Passive recovery of an island bird community after rodent eradication

The number and scale of island invasive species eradications is growing, but quantitative evidence of the conservation efficacy of passive recovery is limited. We compare relative abundances of breeding birds on Hawadax Island (formerly named Rat island), Aleutian Archipelago, Alaska, pre- and post- rat eradication to examine short-term (<1 year post-eradication) changes due to rodenticide application, and medium-term (5 years post-eradication) changes due to the absence of invasive rats. In the short term, Bald Eagle (Haliaeetus leucocephalus) numbers decreased from 24 individuals pre-eradication to two individuals <1 year post-eradication, but recovered to 10 individuals (42 % of pre-eradication) 5 years post-eradication, with all individuals nesting (63 % of the pre-eradication nesting). Five years post-eradication relative abundances of most terrestrial birds surveyed using point counts either significantly increased [Gray-crowned Rosy Finch (Leucosticte tephrocotis), Lapland Longspur (Calcarius lapponicus), Snow Bunting (Plectrophenax nivalis), Song Sparrow (Melospiza melodia)] or did not differ [Pacific Wren (Troglodytes troglodytes)]. Shorebirds also increased 5 years post-eradication with Black Oystercatchers (Haematopus palliates) increasing fivefold, and Rock Sandpiper (Calidris ptilocnemis) nesting increasing from one to five nests. We confirmed two species of ground nesting seabirds [Tufted Puffin (Fratercula cirrhata) and Leach’s Storm-petrel (Oceanodroma leucohoa)] as nesting (puffin) or engaged in courtship behavior (Storm-petrel) 5 years post-eradication. Our results indicate that despite the short-term impact on Bald Eagles, and without further human intervention, most terrestrial and marine birds have newly-colonized, re-colonized, or increased in abundance following the eradication of invasive rats.     

Birds respond similarly to taxidermic models and live cuckoos <Emphasis Type="Italic">Cuculus canorus</Emphasis>

Stuffed birds are widely used in research for identifying effects of predators and nest parasites on bird behaviour, studying levels of aggression and the size of territories. However, the fact that these models do not move or vocalize may question the results of such studies and open them to criticism. One solution would be to determine how the results of research using stuffed dummies correlate with the response of wild animals to enemies under the same environmental conditions. In a first attempt, we examined the correlation between the intensity of mobbing of a dummy cuckoo Cuculus canorus and interactions with live cuckoos in the field during the breeding season in western Poland. A total of 39 bird species mobbed cuckoo dummies; all 39 were found to attack live cuckoos, while 24 species (61.5%) did so during experiments using a dummy. The number of individual birds involved in mobbing a dummy was positively correlated with the number of individuals attacking real cuckoos in the same areas, even when the most commonly mobbing species, the barn swallow Hirundo rustica, was excluded from the analyses. However, we did not find significant differences in frequency of mobbing behaviour depending on cuckoo behaviour described as flight or sitting, or calling rather than remaining quiet. Therefore, we conclude that the use of a dummy for studying mobbing of hosts and non-hosts of the cuckoo provide results that are similar to those made in response to the behaviour of live hosts.     

Estimating the extent of seabird egg depredation by introduced Common Mynas on Ascension Island in the South Atlantic

Common Mynas Acridotheres tristis were introduced to the small, isolated barren island of Ascension in the tropical Atlantic Ocean in the 1880s. The founder population of 52 pairs increased at a rate of 2 % per annum. Mynas cause egg losses in other species by puncturing and consuming eggs, puncturing eggs with no consumption or displacing incubating birds that then desert viable eggs. The principal target seabirds of Mynas on Ascension Island are Sooty Terns Onychoprion fuscatus which number 388,000 birds and constitute 97 % of all seabirds on the island. Five censuses of Mynas and 20 of the Sooty Tern population were carried out between 1994 and 2015, and Myna depredation was monitored on 10 occasions between 2000 and 2008. Of all seabird eggs laid annually, we estimated that 19 % of them were depredated by c. 1000 Mynas. In declining severity of impacts of Mynas on all eggs lost, we estimated that 40 % was attributable to desertion, 39 % to puncturing eggs with no consumption and 21 % to puncturing and consumption. As far as we know, our study is the first to estimate the scale of seabird egg depredation by Mynas. Care is needed when applying our findings to other seabird populations. The scarcity of alternative food sources and the ease of locating high densities of Sooty Tern eggs on Ascension Island may have magnified the frequency of egg depredation by Mynas. That said, it is clear that Mynas are major egg predators and the severity of their impacts on native avian populations can be high.     

