Permanent Territories Research Articles

HUKUM INTERNASIONAL DIDALAM MASYARAKAT DAN PERMASALAHAN WILAYAH ANTARNEGARA

This paper examines international law and the territory between countries. International law was born because of the existence of an international community so that this became the basis for the formation of international law. The international community is used as a sociological foundation in shaping international law. International relations arise because of a factor that requires each other from one country to another in various interests. The territory of the state is part of one element that has a very important meaning. According to international law, the territory of a state consists of land, sea and air. A country's territory will be said to be a permanent territory if it has definite boundaries. State boundaries are something that is very valuable and important in order to clarify or show the boundaries of the country's sovereignty to be implemented. In this case, there will be territorial boundary problems between countries. According to international law, there are several ways of settlement in the form of a peaceful settlement and a forced or violent settlement.

Female and male Eurasian lynx have distinct spatial tactics at different life-history stages in a high-density population.

Knowledge regarding the spatial behavior of the Eurasian lynx is mainly inferred from populations in Europe. We used GPS telemetry to record the spatial behavior of nine individuals in northwestern Anatolia obtaining eleven home ranges (HRs). Analyses revealed the smallest mean HR sizes (nHR ♀ = 4) at 57 km2 (95% kernel utilization distribution, KUD) and 56 km2 (95% minimum convex polygon, MCP), ever reported for adult female Eurasian lynx. Adult males either occupied small permanent territories (nHR♂.T = 2), with a mean of 176 km2 (95% KUD) and 150 km2 (95% MCP), or were residents without territories (floaters, nHR♂. F = 2) roaming across large, stable HRs with a mean size of 2,419 km2 (95% KUD) and 1,888 km2 (95% MCP), comparable to HR sizes of Scandinavian lynx populations. Three disperser subadult males did not hold stable HRs (mean 95% KUD = 203 km2, mean 95% MCP = 272 km2). At 4.9 individuals per 100 km2, population density was one of the highest recorded, suggesting that the presence of adult male floaters was a consequence of a landscape fully occupied by territorials and revealing a flexibility of spatial behavior of Eurasian lynx not previously recognized. Such a high population density, small HRs, and behavioral flexibility may have been aided by the legal protection from and apparent low levels of poaching of this population. The observed spatial tactics are unlikely to be seen in most of the previously studied Eurasian lynx populations, as they either suffer medium to high levels of human‐caused mortality or were unlikely to be at carrying capacity. For effective and appropriate conservation planning, data from felid populations in a reasonably natural state such as ours, where space, density, prey, and pathogens are likely to be the key drivers of spatial dynamics, are therefore essential.

Territory Size and Population Density of the Serra Antwren (Formicivora serrana littoralis) in the Sandy Coastal Plains of the Atlantic Forest in Southeastern Brazil

Territory size is affected by distribution of resources, density of potential competitors, body size of the territory holder and its ability to detect intruders. During four consecutive years (2009–2013), we determined territory size of the serra antwren, a highly territorial bird, that occupies permanent territories in the restinga habitat. We studied seasonal variation and relationship between territory size, number of neighboring territories and floaters (mature individuals without fixed territories), and body size of the territory holders. We also estimated population density using a capture–recapture method. Territory size was smaller during the breeding season with its size affected by number of neighboring territory holders and year. Densities were estimated to be 1.6–5.8 indiv. ha–1, which were 2 to 6 times higher than the value previously estimated by fixed-radius point counts (0.93 indiv. ha–1). This may be due to the high number of floaters, potentially important but usually neglected in density estimates. Neighboring territory holders affected more than floaters territory size, possibly because of their similar individual qualities.

Motivation but not body size influences territorial contest dynamics in a wild cichlid fish

