Biology subjects

Naguib, M.

Publications and source records attributed to Naguib, M..

9 recordsLinked to original sources

bioRxiv2026

Sensitive period for song learning outlasts parent-offspring cohesion in wild zebra finches

Communication is central to social behaviour, with vocalisations playing a crucial role in many species. In some species, vocalisations are learned, with songbirds being key to understanding vocal learning. The Australian zebra finch (Taeniopygia castanotis) is the most studied model organism for vocal learning. In captivity, juveniles are typically housed with their father, where males learn their father song and females develop a preference for that song. In nature, however, the social structure of zebra finches is more dynamic across space and time. To identify the natural social conditions during song learning, we followed zebra finch families across their early life in the wild using automated radio-tracking. The distance between juveniles and their parents increased post-fledging and became similar to the distance between juveniles and unrelated adults by the second half of the song learning period. These findings indicate a highly dynamic social environment during the song learning period and suggest that juvenile males could learn from many tutors and that females may develop broader song preferences. Thus, studies based on one-tutor paradigms should be interpreted carefully with respect to functional implications and highlight that future vocal learning studies could better reflect the social conditions under which song develops.

animal behavior and cognition↗

bioRxiv2026

What do fishermen think? Local perspectives on human crocodile co-existence in Lake Nasser

The increasing impact of humans on natural habitats leads to an increase in human-wildlife conflict (HWC), specifically when there is competition for shared resources. In freshwater systems such as Lake Nasser, Egypt, co-occurrence of local fishermen communities with Nile crocodiles (Crocodylus niloticus) poses critical challenges for both livelihoods and biodiversity conservation. Understanding local perception of crocodiles by local fishermen is therefore essential for developing effective and socially accepted management responses. We used a structured questionnaire to assess how fishermen perceive and respond to crocodiles across three attitudinal domains: (1) perceived threats, (2) perceived economic benefits, and (3) conservation or co-existence values. Forty-two fishermen were interviewed across multiple khors (side arms of the lake). The responses showed a multifaceted picture: while many local fishermen associated crocodiles with gear damage, reduced catches, and livelihood risks, support for crocodile protection and recognition of their ecological role were also widespread. Interest in crocodile-based livelihood opportunities, such as harvesting or collecting the hatchlings, was generally low, suggesting social, cultural, or legal barriers to such approaches. Fishing experience influenced perceptions, with fishermen encountering crocodiles more frequently reporting decreased catches and greater concern. Cluster analysis further revealed three different respondent groups with different attitudes: conflict-oriented, moderate, and coexistence-oriented. Support for crocodile protection was the strongest predictor of belonging to the pro-co-existence group. Our findings underscore the complexity of human- crocodile co-occurrence in Lake Nasser and, on a wider scale, add to the existing cautions against simplistic mitigations of local HWC. Effective conservation and livelihood interventions will require participatory, context-sensitive approaches that integrate the different perceptions and attitudes of local people.

ecology↗

bioRxiv2025

Communication networks of wild zebra finches (Taeniopygia castanotis)

Communication networks are widespread across species, permitting information flow and facilitating social connections across space and time. In birds, communication networks are well studied in territorial species with long-range songs connecting individuals across space, where unintended listeners extract information from others signalling interactions. Yet, acoustic signals also play important social roles at short range, forming communication networks that connect individuals within larger social units. Wild zebra finches (Taeniopygia castanotis) provide a unique model system to examine such communication networks in a non-territorial species. Zebra finches breed in loose colonies in the Australian arid zone, move around in pairs or small groups, and gather at social hotspots, thus forming dynamic, potentially multi-level, societies. Here, we quantified singing activity and connectivity using the individually distinctive male song recorded at two breeding sub-colonies and three social hotspots over one to three days. We identified 1,835 song bouts from 163 males based on spectrographic similarities and we assessed within and between individual song assignments with a deep learning model (BirdNET). We constructed communication networks based on temporal singing proximity at shared locations: social hotspots and breeding colonies. We reveal higher singing activity at social hotspots than at breeding sites, with almost no dawn song at either site. Singing peaked later, yet at different times of day between breeding sites and social hotspots. Communication networks, with distinct males singing in close temporal proximity, were apparent in both contexts, with larger networks at hotspots. These networks included some individuals that sang together repeatedly at either site, but overall networks were not strongly nested, with only very few males maintaining associations across breeding colonies and hotspots. These networks may facilitate synchronised foraging and breeding as adaptations to a harsh and unpredictable environment. Additionally, our approach offers a novel road map for widening the understanding of communication networks.

