Prioritizing species conservation: does the Cape Verde kite exist?

The Cape Verde kite (Milvus milvus fasciicauda) is considered to be one of the rarest birds of prey in the world and at significant risk of extinction. For this reason there is great interest in both the taxonomic and the population status of this group. To help resolve its taxonomic status, we provide phylogenetic analyses based on three mitochondrial genes for a sampling of kites in the genus Milvus, including a broad geographical sampling of black kites (Milvus migrans), red kites (Milvus milvus), Cape Verde kite museum specimens collected between 1897 and 1924, and five kites trapped on the Cape Verde Islands during August 2002. We found that the historical Cape Verde kites, including the type specimen, were non-monophyletic and scattered within a larger red kite clade. The recently trapped kites from the Cape Verde Islands were all phylogenetically diagnosed as black kites. Our findings suggest that the traditional Cape Verde kite is not a distinctive evolutionary unit, and the case for species status, as recently suggested by others, is not supported. We do find support for recognition of at least one clade of yellow-billed kites, traditionally considered as a black kite subspecies, as a distinctive phylogenetic species.     

Space and habitat use by Red Kites Milvus milvus during winter in the Guadalquivir marshes: a comparison between resident and wintering populations

Differences in habitat selection, diet and behaviour of resident and wintering Red Kites Milvus milvus were studied in Donana National Park, southwest Spain. Adult resident Red Kites roosted at their nests, while immature residents and wintering birds gathered at communal roosts. Individuals remained on average for two consecutive nights (range 1–8) at the same communal roost. Wintering kites spent significantly more time foraging gregariously than residents. The use of the marsh was greater by wintering kites while residents more often used the forest. Wintering birds consumed more goose carrion than the residents. Wintering kites had larger core areas, moved farther from their roost sites to feed and changed foraging areas more frequently than residents. Among residents, adult females had the smallest home ranges (core area, distances travelled and time spent flying). We suggest that Red Kites wintering in Donana occupy the marsh because it provides high food availability, and is vacated by Black Kites M. migrans which exploit this profitable habitat during the breeding season.     

Communal roosting behaviour of the black kite (<Emphasis Type="Italic">Milvus migrans govinda</Emphasis>) in an urban metropolis

Research on raptors in general in India is scanty, and it is practically non-existent on black kites (Milvus migrans govinda) which are the major scavenging raptor in many urban areas. The aim of this study was to analyse the seasonal abundance and roosting behaviour of black kites in an urban metropolis. Data on the abundance and behaviour of roosting black kites in this setting were collected using evening roost counts and ad-libitum sampling, respectively. Analysis was performed using separate generalized linear models considering roosting kite abundance, number of black kites arriving to roost and number of black kites showing pre-roosting display as response variables, respectively. We found that black kites roosted communally and that their number varied in different years and seasons, with the abundance highest in the summer and lowest during the winter. Pre-roosting displays also varied seasonally, being highest during the monsoon and at a minimum in the winter. In our urban setting, black kites arrived at the roosting sites mostly after sunset, and their arrival was influenced by sunset time, temperature, relative humidity and season. Some behavioural aspects of black kites within the roosts were also documented. This is the first quantitative assessment of roosting black kite abundance in Kolkata, India, and our data provide insight on the roosting behaviour of these birds relative to various environmental parameters.     

Foraging strategies of black kites (<Emphasis Type="Italic">Milvus migrans govinda</Emphasis>) in urban garbage dumps

Large numbers of black kites (Milvus migrans govinda) forage with house crows (Corvus splendens) at garbage dumps in many Indian cities. Such aggregation of many individuals results in aggressiveness where adoption of a suitable behavioral approach is crucial. We studied foraging behavior of black kites in dumping sites adjoining two major corporation markets of Kolkata, India. Black kites used four different foraging tactics which varied and significantly influenced foraging attempts and their success rates. Kleptoparasitism was significantly higher than autonomous foraging events; interspecific kleptoparasitism was highest in occurrence with a low success rate, while ‘autonomous-ground’ was least adopted but had the highest success rate.     

