Seasonality drives variation in the use of forest strata by adult males of a dimorphic frugivorous bird species

Abstract:To understand how fruit tree characteristics and microhabitats shape the assemblage of birds on fig trees and the pattern of fig–bird interactions, we observed and recorded, over 96 d and 816 h, the frugivorous birds visiting 32 individual trees belonging to 14 species of Ficus that were distributed across four different sites. A total of 30 bird species were recorded as eating figs, comprising 66.7% of the total number of frugivorous bird species recorded at the four sites. Small passerine birds such as bulbuls were the dominant frugivores for fig species. The number of bird species visiting different fig trees was significantly influenced by the crop size and canopy volume. Fruit colour and fruit size did not significantly influence the number of bird species, whereas habitats appeared to influence the composition of visiting birds. The fig–frugivorous bird interaction was asymmetrically structured, and the degree of nestedness appeared to be influenced by the forest type and degree of disturbance: the degree of nestedness in non-limestone forest tended to be higher than limestone forest; forest with less disturbance tend to be more nested compared with the open forest with high disturbance.

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Seasonal changes in distribution and abundance of a local Corncrake population

Journal of Ornithology ◽

10.1007/s10336-020-01827-z ◽

2020 ◽

Author(s):

Michał Budka ◽

Patryk Kokociński ◽

Paweł Bogawski ◽

Maciej Nowak ◽

Joanna Teresa Białas ◽

...

Keyword(s):

Population Size ◽

Breeding Season ◽

Site Fidelity ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Local Population ◽

Bird Species ◽

Adult Males ◽

Habitat Conditions ◽

Population Declines

Abstract Many bird species have experienced short- or long-term population declines. However, the mechanisms and reasons underlying such negative changes are often not fully understood, making it difficult to identify effective conservation measures to recover populations. In this study, we focused on local changes in the abundance and distribution of calling male Corncrakes Crex crex in relation to: (1) within- and between-season site fidelity of adult males, (2) spatial distribution of territories in consecutive years and (3) the effect of habitat conditions on population size. We counted the number of calling males at ten randomly selected study plots (1 km2) in 2014–2018. Additionally, males were caught and individually marked in years 2015–2017. We found significant between-year changes in Corncrake abundance, from a 34% decrease to a 21% increase. On average, 32% of males established territories in the same locations as males recorded in the previous year. Breeding site fidelity was very low, with only 2–5% of males recaptured in the following year. Males selected areas characterized by higher values of NDVI (Normalized Difference Vegetation Index–higher values indicate more biomass) than on average within the study area. Population size in a particular year was significantly affected by the NDVI of the previous year but not by the NDVI in the current breeding season. We suppose that Corncrakes may exhibit a nomadic breeding behavior, and settle at territories when they encounter optimal habitat conditions. Moreover, as population size was negatively correlated with habitat conditions at the beginning of the previous breeding season, we suppose that local population changes may reflect more general trends in a whole population rather than local breeding success. Therefore, we highlight the need for better knowledge of Corncrake dispersal within the main European population and for the coordination of monitoring and conservation efforts, especially in those regions where most Corncrakes breed.

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Behavioural Significance of Duet Interactions: Cues From Antiphonal Duetting Between Males (Cossypha Heuglini H.)

Behaviour ◽

10.1163/156853983x00589 ◽

1983 ◽

Vol 86 (1-2) ◽

pp. 89-99 ◽

Cited By ~ 7

Author(s):

Henrike Hultsch

Keyword(s):

Bird Species ◽

The Other ◽

Overt Aggression ◽

Adult Males ◽

Alliance Formation ◽

Characteristic Features ◽

Territorial Bird ◽

Behavioural Significance

AbstractAntiphonal duetting is regarded as a formalized interaction display between, usually mated, individuals of different sex. Proceeding from observations that antiphonal duetting can also occur between male conspecifics, we investigated the structure and context dependance of the display in aviary kept male robin chats (Cossypha heuglini H.). In the male/male duets, which were confined to a particular dyad of our tests subjects, all characteristic features corresponded to those of the male/female display (Fig. 1). Duet roles were not exchanged between males, and the "female" contribution was exclusively delivered by the younger male. Duetting obviously influenced both, interactions within the dyad (in terms of inhibiting overt aggression) and the territorial behaviours (attacks, chases) towards third introduced conspecifics. During confrontation with such males, the duetters took different roles in attempting to deter an outsider (test 3), which were similar to those observed for mated individuals of a pair. In tests where only one individual could attack, duet rates and attack rates were positively related (Fig. 4). Preceding a duet performance, one male approached the other one (Fig. 3), and restriction of such proximity (tests 1s, 2s) lowered both, duet rates and attack rates against an introduced male (Fig. 4 & 5). Our results allow to discuss relationships between duet behaviour and alliance formation in our males. To our knowledge such a cooperation, though presumably temporary, has not been described for adult males of highly territorial bird species.