Contests over resources are a key facet of social behaviour and have received extensive theoretical attention. However, the assumptions and predictions of the theoretical models have rarely been tested experimentally in wild free-living vertebrates. Here, we look at resource contests in wild Neolamprologus pulcher, a cooperatively breeding cichlid fish that lives in permanent territories in Lake Tanganyika, Africa. To elicit a contest, we removed a dominant breeding male from his territory and held him for either a short (4.5 h) or a long (20 h) period. The original resident male was then returned to his territory, which typically resulted in an aggressive contest with a usurping male that had taken over in the original resident's absence. We found that contests were shorter than those previously observed in a laboratory setting, with more physically aggressive attacks. Contrary to our predictions, the relative size difference between the males had no effect on contest dynamics or outcome, probably because all of the males involved in these contests were similar in body size. Instead, motivational factors influenced contest dynamics. Longer original resident removal times increased usurper male aggression, as well as the duration and intensity of the contests. Original residents were more aggressive when contesting over their sole territory (socially monogamous) than when contesting over one of their multiple territories (socially polygynous). Usurpers won more contests overall, and more aggressive fish were more likely to win contests. To our knowledge, this is the first study to examine resource contests in wild free-swimming cichlids, and our results reveal that subjective resource value is a primary driver of the dynamics and outcome of territorial conflicts among dominant N. pulcher males. Our results further suggest that respect for ownership may reduce conflict in N. pulcher and be important in governing colony structure.

Habitat selection and movement of Cambarus chasmodactylus (Decapoda:Cambaridae) assessed via radio telemetry

We used radio telemetry to track the daily movements of Cambarus chasmodactylus (New River Crayfish) in Anthony Creek, West Virginia, to help us better understand the daily activity and habitat preferences of cambarid crayfish. We fitted ten 0.8-g transmitters to the chelae of C. chasmodactylus (6 form I males/3 form II males/1 female) and released them at their initial point of capture. We tracked animals for 5 consecutive days, after which we initiated a 20-d noninteraction period followed by 6 more days of tracking. After locating an individual, we noted water depth, current velocity, and substrate type at the individual’s position and recorded distance traveled over the previous 24 h. The ephemeral home range concept applied to most movement patterns, a result indicating that individual C. chasmodactylus have multiple home ranges over the course of their lives. Beginning in July, form I males maintained more permanent territories under slab boulders, a behavior theorized to be mediated by reproductive receptivity of females. Smaller adults moved longer distances and more frequently than larger adults. Habitats preferred by C. chasmodactylus had moderate (0.25–0.75 m) water depth and flow velocity (0–1.9 m/s) and slab boulders. Adult C. chasmodactylus appear to be habitat specialists that use slab boulders exclusively as daily retreats. Our results demonstrate the utility of telemetry as a means to obtain data about habitat and ecological associations of crayfishes, knowledge that is currently lacking for many species.

Food availability affects strength of seasonal territorial behaviour in a cooperatively breeding bird

Seasonal patterns in territorial behaviour are common in many species, and are often attributed to the adaptive benefits of increased defence or the provision of information to potential competitors or mates during the breeding season. However, because defence behaviour is likely to be costly in terms of time and energy, an alternative possibility is that decreases in the nonbreeding season are a consequence of reduced food availability. We studied territoriality in the pied babbler, Turdoides bicolor, a cooperatively breeding bird species that defends permanent territories. Groups interacted with rivals less and responded less strongly to an experimentally simulated intrusion of neighbours in nonbreeding periods compared to the breeding season. Foraging efficiency and biomass intake were significantly lower in the nonbreeding season, which resulted in birds being significantly lighter at this time of year. Finally, a feeding experiment in the nonbreeding season showed that groups given supplementary food significantly increased their response to a simulated territorial intrusion. These results indicate that the reduction in territorial behaviour during the nonbreeding season may be attributed, at least in part, to a reduction in food availability. We suggest that future studies on seasonal variation in territorial behaviour, especially those investigating species in which two or more individuals combine their defence, should take this potential constraint into account.

Differential attack by a cichlid fish on resident and non-resident fish of another cichlid species

AbstractAn algivorous cichlid, Variabilichromis moorii( Vm), defends permanent territories in Lake Tanganyika, Africa. A zoobenthivorous cichlid, Neolamprologus mustax( Nm), spends 60% of daylight hours foraging in Vmterritories, from which other zoobenthivorous fishes are chased out and consequently which are much richer in prey animals than areas outside of Vmterritories. We conducted a field experiment to examine whether Nmresidents and non-residents received different degrees of attacks from Vm. Nmfish were caught in their territories, released at a point distant from these territories, and followed to observe interactions with Vmfish. The frequency of attacks received by the displaced Nmfish was greater than attacks received by Nmresidents, indicating that Nmresidents had easier access to Vmterritories than non-residents did. A possible mechanism for this is reduced aggression of Vmtowards Nmresidents, as a result of the ‘dear enemy’ effect that has been reported in territorial contests between rivals. An alternative mechanism is that tolerance towards Nmdiffers among Vmfish and Nmresidents selectively visit more tolerant Vmfish due to previous experience while non-residents randomly approach both tolerant and hostile Vmfish. The ability of Vmto discriminate between Nmresidents and non-residents is essential to the former mechanism but not to the latter. To more specifically examine which mechanism works in the Vm– Nmcommensal system, we will need to follow individually identified Vmfish interacting with Nmresidents and non-residents.