New Haplotypes of the Mitochondrial Gene <Emphasis Type="Italic">CytB</Emphasis> in the Nesting Population of the Siberian Black Kite <Emphasis Type="Italic">Milvus migrans lineatus</Emphasis> Gray, 1831 in the Territory of the Republic of Tyva

We analyzed a fragment of mitochondrial CytB locus obtained from young and adult black kites Milvus migrans lineatus from 19 nests in the Republic of Tyva, Russia. Three previously known (CytB-6, CytB-14, CytB-19) and three new haplotypes identified as CytB-6.1, CytB-6.2, and CytB-19.1 were detected. We described a set of substitutions specific to M. migrans lineatus but not to M. migrans migrans, the European subspecies of black kite.     

Zur Situation der MilaneMilvus milvus fasciicauda (Hartert, 1914) undMilvus m. migrans (Boddaert, 1783) auf den Kapverdischen Inseln

Zusammenfassung WährendMilvus milvus fasciicauda undMilvus m. migrans in den 1950er Jahren noch sympatrisch auf fast allen Inseln anzutreffen waren, umfaßt der Bestand heute, nach der Erfassung in den Jahren 1996 und 1997, lediglich zehn Individuen pro Art auf je einer Insel. Diese drastische Abnahme ist unter anderem auf Landschaftsveränderungen, Vergiftungen und Verfolgung durch den Menschen zurückzuführen.

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Status of the KitesMilvus milvus fasciicauda (Hartert, 1914) andMilvus m. migrans (Boddaert, 1783) on the Cape Verde Islands

Summary In 1996 and 1997 population size ofMilvus milvus fasciicauda andMilvus m. migrans was censused and estimated to be five to six individuals for the former and three to five for the latter. In the 1950's,Milvus m. migrans and the endemicMilvus milvus fasciicauda were sympatric taxa on most of the Cape Verde Islands. While still widely distributed in the 1980's, the Black Kite today is restricted to Boavista, the eastermost island. The Red Kite less widely distributed in the 1950's and in the 1980's restricted to three islands, is now found only on Santo Antao, the westernmost island. There is no evidence of breeding of either of the two Kites.This drastic reduction of Kites on the Cape Verde Islands may be due to habitat changes associated with the expansion of the Sahel region resulting in an increase in aridity on the islands, the pressure from human activities in the form of new settlements, structural changes in agriculture like overgrazing by goats, as well as the use of poisened meat as a bait, the use of rodentizides, and persecution.

     

A text and image analysis workflow using citizen science data to extract relevant social media records: Combining red kite observations from Flickr,eBird and iNaturalist

There is an urgent need to develop new methods to monitor the state of the environment. One potential approach is to use new data sources, such as User-Generated Content, to augment existing approaches. However, to date, studies typically focus on a single date source and modality. We take a new approach, using citizen science records recording sightings of red kites (Milvus milvus) to train and validate a Convolutional Neural Network (CNN) capable of identifying images containing red kites. This CNN is integrated in a sequential workflow which also uses an off-the-shelf bird classifier and text metadata to retrieve observations of red kites in the Chilterns, England. Our workflow reduces an initial set of more than 600,000 images to just 3065 candidate images. Manual inspection of these images shows that our approach has a precision of 0.658. A workflow using only text identifies 14% less images than that including image content analysis, and by combining image and text classifiers we achieve almost perfect precision of 0.992. Images retrieved from social media records complement those recorded by citizen scientists spatially and temporally, and our workflow is sufficiently generic that it can easily be transferred to other species.     