Ticks collected on birds in the state of São Paulo,Brazil

The present study reports a collection of Amblyomma spp. ticks in birds from several areas of the state of São Paulo, Brazil. A total of 568 tick specimens (404 larvae, 164 nymphs) were collected from 261 bird specimens. From these ticks, 204 (36%) specimens (94 larvae, 110 nymphs) were reared to the adult stage, being identified as Amblyomma longirostre (94 larvae, 90 nymphs), Amblyomma calcaratum (13 nymphs), Amblyomma nodosum (2 nymphs), and Amblyomma cajennense (5 nymphs). Additionally, 39 larvae reared to the nymphal stage and 8 nymphs that died before reaching the adult stage were identified as A. longirostre according to peculiar characters inherent to the nymphal stage of this species: scutum elongate, and hypostome pointed. The remaining 271 larvae and 46 nymphs were identified as Amblyomma sp. Ticks were collected from 51 species of birds distributed in 22 bird families and 6 orders. The order Passeriformes constituted the vast majority of the records, comprising 253 (97%) out of the 261 infested birds. Subadults of A. longirostre were identified from 35 species of Passeriformes, comprising 11 families (Cardinalidae, Dendrocolaptidae, Fringillidae, Furnariidae, Parulidae, Pipridae, Thamnophilidae, Thraupidae, Turdidae, Tyrannidae, and Vireonidae), and from 1 species of a non-passerine bird, a puffbird (Bucconidae). Subadults of A. calcaratum were identified from 5 species of Passeriformes, comprising 5 families (Cardinalinae, Conopophagidae, Pipridae, Thamnophilidae and Turdidae). Subadults of A. nodosum were identified from 2 species of Passeriformes, comprising two bird families (Thamnophilidae and Pipridae). Subadults of A. cajennense were identified from 2 species of non-passerine birds, belonging to 2 different orders (Ciconiiformes: Threskiornithidae, and Gruiformes: Cariamidae). Birds were usually infested by few ticks (mean infestation of 2.2 ticks per bird; range: 1–16). Currently, 82 bird species are known to be infested by immature stages of A. longirostre, with the vast majority [74 (90%)] being Passeriformes. Our results showed that Passeriformes seems to be primary hosts for subadult stages of A. longirostre, A. calcaratum, and A. nodosum. However, arboreal passerine birds seem to be the most important hosts for A. longirostre whereas ground-feeding passerine birds seem to be the most important for both A. calcaratum and A. nodosum. In contrast, the parasitism of birds by subadults of A. cajennense has been restricted to non-passerine birds.     

Characteristics of body mass growth in semialtricial and altricial bird species during the nestling period

The dynamics of body mass growth were studied in nestlings of 22 semialtricial and altricial bird species based on materials collected in seven regions of Russia in the years 1976–2013. The bird species belong to four orders and 13 families. The results of the study indicate the nonuniform growth of nestlings in different bird species. Of the species investigated, only seven were found to reach or exceed the mass of adult birds. Over the nestling period, the nestlings of open-nesting species, such as the hooded crow (Corvus cornix), rook (Corvus frugilegus), magpie (Pica pica), fieldfare (Turdus pilaris), song thrush (Turdus philomelos), and goldfinch (Carduelis carduelis), do not reach the weight of adult birds and their growth continues after they leave the nest. In closed-nesting species, only the nestlings of the barn swallow (Hirundo rustica) reach or exceed the definitive mass, whereas the nestlings of the jackdaw (Corvus monedula), starling (Sturnus vulgaris), wryneck (Jynx torquilla), tree sparrow (Passer montanus), and great tit (Parus major) continue to grow after leaving the nest. The body mass of birds on the day of their hatching and before their departure from the nests and the mass of adult birds depend on the nesting type, duration of the nestling period, size groups of species, and their definitive size. The average specific growth rate of body mass and its maximum values for different species are also associated with these factors. The maximum specific growth rate in small-sized and medium-sized bird species was observed on the 0–1st days of life; in large bird species, on the 2nd–4th days. The specific growth rate did not depend on the type of nesting, but it was inversely related to the duration of the nestling period and the definitive sizes of birds.     

