Patagial Tags Research Articles

Semi‐automated detection of tagged animals from camera trap images using artificial intelligence

The use of technology in ecology and conservation offers unprecedented opportunities to survey and monitor wildlife remotely, for example by using camera traps. However, such solutions typically cause challenges stemming from the big datasets gathered, such as millions of camera trap images. Artificial intelligence is a proven, powerful tool to automate camera trap image analyses, but this is so far largely been restricted to species identification from images. Here, we develop and test an artificial intelligence algorithm that allows discrimination of individual animals carrying a tag (in this case a patagial yellow tag on vultures) from a large array of camera trap images. Such a tool could assist scientists and practitioners using similar patagial tags on vultures, condors and other large birds worldwide. We show that the overall performance of such an algorithm is relatively good, with 88.9% of all testing images (i.e. those not used for training or validation) correctly classified using a cut‐off discrimination of 0.4. Specifically, performance was high for correctly classifying images with a tag (95.2% of all positive images correctly classified), but less so for images without a tag (87.0% of all negative images). The correct classification of images with a tag was, however, significantly higher when the tag code was at least partly readable compared with the other cases. Overall, this study underscores the potential of artificial intelligence for assisting scientists and practitioners in analysing big datasets from camera traps.

Wing tags severely impair movement in African Cape Vultures

BackgroundThe use of tracking technologies is key for the study of animal movement and pivotal to ecological and conservation research. However, the potential effects of devices attached to animals are sometimes neglected. The impact of tagging not only rises welfare concerns, but can also bias the data collected, causing misinterpretation of the observed behaviour which invalidates the comparability of information across individuals and populations. Patagial (wing) tags have been extensively used as a marking method for visual resightings in endangered vulture species, but their effect on the aerodynamics of the birds and their flight behaviour is yet to be investigated. Using GPS backpack mounted devices, we compared the flight performance of 27 captive and wild Cape Vultures (Gyps coprotheres), marked with either patagial tags or coloured leg bands.ResultsIndividuals equipped with patagial tags were less likely to fly, travelled shorter distances and flew slower compared to individuals equipped with leg bands. These effects were also observed in one individual that recovered its flight performance after replacing its patagial tag by a leg band.ConclusionsAlthough we did not measure the effects of patagial tags on body condition or survival, our study strongly suggests that they have severe adverse effects on vultures’ flight behaviour and emphasises the importance of investigating the effects that tagging methods can have on the behaviour and conservation of the study species, as well as on the quality of the scientific results.

Effectiveness of the use of patagial wing tags for griffon vultures (Gyps fulvus) in Spain