The function of aggressive chases by breeding Black and Red Kites Milvus migrans and M. milvus during the post-fledging dependence period

Black and Red Kites Milvus migrans and M. milvus chase other raptors approaching their nests. The study of this behaviour during the post-fledging period suggested that it reflects mainly, but not only, anti-predator behaviour. The frequency of vigilance and aggressive chases decreased through the post-fledging period as predicted by theoretical models of nest defence. Although predation risks were similar, Black Kites invested more time chasing intruders than did Red Kites. Black Kites, unlike Red Kites, chased away intruding juveniles, which may be interpreted as a behaviour to avoid investment in unrelated fledglings. Black Kites usually nest in loose colonies where the risk of, and selection pressures against, accidental investment in unrelated fledglings is likely to be greater than for Red Kites. Differences in aggressive chases by Black and Red Kites are better related to this than to different predation risks.     

Family break-up in Black and Red Kites Milvus migrans and M. milvus: is time of independence an offspring decision?

I observed the natural process of family break-up in 13 families of Black Kites Milvus migrans and five families of Red Kites M. milvus in which fledglings had been individually marked. In other broods, I performed experiments which modified the parental investment fledglings received by supplementing nests of both species with food or transferring Black Kite chicks to nests with younger or older chicks of the same species.
The time of family break-up in the Black Kite is mainly an offspring decision which is not affected by an artificial increase of parental investment. The duration of the post-fledging period was not increased in Black Kites that were given supplementary food. Chicks transferred to nests with a younger chick did not extend the post-fledging period, nor did chicks transferred to nests with an older chick shorten the post-fledging period. In Red Kites, parental investment seemed to have more influence on the timing of the family break-up. Red Kite adults invested less as parents than did Black Kites during the post-fledging dependence period, and in nests where supplementary food was given, Red Kite fledglings stayed attached for a longer period.     

Poisoning of reintroduced red kites (<Emphasis Type="Italic">Milvus Milvus</Emphasis>) in England

Programmes to reintroduce predatory birds are resource intensive and expensive, yet there are few long-term studies on the health of these reintroduced birds following release. A total of 326 red kites (Milvus milvus) were released at four sites in England between 1989 and 2006 as part of efforts to reintroduce this species to England and Scotland, resulting in the establishment of several rapidly expanding populations in the wild. Detailed post-mortem examinations were carried out on 162 individuals found dead between 1989 and 2007, involving both released and wild-fledged birds. Toxicological analysis of one or more compounds was performed on 110 of the 162 birds. Poisoning was diagnosed in 32 of these 110 kites, 19 from second-generation anticoagulant rodenticides, 9 from other pesticides and 6 from lead. Criteria for diagnosing anticoagulant rodenticide poisoning included visible haemorrhage on gross post-mortem examination and levels of anticoagulant rodenticide exceeding 100 ng/g, but levels were elevated above 100 ng/g in a further eight red kites without visible haemorrhages, suggesting poisoning may have occurred in more birds. The anticoagulant rodenticides difenacoum and bromadiolone were the most common vertebrate control agents involved during this period. Poisoning of red kites may be slowing their rate of population recovery and range expansion in England. Simple modifications of human activity, such as best practice in rodent control campaigns, tackling the illegal use of pesticides and the use of non-toxic alternatives to lead ammunition, can reduce our impact on red kites and probably other populations of predatory and scavenging species.     

Acute poisoning of Red Kites (Milvus milvus) in France: data from the Sagir network

Red Kites (Milvus milvus) are avian scavengers limited to Europe, and they currently are listed as an endangered species worldwide. Accidental poisoning is often listed as one of the threats to Red Kites throughout their range of distribution. The purpose of this article is to investigate the suspected poisoning cases reported to the French Wildlife Disease Surveillance System. Dead animals are submitted to a local veterinary laboratory for necropsy and when poisoning is suspected, samples are submitted to the Toxicology Laboratory of the College of Veterinary Medicine, Lyon, France. Over the period 1992-2002, 62 Red Kites suspected of poisoning were submitted, and poisoning was the confirmed cause of death for greater than 80% of these cases. The major toxicants found were cholinesterase inhibitors (carbamates and organophosphate insecticides) and anticoagulant compounds. The circumstances of exposure include secondary poisoning after the use of anticoagulants over vast areas to control water vole (Arvicola terrestric) populations, but they also include malicious poisoning with carbamates (aldicarb and cabofuran) in meat baits. Cases of poisoning vary throughout France, with observed mortality rates ranging between 0.1/100 hundred breeding pairs/10 yr and four cases/100 hundred breeding pairs/10 yr. Additional cases of poisoning likely go undetected, and our results suggest that acute poisoning is not uncommon in Red Kites and that it should be considered in the current restoration plans.     

