It's not too late for the harpy eagle (Harpia harpyja): high levels of genetic diversity and differentiation can fuel conservation programs

A reference genome for the Harpy Eagle reveals steady demographic decline and chromosomal rearrangements in the origin of Accipitriformes

The Harpy Eagle (Harpia harpyja) is an iconic species that inhabits forested landscapes in Neotropical regions, with decreasing population trends mainly due to habitat loss, and currently classified as vulnerable. Here, we report on a chromosome-scale genome assembly for a female individual combining long reads, optical mapping, and chromatin conformation capture reads. The final assembly spans 1.35 Gb, with N50scaffold equal to 58.1 Mb and BUSCO completeness of 99.7%. We built the first extensive transposable element (TE) library for the Accipitridae to date and identified 7,228 intact TEs. We found a burst of an unknown TE ~ 13-22 million years ago (MYA), coincident with the split of the Harpy Eagle from other Harpiinae eagles. We also report a burst of solo-LTRs and CR1 retrotransposons ~ 31-33 MYA, overlapping with the split of the ancestor to all Harpiinae from other Accipitridae subfamilies. Comparative genomics with other Accipitridae, the closely related Cathartidae and Galloanserae revealed major chromosome-level rearrangements at the basal Accipitriformes genome, in contrast to a conserved ancient genome architecture for the latter two groups. A historical demography reconstruction showed a rapid decline in effective population size over the last 20,000 years. This reference genome serves as a crucial resource for future conservation efforts towards the Harpy Eagle.

Long-term female bias in sex ratios across life stages of Harpy Eagle, a large raptor exhibiting reverse sexual size dimorphism

The primary (PSR), secondary (SSR) and adult (ASR) sex ratios of sexually reproducing organisms influence their life histories. Species exhibiting reversed sexual size dimorphism (RSD) may imply a higher cost of female production or lower female survival, thus generating biases in PSR, SSR and/or ASR towards males. The Harpy Eagle is the world's largest eagle exhibiting RSD. This species is found in the Neotropical region and is currently threatened with extinction. We used molecular markers to determine the sex of 309 Harpy Eagles spanning different life stages-eaglets, subadults and adults-from 1904 to 2021 within the Amazon Rainforest and Atlantic Forest. Sex ratios for all life stages revealed a female-biased deviation across all periods and regions. Our results suggest that the population bias towards females is an evolutionary ecological pattern of this species, and SSR and ASR likely emerged from the PSR. This natural bias towards females may be compensated by an earlier sexual maturation age of males, implying a longer reproductive lifespan and a higher proportion of sexually active males. A better understanding of the Harpy Eagle's life history can contribute to understanding sex-role evolution and enable more appropriate conservation strategies for the species.

Ex situ population of the Harpy Eagle and its potential for integrated conservation

A main priority in conservation is the protection of species in their natural habitat. However, ex situ management of threatened species is a recognised strategy of conservation. Harpy Eagles (Harpiaharpyja) are removed from the wild due to illegal capture, nest tree destruction, or other conflict sources. This study presents a review of the current ex situ Harpy Eagle populations in Brazil and worldwide, including information on the origin, sex, and year of entrance or year of birth under human care. Worldwide, until 2020 there were 205 Harpy Eagles in 77 different facilities in 16 countries, with 40 institutions in Brazil and 37 in other countries. The largest ex situ Harpy Eagle population is maintained in Brazil, with 139 individuals (75 females and 64 males) in 40 institutions. Of these institutions, there were 24 zoos, seven conservation breeding centres, six commercial breeders, two wildlife shelters, and one wildlife sorting centre. In Brazil, 62% (n = 86) of the individuals were hatched in the wild and 38% (n = 53) were bred in captivity under human care; for the wild individuals, only 73% (n = 64) have a known state of origin, with the majority from Pará state. This investigation provided relevant information to establish an ex situ demographic database. These individuals may potentially constitute a genetically and demographically viable safety population for future conservation strategies, as well as a source for research and education applied to Harpy Eagle integrated conservation.

