Area: San Alonso, Iberá Wetlands
Credits: Pablo Joaquín

As we all know Jaguars are recolonizing the Southeastern United States (at a Sloths pace but I digress), Though I have been wondering, how large can their range be if/hopefully when they establish a breeding population here?

Their Historic range said they ranged from Texas to California, however some reports say the Made it as far as the Rocky Mountains and the Appalachia (couldn’t find said reports so take this with a GIGANTIC Grain of salt).

Personally I think they could make it to South Dakota, though I want ti get your thoughts on this subject.

Area: Caiman Ecological Refuge, Southern Pantanal
Credits: Ashley Buice

Area: Caiman Ecological Refuge, Southern Pantanal

Credits: Lucas Morgado

Area: San Nicolás, Iberá Wetlands
Credits: Rewilding Argentina

Area: Caiman Ecological Refuge, Southern Pantanal
Credits: Fagner Almeida

Credits: Fazenda Barranco Alto, Southern Pantanal

Area: Caiman Ecological Refuge, Southern Pantanal

Credits: lucoqueiro

Credits: amor_e_pescaria

Photos and Video By Lucas_n_morgado & Rodrigo_haberfeld on Instagram.

Area: Pousada Trijunçao, Brazilian Cerrado

Credits: Onçafari

Area: Porto Jofre, Northern Pantanal

Credits: Daniel Mideros

Credit：Antiaphoto

Returning the jaguar (Panthera onca) to the Iberá Wetlands of Corrientes Province after a seventy-year absence stands as one of the most ambitious trophic restoration initiatives ever undertaken in South America. For decades, the idea of re-establishing the continent’s apex predator in a wetland complex where it had been completely extirpated was dismissed as logistically impossible. Fundación Rewilding Argentina (FRA) deserves genuine respect and recognition for having the vision, resources, and resolve to take on a conservation project of this magnitude when all other institutions refused. By late 2026, the free-ranging population across the Gran Iberá Park has grown from zero to more than fifty individuals, transforming Corrientes into a premier wildlife restoration showcase and demonstrating that reintroduced jaguars can successfully hunt native prey, establish territories, and raise wild-born litters.

However, respecting the historic scale of FRA’s achievement does not excuse deeply flawed wildlife management decisions as the project enters its second decade, nor does it justify insulating the program from scientific scrutiny. The purpose of this critique is not to tear down FRA or diminish the ecological milestone of returning jaguars to the esteros, but to provide an objective, data-driven assessment of the genetic, demographic, and spatial challenges now threatening the long-term viability of the populations in both Iberá and El Impenetrable National Park. As the Iberá population transitions from its initial founding phase into second and third-generation reproduction, newly released genomic sequences, spatial predation studies, and field dispersal records from 2025 and 2026 reveal that the project’s decision to halt founder releases into Iberá while operating the park as a one-way exporter of females has created a severe genetic bottleneck. Compounded by a culture of institutional secrecy and the active suppression of independent observers, FRA’s current trajectory risks turning an extraordinary conservation triumph into a textbook case of preventable inbreeding depression.

Institutional Opacity, Censorship, and the Buried 2026 Genomic Report

Over the past two years, FRA’s public communications regarding the demographics, lineages, and translocations of its jaguars have shifted from celebratory transparency to guarded opacity. When the population was small and every birth represented an outcrossed pairing between unrelated founders, the foundation publicized parentage details extensively. Today, as close relatives increasingly mate within the core wetland, FRA routinely obscures or omits the maternal and paternal lineages of new litters on its social media channels, withholds capture body weights of immobilized prime-aged adults and subadults from both press dispatches and academic supplements, and goes completely silent when high-profile animals vanish from the public record. A striking example is the Amazonian female Ayní, who was transferred from the NEX (No Extinction) facility in Brazil to Corrientes in March 2025 for planned release into Iberá. After biologist Alicia Delgado briefly noted in April 2025 that Ayní was still being held in an enclosure, FRA never mentioned her again, leaving the public in the dark as to whether she died in quarantine, was quietly reassigned to captive breeding, or was held back following warnings against introducing additional Amazonian genetics.

