responses were observed around broadband received levels of 130 dB re 1 µPa (rms); more severe responses are hypothesized to occur at received levels beyond 150 dB re 1 µPa, where our study lacked data. Avoidance responses are expected to carry minor energetic costs in terms of increased energy expenditure, but future research must assess the potential for reduced prey acquisition, and potential population consequences, under these noise levels.

Climate change, marine environments, and the US Endangered species act.

Climate change is expected to be a top driver of global biodiversity loss in the 21st century. It poses new challenges to conserving and managing imperiled species, particularly in marine and estuarine ecosystems. The use of climate-related science in statutorily driven species management, such as under the U.S. Endangered Species Act (ESA), is in its early stages. This article provides an overview of ESA processes, with emphasis on the mandate to the National Marine Fisheries Service (NMFS) to manage listed marine, estuarine, and anadromous species. Although the ESA is specific to the United States, its requirements are broadly relevant to conservation planning. Under the ESA, species, subspecies, and "distinct population segments" may be listed as either endangered or threatened, and taking of most listed species (harassing, harming, pursuing, wounding, killing, or capturing) is prohibited unless specifically authorized via a case-by-case permit process. Government agencies, in addition to avoiding take, must ensure that actions they fund, authorize, or conduct are not likely to jeopardize a listed species' continued existence or adversely affect designated critical habitat. Decisions for which climate change is likely to be a key factor include: determining whether a species should be listed under the ESA, designating critical habitat areas, developing species recovery plans, and predicting whether effects of proposed human activities will be compatible with ESA-listed species' survival and recovery. Scientific analyses that underlie these critical conservation decisions include risk assessment, long-term recovery planning, defining environmental baselines, predicting distribution, and defining appropriate temporal and spatial scales. Although specific guidance is still evolving, it is clear that the unprecedented changes in global ecosystems brought about by climate change necessitate new information and approaches to conservation of imperiled species. El Cambio Climático, los Ecosistemas Marinos y el Acta Estadunidense de Especies en Peligro.

Underwater topography determines critical breeding habitat for humpback whales near Osa Peninsula, Costa Rica: implications for Marine Protected Areas

Migrating humpback whales from northern and southern feeding grounds come to the tropical waters near Osa Peninsula, Pacific of Costa Rica, to reproduce and raise their calves. Planning effective marine protected areas that encompass humpback critical habitats require data about which oceanographic features influence distribution during the breeding period. This study examines the relationship between water depth and ocean floor slope with humpback whale distribution, based on sightings during two breeding seasons (2005 and 2006). Data are from the Southern and Northern subpopulations in the Eastern Tropical Pacific (ETP). Analysis followed the basic principles of the Ecological Niche Factors Analysis (ENFA), where indices of Marginality and Tolerance provide insights on the restrictiveness of habitat use. At a fine scale, physical factors such as water depth and slope define the critical breeding and nursing habitat for M. novaeangliae. Divergence in the subsamples means of depths and slope distribution, with the global mean of the study area in both eco-geographical variables, determine habitat requirements restricted by topographic features such as depths (< 100 m) and slope (< 10%), and locate the key breeding and nursing habitat of the species within the continental shelf domains. Proposed Marine Protected Areas (MPA’s) network plans should consider connectivity of Caño island-Drake Bay and the extension of Corcovado National Park maritime borders. Rev. Biol. Trop. 56 (2): 591-602. Epub 2008 June 30.

Las ballenas jorobadas viajan a aguas tropicales para reproducirse y criar a sus ballenatos. Es importante entender las características oceanográficas que influencian su distribución para lograr una planificación efectiva de áreas marinas protegidas con hábitats críticos para estos cetáceos. Este estudio examina la relación entre la profundidad, la pendiente del suelo oceánico y la distribución de estas ballenas, usando avistamientos del 2005 y 2006 en la costa Pacífica de la Península de Osa, Costa Rica (temporada de reproducción del sur y norte en el Pacífico Tropical Oriental). Usamos Análisis de Factores de Nicho Ecológico (ENFA por sus siglas en inglés), donde los índices de Marginalidad y Tolerancia ilustran las restricciones en uso de hábitat. En una escala local, factores físicos como la profundidad y la pendiente definen el hábitat crítico de reproducción y cría de M. novaeangliae. Las divergencias entre las medias de las sub-muestras y la media global del área de estudio en ambas variables eco-geográficas, determinan las limitaciones en requerimientos de hábitat en aspectos topográficos como la profundidad (>100 m) y la pendiente del fondo (>10%), localizando los hábitat críticos para reproducción y cría dentro de la plataforma continental. Los planes y propuestas para un sistema de áreas marinas protegidas deben de considerar la conectividad de la isla del Caño y la Bahía de Drake, así como la extensión de los límites marinos del Parque Nacional Corcovado.