From species to individuals: combining barcoding and microsatellite analyses from non-invasive samples in plant ecology studies

By means of DNA barcoding and microsatellite analyses, we studied the species and individuals of legitimate seed dispersers of the Mediterranean shrub Pistacia lentiscus, a keystone species that represents the main source of food in winter for frugivorous birds. We collected dropping of birds containing seeds, and after DNA extraction we amplified and sequenced a fragment of the mitochondrial COI gene. Through BLASTN queries of the sequenced fragments against registered sequences in the GenBank database we identified the bird species that are currently dispersing P. lentiscus seeds. Further, through the amplification of specific nuclear microsatellite loci we calculated standard genetic diversity parameters of the population of birds from the genus Sylvia (the blackcap and Sardinian warbler), the most important dispersers of P. lentiscus. Five bird species were identified as seed dispersers through their barcode match. Further, we found that S. melanocephala displayed slightly lower levels of genetic diversity than S. atricapilla. In this study we show how the genetic analyses of environmental faecal samples can be a useful and convenient tool for the study of plant-frugivore interactions through the ascertainment of the identity of the species involved and through the analyses of genetic variability of their populations.     

Synchronous fruiting and common seed dispersers of two endemic columnar cacti in the Caatinga,a dry forest in Brazil

This study evaluates the fruiting phenology, fruit traits, and seed dispersal in two Pilosocereus (Cactaceae) species that are widely distributed in Caatinga vegetation. We monitored the fruiting phenology of Pilosocereus gounellei and Pilosocereus chrysostele on a monthly basis for a period of 4 years (45 months from March 2009 to November 2012), including 30 individuals of each species. We also carried out focal observations, captured dispersers, and conducted germination tests, to identify the effective seed dispersers of these species. Both species exhibited sub-annual fruiting patterns and high fruiting synchrony index (O _jk 0.62), with peaks occurring from February to May for P. gounellei and February to April for P. chrysostele. In all, 248 visits by seven bird and two lizard species were recorded for P. gounellei, and 104 visits by five bird species were recorded for P. chrysostele. The two species shared five seed dispersers. The finch Lanio pileatus was the most frequently visiting bird species. The number of visits to the fruits of P. gounellei was higher than to the fruits of P. chrysostele. Passage of seeds through the digestive tracts of all bird species significantly increased the germination rate for P. chrysostele, whereas for P. gounellei, the birds Forpus xanthopterygius and L. pileatus decreased germination rates. Sub-annual fruiting patterns, similar fruit morphology, and high synchronous fruiting are factors that favor resource sharing among the dispersers of Pilosocereus in the Caatinga.     

Throwing the baby out with the bathwater: does laurel forest restoration remove a critical winter food supply for the critically endangered Azores bullfinch?

The invasive Clethra arborea has a dual-role in the diet of the Azores bullfinch, a critically endangered bird species endemic to the island of São Miguel (Azores, Portugal). This is a crucial winter food resource but it lowers the availability of native laurel forest species that compose most of the bird’s diet throughout the year. The removal of this and other invasive alien species is part of current laurel forest habitat restoration programmes, disregarding the impact on the Azores bullfinch population. In order to evaluate the first responses of the Azores bullfinch to habitat restoration, we studied bird diet, foraging behaviour, food availability and habitat occupancy in managed (without C. arborea) and control areas. Significant increases in the availability of native food resources in managed areas were noticeable in the diet, particularly the intake of Ilex perado ssp. azorica and Prunus lusitanica ssp. azorica flower buds. In most of the studied months birds heavily used and foraged in managed over control areas. The one exception was in December, when a resource-gap occurred in managed areas, which may be overcome in the short-term due to re-establishment of native plants following removal of invasive aliens.     