Confirmed presence of territorial groups of golden jackals (Canis aureus) in Slovenia

The article presents the first confirmed records of territorial groups of the golden jackal (Canis aureus) in Slovenia. During the survey at Ljubljansko barje on 20th February 2009, we noted a response by two jackal groups to a broadcasted howling near the village of Bevke (UTM VM82, 288 m a.s.l.). Since we recorded no response at any other location, it seems that the number of territorial golden jackals at Ljubljansko barje is small. Further studies would be needed to determine whether the jackals have already established permanent territories also in other regions of Slovenia.

Breeding biology of the Kalahari Scrub-Robin (Cercotrichas paena) (Muscicapidae)

Aspects of the biology of the Kalahari Scrub-Robin (Cercotrichas paena) were studied in the Polokwane Nature Reserve, South Africa, from June 2004 to March 2007. Pairs occupied permanent territories ranging in size from ∼0.7 to 4.3 ha. The breeding season in the study area extended from August to February, with a peak in November that coincided with the peak of the wet season. The mean clutch-size was 2.1 but there was seasonal variation, with mean clutch-size significantly larger in the later part of the breeding season compared with the early and mid-parts of the season, and there was no significant difference between the early and mid-seasons. Females were responsible for construction of nests and incubation, but both sexes fed nestlings and fledglings. The maximum number of known breeding attempts by a pair in a season was eight, of which two were successful. The Kalahari Scrub-Robin is the first African robin for which triple-brooding was recorded, and the most young fledged by a single pair in one season was seven. The mean incubation and nestling periods were 12.5 (n =11) and 11.9 (n = 28) days respectively. Growth patterns of nestling are described with reference to mass, head-length and tarsal length. The period of dependence after fledging was 4–6 weeks. The overall breeding success was 27.1% and the mean number of young fledged per pair per annum was 2.8.

First record of a golden jackal (Canis aureus) in the Savinja Valley (Northern Slovenia)

The article presents the record of an adult female golden jackal (Canis aureus) accidentally shot in 2005 near Gornji Grad in the Upper Savinja Valley, Northern Slovenia (UTM VM82, 980 m a.s.l.). Although this individual was most likely a vagrant, it indicates that golden jackals may soon, or perhaps already have, established permanent territories in Slovenia. Further studies are necessary to determine the status and distribution of this protected species in Slovenia, as well as public awareness actions, especially among hunters, in order to avoid additional accidents at hunting.

Seasonal variation in male-female competition, cooperation and selfish hoarding in a monogamous songbird

Both cooperation and conflict between the sexes are commonplace in monogamous mating systems. However, little is known about how cooperation and competition varies seasonally in monogamous species that maintain permanent territories. We presented territorial pairs of male and female New Zealand robins (Petroica australis) with a large supply of insect prey at monthly intervals for 2 years. Behavioural observations after food presentation were then made to quantify seasonal and sexual differences in aggressive interactions over prey, prey acquisition rates, mate provisioning, offspring provisioning, selfish food hoarding and cache retrieval. Data were used to evaluate sex-specific behavioural strategies of mediating competition for food. Results showed that males aggressively excluded females from experimental food sources year-round. Females only accessed food sources when males left them unattended. Consequently, females acquired fewer prey than males. After controlling for differences in prey acquisition, both sexes consumed similar amounts of prey in the non-breeding season. Even though males aggressively excluded females from accessing food sources directly, males fed large amounts of prey to females during the breeding season. Both sexes provisioned young at similar rates. Males cached less prey than females in the breeding season but more prey than females in the non-breeding season. Females showed similar caching intensities year-round. Although males tried to defend their hoards, females frequently retrieved male-made caches. Overall, results showed that although New Zealand robins cooperate to raise offspring during the breeding season, conflict between the sexes occurs year-round. Males and females display different behavioural strategies to gain access to experimental food sources, which appear to lessen male–female competition for food and evenly distribute food resources between the sexes.