espanolSe describe el diseno de marcas alares patagiales de lectura dorsoventral de alta durabilidad para el marcaje y seguimiento de ejemplares de buitre leonado Gyps fulvus. Para ello se marcaron aves aclimatadas dentro del Proyecto Canyet de recuperacion del buitre leonado como especie nidificante en el Parque Natural de la Sierra de Mariola (Comunidad Valenciana). Un total de 193 buitres fueron marcados en el periodo 2000-2015 en el punto de muestreo y 43 individuos fueron recapturados, con un valor medio de 1.362 dias (SD ± 543,78). Del mismo modo, se peso a la mitad de la muestra de individuos capturados (n = 20), siendo el valor promedio de 9,11 kg (SD ± 1,14). Se midio asimismo el area de las perforaciones cicatrizadas, siendo la superficie media de perforacion de 85,38 mm2 (SD ± 28,61). Las marcas alares proporcionaron resultados muy satisfactorios, que permiten profundizar en los patrones de comportamiento interespecifico, asi como en los movimientos de nomadismo. Se ha constatado que el diseno final de estas marcas es adecuado, ya que su identificacion a distancia es buena y la incidencia negativa en los individuos es muy reducida. Ademas, este sistema permite la diferenciacion de individuos con una elevada frecuencia. Del mismo modo, se ha constatado que este dispositivo no interfiere en las etapas vitales de la especie y que, adaptandolo convenientemente a escala, resultaria factible para otras especies orniticas. EnglishWe describe the design of patagial wing tags with highly durable lateral readings for marking and tracking griffon vultures Gyps fulvus. Acclimatized birds were tagged within Projecte Canyet for the recovery of the griffon vulture as a nesting species in the Sierra de Mariola Natural Park (Valencia Region). A total of 193 vultures were tagged at the sampling point between 2000 and 2015. Forty-three individuals were recaptured within an average of 1,362 days (SD ± 543.78). Half the sample of captured individuals was weighed (n = 20) and the average was 9.11 kg (SD ± 1.14). The area of the scarred perforations was measured, and the mean perforation size was 85.38 mm2 (SD ± 28.61). Wing tags provided highly satisfactory results and enabled a deeper understanding of the patterns of interspecific behaviour and nomadic movements. The design of the tags was satisfactory because it facilitated identification of individuals at a distance. The negative impact on individuals was low and the device did not interfere in the vital life stages of the species. We suggest the model could be useful for other bird species if adapted to size. catalaEs descriu el disseny de marques alars patagials de lectura dorsoventral d’alta durabilitat per al marcatge i el seguiment d’exemplars de voltor comu Gyps fulvus. Amb aquest objectiu es van marcar ocells aclimatats dins del Projecte Canyet de recuperacio del voltor comu com a especie nidificant al Parc Natural de la Serra de Mariola (Comunitat Valenciana). Un total de 193 voltors van ser marcats en el periode 2000-2015 en el punt de mostreig i 43 individus van ser recapturats, amb un valor mitja de 1.362 dies (SD ± 543,78). De la mateixa manera, es va pesar la meitat de la mostra d’individus capturats (n = 20), els quals van presentar un valor mitja de 9,11 kg (SD ± 1,14). Tambe es va mesurar l’area de les perforacions cicatritzades, la superficie mitjana de les quals va ser de 85,38 mm2 (SD ± 28,61). Les marques alars van proporcionar resultats molt satisfactoris, que permeten aprofundir en els patrons de comportament interespecific, aixi com en els moviments de nomadisme. S’ha constatat que el disseny final d’aquestes marques es adequat ates que la identificacio a distancia es bona i la incidencia negativa en els individus es molt reduida. A mes a mes, aquest sistema permet la diferenciacio d’individus amb una frequencia elevada. S’ha constatat aixi mateix que aquest dispositiu no interfereix en les etapes vitals de l’especie i que, adaptant-lo convenientment a escala, resultaria factible per a altres especies ornitiques.

Effects of Researcher-Induced Disturbance on American Kestrels Breeding in Nest Boxes in Northwestern New Jersey

Abstract Nest boxes for American Kestrels (Falco sparverius) may alleviate local nest site limitation, but there is concern that periodically opening nest boxes or handling adults may negatively affect nesting success. I monitored 536 kestrel breeding attempts (≥1 egg laid) in about 100 nest boxes in northwestern New Jersey, 1995–2012. To study return rates, I opportunistically captured adults in nest boxes and marked them with U.S.G.S. leg bands and patagial tags. To examine possible effects of this disturbance, I compared nesting success (≥1 nestling surviving to banding age) of marked and unmarked adults. Nesting success was 67% for 270 unmarked pairs, 76% for 25 pairs with only the male marked, 82% for 206 pairs with only the female marked, and 91% for 35 pairs with both adults marked. This significant difference likely reflects differences in the probability of capture: successful attempts last longer and successful parents may be more attentive. To control for these correlations, I examined attempts...

Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug

Capsule This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large falcon species.Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons.Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters.Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort.Conclusion Researchers using harness-mounted transmitters on this, and similar, falcon species need to assess how these deleterious effects may impact on species conservation, the welfare of individual birds and the interpretation of their studies.

