Island Biogeography Revisited: Museomics Reveals Affinities of Shelf Island Birds Determined by Bathymetry and Paleo-Rivers, Not by Distance to Mainland.

Island biogeography is one of the most powerful subdisciplines of ecology: its mathematical predictions that island size and distance to mainland determine diversity have withstood the test of time. A key question is whether these predictions follow at a population-genomic level. Using rigorous ancient-DNA protocols, we retrieved approximately 1,000 genomic markers from approximately 100 historic specimens of two Southeast Asian songbird complexes from across the Sunda Shelf archipelago collected 1893-1957. We show that the genetic affinities of populations on small shelf islands defy the predictions of geographic distance and appear governed by Earth-historic factors including the position of terrestrial barriers (paleo-rivers) and persistence of corridors (Quaternary land bridges). Our analyses suggest that classic island-biogeographic predictors may not hold well for population-genomic dynamics on the thousands of shelf islands across the globe, which are exposed to dynamic changes in land distribution during Quaternary climate change.

Why do human and non-human species conceal mating? The cooperation maintenance hypothesis.

Despite considerable cultural differences, a striking uniformity is argued to exist in human preferences for concealing sexual intercourse from the sensory perception of conspecifics. However, no systematic accounts support this claim, with only limited attempts to understand the selective pressures acting on the evolution of this preference. Here, I combine cross-cultural and cross-species comparative approaches to investigate these topics. First, an analysis of more than 4572 ethnographies from 249 cultures presents systematic evidence that the preference to conceal mating is widespread across cultures. Second, I argue that current anthropological hypotheses do not sufficiently explain why habitual concealment of mating evolved in humans but is only seldom exhibited by other social species. Third, I introduce the cooperation maintenance hypothesis, which postulates that humans, and a specific category of non-human species, conceal matings to prevent sexual arousal in witnesses (proximate explanation). This allows them to simultaneously maintain mating control over their partner(s) and cooperation with group members who are prevented from mating (ultimate explanations). I conclude by presenting a comparative framework and predictions to be tested across species and human cultures.

Joint attention skills in wild Arabian babblers ( Turdoides squamiceps): a consequence of cooperative breeding?

Human cooperation strongly relies on the ability of interlocutors to coordinate each other's attentional state: joint attention. One predominant hypothesis postulates that this hallmark of the unique cognitive system of humans evolved due to the combination of an ape-like cognitive system and the prosocial motives that facilitate cooperative breeding. Here, we tested this hypothesis by investigating communicative interactions of a cooperatively breeding bird species, the Arabian babbler ( Turdoides squamiceps). The behaviour of 12 wild social groups was observed focusing on two distinct communicative behaviours: object presentation and babbler walk. The results showed that both behaviours fulfilled the criteria for first-order intentional communication and involved co-orientation of recipients' attention. In turn, recipients responded with cooperative and communicative acts that resulted in coordinated joint travel between interlocutors. These findings provide the first evidence that another animal species shows several key criteria traditionally used to infer joint attention in prelinguistic human infants. Furthermore, they emphasize the influence of cooperative breeding on sophisticated socio-cognitive performances, while questioning the necessity of an ape-like cognitive system underlying joint attentional behaviour.

Near-complete phylogeny and taxonomic revision of the world's babblers (Aves: Passeriformes).

The babblers are a diverse group of passerine birds comprising 452 species. The group was long regarded as a "scrap basket" in taxonomic classification schemes. Although several studies have assessed the phylogenetic relationships for subsets of babblers during the past two decades, a comprehensive phylogeny of this group has been lacking. In this study, we used five mitochondrial and seven nuclear loci to generate a dated phylogeny for babblers. This phylogeny includes 402 species (ca. 89% of the overall clade) from 75 genera (97%) and all five currently recognized families, providing a robust basis for taxonomic revision. Our phylogeny supports seven major clades and reveals several non-monophyletic genera. Divergence time estimates indicate that the seven major clades diverged around the same time (18-20 million years ago, Ma) in the early Miocene. We use the phylogeny in a consistent way to propose a new taxonomy, with seven families and 64 genera of babblers, and a new linear sequence of names.

Component, group and demographic Allee effects in a cooperatively breeding bird species, the Arabian babbler (Turdoides squamiceps).

