Male biased sex ratio of poached elephants is negatively related to poaching intensity over time

Mondol, Samrat; Mailand, Celia; Wasser, Samuel K.

doi:10.1007/s10592-014-0603-2

Cited by 19 publications

(11 citation statements)

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“…In Amboseli > 40% of crop-using bulls were > 30 years old (Chiyo et al, 2012), whereas we did not identify any bulls over the age of 30 in Udzungwa. This probably reflects the history of poaching in Udzungwa, which typically leaves populations with few older bulls (Mondol et al, 2014) and a population structure biased towards younger age classes (Poole, 1989; Nowak et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Using camera traps to study the age–sex structure and behaviour of crop-using elephants Loxodonta africana in Udzungwa Mountains National Park, Tanzania

Smit

Pozo

Cusack

et al. 2017

Oryx

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26Crop losses from elephants are one of the primary obstacles to the coexistence of 27 elephants and people and one of the contributing causes to elephant population 28 decline. Understanding if some individuals in an elephant population are more likely 29 to forage on crops, and the temporal patterns of elephant visits to farms, is key to 30 mitigating the negative impacts of elephants on farmers. We used camera traps as a 31 novel technique to study elephant crop foraging behaviour in farmland adjacent to 32 the Udzungwa Mountains National Park in southern Tanzania from October 2010 to 33 August 2014. Camera traps placed on elephant trails into farmland captured 34 elephants on 336 occasions over the four-year study period. We successfully 35 identified individual elephants from camera trap images for 126 of these occasions. 36All individuals detected on the camera traps were independent males, and we 37 identified 48 unique bulls aged between 10 and 29 years. Two-thirds of the bulls 38 identified were detected only once by camera traps over the study period, a pattern 39 that also held during the last year of study when camera trapping effort was 40 continuous. Our findings are consistent with previous studies that found that adult 41 males are more likely to adopt high-risk feeding behaviours such as crop foraging, 42 though young males dispersing from maternal family units also consume crops in 43 Udzungwa. Our study found a large number of occasional crop-users (32 of the 48 44 bulls identified) and a smaller number of repeat crop-users (16 out of 48), suggesting 45 that lethal elimination of crop-using elephants is unlikely to be an effective long-term 46 strategy for reducing crop losses from elephants. 47 48

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Section: Discussionmentioning

confidence: 99%

Using camera traps to study the age–sex structure and behaviour of crop-using elephants Loxodonta africana in Udzungwa Mountains National Park, Tanzania

Smit

Pozo

Cusack

et al. 2017

Oryx

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“…(; see also Mondol et al . ) to sex representative samples from pure forest (13 samples with posterior probability of being a pure forest elephant >0.95), pure savanna (18 samples with posterior probability of being a pure forest elephant >0.95) and all potential hybrid samples that still had sufficient DNA (35 samples with hybrid probability (HP) >0.95 and one with HP = 0.74) (calculations are presented below in the section: Methods for identifying and classifying hybrids ). Two labelled Y chromosome markers (SRY and AMELY) and one labelled X chromosome marker (PLP) were multiplexed together in a single PCR.…”

Section: Methodsmentioning

confidence: 99%

New evidence for hybrid zones of forest and savanna elephants in Central and West Africa

et al. 2015

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The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification.

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“…In the monitoring of the contemporary illicit trade in African ivory, DNA signatures (e.g. Wasser et al 2008) and other genetic markers (Linacre and Tobe 2011;Ishida et al 2013;Mondol, Mailand and Wasser 2014) have been shown to be rather more effective at this, although the degree of geographical resolution attained is still quite coarse. As sequencing of the genomes of different ivory-bearing species develops, it may become possible to use genetic markers to obtain more precise information regarding the location where the ivory was first obtained.…”

Section: Sourcing Ivorymentioning

confidence: 99%

Introduction: archaeological ivories in a global perspective

Lane

2015

World Archaeology

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Male biased sex ratio of poached elephants is negatively related to poaching intensity over time

Cited by 19 publications

References 19 publications

Using camera traps to study the age–sex structure and behaviour of crop-using elephants Loxodonta africana in Udzungwa Mountains National Park, Tanzania

Using camera traps to study the age–sex structure and behaviour of crop-using elephants Loxodonta africana in Udzungwa Mountains National Park, Tanzania

New evidence for hybrid zones of forest and savanna elephants in Central and West Africa

Introduction: archaeological ivories in a global perspective

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