Rhabdoid melanoma in a harpy eagle (Harpia harpyja)

A 28-year-old male harpy eagle (Harpia harpyja) with a history of anorexia, hyporexia, lethargy, and progressive weight loss was found dead and submitted for post-mortem examination. Gross findings include dark brown discolouration of testes and lungs; the testes were bilaterally enlarged, glistening brown-grey to blackish in appearance, firm, smooth, and multilobulated. The lungs contained a mass with similar features to the testicles, irregularly shaped with multiple nodules. Histology of testis showed round, polygonal and pleomorphic cells, containing melanin pigments and a typical eosinophilic vacuole in their cytoplasm and with severe pleomorphism. An immunohistochemistry panel with Melan-A, vimentin, CK AE1/AE/3, MUM-1 and CD-68 were performed, yielding a positive reaction for Melan-A and vimentin. The morphology of the tumour cells, the presence of melanin pigment and the immunoreactivity for Melan-A and vimentin by the cells led to a diagnosis of rhabdoid melanoma. This is the first case of this pathology in the testis with lung metastasis in a harpy eagle.

Geographic range estimates and environmental requirements for the harpy eagle derived from spatial models of current and past distribution

Understanding species-environment relationships is key to defining the spatial structure of species distributions and develop effective conservation plans. However, for many species, this baseline information does not exist. With reliable presence data, spatial models that predict geographic ranges and identify environmental processes regulating distribution are a cost-effective and rapid method to achieve this. Yet these spatial models are lacking for many rare and threatened species, particularly in tropical regions. The harpy eagle (Harpia harpyja) is a Neotropical forest raptor of conservation concern with a continental distribution across lowland tropical forests in Central and South America. Currently, the harpy eagle faces threats from habitat loss and persecution and is categorized as Near-Threatened by the International Union for the Conservation of Nature (IUCN). Within a point process modeling (PPM) framework, we use presence-only occurrences with climatic and topographical predictors to estimate current and past distributions and define environmental requirements using Ecological Niche Factor Analysis. The current PPM prediction had high calibration accuracy (Continuous Boyce Index = 0.838) and was robust to null expectations (pROC ratio = 1.407). Three predictors contributed 96% to the PPM prediction, with Climatic Moisture Index the most important (72.1%), followed by minimum temperature of the warmest month (15.6%) and Terrain Roughness Index (8.3%). Assessing distribution in environmental space confirmed the same predictors explaining distribution, along with precipitation in the wettest month. Our reclassified binary model estimated a current range size 11% smaller than the current IUCN range polygon. Paleoclimatic projections combined with the current model predicted stable climatic refugia in the central Amazon, Guyana, eastern Colombia, and Panama. We propose a data-driven geographic range to complement the current IUCN range estimate and that despite its continental distribution, this tropical forest raptor is highly specialized to specific environmental requirements.

Analysis of the Genetic Diversity and Structure of the Grey-Faced Buzzard (Butastur indicus) in Japan, Based on mtDNA

The grey-faced buzzard (Butastur indicus) is a raptor that inhabits East Asia, including Japan. Because the number of individuals has decreased by 75% over the last 40 years, this species is classified as vulnerable (VU) in Japan. In the present study, wesought to reveal the genetic structure of the Japanese grey-faced buzzard population at several breeding sites, and to assess the levels of genetic diversity within the Japanese population. We sequenced 555 bp of the mitochondrial DNA of 96 individuals sampled during the breeding season at 18 sites, and 11 individuals sampled during the winter season at one site. In total, 21 variable sites were found in the control region, and we detected 26 haplotypes among the 107 individuals. Fukuoka represented the core breeding area for grey-faced buzzards, as half of all haplotypes were detected there. Four unique haplotypes were detected in the overwintering area. The results of the network and mismatch distribution analyses indicated that the grey-faced buzzard has not experienced a genetic bottleneck in the past, but did experience recent population expansion. In addition, comparisons with other raptors revealed rich genetic diversity in the grey-faced buzzard population. Our results indicate that conservation of both breeding and wintering areas is important for the protection of the grey-faced buzzard.

Reduction of Genetic Diversity of the Harpy Eagle in Brazilian Tropical Forests

Habitat loss and fragmentation intensify the effects of genetic drift and endogamy, reducing genetic variability of populations with serious consequences for wildlife conservation. The Harpy Eagle (Harpia harpyja) is a forest dwelling species that is considered near threatened and suffers from habitat loss in the forests of the Neotropical region. In this study, 72 historical and current samples were assessed using eight autosomal microsatellite markers to investigate the distribution of genetic diversity of the Harpy Eagle of the Amazonian and Atlantic forests in Brazil. The results showed that the genetic diversity of Harpy Eagle decreased in the regions where deforestation is intense in the southern Amazon and Atlantic Forest.