Comparing different types of patagial tags for use on vultures

Raptor research often requires identifying individuals. Researchers place patagial tags on raptors to facilitate such identification. Researchers in southern African use two main types of patagial tags: hard plastic ear tags originally designed for cattle and soft vinyl tags. We deployed both types of tags on vultures in Botswana. Based on our observations, we recommend using soft vinyl tags as they appear to be more aerodynamic and can be read from below when a raptor is soaring, as well as when the bird is perched. Cattle ear tags sometimes flutter when raptors fly and can only be read when the dorsal surface of the wing is visible.

Influence of Nesting Location on Movements and Survival of Juvenile Saker FalconsFalco cherrugDuring the Post-Fledging Dependence Period

We used patagial tags, VHF radio transmitters, and satellite-received transmitters to investigate the movements and survival of juvenile saker falcons fledged from artificial nests in open landscapes and natural nest sites in hilly areas in Mongolia. During the post-fledging dependence period (PFDP) juveniles progressively moved farther from their nest until dispersal from the natal area. Natal home ranges were larger for juveniles fledged at artificial than natural sites and the distance moved by juveniles during PFDP was positively related to fledging date and brood size. Duration of the PFDP was estimated as 40 days (range: 31–52 days). Over the PFDP, the best-fitting model to explain juvenile survival incorporated fledging date and nest site type, with juvenile survival being higher in early fledged broods from natural sites. Predation was identified as a major cause of mortality, especially in open landscapes where artificial nests were located. However, because artificial nests produced more fledglings, we found that overall productivity of juveniles to dispersal at artificial and natural nests sites did not differ significantly.

Turkey Vulture Breeding Behavior Studied with Trail Cameras

Abstract We report initial findings on Turkey Vulture (Cathartes aura) breeding behavior from nests in abandoned buildings in Saskatchewan. We used infrared trail cameras placed at three nests between 2009 and 2011 and we also present anecdotal information from several other nests. Some parents could be identified and differentiated by their patagial tags and satellite transmitter backpacks. In two years, a pair of tagged vultures successfully evicted a prospecting pair from a nest site that the tagged pair had used in the previous year. However, another vulture was observed at four sites in four years, suggesting that breeders are not always philopatric. The trail cameras revealed that additional vultures occasionally roosted on nest buildings of the focal pair, and occasionally entered the nest space during incubation; whether these individuals participated in the nesting activities or were only prospecting for nest sites was unclear. We describe nest preparatory activities and three contexts for the sp...

Survival of theAfrican white‐backed vultureGyps africanusin north‐easternSouthAfrica

AbstractOld World vultures are in decline across their entire range. Although critical for the formulation of effective conservation measures, neither survival nor movement patterns of African vultures are adequately known. This paper presents survival and movement data on theAfrican white‐backed vultures (Gyps africanus) fromSouthAfrica. Survival estimates were modelled on resightings of tagged vultures. Birds were captureden masseand resighted betweenNovember 2005 andDecember 2010. A total of 93 adult and subadult birds were fitted with uniquely numbered patagial tags, which were resighted 3707 times(mean of 39.8 resightings per bird). The programmeMARKwas used to estimate survival. The best model was one where survival and recaptures varied only with time (e.g. year). However, owing to the fading (illegibility) of tags in later years, the relationship with time is probably spurious. The second best model was one where survival and recaptures varied with age and time. Annual survival estimates increased from 85.2% in second‐year birds to 99.9% in adults. This corresponds well with the survival of two otherGypsvultures that have been studied to date and underscores the point that additional mortality of adults in these long‐lived species will result in rapid population declines.

