We used sighting reports, including decades of citizen‐reported Hawaiian monk seal ( Neomonachus schauinslandi ) sightings, to describe female breeding biology and reproductive success in the main Hawaiian Islands. We first used this data set to describe the timing of events in the female reproductive cycle. We then conducted an expert review of patterns in sighting histories to detect unobserved pupping events. Finally, we es...

Identifying, assessing, and ranking the impact of individual threats is fundamental to the conservation and recovery of rare and endangered species. In this analysis, we quantify not only the frequency of specific causes‐of‐death (CODs) among Main Hawaiian Island (MHI) monk seals, but also assess the impact of individual CODs on the intrinsic growth rate, λ, of the MHI population. We used gross necropsy results, histopathology...

The Hawaiian monk seal ( Monachus schauinslandi ) is one of the most critically endangered marine mammals . Less than 1200 individuals remain , and the species is declining at a rate of approximately 4% per year as a result of juvenile starvation , shark predation , and entanglement in marine debris . Some of these problems may be alleviated by translocation; however , if island breeding aggregates are effectively isolated sub...

Total estimated abundance of Hawaiian monk seals was just 1,161 individuals in 2008 and this number is decreasing. Most monk seals reside in the remote Northwestern Hawaiian Islands (NWHI) where the decline is approximately 4%/yr, whereas relatively fewer seals currently occupy the main Hawaiian Islands (MHI). It is widely accepted that the MHI population is increasing, although there are no formal estimates of total abundance...

We evaluated reproductive patterns of the Hawaiian monk seal ( Monachus schauinslandi ) using a combination of fitted age‐specific reproductive curves and analysis of reproductive patterns of individual females. We review the difficulties inherent in the acquisition and modeling of reproductive data with emphasis on the significance of reproductive senescence to populations with dissimilar age/sex compositions. Validation of t...

We investigated the pattern of first sighting of individual seals over the course of a field season, or the “discovery curve,” as a means for estimating abundance of the endangered Hawaiian monk seal, Monachus schauinslandi . We empirically derived a criterion to determine whether or not total enumeration had been accomplished at a given site and year. When greater than 100‐h field effort was expended without a new individual...