Sàlim Javed

The influence of a hot environment on parental cooperation of a ground-nesting shorebird, the Kentish plover Charadrius alexandrinus

BackgroundParental care often increases offspring survival, but is costly to the parents. A trade-off between the cost and benefit of care is expected, so that when care provisioning by both parents is essential for the success of young, for instance in extremely cold or hot environments, the parents should rear their young together. We investigated the latter hypothesis in a ground nesting shorebird, the Kentish plover Charadrius alexandrinus in an extremely hot environment, the Arabian Desert. Midday ground temperature was often above 50°C in our study site in Abu Dhabi (United Arab Emirates), thus leaving the eggs unattended even for a few minute risks overheating and death of embryos.ResultsThrough the use of video surveillance systems we recorded incubation routines of male and female Kentish plovers at 28 nests over a full day (24 h). We show that ambient temperature had a significant influence on incubation behaviour of both sexes, and the relationships are often non-linear. Coordinated incubation between parents was particularly strong in midday with incubation shared approximately equally between the male and the female. The enhanced biparental incubation was due to males increasing their nest attendance with ambient temperature.ConclusionsOur results suggest biparental care is essential during incubation in the Kentish plover in extremely hot environments. Shared incubation may also help the parents to cope with heat stress themselves: they can relieve each other frequently from incubation duties. We suggest that once the eggs have hatched the risks associated with hot temperature are reduced: the chicks become mobile, and they gradually develop thermoregulation. When biparental care of young is no longer essential one parent may desert the family. The relaxed demand of the offspring may contribute to the diverse breeding systems exhibited by many shorebirds.

Conflict between genetic and phenotypic differentiation: the evolutionary history of a 'lost and rediscovered' shorebird.

Understanding and resolving conflicts between phenotypic and genetic differentiation is central to evolutionary research. While phenotypically monomorphic species may exhibit deep genetic divergences, some morphologically distinct taxa lack notable genetic differentiation. Here we conduct a molecular investigation of an enigmatic shorebird with a convoluted taxonomic history, the White-faced Plover (Charadrius alexandrinus dealbatus), widely regarded as a subspecies of the Kentish Plover (C. alexandrinus). Described as distinct in 1863, its name was consistently misapplied in subsequent decades until taxonomic clarification ensued in 2008. Using a recently proposed test of species delimitation, we reconfirm the phenotypic distinctness of dealbatus. We then compare three mitochondrial and seven nuclear DNA markers among 278 samples of dealbatus and alexandrinus from across their breeding range and four other closely related plovers. We fail to find any population genetic differentiation between dealbatus and alexandrinus, whereas the other species are deeply diverged at the study loci. Kentish Plovers join a small but growing list of species for which low levels of genetic differentiation are accompanied by the presence of strong phenotypic divergence, suggesting that diagnostic phenotypic characters may be encoded by few genes that are difficult to detect. Alternatively, gene expression differences may be crucial in producing different phenotypes whereas neutral differentiation may be lagging behind.

Breeding ecology of Kentish Plover Charadrius alexandrinus in an extremely hot environment

Capsule Hot environments are associated with more biparental care, high nest‐site fidelity and low mate fidelity. Aims To investigate the breeding ecology and parental behaviour of Kentish Plovers in an extremely hot environment. Kentish Plovers have an unusually diverse breeding system in which the frequencies of biparental, female‐only and male‐only care vary between populations. A common, but rarely tested, explanation for such a variation is local adaptation: birds exhibit social traits that are adaptive to their breeding environment. In particular, we investigated the effect of a hot environment on breeding success, distribution of care types, and mate and site fidelity. Methods A breeding population of approximately 200 pairs of Kentish Plovers was investigated in 2005 and 2006 at Al Wathba Wetland near Abu Dhabi in the United Arab Emirates. Results We found high nest‐site fidelity, low mate fidelity and more biparental care in Al Wathba than in most temperate zone populations of Kentish Plovers. Conclusions Our results are consistent with the argument that a harsh environment can select for biparental care. However, further studies are warranted to distinguish between alternative hypotheses for the different distribution of social behaviours of breeding populations.

Breeding ecology of Kentish Plover in an extremely hot environment

Capsule Hot environments are associated with more biparental care, high nest‐site fidelity and low mate fidelity. Aims To investigate the breeding ecology and parental behaviour of Kentish Plovers in an extremely hot environment. Kentish Plovers have an unusually diverse breeding system in which the frequencies of biparental, female‐only and male‐only care vary between populations. A common, but rarely tested, explanation for such a variation is local adaptation: birds exhibit social traits that are adaptive to their breeding environment. In particular, we investigated the effect of a hot environment on breeding success, distribution of care types, and mate and site fidelity. Methods A breeding population of approximately 200 pairs of Kentish Plovers was investigated in 2005 and 2006 at Al Wathba Wetland near Abu Dhabi in the United Arab Emirates. Results We found high nest‐site fidelity, low mate fidelity and more biparental care in Al Wathba than in most temperate zone populations of Kentish Plovers. Conclusions Our results are consistent with the argument that a harsh environment can select for biparental care. However, further studies are warranted to distinguish between alternative hypotheses for the different distribution of social behaviours of breeding populations.