Advantage of harmlessness in gaining preferential access to a heterospecific territory

Underwater observations conducted in the shallow waters of the southern part of Lake Tanganyika showed that a zoobenthos‐eating cichlid Neolamprologus mustax preferentially foraged in the permanent territory of an algivorous cichlid Neolamprologus moorii, even though other zoobenthos‐eaters were chased out. Benthic invertebrates were much richer within the territory of N. moorii than outside, suggesting that the territory was an attractive feeding ground for zoobenthos‐eaters. Stomach contents analysis showed that N. mustax rarely ate fish broods, although other zoobenthos‐eaters often did so. It is concluded that the differential tolerance of N. moorii towards zoobenthos‐eaters based on their harmfulness to broods benefits harmless N. mustax by allowing its use of the prey‐rich territory.

Climate change and the demographic demise of a hoarding bird living on the edge.

Population declines along the lower-latitude edge of a species' range may be diagnostic of climate change. We report evidence that climate change has contributed to deteriorating reproductive success in a rapidly declining population of the grey jay (Perisoreus canadensis) at the southern edge of its range. This non-migratory bird of boreal and subalpine forest lives on permanent territories, where it hoards enormous amounts of food for winter and then breeds very early, under still-wintry conditions. We hypothesized that warmer autumns have increased the perishability of hoards and compromised subsequent breeding attempts. Our analysis confirmed that warm autumns, especially when followed by cold late winters, have led to delayed breeding and reduced reproductive success. Our findings uniquely show that weather months before the breeding season impact the timing and success of breeding. Warm autumns apparently represent hostile conditions for this species, because it relies on cold storage. Our study population may be especially vulnerable, because it is situated at the southern edge of the range, where the potential for hoard rot is most pronounced. This population's demise may signal a climate-driven range contraction through local extinctions along the trailing edge.

Breeding territory fidelity in a partial migrant, the American dipper Cinclus mexicanus

178.American dipper Cinclus mexicanus populations are frequently composed of residentindividuals that occupy permanent territories year round and migratory individualsthat overwinter with residents but migrate to breeding territories on higher elevationcreeks each spring. Between 1999 and 2004 we examined how migratory strategy(resident/migratory) and sex differences influence breeding territory fidelity ofAmerican dippers occupying the Chilliwack River watershed, British Columbia,Canada. Counter to expectation we found that the migratory strategy of Americandippers did not influence whether birds breeding in one year were found on theirformer breeding territory in the next. Migratory strategy also did not affect theprobability that known surviving dippers occupied the same breeding territory in thefollowing year. Males and females were equally likely to be found on their formerterritory in the following year (females 43%, males 41%) and known survivors hadsimilar levels of breeding territory fidelity (females 74%, males 68%). However,breeding territory fidelity of males and females varied in response to different factors.Surviving female dippers were more likely to be found on their former breedingterritory in the subsequent year following a successful breeding attempt than anunsuccessful breeding attempt. Prior reproductive performance did not influencewhether surviving male dippers were found on their former breeding territory. Maledippers were more likely to be found on their former territory and, if they survived,have higher breeding territory fidelity when their mate also returned to that sameterritory. Mate retention also influenced whether females were found on their formerterritory in the following year but had no effect on the breeding territory fidelity ofknown survivors. We argue that sex-specific dispersal decision rules in Americandippers are driven by sex differences in the predictability of breeding performancebetween years and sex differences in how mate retention influences subsequentreproductive success.H. A. Middleton and D. J. Green (correspondence), Centre for Wildlife Ecology,Department of Biological Sciences, Simon Fraser University, 8888 University Drive,Burnaby, BC V5A 1S6 CANADA. E-mail: djgreen@sfu.ca. C. A. Morrissey, CanadianWildlife Service, 5421 Robertson Road, Delta, BC V4K 3N2 Canada.