OE, Williams RN. Unexpectedly low rangewide population genetic structure of the imperiled eastern box turtle Terrapene c. carolina

Rangewide studies of genetic parameters can elucidate patterns and processes that operate only over large geographic scales. Herein, we present a rangewide population genetic assessment of the eastern box turtle Terrapene c. carolina, a species that is in steep decline across its range. To inform conservation planning for this species, we address the hypothesis that disruptions to demographic and movement parameters associated with the decline of the eastern box turtle has resulted in distinctive genetic signatures in the form of low genetic diversity, high population structuring, and decreased gene flow. We used microsatellite genotype data from (n = 799) individuals from across the species range to perform two Bayesian population assignment approaches, two methods for comparing historical and contemporary migration among populations, an evaluation of isolation by distance, and a method for detecting barriers to gene flow. Both Bayesian methods of population assignment indicated that there are two populations rangewide, both of which have maintained high levels of genetic diversity (H_O = 0.756). Evidence of isolation by distance was detected in this species at a spatial scale of 300 – 500 km, and the Appalachian Mountains were identified as the primary barrier to gene flow across the species range. We also found evidence for historical but not contemporary migration between populations. Our prediction of many, highly structured populations across the range was not supported. This may point to cryptic contemporary gene flow, which might in turn be explained by the presence of rare transients in populations. However these data may be influenced by historical signatures of genetic connectivity because individuals of this species can be long-lived.

DNA Barcodes of Arabian Partridge and Philby's Rock Partridge: Implications for Phylogeny and Species Identification

Recently, DNA barcoding based on mitochondrial cytochrome c oxidase subunit I (COI) has gained wide attention because of simplicity and robustness of these barcodes for species identification including birds. The current GenBank records show the COI barcodes of only one species, chukar partridge (Alectoris chukar), of the Alectoris genus. In this study, we sequenced the 694 bp segment of COI gene of the two species including, Arabian partridge (Alectoris melanocephala) and Philby's rock partridge (Alectoris philbyi) of the same genus. We also compared these sequences with earlier published barcodes of chukar partridge. The pair-wise sequence comparison showed a total of 53 variable sites across all the 9 sequences from 3 species. Within-species variable sites were found to be 4 (Alectoris chukar), 0 (Alectoris philbyi) and 3 (Alectoris melanocephala). The genetic distances among the 9 individuals varied from 0.000 to 0.056. Phylogenetic analysis using COI barcodes clearly discriminated the 3 species, while Alectoris chukar was found to be more closely related to Alectoris philbyi. Similar differentiation was also observed using 1155 bp mitochondrial control region (CR) sequences suggesting the efficiency of COI gene for phylogenetic reconstruction and interspecific identification. This is the first study reporting the barcodes of Arabian partridge and Philby's rock partridge.

The use of genetics for the management of a recovering population: temporal assessment of migratory peregrine falcons in North America

BACKGROUND

Our ability to monitor populations or species that were once threatened or endangered and in the process of recovery is enhanced by using genetic methods to assess overall population stability and size over time. This can be accomplished most directly by obtaining genetic measures from temporally-spaced samples that reflect the overall stability of the population as given by changes in genetic diversity levels (allelic richness and heterozygosity), degree of population differentiation (F(ST) and D(EST)), and effective population size (N(e)). The primary goal of any recovery effort is to produce a long-term self-sustaining population, and these genetic measures provide a metric by which we can gauge our progress and help make important management decisions.

METHODOLOGY/PRINCIPAL FINDINGS

The peregrine falcon in North America (Falco peregrinus tundrius and anatum) was delisted in 1994 and 1999, respectively, and its abundance will be monitored by the species Recovery Team every three years until 2015. Although the United States Fish and Wildlife Service makes a distinction between tundrius and anatum subspecies, our genetic results based on eleven microsatellite loci suggest limited differentiation that can be attributed to an isolation by distance relationship and warrant no delineation of these two subspecies in its northern latitudinal distribution from Alaska through Canada into Greenland. Using temporal samples collected at Padre Island, Texas during migration (seven temporal time periods between 1985-2007), no significant differences in genetic diversity or significant population differentiation in allele frequencies between time periods were observed and were indistinguishable from those obtained from tundrius/anatum breeding locations throughout their northern distribution. Estimates of harmonic mean N(e) were variable and imprecise, but always greater than 500 when employing multiple temporal genetic methods.

CONCLUSIONS/SIGNIFICANCE

These results, including those from simulations to assess the power of each method to estimate N(e), suggest a stable or growing population, which is consistent with ongoing field-based monitoring surveys. Therefore, historic and continuing efforts to prevent the extinction of the peregrine falcon in North America appear successful with no indication of recent decline, at least from the northern latitude range-wide perspective. The results also further highlight the importance of archiving samples and their use for continual assessment of population recovery and long-term viability.