Microsatellite polymorphism in the endangered snail kite reveals a panmictic,low diversity population

Genetic structure and genetic diversity are key population characteristics that can inform conservation decisions, such as delineating management units or assessing potential risks for inbreeding depression. Evidence of genetic structuring or low genetic diversity in the critically endangered snail kite (Rostrhamus sociabilis plumbeus) would have implications for monitoring and planning decisions. Recent work on understanding connectivity across the snail kite range indicated that there is less dispersal between northern and southern parts of the current range, and that dispersal is shaped by individual habitat preference. We examine whether there is neutral genetic structure and the amount of genetic variation in the population by non-lethally sampling 235 nestlings from unique nests across the entire breeding range between 2013 and 2014. Data on 15 microsatellite revealed low diversity (e.g., N _a?=?2.54, H _e?=?0.37) and range-wide panmixia based on AMOVA, Bayesian clustering, spatial autocorrelation, isolation by distance, and spatially explicit ordination analyses. Our results emphasize that long-term recovery goals and management strategies should be based on viewing snail kites as a single genetic population, despite evidence for non-random dispersal between wetlands over ecological time scales. These results also highlight the need to understand potential effects of low genetic diversity on population dynamics and viability of snail kites. More broadly, these results add to the growing evidence for potential discrepancies between dispersal and genetic patterns, emphasizing that care should be taken if using one to interpret the other, particularly for widely-ranging species.     

Experiments on direct and secondary poisoning by fluoroacetamide (1081) in wildlife and domestic carnivores.

Fluoroacetamide (1081 or F.A.A) is used in Israel for field rodent control. Experiments on direct and secondary, short and long term poisoning caused by 1081 were carried out. Mongoose (Herpestes ichneumon), hyena (Hyaena hyaena), cats and dogs were susceptible. Barn owls (Tyto alba), buzzards (Buteo buteo) and black kites (Milvus m. migrans) were markedly resistant. Barn owls tolerated total direct poisoning ranging from 6.8 to 10.9, and a final dose ranging from 0.8 to 2.0 mg/kg. In secondary poisoning, total doses ranging from 1.7 to 7.1, and final doses ranging from 0.2 to 1.3 mg/kg were tolerated. Buzzards tolerated total direct poisoning ranging from 6 to 12.0, and final doses ranging from 0.7 to 1.3 mg/kg. In secondary poisoning, doses ranging from 0.8 to 10.3 and final doses ranging from 0.2 to 2.4 mg/kg were tolerated. One black kite tolerated a total direct dose of 6.1 and final dose of 0.7 mg/kg, another survived a total dose of 2.3 and final dose of 0.2 mg/kg in secondary poisoning. A small-scale secondary poisoning experiment on two Palestine vipers (Vipera palestinae), a Syrian black snake (Coluber jugularis) and two Montpellier snakes (Malpolon monspessulanus) indicated that these species were resistant to total doses ranging from 0.1 to 3.2 and final doses of 0.1 to 0.8 mg/kg.     

Systematics and conservation of the hook-billed kite including the island taxa from Cuba and Grenada