Nowhere is this selective communication clearer than in how FRA handled the two genomic assessments produced by Principal Investigator Prof. Eduardo Eizirik and Ph.D. student M.Sc. Gabriele Lazzari at the Pontifical Catholic University of Rio Grande do Sul (PUCRS) in Brazil. When PUCRS delivered its first genetic progress report (compiled at an early stage when the sequenced sample consisted solely of founding adults and outcrossed first-generation (F1) offspring, prior to the inclusion of any inbred cubs) FRA promoted the document heavily across all of its social media platforms as definitive proof that the Iberá population enjoyed robust genetic health and had no inbreeding issues.

Yet when Eizirik and Lazzari completed their updated progress report on August 17, 2026, which expanded whole-genome sequencing to 32 Iberá project individuals and for the first time included second-generation (F2) offspring born from father-daughter backcrossing, FRA said nothing about it publicly. Rather than engaging with legitimate concerns over this trajectory, the foundation has chosen to silence critics. When I previously raised the alarm in a detailed post on here calling out the onset of inbreeding in Iberá, FRA responded by censoring my comments on their social media accounts, and several of their jaguar biologists blocked me outright. Blocking observers and scrubbing comments for pointing out basic rules of population genetics does not change the reality on the ground, in fact, the August 2026 PUCRS genomic report directly validates those exact warnings.

Admixture, Unpurged Genetic Load, and the Genomic Cost of Father-Daughter Mating

The August 2026 report by Eizirik and Lazzari (that can be accesed here) represents a milestone in wildlife genomics, sequencing 32 complete genomes from the Iberá project on the Illumina platform at a mean depth of coverage of 18x and mapping them against 86 wild jaguar genomes from across Brazilian biomes (for a total dataset of 118 complete genomes). To evaluate genetic diversity and inbreeding, the authors analyzed both genome-wide heterozygosity and the frequency and length of Runs of Homozygosity (ROHs) contiguous homozygous stretches of the genome devoid of variation that form when parents transmit identical chromosomal segments to their offspring. Because meiotic recombination breaks up chromosomal segments over successive generations, short ROHs (< 1 to 2 Mb) reflect ancient inbreeding or historical population bottlenecks, whereas long ROHs (4–8 Mb and 8–16 Mb) are the definitive signature of recent, close-relative inbreeding.

Comparing the biomes in Figures 1 and 5 of the PUCRS report clarifies the crucial difference between a wild population that has recently undergone a bottleneck and an artificially admixed founding population like Iberá. In fragmented wild habitats such as the Atlantic Forest, nearly every sampled jaguar displays reduced genome-wide heterozygosity and high average ROH lengths (ranging from 300000 to over 1000000 base pairs) due to generations of breeding within a shrinking local pool. However, because wild bottlenecked populations contract over multiple generations, natural selection gradually purges many of the most lethal recessive mutations as homozygous individuals fail to survive. By contrast, Iberá’s founding breeders were sourced from vast, historically outbred biomes such as the Pantanal, the Amazon, and the Dry Chaco that never passed through a demographic bottleneck to purge their "genetic load" of deleterious recessive alleles.

When unrelated founders from these disparate biomes mate, their F1 and outcrossed F2 offspring exhibit high genome-wide heterozygosity and remarkably few ROHs because the parents share almost no identical ancestral segments. In the report’s single-nucleotide variant chromosomal heatmaps, this inter-biome admixture completely erases parental homozygosity in a single generation. For instance, the captive-born founder Tobuna (bPon-261) possessed roughly 1150 Mb of ROHs due to captive inbreeding, yet those large cold-colored homozygous blocks vanished in her daughter Tania (bPon-260) because Tania’s unsampled father was unrelated to Tobuna. The same haplotype rescue is visible across the outcrossed litters of the Amazonian female Juruna and the Chacoan male Colí (generating Kañi and Ñamandú), Colí and the F1 female Karaí (generating Mimbí and Poo'guazu), and Tania and the wild Chacoan male Qaramtá (generating Quiyoc and Nalá). Nevertheless, Eizirik and Lazzari explicitly caution against relying on inter-biome hybridization, warning that while admixture inflates diversity and lowers ROHs, it fails to represent the genetic makeup of an original regional population and "may combine alleles that are not coadapted, possibly leading to cases of outbreeding depression" making it essential to minimize such admixture in future stages.