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Life-stage and sex influence Philornis ectoparasitism in a Neotropical woodpecker (Melanerpes striatus) with essential male parental care

10.1101/2021.12.22.473830 ◽

2021 ◽

Author(s):

Joshua Burke LaPergola

Keyword(s):

Parental Care ◽

Recent Work ◽

Life Stage ◽

Bird Species ◽

Adult Males ◽

Sex Influence ◽

Adult Females ◽

Overnight Incubation ◽

Per Se ◽

Host Life

The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectoparasitism. While nestlings are typically considered the intended targets, recent work indicates that Philornis infest adult birds more frequently than previously appreciated, yet few studies have concurrently surveyed nestlings and adults for Philornis in the same population. Over six field seasons (2012 to 2017), I documented the presence of current or recent subcutaneous Philornis infestations on adult and nestling Hispaniolan Woodpeckers (Melanerpes striatus) from the same population. I tested the following three non-mutually exclusive hypotheses regarding occurrence of Philornis on adult birds: (1) nestlings are more vulnerable to Philornis parasitism than adults, (2) nesting is associated with Philornis parasitism in adults, and (3) Philornis parasitism is associated with incubation and brooding investment. While nestling and adult woodpeckers exhibited similar prevalence of parasitism, parasitized nestlings hosted on average 3.5 times more Philornis wounds (larvae plus scars) than parasitized adults. Nesting per se was not significantly associated with parasitism among adults, as breeding and non-breeding adults showed similar prevalence and intensity. However, adult males, which perform overnight incubation and brooding, were significantly more likely to be parasitized than adult females. This last result supports the hypothesis that incubation and brooding investment increase the risk of Philornis parasitism for adults, but this conclusion is complicated by the lack of an association between parasitism and nesting status. Together, these results raise questions about the degree of host life-stage specialization and whether adult parasitism is incidental or part of an alternative parasitic strategy for Philornis.

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Carotenoid Pigments in Male House Finch Plumage in Relation to Age, Subspecies, and Ornamental Coloration

The Auk ◽

10.1093/auk/118.4.900 ◽

2001 ◽

Vol 118 (4) ◽

pp. 900-915 ◽

Cited By ~ 11

Author(s):

Caron Y. Inouye ◽

Geoffrey E. Hill ◽

Riccardo D. Stradi ◽

Robert Montgomerie ◽

C. Bosque

Keyword(s):

Total Concentration ◽

Age Groups ◽

Bird Species ◽

Analytical Techniques ◽

Carpodacus Mexicanus ◽

Carotenoid Pigments ◽

Adult Males ◽

Red Pigments ◽

House Finches ◽

Male House

Abstract Like males of many bird species, male House Finches (Carpodacus mexicanus) have patches of feathers with ornamental coloration that are due to carotenoid pigments. Within populations, male House Finches vary in expression of ornamental coloration from pale yellow to bright red, which previous research suggested was the result of variation in types and amounts of carotenoid pigments deposited in feathers. Here we used improved analytical techniques to describe types and amounts of carotenoid pigments present in that plumage. We then used those data to make comparisons of carotenoid composition of feathers of male House Finches at three levels: among individual males with different plumage hue and saturation, between age groups of males from the same population, and between males from two subspecies that differ in extent of ventral carotenoid pigmentation (patch size): large-patched C. m. frontalis from coastal California and small-patched C. m. griscomi from Guerrero, Mexico. In all age groups and populations, the ornamental plumage coloration of male House Finches resulted from the same 13 carotenoid pigments, with 3-hydroxy echinenone and lutein being the most abundant carotenoid pigments. The composition of carotenoids in feathers suggested that House Finches are capable of metabolic transformation of dietary forms of carotenoids. The hue of male plumage depended on component carotenoids, their relative concentrations, and total concentration of all carotenoids. Most 4-keto (red) carotenoids were positively correlated with plumage redness, and most yellow carotenoid pigments were negatively associated with plumage redness, although the strength of the relationship for specific carotenoid pigments varied among age groups and subspecies. Using age and subspecies as factors and concentration of each component carotenoid as dependent variables in a MANOVA, we found a distinctive pigment profile for each age group within each subspecies. Among frontalis males, hatch-year birds did not differ from adults in mean plumage hue, but they had a significantly lower proportion of red pigments in their plumage, and significantly lower levels of the red piments adonirubin and astaxanthin, but significantly higher levels of the yellow pigment zeaxanthin, than adult males. Among griscomi males, hatch-year birds differed from adults in plumage hue but not significantly in pigment composition, though in general their feathers had lower concentrations of red pigments and higher concentrations of yellow pigments than adult males. Both adult and hatch-year frontalis males differed from griscomi males in having significantly higher levels of most yellow carotenoid pigments and significantly lower levels of most red carotenoid pigments. Variation in pigment profiles of subspecies and age classes may reflect differences among the groups in carotenoid metabolism, in dietary access to carotenoids, or in exposure to environmental factors, such as parasites, that may affect pigmentation.

