Dispersal dynamics of juvenile Secretarybirds<i>Sagittarius serpentarius</i>in southern Africa

Whitecross, M.A.; Retief, Ernst F; Smit‐Robinson, Hanneline

doi:10.2989/00306525.2019.1581295

Cited by 5 publications

(2 citation statements)

References 34 publications

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“…The larger non-breeding range is more likely associated with post-breeding and juvenile dispersal than migration. Tracking of several large-bodied bird species has revealed extensive dispersal across the subregion (Reading et al 2019, Whitecross et al 2019). The sustained presence of birds in the Kruger National Park points to the importance of this conservation area to this species.…”

Section: Discussionmentioning

confidence: 99%

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

Lee

Whitecross

Smit‐Robinson

et al. 2023

Bird Conservation International

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Summary Across South Africa, Lesotho, and Eswatini, long-term citizen science atlas data have suggested concerning declines in the population of Black Stork Ciconia nigra. Unlike the Asian and European populations, the southern African Black Stork population is described as resident and is listed as “Vulnerable” in South Africa, Lesotho, and Eswatini. Here we report on surveys of historical nesting locations across northern South Africa, finding evidence for nest site abandonment and limited evidence of recent breeding. We undertook detailed species distribution modelling within a maximum entropy framework, using occurrence records from the BirdLasser mobile app. We cross-validated the models against information in the Southern African Bird Atlas Project (SABAP2) database, highlighting Lesotho as an important potential breeding area. Additionally, we used SABAP2 to assess population trends by investigating interannual patterns in reporting rate. Comparing current reporting rates with those from SABAP1 (1987–1992), we found that there has been a dramatic decrease. We noted that a large proportion of the population occurs outside the breeding range during the breeding season, suggesting a considerable non-breeding population, especially in the extensive wildlife refuge of the Kruger National Park. The slow declines observed might be indicative of a population which is not losing many adults but is failing to recruit significant numbers of juveniles due to limited breeding. Using densities derived from transect surveys, we used predictive models to derive estimates of breeding range carrying capacity and a population estimate, which suggested declines to numbers around 600 for this subregion. Minimising disturbance at breeding sites of this cliff-nesting species and improving water quality at key population strongholds are pathways to improving the status of the species in the subregion.

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Section: Discussionmentioning

confidence: 99%

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

Lee

Whitecross

Smit‐Robinson

et al. 2023

Bird Conservation International

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“…Mark–recapture studies are limited by low re‐encounter rates and coarse temporal resolution, global tracking technologies are effective (Nathan ; e.g. Urios et al , Murphy et al , Whitecross et al ) but currently expensive, and genetic markers are seldom informative about behavior at the scale of the individual (Battey et al ). Although tracking technologies and genetic markers continue to improve rapidly (Webster et al , Kays et al ), both approaches continue to be constrained by cost.…”

Section: Introductionmentioning

confidence: 99%

Seasonal and directional dispersal behavior in an ongoing dove invasion

Slager

2020

Journal of Avian Biology

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Range expansions require the dispersal of individual organisms, but dispersal behavior is notoriously difficult to study. Eurasian collared‐doves have colonized both Europe and North America this century, with both initial invasions proceeding northwestward via ‘jump’ dispersal. The European population has reached carrying capacity, but in the Americas, where exponential population growth continues, little is known about dispersal behavior. I queried citizen science field notes to investigate Eurasian collared‐dove dispersal behavior in North America along the Pacific Ocean, a natural barrier to northwestward landbird dispersal. I examined coastal and pelagic records of Eurasian collared‐doves to determine the seasonality and directionality of dispersal flights and to assess changes in the frequency of dispersal‐related behavior across years. Most reports of Eurasian collared‐doves flying in flocks along the coast and most pelagic sightings were in March–May, mirroring the spring natal dispersal documented during the European invasion. Almost all spring coastal flocks were flying north, consistent with the overall northwestward direction of the initial North American invasion and northward deflection of northwest‐bound birds upon encountering the Pacific Ocean. Spring flying flock observations showed no significant change in frequency from 2010 to 2018 after controlling for overall increases in spring collared‐dove reports. This refined understanding of Eurasian collared‐dove dispersal behavior informs full life cycle management of this rapidly increasing invader in the Americas, raises new questions about evolutionary mechanisms driving this spectacular invasion, and illustrates the potential power of citizen science field notes for documenting dispersal behavior, a longstanding challenge in ecology.

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Assessing the susceptibility of raptor species to electrocution: A framework for Kenya

Ngila,

Chiawo,

Owuor

et al. 2024

Environmental and Sustainability Indicators

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Dispersal dynamics of juvenile SecretarybirdsSagittarius serpentariusin southern Africa

Cited by 5 publications

References 34 publications

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

Seasonal and directional dispersal behavior in an ongoing dove invasion

Assessing the susceptibility of raptor species to electrocution: A framework for Kenya

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