Metal and metalloid concentrations in the eggs of threatened Florida scrub-jays in suburban habitat from south-central Florida

Monitoring and assessing changes in contaminants in urban and suburban environments is essential to assessing ecosystem well-being in human-influenced landscapes. We analyzed metal and metalloid levels in the eggs of the threatened Florida scrub-jay ( Aphelocoma coerulescens), an extremely sedentary and modestly long-lived passerine bird that is federally threatened and endemic only in Florida. Eggs that failed to hatch were collected in a suburban environment to compare with the long-term study of this species at the Archbold Biological Station, located 8 km south in a more rural part of south-central Florida. Florida scrub-jays remain in a permanent territory in scrub oak habitat where they feed mainly on insects and acorns, but in suburban habitats human-provided foods comprise 30% of their diet. From the data previously collected at Archbold, and their low position on the food chain, we expected levels of contaminants to be comparatively low and remain relatively constant over time. Except for the low mercury value, all means were within the range of mean values reported for a wide range of non-passerine species (including those at higher tropic levels), are lower than concentrations associated with abnormalities in birds, and are lower than those previously reported for scrub-jays from Archbold Biological Station. A significant increase in selenium occurred from 1996 to 2001, but did not appear associated with changes in human density.

Do cleaning stations affect the distribution of territorial reef fishes?

We investigated the role of cleaning stations in determining the distribution of territorial reef species. Cleaner fish reduce their clients' ectoparasite loads and, therefore, proximity to cleaning stations should be advantageous for territorial fish. We focused on five damselfish species which hold permanent territories and cleaning stations occupied by cleaning gobies (Elacatinus spp.) on a Caribbean reef. Contrary to our predictions of higher densities near cleaning stations, we found that bicolor damselfish were less abundant near cleaning stations than at ecologically similar points without cleaning gobies whereas no effects were seen for longfin, dusky, yellowtail, and threespot damselfish. In addition, although damselfish densities were higher in the immediate vicinity of cleaning stations than 1.5–3 m away for most species, this was also the case at points without cleaners. Because cleaning stations are usually located on prominent coral heads or sponges, the overall significant attraction of damselfish to such structures, whether occupied by cleaning gobies or not, could reflect attraction to past or potential cleaning stations. However, it is more likely that interspecific competition and/or the low benefits of being cleaned at our study site prevent aggregation around cleaners. Cleaning stations may play only a minor role in determining the distribution of territorial reef fishes.

Effects of Roads on Movements by Understory Birds in Mixed‐Species Flocks in Central Amazonian Brazil

Abstract: Roads through tropical forest create linear disturbances that have unknown consequences for forest birds. We studied how a narrow, rarely used road through otherwise undisturbed Amazonian forest affected the movements and area requirements of understory birds that form mixed‐species flocks. Differences in road maintenance led to two distinct treatments along the same road. Trees along the “closed” road formed a partial canopy connecting the two sides of the road, although the roadway itself was kept open. The “open” road was regularly maintained, making a complete opening 10–30 m wide.We followed 15 flocks, 5 each in interior forest, along the open road, and along the closed road. These flocks were led by Thamnomanes antshrikes, and each flock had a discreet, permanent territory. Flock territory size (mean = 8.5 ha) did not differ among the three locations. The open road formed the territorial boundary for all five flocks, although birds moved within a few meters of the edge of the road. The closed road was less of a barrier: 2 of 5 flocks used both sides of the closed road. Playback experiments showed that flocks readily crossed the closed road to approach agonistic vocalizations. Along the open road, even though birds responded to playback by becoming agitated and moving to the extreme edge of the roadside vegetation, they were less likely to cross the road and did so only after a longer duration of playback. Our results suggest that flocks respond to a road as they would to a long linear gap. They use the vegetation along the edges of the road, but because they are unwilling to cross the open area, it becomes a flock territory boundary. Similarly, as in forest gaps, successional change along the closed road produced suitable habitat for flocks. Although this suggests that roads are a trivial problem, we caution that this result applies only to narrow roads that are not accompanied by deforestation or other disturbance.

Metal concentrations in the eggs of endangered Florida scrub-jays from central Florida.

We analyzed metal levels in the eggs of the endangered Florida scrub-jay (Aphelocoma coerulescens), an extremely sedentary and modestly long-lived passerine bird. Eggs were obtained as part of the long-term study of this species at the Archbold Biological Station, located in south central Florida. Following a brief and usually short dispersal, Florida scrub-jays remain in a permanent territory in their scrub oak habitat, where they feed mainly on insects and acorns. As they are low on the food chain and sedentary, we expected levels of contaminants to be comparatively low and to reflect the local environment. No significant yearly differences existed for any metal between eggs collected in 1997 (n = 11) and 1998 (n = 5). Arithmetic mean metal concentrations (whole egg, dry weight) were low for arsenic (34 ppb), cadmium (25 ppb), mercury (74 ppb), and lead (66 ppb), intermediate for chromium (226 ppb), and higher for selenium (1,470 ppb) and manganese (2,230 ppb). Except for the low mercury value, all these means were within the range of mean values reported for a wide range of nonpasserine species, including those at high trophic levels, but are lower than concentrations associated with abnormalities in birds. The three essential elements (chromium, selenium, and manganese) were approximately normally distributed, whereas arsenic, cadmium, lead, and mercury were highly skewed (arithmetic mean much higher than geometric mean).