animal behavior and cognition↗

bioRxiv2025

Zebra finches produce intralaryngeal laminar flow whistles during panting

Birds and mammals converged upon the same physical mechanism of vocal fold vibration to produce their broad range of voiced sounds critical to communication1. The frequency range of vocal fold vibration is limited per species by biophysical constraints to 3-4 octaves2. However, recent work reported vocalizations in zebra finches with apparent fundamental frequencies of 7-11 kHz3 that far exceed the range of regular calls and song (0.5-1.5 kHz)4,5. These "heat" or "incubation" calls are suggested to have close-range communicative relevance in the global temperature rise context3,6, but their acoustics are poorly described and by what biophysical mechanism they are produced remains unknown. We recorded heat calls in adult zebra finches in vivo and show they are extremely soft, frequency-modulated calls with source levels of 13.9 {+/-} 3.3 dB SPL at one meter with dominant frequencies of 6.8 {+/-} 0.6 kHz. Through a series of in vitro experiments, we establish that these calls are aerodynamic whistles produced inside the avian larynx, not syrinx, during inspiration. Respiratory air flow during whistle production is an order of magnitude higher than song and consistent with thermal panting for evaporative cooling6,7. Laryngeal geometry and dimensional flow analysis suggest that these whistles are laminar flow whistles that occur when a flow boundary layer is in a transition phase from laminar to turbulent flows8,9. Birds, like some rodents10-12, are thus able to produce both voiced sounds and aerodynamical whistles in their vocal tract.

physiology↗

bioRxiv2024

Evolution of vocal production learning in parrots

Vocal production learning (VPL), the capacity to imitate sounds, is a crucial, but not exclusive component of human language. VPL is rare in animals but common in birds, where it evolved independently in songbirds, hummingbirds, and parrots. Parrots (Psittaciformes) learn new vocalizations throughout their lives and exhibit astonishing vocal flexibility and imitation capacity. They can copy allospecific sounds, e.g., human words and learn their associated meanings. Parrots, therefore, present an intriguing model to shed light on how VPL evolved and how it may relate to other language-relevant traits. How widely VPL is distributed across Psittaciformes and to what extent (qualitative) species differences exist, remains unknown. Here, we provide the first comprehensive overview of the phylogenetic distribution of (allospecific) VPL in this clade by conducting surveys of publicly available video footage. Out of the 398 currently recognized extant species, we found videos for 163, of which 136 showed evidence of VPL. Phylogenetic analyses suggest secondary losses and reacquisitions of VPL covarying with socioecological parameters (gregariousness), life-history (longevity), and morphological (body size) traits. This study provides the first insights into interspecific variation in vocal learning across all parrot species and reveals potential socio-ecological drivers of its evolution. SignificanceLittle is known about the selective forces that favor the evolution of vocal production learning (VPL), a rare trait in animals and a prerequisite for the evolution of human language. We provide the first insights into interspecific variation in VPL in the evolutionary history of parrots and uncover candidate evolutionary drivers. The current data suggest that the evolution of VPL within parrots has been highly dynamic, with multiple secondary losses and reacquisitions. Our model showed that VPL most likely was the ancestral state. Sociality, longevity and body size explain variation in VPL together with a highly uncertain effect of brain size. The findings may motivate comparative work in other taxa and contribute to research into the evolutionary origins of human language.

evolutionary biology↗

bioRxiv2024

Constant companions: Wild zebra finch pairs display extreme spatial cohesion

Many animals maintain long-term monogamous partnerships, but the extent to which partners associate varies substantially and has implications for the scope of cooperation between pair members. Zebra finches (Taeniopygia castanosis) are monogamously paired for life and maintain continuous partnerships, raising questions as to if and how they maintain pair cohesion despite being nonterritorial and having only short-range acoustic signals. While zebra finches are the best studied songbird in captivity, their social and spatial behaviour in the wild is poorly understood. Determining pair cohesion in songbirds to date has almost exclusively been studied at specific locations where pairs would be expected to meet, such as nesting or feeding sites, without quantifying broader movements. Here, we used solar-powered automated tracking to simultaneously monitor the movements of radio-tagged zebra finch pairs during periods with breeding activity. We reveal extremely high spatial cohesion with pairs using nearly identical home ranges and maintaining close spatial proximity across large areas. This characterisation of extremely high spatio-temporal coordination of zebra finch pairs provides important insights into the operation and benefits of monogamous relationships in highly mobile taxa, such as birds.

animal behavior and cognition↗

bioRxiv2024

Fingerprint localisation for fine-scale wildlife tracking using automated radio telemetry