Wing marker woes: a case study and meta-analysis of the impacts of wing and patagial tags

The marking of individual birds has a long history in ornithology. This inexpensive and simple practice has been used to shed light on migration, behavior, and age-specific survival and recruitment. However, problems associated with markers and tags have often been overlooked. Wing tags have been used for over 40 years on frigatebirds, but their effects on this family of highly aerial seabirds have not been examined. Following higher than expected nest failure of treatment birds in the previous breeding season, we designed a study to test the impact of wing tagging and other standard capture and sampling methods on the nest success of Magnificent Frigatebirds (Fregata magnificens). Twelve nests were assigned to each of various band, measure, bleed, wing tag, and control treatments in the 2010/2011 breeding season on Barbuda, West Indies. We modeled nest fates using generalized linear models. Wing tags had a substantial negative effect on pre-fledging nest success, which was 42 % (10/24) for control nests, 39 % (14/36) for all non wing-tagged treatments, and 15 % (7/48) for wing-tagged treatments. We also conducted two meta-analyses, with different effect size calculations, to explore the general impact of wing and patagial tags on all birds. Our log odds ratio model showed a significant effect on survival and hatch and nest success, while our standardized mean difference model dealing largely with outcomes of behavioral, condition, and reproductive parameters (e.g., number of chicks and hatch date) showed no difference between marked and control birds. We consider possible mechanisms by which wing tags might contribute to lower nest success in frigatebirds, and propose that alternative markers be considered carefully before being applied to any species.

Reporting Difference for Colored Patagial Tags on Ring‐Billed Gulls

ABSTRACT The possible role of tag color in mediating behaviors that could bias resighting rate has not been examined. In a study that began in 2007, we marked 725 ring‐billed gulls (Larus delawarensis) with Bondcote royal blue, green, yellow, or orange patagial tags. Reports we gathered over 2 years indicated approximately a 3.4:1 bias in resighting rate toward yellow or orange tags. The observed bias is inconsistent with color‐associated visibility bias or differential mortality among color‐tagged breeding adults. Potential behavioral effects of tag color on individuals and conspecifics should be considered by biologists when planning marking studies.

Growth and demography of a re‐introduced population of White‐tailed Eagles Haliaeetus albicilla

White‐tailed Eagles Haliaeetus albicilla became extinct in Britain in 1918 following prolonged persecution. Intensive conservation efforts since the 1970s have included the re‐introduction of the species to Britain through two phases of release of Norwegian fledglings in western Scotland in 1975–85 and 1993–98. Population growth and breeding success have been monitored closely to the present day, aided by the use of patagial tags to individually mark most released birds as well as a high proportion of wild‐bred nestlings. This study reviews the growth and demography of this re‐introduced population, and makes comparisons with other European populations. For the first time, we compare the demographic rates of released and wild‐bred birds in the Scottish population. Breeding success in the Scottish population has increased over time as the average age and experience of individuals in the population have increased, and success tends to be higher where one or both adults are wild‐bred. Current levels of breeding success remain low compared with some other populations in Europe, but similar to those in Norway where weather conditions and food availability are likely to be most similar. Survival rates in Scotland are similar to those recorded elsewhere, but survival rates of released birds are lower than those of wild‐bred birds, especially during the first 3 years of life. Despite the effect of lower survival rates of released birds in limiting overall population growth rate, the recent rate of growth of the Scottish population remains high relative to other recovering populations across Europe. Differences in demographic rates of wild‐bred and released birds suggest that in future re‐introduction programmes, steps to maximize the success and output of the earliest breeding attempts would help ensure the most rapid shift to a population composed largely of wild‐bred birds, which should then have a higher rate of increase.

Update on Longevity and Movements of Carnaby?s Black Cockatoo

Carnaby's Black Cockatoo Calyptorhynchus latirostris is an endangered species, found only in the southwest of Western Australia. Between 1971 and 1976 this species was the subject of a detailed ecological study (Saunders 1982). As part of that study, adults and fledglings were individually marked on each wing with stainless steel tags (patagial tags) described by Rowley and Saunders (1980). They were also marked with a numbered leg band of stainless steel supplied by the Australian Bird Banding Scheme. Observations made of tagged individuals provided much of the data used to explain the breeding biology, behaviour and movements of this species (Saunders 1980, 1982, 1986; Saunders and Ingram 1998). Despite major problems associated with the use of patagial tags (Saunders 1988), much of the ecology of the species could not have been investigated without their use.