Resource control by territorial male cichlid fish in Lake Malawi

1. The rocky habitat communities of Lake Malawi contain a high diversity of ecologically similar, predominantly herbivorous, cichlid fish species. How so many species can coexist is still unknown. 2. Adult males of the majority of these species hold permanent territories which form dense multispecies mosaics across the shores. 3. The study examined six coexisting species of cichlids from the rocky habitat where males are known to control access to the algal food resources within their territorial space. These included four sibling species of the Pseudotropheus (Tropheops) species complex, which are specialized epilithic algal herbivores, and two sibling species of the trophically more generalist P. (Maylandia) species complex which feed upon both epilithic algae and plankton. 4. The hypotheses that both intraspecific and interspecific territoriality occur in these communities and that interspecific aggression initiated by territorial males is preferentially directed at species with the most similar diets to their own were tested. 5. It was found that males preferred to exclude conspecific intruders, while they tolerated intruders with different diets to their own. Also, male P. (Tropheops) preferentially excluded similar heterospecific dietary specialists, while male P. (Maylandia) tolerated similar heterospecific dietary generalists. 6. Based on this study, it is proposed that interspecific territoriality may be reducing competition between species with different diets and promoting their coexistence, while it may be enhancing competition between species with the same diet. Furthermore, it suggests that ecological generalism may be reducing the intensity of interspecific competition, while specializations for the same resources may be increasing competition.

Abundance, Zonation and Foraging Ecology of Birds in Mangroves of Darwin Harbour, Northern Territory.

The density, seasonality, habitat utilization and foraging ecology of birds in mangals (mangrove forests) at a site on the upper reaches of Darwin Harbour were investigated by transect censusing and colour-banding over three years. Despite having only 10 species of plants, the site supported 17 confirmed and five probable breeding resident species of birds, and was visited by 30 more. From variable-width transect censuses, the mean density of birds on a 4-ha plot was estimated to be 25 ha-1, fairly consistent with densities obtained from territory mapping of colour-banded birds. Nearly 70% of the individuals belonged to just 4 species: two mangal-dependent species, the red-headed honeyeater (Myzomela erythrocephala) and the yellow white-eye (Zosterops lutea) and two more generalised species, the large-billed gerygone (Gerygone magnirostris) and the brown honeyeater (Lichmera indistincta). Only the red-headed honeyeater showed significant seasonal variation in abundance, with highest numbers during the late dry season after breeding. This coincided with the period of greatest food (nectar) availability in the mangal, due to flowering Bruguiera exaristata. Lowest numbers of the red-headed honeyeater (and the brown honeyeater) occurred in the late wet season when nectar was scarce in the mangal but abundant in Melaleuca cajuputi fringing the mangal. Several resident species held permanent territories, while others apparently shifted landward during the wet season, possibly due to the wetter conditions created by freshwater runoff and high spring tides Many species showed strong associations with particular mangal zones. Large-billed gerygones, grey whistlers (Pachycephala simplex), shining flycatchers (Myiagra alecto) and mangrove fantails (Rhipidura phasiana) were associated with the Rhizophora zone at the wetter (more frequently inundated) end of the plot; mangrove robins (Eopsaltria pulverulenta) and mangrove gerygones (Gerygone laevigaster), were encountered most in the Ceriops zone; and green-backed gerygones (Gerygone chloronata) strongly favoured the dry landward edge. Four foraging guilds were evident among 13 of the most abundant species, the largest of which was the insectivorous foliage-foraging guild. Species in this group partitioned resources by differential selection of mangrove species, heights and foraging techniques. The tiny (6.4 g) mangrove gerygone was the most specialized species, spending 80% of its time on Avicennia marina. Contrary to the literature, breeding of mangal-dwelling birds peaked during the dry season. The ecology, evolution and biogeography of mangrove-endemic birds is reviewed in the light of this study and recent information from Western Australia.