1: Automated radio telemetry systems are among the most widely applicable method for tracking wildlife at fine spatiotemporal scales. These systems are increasingly applying large networks of simple receivers to detect radio signal strength (RSS) from radio tagged individuals. Analytical methods to derive position estimates using RSS localisation, however, are relatively underdeveloped in the field of wildlife tracking. Here, we apply approaches from indoor positioning systems to develop a new method, radio fingerprinting, for localizing radio tagged animals in structurally complex, outdoor environments. This method characterizes the RSS patterns at known locations to generate a radio map of the study area, which is then used to predict the location of new RSS patterns. 2: We conducted field tests to evaluate the localisation accuracy of radio fingerprinting relative to multilateration, a commonly used method for RSS localisation. To do so, we established an experimental receiver network covering multiple habitat types and compared the localisation accuracy of radio fingerprinting to multilateration. Additionally, we evaluated how a variety of features characteristic of typical tracking datasets affected the accuracy of both methods. 3: While both methods had a similar median error ([~]30 m), the fingerprint localisation method offered several advantages over multilateration. Multilateration localisation estimates were highly affected by missed detections from the nearest receiver to the test point, which occurred in 30% of cases. In these cases, the median error was 97 m, over a 3-fold increase. Distance to the nearest receiver also biased multilateration estimates with error increasing as the distance increased. Additionally, errors from multilateration estimates were higher in more densely vegetated areas. In contrast, fingerprinting position estimates were largely robust to each of these scenarios. 4: Automated radio telemetry enables the fine-scale, continuous tracking of range-resident animals. We present radio fingerprinting as a localisation method in outdoor environments where standard localisation methods may be inadequate. This approach can be applied to any automated radio telemetry hardware and to any study system where a radio map can be generated.

animal behavior and cognition↗

bioRxiv2023

Evolution of sex differences in cooperation:the role of trade-offs with dispersal

AbstractExplaining the evolution of sex differences in cooperation remains a major challenge. Comparative studies highlight that offspring of the more philopatric sex tend to be more cooperative within their family groups than those of the more dispersive sex but we do not understand why. The leading Philopatry hypothesis proposes that the more philopatric sex cooperates more because their higher likelihood of natal breeding increases the direct fitness benefits of natal cooperation. However, the Dispersal trade-off hypothesis proposes that the more dispersive sex cooperates less because preparations for dispersal, such as extra-territorial prospecting, trade-off against natal cooperation. Here, we test both hypotheses in cooperatively breeding white-browed sparrow weavers (Plocepasser mahali), using a novel high-resolution automated radio-tracking method. First, we show that males are the more dispersive sex (a rare reversal of the typical avian sex-difference in dispersal) and that, consistent with the predictions of both hypotheses, females contribute substantially more than males to cooperative care while within the natal group. However, the Philopatry hypothesis cannot readily explain this female-biased cooperation, as females are not more likely than males to breed within their natal group. Instead, our radio-tracking findings support the Dispersal trade-off hypothesis: males conduct pre-dispersal extra-territorial prospecting forays at higher rates than females and prospecting appears to trade-off against natal cooperation. Our findings thus highlight that the evolution of sex differences in cooperation could be widely attributable to trade-offs between cooperation and dispersal; a potentially general explanation that does not demand that cooperation yields direct fitness benefits.

evolutionary biology↗

bioRxiv2021

Disrupting D2-NMDA receptor heteromerization blocks the rewarding effects of cocaine but preserves natural reward processing

Addictive drugs increase dopamine in the nucleus accumbens (NAc), where it persistently shapes excitatory glutamate transmission and hijacks natural reward processing. Herein, we provide evidence, from mice to human, that an underlying mechanism relies on drug-evoked heteromerization of glutamate NMDA receptors (NMDAR) with dopamine receptor 1 (D1R) or 2 (D2R). Using temporally-controlled inhibition of D1R-NMDAR heteromerization, we unraveled their selective implication in early developmental phases of cocaine-mediated synaptic, morphological and behavioral responses. In contrast, preventing D2R-NMDAR heteromerization blocked the persistence of these adaptations. Importantly, interfering with these heteromers spared natural reward processing. Strikingly, we established that D2R-NMDAR complexes exist in human samples and showed that, despite a decreased D2R protein expression in the NAc, psychostimulant-addicts display a higher proportion of D2R forming heteromers with NMDAR. These findings contribute to a better understanding of molecular mechanisms underlying addiction and uncover D2R-NMDAR heteromers as targets with potential therapeutic value.

neuroscience↗