Dispersal of juvenile Marabou Storks Leptoptilos crumeniferus as determined by resightings

A total of 114 Marabou Stork chicks were ringed in the years 2003–2007 at the most southerly African breeding colony, Swaziland. Just one of 35 chicks fitted with colour rings was resighted by December 2007, while 17 of 79 chicks fitted with patagial tags were resighted. Juvenile Marabou Storks can disperse over 1 500 km within their first year after fledging, sufficient to cover the large distances between breeding colonies.

MOVEMENTS OF BLACK VULTURES BETWEEN COMMUNAL ROOSTS IN FLORIDA

Communal roosts are important resources for local populations of the Black Vulture (Coragyps atratus), but these roosts are increasingly becoming the focus for complaints of wildlife damage. We studied movements of Black Vultures between communal roosts in Florida using mark-resight methods. We marked 416 Black Vultures with patagial tags at two communal roosts in Orange County, Florida. A total of 1,245 resightings of 226 individuals were recorded over a 3-year period. Black Vultures made one-way movements between communal roosts of up to 152 km, and two-way movements (i.e., birds left a site and subsequently returned) between communal roosts of up to 144 km. Patterns of resightings indicated that some Black Vultures use several roosts over wide geographic ranges during parts of their lives. Long distance exchanges between roosts and high nightly turnover of membership at roosts leads to concerns that control of nuisance Black Vulture roosts has the potential to impact nontarget populations in a geographic area well beyond a given communal roost.

Feeding Rates and Individual Contributions to Feeding at Nests in Cooperatively Breeding Western American Crows

Helpers increase the reproductive success of breeders in many species of cooperatively breeding birds. Several mechanisms by which they do so involve the feeding of nestlings. The presence of additional feeders may result in increased amounts of food brought to nests, which can increase growth rates of nestlings (Dickinson et al. 1996) and reduce starvation (Rowley 1978, Reyer 1980, Emlen and Wrege 1991, Heinsohn 1992). Alternatively, helpers may not increase total feeding rates at nests but instead reduce the workload of one or both breeders. Lightening the load of breeders may translate into increased success in several ways. Relief of feeding responsibilities may allow breeders to devote more time to vigilance and antipredator behavior (Rabenold 1984, Austad and Rabenold 1985). For some species, subsequent survival is higher for members of assisted pairs than for unassisted ones (Stallcup and Woofenden 1978, Reyer 1984, Russell and Rowley 1988). Additionally, in some multiple-brooded species, helper assistance results in shortened interbrood intervals, allowing for the production of more clutches per season (Rowley 1965, Brown and Brown 1981, Rabenold 1984, Russell and Rowley 1988). Here, I describe the feeding contributions made by individuals at assisted and unassisted nests of Western American Crows (Corvus brachyrhynchos hesperis) and examine the effects that the feeding contributions of helpers have on nestling feeding rates. I also examine other factors that could affect feeding rates, and the consequences of variation in feeding rates on breeding success. Methods.-I studied members of a resident population of crows on the Balboa and Encino golf courses in Encino, California, from March 1985 through August 1990. The habitat consisted of tracts of grass separated by rows of trees, with additional clumps of trees scattered throughout the site. The climate was southern Californian Mediterranean, with hot, dry summers and occasional winter rains between December and February. I captured 173 free-flying individuals (63 males, 54 females, 56 unsexed) using large walk-in traps and a cannon net. Trapped crows were weighed, measured, and marked with identical patagial tags bear-

Survival of adult and nestling western lon-billed corellas, Cacatua pastinator, and Major Mitchell cockatoos, C. leadbeateri, in the wheatbelt of western Australia