Yellow crazy ants (<Emphasis Type="Italic">Anoplolepis gracilipes</Emphasis>) reduce numbers and impede development of a burrow-nesting seabird

Yellow crazy ants (Anoplolepis gracilipes) are a significant threat to biodiversity due to a rapidly expanding range and the potential to disrupt ecosystem interactions at multiple trophic levels. Extirpation of ground-nesting seabirds subsequent to yellow crazy ant invasion has been reported anecdotally. Yellow crazy ant control is difficult and resulting positive effects on nesting seabirds is undocumented. We report the effects of ant invasion and subsequent control on burrow-nesting seabirds following the invasion of more than half of a 1.25-ha wedge-tailed shearwater (Ardenna pacifica) colony located on eastern O‘ahu. The number of active seabird burrows in invaded areas dropped from 125 in 2006 to 6 in 2010, with no corresponding decline in active burrows in adjacent, uninvaded areas. Ant control efforts in 2011 reduced ant densities by more than 97% and resulted in a substantial increase in active burrows (43 in 2011). In invaded areas, burrows appeared to be abandoned by adults prior to egg-laying. Chicks surviving in invaded areas exhibited mild to severe developmental abnormalities, and overall had shorter culmens, tarsi and wingchords, smaller eye diameters, and lower weights than chicks outside invaded areas. We conclude that yellow crazy ants constitute a significant, and likely underestimated, risk to ground-nesting seabirds. Loss of seabird nesting colonies can have significant effects on nutrient inputs, and can bring about shifts in plant communities and faunal composition. Range expansion of yellow crazy ants is expected and ant/seabird interactions are likely to increase.     

PCR-based molecular diagnosis of botulism (types C and D) outbreaks in aquatic birds

Clostridium botulinum is a strictly anaerobic spore forming bacterium found in soil and sediments, producing botulinum neurotoxins. Group III strains of this organism are only able to produce neurotoxin types C, mosaic C/D, D/C, and D, which are associated with bird botulism. The threats and outbreak cycle of bird botulism are enhanced in the aquatic environment via a food web-environment-avian interface in response to global climatic changes. The aim of this review was to describe and discuss the development of PCR-based markers, diagnostic assays, and applications with special emphasis to botulism detection in aquatic birds. We employed a text-mining approach for collection of current diagnostic information to bird botulism in aquatic environments. Using the PubMed search engine, we have comprehensively collected relevant information from 124 articles and then summated for the purpose of this review. Genes coding for botulinum neurotoxin (bont/C, bont/C/D, bont/D/C, and bont/D), nontoxic components (ha70, ha17, ha33, and ntnh), and flagellin (fliC) were the molecular markers most commonly found for the genotyping of group III strains from environmental samples. “GeneDisc” real-time PCR system was a robust and reliable diagnostic technique for discrimination of neurotoxin types in the large sampled areas. PCR-based assays were the most perceptive and widely established for detection of bird botulism, even if several biochemical and molecular diagnostic techniques have been available. Thus, timely and accurate identification of its mortality is needed to provide a biosecurity, disease control management, and conservation of aquatic birds. PCR-based diagnosis is a promising alternative to the mouse bioassay. Hence, the present paper makes an attempt to review the PCR-based detection assays including primers, specificity, sensitivity, and detection limit and explore their potential applications in wildlife microbiology.     

Non-redundancy in seed dispersal and germination by native and introduced frugivorous birds: implications of invasive bird impact on native plant communities