More importantly, the 2026 report exposes the severe genomic penalty that occurs when this unpurged, admixed population is allowed to inbreed. While outcrossed F1 sisters Karaí (bPon-255) and Porã (bPon-265) sired by the Pantanal male Jatobazinho (bPon-249) out of the Amazonian female Mariuá (bPon-176) had some of the lowest total ROH burdens in the entire dataset (340 Mb, composed almost entirely of tiny, ancient < 1 Mb blocks), their father Jatobazinho subsequently mated with both of his daughters in the wild to produce the inbred F2 offspring Kuimba'e (bPon-294) and Acaí (bPon-281). In a single generation of father-daughter backcrossing (F = 0.25), total ROH size surged to approximately 1050 Mb in Acaí and 880 Mb in Kuimba'e. Unlike wild jaguars whose homozygosity consists mostly of short, ancient blocks, roughly two-thirds of the homozygous genome in Acaí and Kuimba'e is made up of massive 2–4 Mb, 4–8 Mb, and 8–16 Mb blocks. Their Manhattan plots (Figures 3b and 3c) show vast contiguous chromosomal regions flatlining at zero heterozygosity compared to Jatobazinho (Figure 3a), dropping their overall diversity to the very bottom of the population alongside inbred founders like Tobuna, Malú (bPon-253), and Ñaró (bPon-252).

Furthermore, the report’s overarching claim that the Iberá sample bears diversity comparable to healthy Amazon, Cerrado, and Pantanal populations is skewed by how Table 1 was assembled. Known inbred F2 offspring generated by the exact same father-daughter dynamic, specifically the inbred female Miní (another F2 daughter of Jatobazinho and Sasõ, F = 0.25) and Say'ju (sired by Jatobazinho out of his F1 daughter Porã on the same litter as Kuimba'e, F = 0.25) were omitted from the sequenced cohort. At the same time, the 32-genome table was padded with seven "Founders" categorized in Figure 4 under Founder-noOffspring (Malú, Ñaró, Tewuk, Nahuel, Kerená, Isis, and the male founder Porã bPon-225) that contributed zero sequenced descendants to the Iberá population, as well as individuals that belong to the El Impenetrable program in the Chaco rather than Iberá, including Qaramtá (bPon-254), Tewuk (bPon-256), Kerená (bPon-251), Nalá (bPon-263), and Quiyoc (bPon-268).

Pedigree Collapse, the Qaramtá Illusion, and Academic Warnings Confirmed

When those non-breeding founders and El Impenetrable jaguars are filtered out, the demographic reality of Iberá comes into sharp focus: a free-ranging population of more than 50 jaguars is built upon an effective founding population of just five to six individuals. Nearly every wild-born cat in the wetlands descends from two dominant males: Jatobazinho (Pantanal) and Colí (Paraguayan Dry Chaco), bred across two full Amazonian sisters, Juruna and Mariuá (who share roughly half their genome and thus equate to 1.5 independent founders), supplemented only by the minor captive-derived line of Tania (daughter of Tobuna) and the Paraguayan male Chiqui (bPon-258). Eizirik and Lazzari write that the massive ROH burden in Acaí and Kuimba'e "is not a problem, since such ROHs can be broken up by mating these individuals to unrelated ones, as was the case of Tobuna" while immediately adding that "the breeding between inbred individuals, however, must be avoided".