The western long-billed corella, Cacatua pastinator, and the Major Mitchell cockatoo, C. leadbeateri, were studied in the central wheatbelt of Western Australia from 1977 to 1983. Nestling and breeding adult birds were individually marked with patagial tags and their survival was calculated from resighting of tagged birds. Mean annual survival of adult male and female western long-billed corellas and Major Mitchell cockatoos were 94.2%, 93.2%, 92.9% and 81.3%, respectively. Survival of immature birds was less than that of adults and only 9% of male and 23% of female western long-billed corellas survived to age of first breeding at three and five years, respectively; 20% of male and 31% of female Major Mitchell cockatoos survived to age of first breeding at two and three years, respectively. The use of patagial tags had no significant effect on the survival of adult birds; the situation with immature birds is less certain, but the data suggest that any effect was small. Dispersal had only a slight negative effect on 'survival' of immature Major Mitchell cockatoos. The lower survival of immature birds was attributed to increased predation while in the locally nomadic immature flocks. Data on survival and productivity suggest that the populations should be stable or slowly increasing and this is in agreement with the data on the populations.

RANGE EXPANSION AND MIGRATION OF THE CATTLE EGRET

Summary Maddock, M. & Geering, D. 1994. Range expansion and migration of the Cattle Egret. Ostrich 65: 191–203. The expansion of the range of the Cattle Egret Bulbulcus ibis from its origins in tropical Africa and Asia to Europe, the Americas and Australasia are summarised, and implications of research in Australasia based on birds marked with patagial tags on the spread of the species discussed.

Survival and Seasonal Movements of the Cattle Egret in Eastern Australia

Recoveries from 7849 Cattle Egrets Ardeola ibis coromandus banded as nestlings at eight heronries in southeast Queensland and north-east New South Wales over six nesting seasons were analysed six years after banding finished. The live recovery rate was 0.9070 and the dead and injured recovery rate, 0.88%. Birds with patagial tags apparently survived less well than colour banded birds and dispersed less far in winter. The oldest recovery of A. i. Coromandus is 11.1 years and mean life expectancy at fledging is 2.63 years and at one year of age it is 3.09 years, values similar to those of the nominate A. i. Ibis. The Cattle Egret is a partial migrant in eastern Australia. The pattern of its recoveries suggests a post-breeding migration predominantly south along the coastal plain, with the birds either becoming progressively more sedentary as they grow older and/or the more sedentary birds living longer than the long-distance migrants. Evidence for a general (although not invariable) philopatry comes from direct observation and a summer contraction of the recoveries towards the natal heronry, especially those of first year birds. The Cattle Egret's low first year mortality rate (40.6% in the present study) compared with certain other Ardeinae, seems to be a characteristic of populations of A. i. Coromandus and A. i. Ibis and may give impetus to the colonising process.

Ectoparasitism and the role of green nesting material in the European starling.

The use of green nesting material is widespred among birds. Recent evidence suggests that birds use secondary chemicals contained in green plants to control ectoparasites. We manipulated green nesting material and ectoparasites of European starlings (Sturnus vulgaris) to test two hypotheses: (1) ectoparasites adversely affect prefledging survival and morphometrics or postfledging survival, and (2) green nesting material ameliorates the effects of ectoparasites. We recorded fat score, numbers of scabs, tarsal length, body mass, and hematocrit level on each nestling 17 days after hatching. We also fitted each nestling with unique patagial tags and resighted the starlings for 6-8 weeks after fledging to estimate survival and sighting rates. Nests devoid of green nesting material and dusted with the insecticide, carbaryl, had fewer high ectoparasite infestations, and nestlings had significantly lower scab scores, and significantly higher body masses than nestlings in undusted boxes. However, there was no difference in postfledging survival between birds from carbaryl-treated and undusted nests. There also was no difference in prefledging survival and morphometrics or postfledging survival between nestlings from boxes with and without green nesting material. These results do not support the hypothesis that starlings use green nesting material to control nest ectoparasites. We suggest an alternative hypothesis; green nesting material is used for mate selection or pairbonding in the starling.