Taxonomic uncertainties within the genus Chondrohierax stem from the high degree of variation in bill size and plumage coloration throughout the geographic range of the single recognized species, hook-billed kite Chondrohierax uncinatus . These uncertainties impede conservation efforts as local populations have declined throughout much of its geographic range from the Neotropics in Central America to northern Argentina and Paraguay, including two island populations on Cuba and Grenada, and it is not known whether barriers to dispersal exist between any of these areas. Here, we present mitochondrial DNA (mtDNA; cytochrome B and NADH dehydrogenase subunit 2) phylogenetic analyses of Chondrohierax , with particular emphasis on the two island taxa (from Cuba, Chondrohierax uncinatus wilsonii and from Grenada, Chondrohierax uncinatus mirus ). The mtDNA phylogenetic results suggest that hook-billed kites on both islands are unique; however, the Cuban kite has much greater divergence estimates (1.8–2.0% corrected sequence divergence) when compared with the mainland populations than does the Grenada hook-billed kite (0.1–0.3%). Our findings support species status for the Cuban form, as Chondrohierax wilsonii , and subspecific status for the Grenada form. For mainland taxa, we do not find support for the currently recognized subspecies Chondrohierax uncinatus aquilonis in western Mexico, but we do find evidence for a genetic subdivision between populations in Central and South America, a difference previously unsuspected. The results of this study help identify conservation priorities associated with these unique Neotropical raptors. This information is of immediate interest because the Cuban kite has not been reliably seen since 1992, and <50 hook-billed kites currently inhabit Grenada.     

Growth of nestling black kites Milvus migrans: effects of hatching order, weather and season

The growth of black kites Milvus migrans was studied in 1981, 1982 and 1984 at the Doñana Biological Reserve (south-west Spain). Fifteen variables were submitted to a principal component analysis in order to characterize the growth pattern of the young. In general, in the nestlings that fledged, rapid weight gain corresponded to rapid growth of the tarsus and feathers. For nestlings that starved, tarsus growth took priority over weight gain. Within the same brood, the last-hatched sibling grew more slowly than its older sibling and the differences between them increased in proportion to the hatching asynchrony. Brood size did not affect growth as clearly as hatching order and hatching asynchrony. Increased rainfall and lower maximum temperature, factors that seem to make the search for food more difficult, had negative effects on the youngest sibling in a multiple brood and on single nestlings. The only environmental variable that had an effect on all of the nestlings was the hatching date.     

Experimental analysis of diet specialization in the snail kite: the role of behavioral conservatism

We examined factors maintaining extreme diet specialization in the snail kite (Rostrhamus sociabilis), a medium-sized hawk which feed almost exclusively on Pomacea snails, by determining why during some months kites eat crabs (Dilocarcinus dentatus) in the Ilanos of Venezuela. We offered snails and crabs of different sizes to wild free-flying birds to develop estimates for a prey choice model. Handling times of Pomacea doliodes snails averaged 90±39 s and were positively correlated with snail size. Handling times for crabs (x=353±130 s) were significantly longer and exhibited greater variation than for snails, and were not correlated with crab size. Edible crab tissues had greater dry weights and contained more energy (25.37 kJ/g) than tissues of snails (16.91 kJ/g). Total energy of crabs was much greater than that of snails, and total energy of both foods was highly related to body length. We constructed an allometric equation for profitability of snails and crabs. Snails were more profitable than all but the largest crabs, but estimates of variance in profitability were greater for crabs. Predictions from the model were tested by offering crabs that represented equal, greater and much greater profitability than snails, to determine whether kites chose prey according to profitability. Only 15.6% of 289 food items chosen were crabs. Half of the 18 kites tested did not eat crabs and only 3 birds switched from snails to more profitable crabs. Four fledglings showed no preference for snails. The role of neophobia in food choice was investigated by offering unfamiliar snails (Pomacea urceus) to kites. Kites exhibited neophobic behaviors, and 5 of 12 birds chose not to capture P. urceus. Two-thirds of the 12 snails chosen were rejected immediately, but the others were handled efficiently (x=133±89 s). Although morphological adaptations allow kites to specialize on snails, the costs of specialization were overcome for kites when the profitability of alternative food increased sufficiently. Our results suggest a role for behavioral conservatism, in the form of risk-averse foraging and neophobia, in maintaining severe diet specialization in the snail kite.     

