Patterns in island endemic forest-dependent bird research: the Caribbean as a case-study

From Springer Nature via Jisc Publications RouterHistory: received 2018-10-25, rev-recd 2019-03-19, registration 2019-04-26, accepted 2019-04-26, online 2019-05-04, epub 2019-05-04, ppub 2019-06Publication status: PublishedAbstract: Unequal patterns in research effort can result in inaccurate assessments of species extinction risk or ineffective management. A group of notable conservation concern are tropical island endemic birds, many of which are also forest-dependent, which increases their vulnerability to extinction. Yet, island bird species have received limited research attention compared to their continental congeners, despite this taxon being globally regarded as well-studied. We used the insular Caribbean, a globally important endemism hotspot with high rates of deforestation, to explore research bias of island and regional endemic forest-dependent birds. A review of the published literature (n = 992) found no significant increase in the number of studies over the search period. Research effort was significantly higher among species with threatened status, long generation time, wide habitat breadth and low to intermediate elevational distributions. Among family groups, the Psittacidae received the highest research effort, while the Cuculidae were the most underrepresented family (30-fold higher and six-fold less than expected, respectively). We found geographic biases in effort, with Jamaica having six-fold less and Puerto Rico eight times more research than expected for their level of endemism. These patterns likely reflect individual interests and limited capacity and funding, typical of Small Island Developing States. With over 50% of species in this review having declining population trends, we recommend prioritizing research that emphasises conservation- and management-relevant data across underrepresented families and islands, by fostering greater collaboration between researchers, practitioners and the existing local amateur ornithological community

A call to action for climate change research on Caribbean dry forests

The final publication is available at Springer via https://doi.org/10.1007/s10113-018-1334-6Tropical dry forest (TDF) is globally one of the most threatened forest types. In the insular Caribbean, limited land area and high population pressure have resulted in the loss of over 60% of TDF, yet local people’s reliance on these systems for ecosystem services is high. Given the sensitivity of TDF to shifts in precipitation regimes and the vulnerability of the Caribbean to climate change, this study examined what is currently known about the impacts of climate change on TDF in the region. A systematic review (n = 89) revealed that only two studies addressed the ecological response of TDF to climate change. Compared to the rapidly increasing knowledge of the effects of climate change on other Caribbean systems and on TDF in the wider neotropics, this paucity is alarming given the value of these forests. We stress the need for long-term monitoring of climate change responses of these critical ecosystems, including phenological and hotspot analyses as priorities

Parameter values for the three population models.

<p>Parameter values for the three population models.</p

Model selection results for fitting probability distributions to carnivore litter size frequencies.

<p>The number of datasets tested for each species (denominator, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060.s001" target="_blank">Table S1</a> for details) and the number of datasets that were adequately fitted by a given distribution (numerator, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060.s002" target="_blank">Table S2</a> for details). Bold indicates distributions that were most parsimonious for at least one dataset. SP: Shifted Poisson; ZTP: Zero-truncated Poisson; SB: Shifted binomial; ZTB: Zero-truncated binomial; SNB: Shifted negative binomial; ZTNB: Zero-truncated negative binomial; SGP: Shifted generalised Poisson; ZTGP: Zero-truncated generalised Poisson; DN: Discretised normal; DLN: Discretised lognormal; DSB3; Discretised stretched-beta (3 parameter form); DSB2; Discretised stretched-beta (2 parameter form).</p

Model outcomes for 12 probability distributions against the variance (left panel) and skew (right panel) of distributions, showing quasi-extinction probabilities and probability of successful disease control, with 95% confidence intervals.

<p>(A, B) Island fox <i>Urocyon littoralis</i> PVA: west and east subpopulations; (C, D) red fox <i>Vulpes vulpes</i>; (E, F) African wild dog <i>Lycaon pictus</i> PVA without an Allee effect; (G, H) African wild dog PVA with an Allee effect included as a decrease in litter size as a function of group size. Solid error bars indicate distributions with ΔAIC ≤6. ▾ indicates the estimate from the previously published model, with the empirical litter size variance in the left panels and empirical litter size skew in the right panels (except G and H, for which there is no previous model estimate).</p

Observed litter size frequencies with fitted distributions with ΔAIC ≤6.

<p>The top two panels show for a range of sample sizes (of litters sampled), mean litter size, and carnivore families. The third panel from the top shows three populations of <i>Vulpes vulpes</i> with litter size determined by placental scars and the bottom panel illustrates three different methods for determining litter size of a Bristol population of <i>V. vulpes</i> (Harris, <i>unpublished data</i>). (A) <i>Lycaon pictus,</i> n = 36 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Creel1" target="_blank">[53]</a>; (B) <i>Crocuta crocuta,</i> n = 108 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Watts1" target="_blank">[54]</a>; (C) <i>Panthera tigris altaica</i>, n = 16 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Kerley1" target="_blank">[55]</a>; (D) <i>Ursus arctos,</i> n = 303 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Miller1" target="_blank">[56]</a>; (E) <i>Meles meles</i>, n = 37 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Neal1" target="_blank">[57]</a>; (F) <i>Lontra canadensis,</i> n = 9 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Hamilton1" target="_blank">[58]</a>; (G) <i>V. vulpes</i>, n = 112 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Vos1" target="_blank">[59]</a>; (H) <i>V. vulpes</i>, n = 506 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060-Englund1" target="_blank">[60]</a>; (I) <i>V. vulpes</i>, London, n = 158 (Harris, <i>unpublished data</i>); (J) <i>V. vulpes</i>, placental scars, n = 340; (K) <i>V. vulpes</i>, embryos, n = 60; (L) <i>V. vulpes</i>, direct counts, n = 191. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058060#pone.0058060.s001" target="_blank">Table S1</a> for details of datasets. Distribution abbreviations: observed frequencies (Obs); shifted Poisson (SP); ZT Poisson (ZTP); discretised normal (DN); discretised lognormal (DLN); discretised stretched beta –2 parameter form (DSB2); discretised stretched beta 3 parameter form (DSB3); shifted generalised Poisson (SGP); ZT generalised Poisson (ZTGP); shifted binomial (SB); ZT binomial (ZTB); shifted negative binomial (SNB); ZT negative binomial (ZTNB).</p