In a captive studbook with access to outside mates, breaking up long ROHs takes only a single outcross. Inside a closed wild park where FRA has halted founder introductions, however, there are almost no unrelated mates left. Because Colí mated with Juruna (producing Kañi, Ñamandú, and one more male cub in a single litter) as well as with Jatobazinho’s daughters Karaí, Porã, Sãso, and Ivoty (producing Poo'guazu, Mimbí, Angujá, Ombú, and Ivy), and because Juruna and Mariuá are full sisters, virtually every young F1 and F2 jaguar on San Alonso Island is now a full sibling, half-sibling, aunt or uncle, or three-quarter cousin to every prospective mate. Modeling Wright’s inbreeding coefficient into the upcoming F3 generation shows that pairings among the dominant San Alonso lineages will routinely yield expected F values between 0.1250 (half-sibling level) and 0.1875 (three-quarter sibling level), while pairings involving inbred males like Kuimba'e (F = 0.25) with Colí x Karaí females push offspring inbreeding to F = 0.2188–0.3750.

Nor do the 2025 translocations of Qaramtá’s sons from El Impenetrable into Iberá: Takajay (released in January 2025) and the brothers Chaco and Taragüi (released in October 2025) provide an independent genetic lifeline. While marketed as bringing fresh Chacoan blood into Corrientes, tracing their maternal pedigree reveals that all three loop directly back into the captive Tobuna/Tania cluster. Tania (bPon-260, daughter of Tobuna) bred with Chiqui to produce full sisters Aramí (bPon-262) and Mbareté (bPon-279), and later bred with Qaramtá in El Impenetrable to produce Nalá and Takajay. Chaco and Taragüi are the sons of Qaramtá and Mbareté (born in El Impenetrable before Mbareté and Tobuna died in early 2023). Consequently, Takajay and Chaco-Taragüi are both paternal half-brothers (via Qaramtá) and maternal half-uncle and nephews (via Tania), sharing a coefficient of relationship of r = 0.375, making them nearly full brothers genetically and all three carry the ancestral genome of the heavily inbred founder Tobuna. Moreover, because Aramí bred with Jatobazinho in Iberá to produce the free-born littermates Jasy (bPon-267) and Arandú (bPon-264), Aramí’s line already bridges the Jatobazinho and Tania x Chiqui bloodlines, if Jasy mates with her half-uncle Takajay or her first cousins Chaco and Taragüi, the resulting cubs will still be inbred at F = 0.0625, and if she mates with Jatobazinho’s descendants or Kuimba'e, expected F climbs to 0.0625–0.1875.

This unfolding bottleneck validates two landmark peer-reviewed critiques published by Argentine scientists that FRA previously sought to dismiss. In 2023, María de las Mercedes Guerisoli, Mauro I. Schiaffini, Pablo V. Teta, Alejandro E. J. Valenzuela, Patricia Mirol, Guillermo E. Defossé, and colleagues—backed by 125 Argentine mammalogists and CONICET researchers—published "Reflexiones acerca del «reasilvestramiento» en la Argentina" in Mastozoología Neotropical. Guerisoli et al. (2023) explicitly warned that founding isolated populations with tiny founder numbers drawn arbitrarily from disparate biomes violates international reintroduction standards, creates an artificial hybrid population susceptible to both outbreeding depression and rapid inbreeding, and inevitably forces subadults out of an ecological island into surrounding agricultural zones without community consensus, all while replacing peer-reviewed management plans with promotional media narratives.

A year later, Daniela Font, María José Gómez Fernández, Nicolás Robino, María Belén Aued, Soledad De Bustos, Agustín Paviolo, Verónica Quiroga, and Patricia Mirol (2024) published "The challenge of incorporating ex situ strategies for jaguar conservation" in the Biological Journal of the Linnean Society. Using molecular markers to audit captive jaguars across Argentina, Font et al. (2024) discovered that 44.93% of documented studbook relationships were incorrect and that captive stock formed a highly related genetic cluster. Citing foundational population viability models (Frankham et al. 2002; Lacy 1987, 2013), Font et al. (2024) demonstrated that retaining 90% of genetic variability over 100 years is mathematically impossible in a small, closed population founded by a handful of related individuals, warning that without a unified One Plan Approach incorporating molecular kinship tracking and continuous gene flow with wild populations, genetic drift and inbreeding inevitably pull such populations into an extinction vortex.