Seed dispersal by vertebrate animals is important for the establishment of many fleshy-fruited plant species. Different frugivorous species can provide different seed dispersal services according to their specific dietary preferences as well as behaviour and body traits (e.g. body size and beak size of birds). Our aim was to study redundancies and complementarities in seed dispersal and germination between the two main native seed disperser birds and the introduced silver pheasant Lophura nycthemera in the temperate Patagonian forests. For this, we collected fresh droppings from the studied species and analyzed seed content. We conducted germination trials for four plant species common in bird droppings; two native species (Aristotelia chilensis and Rhaphithamnus spinosus) and two invasive non-native species (Rubus ulmifolius and Rosa rubiginosa). Both native frugivorous birds and the silver pheasant dispersed fruits of non- native fleshy-fruited plants, but their roles were non-redundant in terms of species dispersed and effect on seed germination. The silver pheasant dispersed a proportionally high number of non-native seeds, while native birds dispersed a high number of native seeds. In addition, the effect of gut treatment in seed germination differed between seed dispersers. Native birds promoted the germination for the two native plant species studied, while the silver pheasant promoted the germination of one non-native plant. This suggests that seed dispersal by the silver pheasant may contribute to the spread of some invasive fleshy-fruited plants in the ecosystems that otherwise would not be dispersed by any other bird. The understanding of redundancies and complementarities on seed dispersal and germination between native and introduced birds will allow improving the management of fleshy-fruited non-native plants.     

Birds as hosts of ixodid ticks (Acarina,Ixodidae)

rophic relations between ixodid ticks of the world fauna parasitizing as adults on birds are analyzed. These ticks include 60 out of 650 species of the family Ixodidae and belong to the genera Ixodes, Haemaphysalis, and Amblyomma. Relations between birds and ticks of the genus Ixodes are most ancient. Colonial marine birds seem to be the first hosts of ixodid ticks in the class of birds. Trophic specialization of ticks is not associated with bird taxa, because in most cases no tick specificity is caused by either phylogenetic features of hosts, or specific environmental conditions.     

Biocontrol of <Emphasis Type="Italic">Cameraria ohridella</Emphasis> by insectivorous birds in different landscape contexts

The horse chestnut leaf miner (HCLM) Cameraria ohridella Deschka and Dimic (Lepidoptera, Gracillariidae) is a novel but significant pest in Europe. Current control measures are either inefficient or environmentally harmful. Tits (Parus spp.) open the mines and prey on HCLM, but the biocontrol efficiency of this behaviour has not yet been quantified. We installed bird nesting-boxes in a biennial field study on four sites close to Brunswick (Germany). On the same sites, we counted HCLM pupae, larvae, opened and closed mines, and parasitised larvae and pupae in leaves collected from horse chestnut (Aesculus hippocastanum L., Hippocastanaceae) trees with and without bird exclusion. In both years, the HCLM number and the proportion of closed mines were higher in bird exclusion trees, particularly on sites with high abundance of tits. Hence, we suggest including the facilitation of birds, particularly tits, in future HCLM biocontrol strategies.     

<Emphasis Type="Italic">Haematospirillum</Emphasis> and insect <Emphasis Type="Italic">Wolbachia</Emphasis> DNA in avian blood

In this study, blood samples of 259 Acrocephalus sp. warblers were molecularly analysed for Anaplasmataceae and Rhodospirillaceae based on PCR amplification of 16S rRNA gene fragments. One bird blood sample (from Reed Warbler, Acrocephalus scirpaceus) yielded a sequence with 99.8% identity to Haematospirillum jordaniae. This is the first molecular evidence for the occurrence of this species in the blood of any vertebrate other than human. Another bird blood sample (from Marsh Warbler: Acrocephalus palustris) yielded a Wolbachia sequence, closely related to a moth endosymbiont with 99.8% identity. A nematode origin of Wolbachia DNA detected here in avian blood can be excluded, because results of phylogenetic analysis showed its closest alignment with insect wolbachiae. This is the first finding of insect Wolbachia DNA in the circulatory system of birds, which can be explained either by the inoculation of wolbachiae by blood-sucking vectors, or passing of Wolbachia DNA from the gut into the blood of this insectivorous bird species.     

Prevalence of blood parasites in seabirds - a review

Introduction

While blood parasites are common in many birds in the wild, some groups seem to be much less affected. Seabirds, in particular, have often been reported free from blood parasites, even in the presence of potential vectors.