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Recent data about the fish consumption of great Cormorant in the area of Hortobágy Fish Farm Co

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/65/1881 ◽

2015 ◽

pp. 75-80

Author(s):

Norbert Tóth ◽

Péter Gyüre ◽

Péter Juhász ◽

Lajos Juhász

Keyword(s):

Fish Species ◽

Bird Species ◽

Fish Farm ◽

Great Cormorant ◽

Adult Males ◽

Phalacrocorax Carbo ◽

Fish Stocks ◽

Significant Difference ◽

Preventive Methods ◽

Near Future

The cormorant (Phalacrocorax carbo) is a bird species that nests sporadically but in colonies, besides larger fishponds and rivers in Hungary. The number of its individuals has been increasing during the last two decades. The species eats solely fish, therefore it can cause serious depredation of the fish stocks in fishponds of intensive system and after the freezing of the ponds, in larger rivers, which are not yet frozen. The aim of our research was to reveal the damages the birds can cause on the studied areas and the extent of the losses the Hortobágy Fish Farm Co. has to realize. Our studies were carried out between April 2012 and November 2014. During cleaning, the investigation of the craw contents of the birds and their biometric studies were conducted. The results revealed the diverse food base of the species. In the samples, we have determined 379 fish individuals; in 368 cases, the exact fish species were determined, too. Significant differences were found between the consumed fish species rations of the units (P=0.05% beside). We have also found significant difference in the fish consumptions of adult males and females. Under the ever harder fish production conditions, the presence and thus the permanent predation of the birds affect the fishermen. In favour of maintaining ecological balance as well as to hold the income of the fish farmers, elaboration of adequate protective and preventive methods will be needed in near future.

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First full annual cycle tracking of a declining aerial insectivorous bird, the Common Nighthawk (Chordeiles minor), identifies migration routes, nonbreeding habitat, and breeding site fidelity

Canadian Journal of Zoology ◽

10.1139/cjz-2017-0098 ◽

2018 ◽

Vol 96 (8) ◽

pp. 869-875 ◽

Cited By ~ 6

Author(s):

J.W. Ng ◽

E.C. Knight ◽

A.L. Scarpignato ◽

A.-L. Harrison ◽

E.M. Bayne ◽

...

Keyword(s):

Annual Cycle ◽

Site Fidelity ◽

Bird Species ◽

Breeding Site ◽

Home Ranges ◽

Adult Males ◽

Population Declines ◽

Migration Routes ◽

Nonbreeding Season ◽

North American Bird

Over one third of North American bird species are in decline, and for many species, we still lack fundamental biogeographic information such as migration routes and nonbreeding areas. Identifying causes of declines is limited because tracking many species throughout their annual cycle with high precision and accuracy is challenging. Common Nighthawks (Chordeiles minor (J.R. Forster, 1771)) have declined throughout much of their range and have yet to have their migratory and nonbreeding areas identified and characterized. We tracked Common Nighthawks by deploying a new 3.5 g Pinpoint GPS-Argos tag on adult males. Seven of 10 (70%) tags uploaded locations, providing the first data on migration, nonbreeding habitat, and annual site fidelity to breeding areas. Birds used similar loop migration routes and overwintered in Brazil’s Cerrado and Amazon regions. Nonbreeding season roosting home ranges were 148.22 ± 121 ha (mean ± SE) and included forest, grassland, and cropland. Breeding home-range fidelity was high; all tracked birds returned to within 1.27 ± 0.27 km of original capture locations. Our study is the first tracking of Common Nighthawks throughout their full annual cycle. Continued miniaturization of tracking technology, like the GPS-Argos transmitters used, is critical for identifying the causes of population declines of previously enigmatic migratory species.

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Projected impacts of climate change on functional diversity of frugivorous birds along a tropical elevational gradient

Scientific Reports ◽

10.1038/s41598-019-53409-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 6

Author(s):

Irene M. A. Bender ◽

W. Daniel Kissling ◽

Katrin Böhning-Gaese ◽

Isabell Hensen ◽

Ingolf Kühn ◽

...