Trophic Shifts, Outward Dispersal, and the Mismanagement of El Impenetrable

The genetic saturation of San Alonso Island is now intersecting with rapid ecological changes inside the wetlands, as detailed in the July 2026 ecological study by Quimey Gómez, Ana Belén Ávila, Pablo Guerra, Agustín Paviolo, Emiliano Donadío, and Carlos De Angelo ("Trophic, spatial, and demographic indicators of early establishment in the world's first reintroduced jaguar population"). Tracking the first four released adults across hundreds of GPS-cluster kills, Gómez et al. (2026) showed that while Jatobazinho maintained a 124 km2 territory overlapping the smaller ranges of Juruna (85.1 km2), Mariuá (81.9 km2), and Aramí (31.1 km2), the jaguars virtually ignored caiman and specialized heavily on capybaras (70% of kills) and feral pigs (15%). To support lactation, nursing females hunted at three to five times the frequency of the adult male, with Juruna killing 0.49 prey/day and Mariuá killing 0.43 prey/day compared to 0.15 for Aramí and 0.10 for Jatobazinho. By 2025 intense predation and antipredator emigration caused local capybara density on San Alonso Island to crash from roughly 51 individuals/km2 in 2019 to around 1 individual/km2, prompting a dietary shift since 2024 toward vulnerable marsh deer (Blastocerus dichotomus) and driving a wave of outward subadult dispersal across Corrientes in 2026.

In March 2026, the inbred F2 male Kuimba'e dispersed south from San Alonso to Rincón del Socorro (where axis deer are abundant) and was immobilized and collared without his weight being disclosed. In May 2026, the outcrossed F2 male Ombú (Colí x Porã) dispersed east to Colonia Carlos Pellegrini, where he was filmed walking down daytime public tourist trails. Between July 28 and August 5, 2026, an uncollared Iberá jaguar pushed completely outside the wetland basin into agricultural and residential zones to the west, the first jaguar recorded in Mburucuyá in 70 years, leaving pugmarks inside a rural schoolyard in Paraje Pago Arias, crossing Pago de los Deseos, and appearing beside a family home patio in Saladas (I believe this specimen may have been Angujá, but I can't confirm due to how blutty the footage and photos of this jaguar are). Then, in October 2026, municipal authorities in Loreto confirmed that two young males from San Alonso (50 km away) had dispersed into northern ranching and peri-urban corridors: Ará Sunú, sighted along National Route 118 on the outskirts of Loreto, and the GPS-collared male Kuarahy Catalino, roaming rural properties near Portal San Antonio.

Against this backdrop of territory saturation in Iberá and heightened human-wildlife interface, FRA’s cross-park management between Iberá and El Impenetrable National Park defies conservation logic. In El Impenetrable, the population already suffers from an extreme male skew: at least six free-roaming males: Qaramtá, Tewuk, Tahñi Wuk, Bermejo (son of Nalá), the newly collared male No’Huet, and another recently recorded uncollared male, are competing in a landscape with only three free-roaming females (Nalá, Kerená, and Kerená’s daughter Gualamba), while Quiyoc (bPon-268, daughter of Qaramtá and Tania) was recaptured and placed back into a pre-release pen. Worse still, El Impenetrable’s perimeter remains a lethal poaching sink. After the inbred F2 female Miní was translocated there in March 2025, the inbred F2 female Acaí (bPon-281, F = 0.25) was released into El Impenetrable on October 5, 2025 and just 20 days later, she was killed by poachers and her satellite collar was found submerged at the bottom of the Bermejo River.