Results

From a literature review of hemosporidian prevalence in seabirds, we collated a dataset of 60 species, in which at least 15 individuals had been examined. These data were included in phylogenetically controlled statistical analyses of hemosporidian prevalence in relation to ecological and life-history parameters. Haemoproteus parasites were common in frigatebirds and gulls, while Hepatozoon occurred in albatrosses and storm petrels, and Plasmodium mainly in penguins. The prevalence of Haemoproteus showed a geographical signal, being lower in species with distribution towards polar environments. Interspecific differences in Plasmodium prevalence were explained by variables that relate to the exposure to parasites, suggesting that prevalence is higher in burrow nesters with long fledgling periods. Measures of Plasmodium, but not Haemoproteus prevalences were influenced by the method, with PCR-based data resulting in higher prevalence estimates.

Conclusions

Our analyses suggest that, as in other avian taxa, phylogenetic, ecological and life-history parameters determine the prevalence of hemosporidian parasites in seabirds. We discuss how these relationships should be further explored in future studies.

     

Breeding sites and population of seabirds on Admiralty Bay,King George Island,Antarctica

The monitoring of the status and distribution of seabird populations is necessary to understand their spatial and temporal responses to rapid climate changes occurring in the Western Antarctic Peninsula area. We surveyed and mapped Admiralty Bay bird communities and related them to climate variables—temperature, temperature anomaly, Antarctic Oscillation Index and El-Niño Southern Oscillation Index. We recorded 13 breeding seabird species over three seasons (2009/2010, 2010/2011 and 2011/2012) and mapped 10 of them over an area of 149.5 ha. The ice-free areas with the greatest number of species were Point Thomas, Keller Peninsula and Hennequin Point. The most abundant species was the Adelie Penguin (Pygoscelis adeliae) followed by the Chinstrap Penguin (P. antarcticus). We observed that the number of breeding pairs of Gentoo Penguins (P. papua), Chinstrap Penguins and skuas (Catharacta maccormicki and C. antarctica) are related to temperature, temperature anomaly and El-Niño Southern Oscillation Index. The size of breeding populations and their distributions have been fluctuating over the last 30 years in ice-free areas of Admiralty Bay. Most species showed a decreasing trend from 1978 to 2012, with the exception of Chinstrap Penguins, Southern Giant Petrels (Macronectes giganteus) and skuas, which seem to be stable in numbers in the last two decades. Decreases in seabird populations from the Antarctic Peninsula are widely recognized as a response to environmental change and anthropogenic influences such as tourism and building activities, thus highlighting the importance of monitoring to support mitigation measures.     

Wild birds and urban pigeons as reservoirs for diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> with zoonotic potential

In order to describe the role of wild birds and pigeons in the transmission of shiga toxigenic Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) to humans and other animals, samples were collected from cloacae and oropharynx of free-living wild birds and free-living pigeons. Two STEC (0.8%) and five EPEC strains (2.0%) were isolated from wild birds and four EPEC strains (2.0%) were recovered from pigeons. Serogroups, sequence types (STs) and virulence genes, such as saa, iha, lpfA _O113, ehxA, espA, nleB and nleE, detected in this study had already been implicated in human and animal diseases. Multidrug resistance (MDR) was found in 25.0% of the pigeon strains and in 57.0% of the wild bird strains; the wild birds also yielded one isolate carrying extended-spectrum β-lactamases (ESBLs) gene bla _CTX-M-8. The high variability shown by PFGE demonstrates that there are no prevalent E. coli clones from these avian hosts. Wild birds and pigeons could act as carriers of multidrug-resistant STEC and EPEC and therefore may constitute a considerable hazard to human and animal health by transmission of these strains to the environment.     