Keyword(s):

Climate Change ◽

Seed Dispersal ◽

Functional Diversity ◽

Bird Species ◽

Elevational Gradient ◽

Frugivorous Birds ◽

Bird Assemblages ◽

Functional Changes ◽

Frugivorous Bird ◽

Functional Dispersion

AbstractClimate change forces many species to move their ranges to higher latitudes or elevations. Resulting immigration or emigration of species might lead to functional changes, e.g., in the trait distribution and composition of ecological assemblages. Here, we combined approaches from biogeography (species distribution models; SDMs) and community ecology (functional diversity) to investigate potential effects of climate-driven range changes on frugivorous bird assemblages along a 3000 m elevational gradient in the tropical Andes. We used SDMs to model current and projected future occurrence probabilities of frugivorous bird species from the lowlands to the tree line. SDM-derived probabilities of occurrence were combined with traits relevant for seed dispersal of fleshy-fruited plants to calculate functional dispersion (FDis; a measure of functional diversity) for current and future bird assemblages. Comparisons of FDis between current and projected future assemblages showed consistent results across four dispersal scenarios, five climate models and two representative concentration pathways. Projections indicated a decrease of FDis in the lowlands, an increase of FDis at lower mid-elevations and little changes at high elevations. This suggests that functional dispersion responds differently to global warming at different elevational levels, likely modifying avian seed dispersal functions and plant regeneration in forest ecosystems along tropical mountains.

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Response of Understory Avifauna to Annual Flooding of Amazonian Floodplain Forests

Forests ◽

10.3390/f12081004 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1004

Author(s):

Anaís Rebeca Prestes Rowedder ◽

Thiago Orsi Laranjeiras ◽

Torbjørn Haugaasen ◽

Benjamin Gilmore ◽

Mario Cohn-Haft

Keyword(s):

Amazon Basin ◽

Bird Species ◽

Vertical Displacement ◽

High Water ◽

Floodplain Forest ◽

Vertical Position ◽

Floodplain Forests ◽

Vegetation Density ◽

Central Amazonia ◽

Forest Strata

The annual flooding in the Amazon basin transforms the understory of floodplain forests into an aquatic environment. However, a great number of non-aquatic bird species occupy the understory and midstory of these forests. In general, these birds are thought to be sedentary and territorial, but the way they adapt to this dramatic seasonal transformation has never been described in detail. In this study, we describe avifaunal strategies to cope with seasonal flooding in the lower Purus region, central Amazonia, Brazil. We conducted focal observations of five insectivorous species occupying the lowest forest strata in two types of floodplain forest (black- and whitewater) during the low- and high-water seasons. For each observation, the height of the bird above the substrate (ground or water), its vertical position in the forest, and vegetation density around the bird were noted. All species remained present in the floodplain forests during the two seasons and were not recorded in adjacent unflooded (terra firme) forest. In general, birds migrated vertically to higher forest strata and most species (three of the five) occupied similar vegetation densities independent of water level. Despite the tendency of all species to rise in relative vertical position at high water, there was a reduction in height above substrate for four of the five species, suggesting that their position relative to water was not an important microhabitat element for them. Responses were similar in the two floodplain forest types. It is likely that the decrease in available space during the flood, combined with similar vertical displacement in arthropods, leads to increased prey density for understory insectivorous birds and permits year-round territoriality without major habitat shifts.

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Decadal persistence of frugivorous birds in tropical forest fragments of northern Paraná

Biota Neotropica ◽

10.1590/1676-06032015008414 ◽

2015 ◽

Vol 15 (2) ◽

Cited By ~ 2

Author(s):

Tiago Zaiden ◽

Fernanda Cristina Marques ◽

Hugo Reis Medeiros ◽

Luiz dos Anjos

Keyword(s):

Bird Species ◽

The Other ◽

Forest Fragments ◽

Forest Fragment ◽

Frugivorous Birds ◽

Point Counts ◽

Bird Populations ◽

Frugivorous Bird ◽

Line Transects ◽

Extinction Events

Forest fragmentation is a major cause of loss of species. We evaluated the local extinction of medium-large frugivorous bird species in six forest fragments of northern Paraná: the Parque Estadual Mata dos Godoy (PEMG), the largest and most preserved forest fragment in the region, and five other fragments. Fixed-width point counts and line transects were conducted along trails in the PEMG for 10 days: from September 2010 to March 2011, and from August 2011 to November 2011. Avian surveys in each of the other forest fragments were made over four days from October to December 2011. We compared data with a previous census carried out 10 years earlier. No extinction events were recorded from the PEMG. However, the relative abundance of species significantly changed during the ten years between surveys. In all the other forest fragments at least two frugivorous bird species disappeared, and in some as many as seven. Protecting the PEMG is crucial for the maintenance of frugivorous bird populations in our studied landscape.

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