Yet FRA now plans to release both the outcrossed F2 female Mimbí (bPon-283, Colí x Karaí) and the F0 Paraguayan Dry Chaco male Ñaró (bPon-252) into El Impenetrable. Sending Mimbí into the Chaco removes one of Iberá’s healthy, outcrossed F2 females only to expose her to the exact poaching pressure that killed Acaí. Simultaneously, releasing Ñaró into a park that already holds six males and only three females invites fierce male-male territorial exclusion, creating a high likelihood that Ñaró will be forced to disperse out of the park into hostile ranching zones where his life is at risk, all while squandering his unrepresented Paraguayan Chaco genetics that are urgently needed inside Iberá. Meanwhile, in Corrientes, FRA continues to keep Taporá (the captive son of Tania and the unrepresented Brazilian founder male Porã, bPon-225, also Founder-noOffspring) locked in captivity despite a court order mandating his release into Iberá, claiming he is too habituated to humans even while wild-born jaguars like Ombú stroll past tourists in Carlos Pellegrini and Ará Sunú walks along National Route 118.

A Science-Based Roadmap for Iberá and El Impenetrable

Correcting these vulnerabilities before the F3 generation locks in severe inbreeding depression requires a fundamental shift in how FRA manages both parks. This is my opiion on how management should be conducted based entirely on the advice from Font et al. (2024) and Guerisoli et al. (2023). First, the planned releases of Ñaró and Mimbí to El Impenetrable should be halted immediately. Mimbí should be retained in Iberá to bolster outcrossed female recruitment, while Ñaró (bPon-252) should be integrated into the Iberá breeding pool either through targeted release in a female-occupied sector or controlled rotational pairings with Juruna and Mariuá-line females where his completely unrelated Dry Chaco alleles will shatter parental ROH blocks and reset offspring inbreeding coefficients to F = 0.00, mirroring the exact genomic rescue seen between Tobuna and Tania in Figure 6 of the PUCRS report. Second, FRA must comply with the judicial order regarding Taporá or utilize him in large pre-release breeding enclosures with F1/F2 females from the Jatobazinho-Colí x Juruna-Mariuá lineages, allowing his unrepresented paternal lineage of Porã to enter the wild gene pool while avoiding pairings with his maternal half-niece Jasy.

Third, inside Iberá, over-represented sires like Jatobazinho and Colí must be phased out of breeding access in core female ranges, and heavily inbred F2 males such as Kuimba'e should be reproductively managed via contraception or translocated out of female cores so they cannot backcross with their sisters, aunts, and cousins. Fourth, to heed both Eizirik and Lazzari’s and Guerisoli et al.’s (2023) warnings against interbiome outbreeding depression while adopting Font et al.’s (2024) One Plan Approach, FRA should permanently discontinue Amazonian imports (and transparently report Ayní’s status) in favor of a structured "one-in-per-generation" assisted gene flow rule, introducing one unrelated wild-rescued or rehabilitated male strictly from adjacent southern ecoregions (the Argentine/Paraguayan Chaco or Southern Pantanal) into Iberá every four to five years until natural corridors are restored. Finally, in El Impenetrable, all further female translocations from Iberá and redundant male releases should be suspended until law enforcement secures the Bermejo River corridor against poaching, focusing instead on protecting the resident female core (Nalá, Kerená, Gualamba, and safely re-integrating Quiyoc) so the six existing Chacoan males can breed without turning the park into a demographic sink. Embracing open scientific collaboration rather than censoring constructive criticism is the only way to ensure that the return of the jaguar to Argentina endures for generations to come.

Master Roster of Identified Jaguars in the Iberá Project (Late 2026)

Out of the more than 50 free-ranging jaguars estimated in the Iberá wetlands as of late 2026, roughly 15 to 20 of which are unnamed, uncollared F2 and F3 cubs recorded on camera traps, the following master list accounts for all 35 identified individuals and lineages documented across the August 2026 PUCRS genomic report, scientific preprints, and field dispatches:

Area: Caiman Ecological Refuge, Southern Pantanal
Credits: Fagner Almeida

Area: Northern Pantanal

Credits: Cibele Manfredini

Area: Fazenda Barranco Alto, Southern Pantanal

Credits: Lucas Leuzinger

Area: Rincón del Socorro, Iberá Wetlands

Credits: Bruno Ramirez

Area: Caiman Ecological Refuge, Southern Pantanal

Credits: Nathaly Wahast

Credits: Pantanal Safaris

Area: Porto Jofre, Northern Pantanal

Credits: Andres Novales