In population dynamics, inverse density dependence can be manifested by individual fitness traits (component Allee effects), and population-level traits (demographic Allee effects). Cooperatively breeding species are an excellent model for investigating the relative importance of Allee effects, because there is a disproportionately larger benefit to an individual of being part of a large group. As a consequence, larger groups have greater performance than small groups, known as the group Allee effect. Although small populations of cooperative breeders may be prone to all levels of Allee effects, empirical evidence for the existence of a demographic Allee effects is scarce. To determine the extent to which Allee effects are present in a cooperatively breeding species, we used a comprehensive 35-year life history database for cooperatively breeding Arabian babblers (Turdoides squamiceps). Firstly, we confirmed the existence of a component Allee effect by showing that breeding individuals in large groups receive greater benefits than those in small groups; second, we confirmed the existence of group Allee effect by showing that larger groups survive longer. And thirdly, we identified a demographic Allee effect by showing that per capita population growth rate is positively affected by population density. Finally, we found that emigration and immigration rates, although dependent on group size, do not buffer against component and group-level Allee effects becoming a demographic Allee effect. Our finding of the existence of all three levels of Allee effects in a cooperative breeder may have important implications for future research and conservation decisions.

High temperatures during early development reduce adult cognitive performance and reproductive success in a wild animal population.

Global warming is rapidly changing the phenology, distribution, behaviour and demography of wild animal populations. Recent studies in wild animals have shown that high temperatures can induce short-term cognitive impairment, and captive studies have demonstrated that heat exposure during early development can lead to long-term cognitive impairment. Given that cognition underpins behavioural flexibility and can be directly linked to fitness, understanding how high temperatures during early life might impact adult cognitive performance in wild animals is a critical next step to predict wildlife responses to climate change. Here, we investigated the relationship between temperatures experienced during development, adult cognitive performance, and reproductive success in wild southern pied babblers (Turdoides bicolor). We found that higher mean daily maximum temperatures during nestling development led to long-term cognitive impairment in associative learning performance, but not reversal learning performance. Additionally, a higher number of hot days (exceeding 35.5 °C, temperature threshold at which foraging efficiency and offspring provisioning decline) during post-fledging care led to reduced reproductive success in adulthood. We did not find evidence that low reproductive success was linked to impaired associative learning performance: associative learning performance was not related to reproductive success. In contrast, reversal learning performance was negatively related to reproductive success in breeding adults. This suggests that reproduction can carry a cost in terms of reduced performance in cognitively demanding tasks, confirming previous evidence in this species. Taken together, these findings indicate that naturally occurring high temperatures during early development have long-term negative effects on cognition and reproductive success in wild animals. Compounding effects of high temperatures on current nestling mortality and on the long-term cognitive and reproductive performance of survivors are highly concerning given ongoing global warming.

Unraveling the unknown: Adaptive spatial planning to enhance climate resilience for the endangered Swamp Grass-babbler (Laticilla cinerascens) with habitat connectivity and complexity approach.

The endangered and poorly known Swamp Grass-babbler, Laticilla cinerascens (Passeriformes: Pellorneidae), confronts critical threats and vulnerability due to its specific habitat requirements and restricted populations in the northeastern region of the Indian Subcontinent. This study investigates the distribution of the species, habitat quality, geometry and shape complexity of connectivity among the protected areas (PAs), and responses to climate change in Northeast India under different climate change pathways by utilizing ensemble distribution models, and ecological metrics. From the total distribution extent (1,42,000 km2), approximately 9366 km2 (6.59 %) is identified as the suitable habitat for this threatened species. Historically centered around Dibru Saikhowa National Park (DSNP), the species faced a drastic decline due to anthropogenic activities and alteration in land use and lover cover. The study also reveals a significant decline in suitable habitat for L. cinerascens in future climate scenarios, with alarming reductions under SSP126 (>10 % in the timeframe 2041-2060 and > 30 % from 2061 to 2080), SSP245 (>90 % in both time periods), and SSP585 (>90 % in both timeframes) from the present scenario. At present, DSNP has the most suitable habitat within the distribution range but is projected to decline (>90 %) under more severe climate change scenarios, as observed in other PAs. Landscape fragmentation analysis indicates a shift in habitat geometry, highlighting the intricate impact of climate change. It predicts a substantial 343 % increase (in the SSP126) in small habitat patches in the future. Connectivity analysis among PAs shows a significant shift, with a decline exceeding 20 %. The analysis of shape complexity and connectivity geometry reveals a significant increase of over 220 % in the fragmentation of connectivity among PAs between 2061 and 2080 under the SSP585 climate change scenario compared to the present conditions. The study underscores the urgent need for conservation actions, emphasizing the complex interplay of climate change, habitat suitability, and fragmentation. Prioritizing PAs with suitable habitats and assessing their connectivity is crucial. Adaptive management strategies are essential to address ongoing environmental changes and safeguard biodiversity. Future research in critical areas is needed to establish long-term monitoring programs to lead/extend effective conservation strategies.