Nesting, distribution and conservation of the Crab Plover, Dromas ardeola, in the United Arab Emirates

Abstract We studied the nesting and distribution of the Crab Plover, Dromas ardeola, in the United Arab Emirates through regular monitoring of colonies during the breeding season and counts at other key waterbird sites throughout the country during the non-breeding season. Based on counts of active nests, we estimate 1400–1500 breeding pairs of Crab Plovers in the United Arab Emirates at the two active colonies, accounting for over 30% of the Arabian breeding population. Discovery of a newly formed colony in 2004 and abandonment of the old colony on Abu Al Abyad demonstrate the potential of expansion of colonies in other areas. With breeding confirmed at only two islands in the Emirate of Abu Dhabi, from a conservation perspective this species is one of the most important breeding birds in the United Arab Emirates. Outside the breeding season, Crab Plovers congregate at few coastal sites in the country. Long-term conservation of Crab Plovers in the Emirates depends on the continued protection of the few breeding sites and urgent protection of the key sites used outside the breeding season.

First description of autumn migration of Sooty Falcon Falco concolor from the United Arab Emirates to Madagascar using satellite telemetry

The movement and migration pattern of the ‘Near Threatened’ Sooty Falcon Falco concolor is poorly known. Sooty Falcons breed on the islands of the Arabian Gulf after arriving from their non-breeding areas that are mainly in Madagascar. In the first satellite tracking of the species we fitted a 9.5 g Argos solar powered transmitter on an adult breeding Sooty Falcon off the western coast of Abu Dhabi in the United Arab Emirates. The bird successfully undertook autumn migration to Madagascar, a known wintering area for the species. We document the Sooty Falcon’s autumn migration route and stop-over sites. The adult Sooty Falcon initiated its migration at night and with tailwinds, and travelled mainly during daytime hours for 13 days over an inland route of more than 5,656 km. The three stop-over sites in East Africa were characterised by moderate to sparse shrub cover associated with potential sources of water. We discuss the migration pattern of the tracked bird in relation to importance of non-breeding areas for Sooty Falcons and recent declines in numbers in their breeding range.

Breeding status of the Red-billed Tropicbird, Phaethon aethereus (Aves: Phaethontidae), on Jarnein Island, United Arab Emirates

Abstract The Red-billed Tropicbird, Phaethon aethereus breeds only on three islands in the United Arab Emirates. In March 2007, extensive searches and mapping of tropicbird nests were carried out on Jarnein Island in Abu Dhabi, UAE. A total of 217 nests was recorded of which 71% (155) were active with either chick or egg or adult bird present. Considering only those nests with birds or other signs (egg or chick) present, the 155 nests represent an almost 150% increase on previous estimates. Of the 217 nests, nearly 40% were with grown-up chicks while nearly 28% were with adult birds, either incubating or tending downy chicks. The three main hills and all small rocky outcrops with crevices are extremely important for tropicbird conservation on the island as these habitats account for more than 85% of the entire UAE breeding number. The tropicbird is a priority species for conservation in the UAE and protection of the biggest breeding site is essential for the long-term conservation of the species in the UAE.

Nest Site Selection by Sooty Gulls on Jarnein Island, United Arab Emirates

Abstract Nest-site selection and nesting habitat use by the Sooty Gull (Larus hemprichii) was studied on Jarnein Island in the United Arab Emirates during the 2002 breeding season. Sooty Gull nests were located mainly on the north and northeast sides of the island. Birds showed definite preference for rocky substrates.

Greater Flamingo (Phoenicopterus roseus): Important wintering sites and breeding records in the United Arab Emirates

Greater Flamingo (Phoenicopterus roseus) monitoring was undertaken in the United Arab Emirates from 2003 to 2015 at 36 permanent sites to find key wintering and breeding sites. Bul Syayeef Marine Protected Area with monthly mean of 6553 (±3594) flamingos followed by Al Wathba Wetland Reserve with 1228 (±1190) flamingos topped the list. In addition, Shahama Wetland and Al Aryam Mudflats in Abu Dhabi Emirate form a complex of four nearby sites that hold the majority of nearly 15,000–20,000 birds wintering in the country. Lagoons (Khors) in the northern emirates are the other key wintering sites, that suffer habitat destruction and high disturbance. Breeding has been sporadic and infrequent since the first breeding attempt in 1993. Greater Flamingos have bred successfully only in the Abu Dhabi Emirate on 10 occasions at three sites with the highest eight breeding attempts at Al Wathba and one each at Shahama and Bul Syayeef. A total of 1,972 young have fledged with a high overall breeding success of 43%. The highest number of 801 young fledged at Bul Syayeef in 2009 followed by 420 at Al Wathba in 2015 and 350 at Shahama in 2007. Successful breeding occurred both in summer and winter seasons, breeding attempts were more (58%) in summer compared to winter. Flamingos have bred regularly at Al Wathba Wetland Reserve since 2011, this was made possible due to the provision of an artificial island to aid nesting and better control of predators. Breeding is successful at sites that maintain higher bird numbers and are free from disturbance.

Satellite tracking of a young Steppe Eagle from the United Arab Emirates during two spring and autumn migrations

Following recovery and successful rehabilitation, a young Steppe Eagle Aquila nipalensis was tagged with a 45 g GPS satellite transmitter to track its migration and identify potential wintering and summering areas of the species passing through the United Arab Emirates (UAE). The study is part of a larger study on understanding migration of important birds of prey species from the UAE. The satellite-tagged Steppe Eagle was released near the town of Al Ain, UAE on 5 January 2009 and was tracked until 6 November 2010. Two complete spring and autumn migrations were tracked in addition to its onward autumn migration from the UAE. The tagged eagle continued its autumn migration from its release site and reached Yemen after stopovers in Saudi Arabia. Unlike other Steppe Eagles, the bird did not cross the strait of Bab-al-Mandeb and wintered in the area before undertaking its first spring migration. In the second spring migration in 2010, the bird migrated along the Suez–Eilat route and demonstrated a loop migration. The bird spent the summer on the steppes in Kazakhstan, with marked differences in the home ranges between 2009 and 2010, whereas wintering areas used in 2009 and 2010 in Tanzania were overlapping.