Multiscale patterns of movement in fragmented landscapes and consequences on demography of the snail kite in Florida

1. Habitat loss and fragmentation are major factors affecting vertebrate populations. A major effect of these habitat alterations is that they reduce movement of organisms. Despite the accepted importance of movement in driving the dynamics of many natural populations, movement of vertebrates in fragmented landscapes have seldom been estimated with robust statistical methods. 2. We estimated movement probabilities of snail kites Rosthramus sociabilis within the remaining wetlands in Florida. Using both radio-telemetry and banding information, we used a multistate modelling approach to estimate transition probabilities at two temporal scales (month; year) and multiple spatial scales. We examined kite movement among wetlands altered by three different levels of fragmentation: among wetlands separated by small physical barriers (e.g. road); among wetlands separated by moderate amount of matrix (< 5 km); and among wetlands separated by extensive matrix areas (> 15 km). 3. Kites moved extensively among contiguous wetlands (movement probability 0.29 per month), but significantly less among isolated wetlands (movement probability 0.10 per month). 4. Kites showed high levels of annual site fidelity to most isolated wetlands (probability ranged from 0.72 to 0.95 per year). 5. We tested the effects of patch size and interpatch distance on movement. Our modelling indicated an effect of both distance and patch size on juveniles' movement (but not adult) when examining movements among fragments. 6. Only a small proportion of kites escaped a regional drought by moving to refugia (wetlands less affected by drought). Many individuals died after the drought. During drought adult survival dropped by 16% while juvenile survival dropped by 86% (possibly because juveniles were less likely to reach refugia). 7. We hypothesize that fragmentation may decrease kite's resistance to drought by restricting exploratory behaviour.     

Genetic divergence and analysis of the relationships between species of Mosla (Labiatae)

Seven species were recognized in Mosla in China. M. pauciflora (C. Y. Wu) C. Y. Wu et H. W. Li is an allotetraploid (2n=36 ), while the other six species are diploids (2n=18). Cluster analysis based on allozyme data from 28 loci of 15 enzyme systems reveals that the six diploid species formed three species pairs. M. cavaleriei Lévl.is closely related to M. dianthera (Buch.-Ham. ex Roxb. ) Maxim., M. chinensis and M. hangchouensis Matsuda are sibling species, and M. scabra (Thunb.) C. Y. Wu et H. W. Li is allied to M. soochouensis. Although M. cavaleriei and M. dianthera are close relatives, considerable genetic divergence has been detected between them. One third of alleles are unique to either of them, and 28.6 % of their loci have different alleles fixed. The average genetic identity ( 1 ) between populations of these two species is 0.770, and the average genetic distance (D) is 0.261. M. scabra and M. soochouensis are the least divergent species pair (I =0.979, D＝0.025). No completely divergent locus was detected, and the percentages of unique alleles are 11.1% to M. scabra and 16.7 % to M. soochouensis. This finding indicates that a high level of genetic differentiation is unnecessarily a prerequisite of speciation. A moderate divergence is detected between M. chinensis and M. hangchouensis (I＝0.899, D=0.107, and 7.1% of completely diverged loci) yet the latter harbors four times as many unique alleles (45.1% ) as the former does(11.8 % ). Compared to the genetic divergence between M. scabra and M. soochouensis, M. dianthera and M. hangchouensis and may well been undergoing active speciation have the high genetic distance betweenpopulations (0.034 and 0.026 respectively).     

Genetic relationship among Japanese sentinel crabs (Decapoda: Ocypodidae: genus Macrophthalmus)

Seven species (eight populations) of sentinel crabs (genus Macrophthalmus) from the Japan coast and Uca vocans and Ocypode ceratophthalma, were examined electrophoretically for genetic variations in 13 enzymatic and one non-enzymatic protein comprising 17 loci. Most species were highly differentiated from each other (Nei's genetic distance, 0.29-1.63). The least genetic distance was found between M. japonicus and M. banzai, the genetic distinctiveness of the two taxa being supported by three divergent loci with no common allele. The genetic relationships among Macrophthalmus species differed greatly from those inferred from morphological features, with a UPGMA tree suggesting that the sub-genus Macrophthalmus is polyphyletic.