NEW SPECIES AND NEW RECORDS OF PRICEIELLA (PHTHIRAPTERA: ISCHNOCERA: BRUEELIA-COMPLEX) FROM SOUTH CHINA.

Seven new species of chewing lice in the genus PriceiellaGustafsson and Bush, 2017, are described and illustrated based on specimens collected in south China. They are Priceiella (Camurnirmus) tanydrepanus n. sp. from Garrulax castanotis castanotis (Ogilvie-Grant, 1899); Priceiella (Camurnirmus) nanlingensis n. sp. from Garrulax maesi maesi (Oustalet, 1890); Priceiella (Thescelovora) brutifrons n. sp. from Turdinus brevicaudatus stevensi (Kinnear, 1925); Priceiella (Thescelovora) chuae n. sp. from Pellorneum albiventre cinnamomeus (Rippon, 1900); Priceiella (Thescelovora) catanachei n. sp. from Stachyris strialata swinhoei Rothschild, 1903; Priceiella (Thescelovora) dehongensis n. sp. from Stachyris nigriceps yunnanensis La Touche, 1921; and Priceiella (Thescelovora) rotundiceps n. sp. from Pomatorhinus ruficollis styani Seebohm, 1884. Several of these new species constitute the second species of Priceiella known from the host, suggesting that local endemism may be high in this louse genus. We also provide new host records for Priceiella (Thescelovora) coleyaeGustafsson et al., 2018, and Priceiella (Thescelovora) austiniGustafsson et al., 2018, and correct the type host subspecies for the latter. Finally, we amend the subgenus descriptions of CamurnirmusGustafsson and Bush, 2017, and ThescelovoraGustafsson and Bush, 2017. As a result of these changes, Priceiella najeriGustafsson et al., 2018, is moved to subgenus Thescelovora. An updated checklist of the genus Priceiella is provided.

Four new species of Myrsidea (Phthiraptera: Amblycera: Menoponidae) from Chinese babblers (Passeriformes: Leiothrichidae, Paradoxornithidae, Timaliidae).

Four new species of amblyceran chewing lice of the genus Myrsidea Waterston, 1915 are described from hosts of the babbler families Leiothrichidae, Paradoxornithidae and Timaliidae in China. They are: Myrsidea attenuata n. sp. from Garrulax maesi maesi (Oustalet, 1890), Myrsidea zhangae n. sp. from Ianthocincla berthemyi (Oustalet, 1876), Myrsidea liopari n. sp. from Lioparus chrysotis amoenus (Mayr, 1941) and L. chrysotis swinhoii (Verreaux, 1871), and Myrsidea suthorae n. sp. from Suthora verreauxi verreauxi Sharpe, 1883. A checklist of host-louse associations for identified and unidentified Myrsidea species known from babblers is provided.

The benefits of pair bond tenure in the cooperatively breeding pied babbler (Turdoides bicolor).

The benefits of stable pair bonds (that persist between breeding attempts) have been well described, but are relatively less well known in cooperatively breeding species. If pair bonds are beneficial, then it is possible that the bond between the behaviorally and socially dominant pair may influence factors such as reproductive success and group stability in cooperative species. Here, we used long-term data to investigate the relationships between pair bond tenure, reproductive success, and group stability in the cooperatively breeding pied babbler (Turdoides bicolor). Pair bond tenure positively influenced both the number of offspring recruited annually per pair and total reproductive success (over entire pair bond duration), indicating that pair bond tenure has an important influence on reproductive success. The likelihood of immigration into the group was lower for groups containing a bonded pair with long tenure, indicating that the duration of pair bonds may impact group stability. These findings suggest that pair tenure, a hitherto relatively unexplored factor in cooperative species, may have an important influence on group dynamics.