Influences of the invasive tamarisk leaf beetle (<Emphasis Type="Italic">Diorhabda carinulata</Emphasis>) on avian diets along the Dolores River in Southwestern Colorado USA

The tamarisk leaf beetle (Diorhabda carinulata), introduced from Eurasia in 2001 as a biological control agent for the invasive plant Tamarix ramosissima, has spread widely throughout the western USA. With D. carinulata now very abundant, scientists and restoration managers have questioned what influence this introduced arthropod might have upon the avian component of riparian ecosystems. From 2009 through 2012 we studied the consequences of biological invasions of the introduced tamarisk shrub and tamarisk leaf beetles on the diets of native birds along the Dolores River in southwestern Colorado, USA. We examined avian foraging behavior, sampled the arthropod community, documented bird diets and the use of invasive tamarisk shrubs and tamarisk leaf beetles by birds. We documented D. carinulata abundance, on what plants the beetles occurred, and to what degree they were consumed by birds as compared to other arthropods. We hypothesized that if D. carinulata is an important new avian food source, birds should consume beetles at least in proportion to their abundance. We also hypothesized that birds should forage more in tamarisk in the late summer when tamarisk leaf beetle larvae are more abundant than in early summer, and that birds should select beetle-damaged tamarisk shrubs. We found that D. carinulata composed 24.0 percent (±?19.9–27.4%) and 35.4% biomass of all collected arthropods. From the gut contents of 188 birds (25 passerine species), only four species (n?=?11 birds) contained tamarisk leaf beetle parts. Although D. carinulata comprised one-quarter of total insect abundance, frequency of occurrence in bird gut contents was only 2.1% by abundance and 3.4% biomass. Birds used tamarisk shrubs for foraging in proportion to their availability, but foraging frequency did not increase during the late summer when more tamarisk leaf beetles were present and birds avoided beetle-damaged tamarisk shrubs. Despite D. carinulata being the most abundant arthropod in the environment, these invasive beetles were not frequently consumed by birds and seem not to provide a significant contribution to avian diets.     

Dispersal of remnant endangered trees in a fragmented and disturbed forest by frugivorous birds

Most endangered plant species in a fragmented forest behave as a unique source population, with a high dependence on frugivorous birds for recruitment and persistence. In this study, we combined field data of dispersal behavior of birds and GIS information of patch attributes to estimate how frugivorous birds could affect the effective dispersal pattern of Chinese yew (Taxus chinensis) in a fragmented and disturbed forest. Nine bird species were observed to visit T. chinensis trees, with Urocissa erythrorhyncha, Zoothera dauma and Picus canus being the most common dispersers. After foraging, six disperser species exhibited different perching patterns. Three specialist species, P. canus, Turdus hortulorum, and Z. dauma stayed in the source patch, while three generalist species, U. erythrorhyncha, Hypsipetes mcclellandii, and H. castanonotus, could perch in bamboo patches and varied in movement ability due to body size. As a consequence of perching, dispersers significantly contributed to the seed bank, but indirectly affected seedling recruitment. Moreover, the recruitment of T. chinensis was also affected by patch attributes in a fragmented forest (distances to source patch, patch type, size). Our results highlighted the ability of unique source population regeneration of T. chinensis in a fragmented forest, with high dependence on both frugivorous birds and patch attributes, which should be considered in future planning for forest management and conservation.     

<Emphasis Type="Italic">Salmonella</Emphasis> in Wild Birds Utilizing Protected and Human Impacted Habitats,Uganda

As human populations in Africa expand, humans encroach and modify wildlife habitats for farming, fishing, tourism, or settlement. Anthropogenic activities in shared environments may promote transmission of zoonotic pathogens between humans, domestic animals, and wildlife. Between July 2012 and February 2014, we evaluated Salmonella prevalence, serovars, genotypes, and antibiotic resistant phenotypes in resident and migratory birds utilizing human-impacted habitats in northwestern Lake Victoria and protected habitats in Queen Elisabeth National Park. Salmonella occurrence in the urban environment was assessed by sampling storm-water and wastewater from a channel that drains Kampala City into Lake Victoria. Salmonella was detected in 4.3% pooled bird fecal samples, and 57.1% of environmental samples. While birds in impacted and protected areas shared serovars, the genotypes were distinct. We found distinct strains in birds and the environment suggesting some strains in birds are host adapted, and strains circulating in the environment may not necessarily disseminate to birds. Conversely, birds in both impacted and protected areas shared strains with the urban environment, suggesting Salmonella disseminates between impacted environments and birds across sites. Overall, more strains were observed in the urban environment compared to birds, and poses risk of Salmonella reemergence in birds and transmission across species and space.